The Energy From Biomass Programme of the Commission of the European Communities

Commission of the European Commun1ties Brussels Summary In the past decade, bioenergy has been the subject of considerable R&D In the E.C., In other industrialized countries and developing countries. At large scale, biomass cannot be used as a fuel without reference to the social and economic framework in whlch food and fibre are produced. The main objectives of "Energy from BIomass https://www.w3.org/1998/Math/MathML">   ' ' R & D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> should therefore now be directed into the following key 1ssues: energy security, environmental aspects, relieving the overproduction in some agricultural sectors, creation of jobs 1 n rural areas. Biofuels may have an extra chance https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the frame of the new European fuel blend pollcy. The most likely scheme foresees replacing lead by https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of methanol and https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of co-solvents. Co-solvents derived from biomass by fermentation could form the basis of such a strategy. Biomass utillzation schemes would offer great promise for rural development. Energy plantations, collection of agricultural residues and copplce and thefr conversion into energy carriers of higher density could be part of a reglonal network. Many jobs could be created, large amounts of wastes could be recycled and unused forests could become accessible for new commercial exploitatlon. There is therefore a good reason for further developing this alternative, renewable energy resource. In the past decade, the production and use of biomass for energy purposes has been the subject of considerable R&D efforts in many industrialized and some developing countries. The technologies which drew the main attention were wood and straw-burning, biogas production from agricultural wastes and thermochemical conversion by processes such as pyroIysis and gasification. Since 1975 "Energy from Biomass" has been a major toplc of the European Communtty's First and Second Energy R&D Programmes. In 1980 these R&D programmes were completed by a granting scheme for energy demonstration projects, Including biomass production and conversion. The results of the LA BIOMASSE DANS LA COMPETITION ENERGETIQUE A. GIRAUD Professeur à 1'Uni versitē PARIS-DAUPHINE ancien Ministre de 1 'Industrie Abstract Les ënergies fossiles, le pétrole, le gaz naturel et le charbon sont des produits de transformation de la biomasse. on sait que le charbon rësulte de l'enfoulssement et de la deccomposition des grandes forets de l ere primaire. Le petrole a pour origine le phyto et le zooplancton qui s'est formé puis dēpose avec des sédimente dans les zones marines peu profondas et peu oxymënées. Quant au gaz naturel, son origine est moins bien connue, et peut-être plus diversifiée. Certains gisements paraissent associēs à des zones carbonlferes, et le grisou luf-même est d'ailleurs du mëthane. Dans d'autres cas, le gaz parait s'etre formé au cours du même proces sus que celuí qui a conduit au pëtrole. Enfin des résultats rëcents attribuent la formation des grands gisements de gaz profonds a la transformation de p'enserible des matierres organiques qui se sont dēvelopoêes, puis déposées, dans des zones saumâtres de marais et de deltas analogues à celles que https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on trouve aujourd'hui dans certaines zones tropicales. La nature de la biomasse d'origine est peu connue. Ce que https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on sait le mieux se rapporte a la tourbe et au charbon. I https://www.w3.org/1998/Math/MathML"> s ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> agissalt de plantes lignocellulosiques; on a retrouvé des troncs d'arbres et de grandes fougères. Le pẽtrole, lui, parait plutôt descendre de microalgues. Quant aux processus de transformation, on ne peut non plus les identifier avec certitude. La température, la pression créee par l'accumulation des sédiments ont sürement joué un rôle, les micro-organismes et la catalyse enzymatique aussi. ce qui nous reste de biomasse transformée est extraordinairement faible par rapport à la quantité qui s'est formée au cours des millénaires et il ne nous reste plus, en fait, que les produ1ts les moins degradables: les hydrocarbures saturés, les novaux aromatiques ou naphtêniques. Pas d'hydrocarbures oléfiniques ou acétyléniques, pas de produits oxygënés sauf le co2 lui-même, présent dans les gaz. Le soufre \etaue l'on rencontre dans la matiere organique se retrouve en effet frëquemment en quantites notables dans le pétrole, le gaz ou le charbon. Ceci nest pas le cas, par contre, de pazote, constituant important des protéines, qui https://www.w3.org/1998/Math/MathML"> n ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> apparaît que dans certains gaz, ramené à https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> état d'êement. Finalement, nous récupérons ces produits ultimes et rares de transformation de la bjomasse enfouis dans les profondeurs du sol. La nature et les millenaires ont pris soin de sa fabrication. I1 nous reste à supporter le coût de sa détection puis de son extraction des nièges forcément relativement inviolables aui ont pu les retenir jusqu'ici: si la fabrication ne nous a rien coûté, la dëcouverte et 1'extraction sont, elles, difficiles et dispendieuses. La question qui se pose à nous, alors que nous consommons ces ressources qui ne sont pas illimitëes et dont le coût va bon an, mal an, en croissant, est la suivante: la biomasse contemporaine peutelle concurrencer la biomasse fossile? Le premier point à etablir est de savoir de quelle biomasse contemporaine https://www.w3.org/1998/Math/MathML"> 11   s ' g gt . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pas necessairement, et meme probablement pas de celle qui a donne naissance aux combustibles fossiles: soit au'ils ne soient 1 us répandus sur la terme dans les omptikams actuelles comme les grandes fougëres de 'íepoque carbonifere, soit que leur croissance soit troo lente ou leur concentration trob diluée comme le phytoplancton pétroligēne. Il ne s'agit pas davantage - et p'on doit insister sur ce point des plantas cultivēes actuelles gui ont ëté sélectionnëes et développees par des gēnêrations d'agriculteurs, savants et moins savants, pour des objectifs tout autres qu'energetiques: soit pour fournir de la nourriture comme la canne à sucre, la betterave, le blé 1 arachide, le colza ou la luzerne, soit pour fournir des matieres premieres industrielles comne le coton, l'hëvéa ou le sadin du Nord. Des circonstances particulieres ont cependant conduit les hommes à utiliser certaines de ces plantes existantes à des fins ēnergetiques, soit telles quelles comne le bois de feu, soit apres transformation comme la canne à sucre ou le maris. La connaissance de ces procédés de transformation a suggéré á son tour, le recours à https://www.w3.org/1998/Math/MathML"> d ' a u t r e s p l a n t e s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur lesquelles certaines connaissances, plus ou moins avancées, ont été acquises. C'est ainsi qu'il est devenu possible de dresser un état provisoire et simplifié du domaine de la biomasse énergétinue. Celui-ci est caractërisé par une liste d'espēces vëgëtales assurant une transformation relativement efficace de l'energie solaire reçue en composants (figure 1) dont la conversion en produjts énergëtiques est connule, aboutissant à une gamme acceptable de coûts. Figure 1 POLYSACCHARIDESCelluloseStarchInulin https://www.w3.org/1998/Math/MathML"> C 6 H 10 O 5 N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Pour que https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on puisse parler de biomasse énergétique, il faut que le produit, s'il ne l'est déjā, soit mis sous une forme qui lui perimette soit d'alimenter un foyer de combustion, soit de faire fonctionner un moteur. If n'est pas necessaire pour cela de fabriquer des sosies des prodults pétroliers. Encore faut-il an pratique respecter certaines conditions essentielles, et celles-ci sont parfois surprenantes. Ainsi la gazéification directe du bois a-t-elle bien du mal à alimenter les moteurs qu'elle encrasse. dans presgue tous les cas, le passage par le charbon de bois finit par être moins couteux. Les inenagères africaines éprouvent beaucoup de réticence à remplacer le bois sec traditionnel par des agglomérés de pulpe de café our autres qui refusent de https://www.w3.org/1998/Math/MathML"> s ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a 11 umer colmodément. Dans l'état actuel de la question, la liste des produits que l'on peut reeflement considerer comme capables de figurer de façon importante dans le bilan energétique est très limitee. Elle comprend (figure 2) le bois lui-même, le charbon de bois (ou le bois torrêfié), le methanof et fiethano1 qui sont des produits de base ie mélange acetonobuty ique, sensiblement plus couteux pour linstant, peut etre nécessaire coime solvant de ' 'alcool dans l'essence. Nous ne retenons pas, pour linstant, les huiles vegétales qui devraient, cependant, etre reintroduites https://www.w3.org/1998/Math/MathML"> s 1 i 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> apparaissait la possibilite de troiver un suistitut standard et êconomique au gas oil: n'oublions pas aussi que le moteur a essence peut être substitué au moteur diesel: en outre, dans beaucoup de pays elles doivent être réservées à 1 alimentation. Nous n'ēvoquons pas non plus les résidus divers dont nous savons, bien sur, qu'ils peuvent contuira a des utilisations locales ëconomiques mais qui ne représentent pas de forts tonnages. Enfin, nous ne comptons pas pour https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> instant la méthanisation directe des plantes car nous n'en voyons pas encore a ' norizon la viabilitë industrielle a grande échelle sauf pour la dépollution. Figure 2 Sur le plan technique, il est aujourd'hui démontré que le méthanol et rethanol, quitte à leur ajoiter un tiers solvant comme le mélange acétonobutylique, peilvent remplacer l'essence dans les moteurs avec equivalence en volume pour les faibles pourcentages et en pourvir calorifique au-dessus de nuelnues %. Pour ce faire, les voitures doivent connaitre quelques Et T'on peut mểm dire deja quirf coüte beaucoup moins cher que te charbon national français de certains bassins. Nous pourrions avoir intérêt à transformer une partie de nos mineurs en bûcherons et charbonniers Il ne s'agit pas là d'un rêve. Nous sommes dans un domaine scientifigue en plein mouvement et le rendement it https://www.w3.org/1998/Math/MathML"> t h → t h a n o l u d 1 u n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hectare de terre s"eléve aujourd'hui seulement à https://www.w3.org/1998/Math/MathML"> 0,1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de https://www.w3.org/1998/Math/MathML"> γ ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> energie solaire recue. Mais les problémes rencontrés par l' eccoulement des excédents agricoles obligent a se demander sil ne vaudrait pas mieux convertir des maintenant. une partie de nos terres vers des cultures ēnergétiques. On observe en effet que toute polltique agricole qui dépasse ' autosuffisance est forcement coutteuse. Les excédents ne peuvent s'ēcouler que sur un marchë de surplus où les oroduits sont brades, tandis que les surplus des autres pays viennent frapper a nos frontieres et pessent, peu ou prou - en empruntant des détours - sur nos prix intêrieurs. Le marché du pétrole, Tuí, n'est pas un marché de surplus. or, on peut calculer que si 1 on applinuait aux cultures ennergetiques, les subventions appliquêes actuellement aux excêdents agricoles, les carburants de biomasse pourraient, alors, devenir compêtitifs (voir tableau2, col. 5). Tableau Coût des carburants et combustibles dans la C.E.E. J.J. BECKER - thẽse non publiée (1) Cout tu substrat agrıcole ēvalué en supposant la conservation de la main d'oeuvre agricole sur https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> exploitation (2) Coût du substrat agricole évalué en ne conservant que la main d'oeuvre nécessaire à 1 'activitē énergétique On devrait conclure qu'il convient de s'engager sans tarder dans cette voie. On peut prédire, cependant, que celle-ci risque d'être tout comme la politique agricole commune actuelle - une nouvelle Impasse si on ne trace pas des le départ une politique qui doit s'attacher à résoudre en tout cas deux problèmes: Le premier est de donner aux aides de la Communaute une forme qui conduise la biomasse au progres. Ces aides doivent etre construites pour disparaitre au fur et a mesure que les filieres ennergëtiques feront des progres. Il faut qu'elles les poussent au progres. Il ne faut pas raisonner seulement sur les moyens de financer un "coup sec" tel que la construction isolëe d'une usine d'alcool. Il ne faut pas en faire un nouveau rachat d'excédents. Le deuxieme problème dont il faut se préeoccuper est la façon dont https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> agriculture et lindustrie vont se raccorder pour faire reussir une filiere agro-industrielle. L'agriculture ne pourra pas, seule, distribuer ses prodults: 'i industrie du pëtrole ne sait ni faire pousser des plantes, ni les collecter, ni les conserver et les conditionner au besoin par une premiene transformation. Certains rêvent sans doute d'un office d'Etat rachetant les alcools comme des surplus agricoles et les revendant, au besoin par la force des reglements, et à perte, aux distributeurs. Comment ne pas voir qu'un tel dispositif maximiserait plutôt la divergence des intërêts que leur convergence, condamnant ainsi le développement de la biomasse a "'echec. Il faut, au contraire, intéresser les differents partenaires au succès, chacun faisant ce pour quoi il est le plus compëtent. En analysant le développement de la filiere, on se dit que le bon point de raccordement se situe peut-être au milieu du processus de transformation: la premiere étape, pratíquée dans un díspositif de type cooperative agricole, consisterait a elaborer des produits bruts aisément transportables qui seraient terminés dans des usines de type pétrolier. Dans les PVD, la biomasse ne présente pas les mêmes caractères. Les rendements peuvent être, en certains endroits, plus èlevês et les especes utilisables ne sont pas les mêmes. La structure des coutts n'est pas non plus identique. Arithmétiquement, le probleme de la surface disponible ne se pose pas car la consommation des produits pëtroliers est généralement tres faible comme le montre le tableau 3 sur quelques exemples. Ces chiffres montrent naturellement qu'il est parfaitement possible, en choisissant opportunement les filieres, de ne pas empieter sur les surfaces consacrées aux cultures alimentaires. Des végétaux tels que 1 'herbe de Napier (herbe à éléphant) ou https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> eucalyptus pourraient donner de la matière sèche compétitive avec celle de la canne a sucre. Les obstactes rencontrēs dans les PVD sont d'un autre ordre et sont malheureusement três variés. Malgré de grands efforts, la World Bank https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a constatē, il est trẽs difficile de trouver un pays où https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> un de ces obstacles au moins ne soít pas présent empêchant un projet industriel de se mettre en place. On peut citer: TABLEAU 3 PAYS (1) SURFACE KM2 (2) IMPORTATI ONS NETTES PETROLIERES MiLIERS DE TEP (3) SURFACE POUR BI OMASSE EQUIVALENTE % SURFACE ETHIOPIE 1221900 560 1400 0.11 GHANA 239460 870 2175 0.91 KENYA 582646 1237 3100 0.53 MAROC 458730 4055 10135 2.21 SOMALIE 639969 249 620 0.09

le fait que la culture qui serait favorable n'est pas encore suffisamment etudiee. (un projet fondé sur le manioc en Nouvelle-papouasie est dans ce cas: de même, on n'en sait pas assez long sur les végétaux adaptés aux zones arides).

la difficulté de modifier, fut-ce tres peu, les engins d'utilisation (les fourneaux des ménagères, les voitures et les moteurs existants), simplement les habitudes (remplacer le kérosene par du charbon de bois).

Irinaccessibilité de nouvelles zones de culture,

le temps nécessaire pour former la main-d oeuvre,

la faible taille des projets envisages.

On fait couramment par exemple les calculs sur une unitê https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> éthanol de 500 T/j: https://www.w3.org/1998/Math/MathML"> c ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ordre de grandeur de la consommation d'essence de toute 'Ethiopie. 0r, on ne peut pas convertir du jour au lendemain toutes les automobiles d'un pays, etc... etc.. De ce fajt, on doit être prudent a liegard des evaluations ëconotniques qui sont ëtablies sur des cas thêoriques ou même. sur celles qui correspondent a des projets assez détaillës, car il y a toujours une étape de ceux-ci qui comporte un certajn pari. Cependant, les chiffres sont déja favorables (tableau 4). Bien fabriqué, le charbon de bois est déja deux à trois fois moins cher que le kërosène et le gas oil, quatre à cinq fois moins que les GPL. Le prix de gaz fabriqué dans un gazogẽne rivalise avec celui du gas oil et serait ainsi utilisable pour les camions et les moteurs fixes. La fabrication de methanol ou d' ethanol, dans des conditions convenables (taille suffisante, combinaison de cultures) pourrait être à peu près compétitive, comme' https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a montré https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> exemple brësilien. Tableau 4 COUT DES CARBURANTS ET COMBUSTIBLES DANS LES PVD Prix F/T Poc TWT Prix A LA TERNIE https://www.w3.org/1998/Math/MathML"> d / T H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> SURERCARBURANT https://www.w3.org/1998/Math/MathML"> 2500   A 5000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 10500 https://www.w3.org/1998/Math/MathML"> 24   A 48 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> METHASIOL EX BOIS https://www.w3.org/1998/Math/MathML"> 800   A 1300 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4750 https://www.w3.org/1998/Math/MathML"> 17   A 27 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ETHANOL https://www.w3.org/1998/Math/MathML"> 2000   A 3500 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 6390 https://www.w3.org/1998/Math/MathML"> 31   A 55 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FUEL LOURD https://www.w3.org/1998/Math/MathML"> 1500   A 3000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9600 https://www.w3.org/1998/Math/MathML"> 15.5   A 31 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CHARBON https://www.w3.org/1998/Math/MathML"> 450   A https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 900 6000 https://www.w3.org/1998/Math/MathML"> 7.5   A 15 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BOIS https://www.w3.org/1998/Math/MathML"> 65   A https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 100 1900 https://www.w3.org/1998/Math/MathML"> 3.5   A 5.3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CHARBON BOIS https://www.w3.org/1998/Math/MathML"> 550   A https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 750 7000 https://www.w3.org/1998/Math/MathML"> 8   A 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> J.J. BECKER - thèse non publiēe Résoudre le problème devient ainsi une affaire de volonté et d'obstination. Quatre-vingt quatre nations en voie de développement reprësentant des milliards d'hormes importent ensemble environ 300 millions de tonnes d'hydrocarbures. Cela constitue pour beaucoup d'entre elles une charge énorme : https://www.w3.org/1998/Math/MathML"> 30 % , 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , parfois plus, du montant de leurs exportations, une charge annuelle pour leurs économies du même ordre de grandeur que le montant total de leur dette. C'Est pourtant ce qu'il serait possible de produire sur 100 millions d'hectares seulement, alors que l'Ethiopie seule compte 8 millions d'hectares de forêts et 20 millions d 'hectares de savane, et que la superficie du Bresil est de 850 millions d'hectares et celle de 1'Afriaue de 3 milliards https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hectares. I1 n'est pas possible de rester indifferent devant cet enjeu et 11 faut souhaiter que la Banque Mondiale, qui en a mesuré 1 importance et les difficultēs, reçoive tous les concours neacesaires, financiers, industriels et scientifiques. Ainsi, que ce soit en Europe ou dans le Tiers Monde, le moment est venu pour la biomasse de commencer à faire son entrée dans le bilan énergētique. Les problëmes sont identifiés, il faut les résoudre. BIOMASS FUELS IN A EUROPEAN CONIEXT R.M. SEITIGMAN, B.A. (Oxon) Member of the European Parliament for West Sussex, U.K. and Vice-Chairman of the Connttee on Energy, Research, and Technology Sumary Abstract Two and a half years after the European Parlitament called for a 60 million ECU 5 year programe on Energy from Blomass, the Councll of Ministers in Brussels has acopted such a programe, albelt a somewhat reduoed ane. The प्रEC, therefore, has to choose where to concentrate 1 ts efforts In the enormots field of Blomass energy. The writer considers that the areas where energy crops can make the most inportant economic and political impact are in Short Rotation Forestry for methanol production, and in root and cereal crops for Ethanol production, both to be used as ingredients of Motor Fuel. Biotechnology and inproved equipment are causing Agricultural Productivity to increase relentlessly, productng unwanted food surpluses. Energy crops nust replace these surpluses. The use of Agricultural oxygenates in Motor Fuel w.1.1 not only reduce dependence on imported ofl, it will improve the balance of payments, provide work for farmers, help the energy problems of the developing countries and, more recently, offer a solution to the octane and envinonmental problems of tuleaded petrol. Major research efforts are now needed, using advanced biotechnology and process engineering, to reduce the cost of the agricultural oxygenates and to find profitable uses for the bypucoducts. Ways to surmount the various political and economic obstacles, and the doubts and objections to the adloption of bto-energy, w1II be examined. 1.1 Introduction It is my intention today to corment on the political and economic realitles which lie behind the move towards bianass energy. The oil crises of 1973 and 1979 greatly increased interest in Alternattre Finergy Sostreces. Unfortumately, it also tncreased the tmportance in alternative non-Opec oil sources. like Mexion and the North Sea. orodilction increased in 4 vears from https://www.w3.org/1998/Math/MathML"> 2.5   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to neariv 9 m Bial Horld recession which resulted from htgh oll prices, combined with the new sources of ofl, resulted in the present glut of ofl. This ofl glut then causea the slowing down or abandonment of many very pramising R and D projects in Altermative mergles - not least ooal Ifquification and gaslfication, blamass, solar and geothenral energy. But my inpression is that there https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> now a renewed interest in Alternative Fuels, because oll prices are expected to rise agatn in the next 10 years, as economic recovery accelerates. As Henry Ktssinger said tn the Sunday TImes recently, "The present terporary respite from oll pressures mist be used to expand conservation policies and to encourage the development of Alternative sources of energy - exactly the opposite of the present shameful trends. "Otherwise the https://www.w3.org/1998/Math/MathML"> 1990 ' s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , once more facing an energy shortage, may well CURSE the BLINDNESS and the lack of foresight of Current Leaders". Our generation Mr. President - will go down in history as immoral and grossly selfish. In the short space of 70 years - one short life time - we have squandered fint te resources of oil and gas, in blissful disregard for future generations - spending pathetically little on research in Renewable energy and rejecting an energy or ofl import tax, because it would inhtbit the greedy guzzilng of Imported non-renewable fuel. The revenue from such a tax could well be used for research into energy conservation, and alternative renewable fuels, fuels whtch came from the Sun's energy. I sometimes despair of short-sighted politiclans. But, Mr. President, I think things are beginning to move our way. background to the growth of energy from Bicmass is becontng datly more Eavolmable. Not only is North sea ofl production reachtng its peak, shortiy to decline, but the world is becantng more enviramentally conscious every day Citizens are turning their minds away fram the politics of war, and turning more towards the polltics of fighting pollution. And every ant https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pollution move brtngs us closer to Blamass energy. Not only does buming coal, ofl and gas as a fuel, waste a large number of complex and valuable ingredients, which go up the chimey in sunoke - it also generates sulphur and nitric actois which pollute the atr we breaths and probably kills trees, lakes and fish as well. Nuclear power is probably one of the cleanest and safest forms of electricity generation, but you cannot use that for driving motor cars, motor boats or aeroplanes. The Green movement in Eurcoe is gaininc polltical influence, especially in Germany. This means that we have to listen to them. And their message on energy 1 s contained in an amendment to the Energy Pricing policy of the EEC, which the Greens pushed through in Strasbourg last week. "Parliament notes that Research indicates that biamass can be used to cover up to 20 per cent of Member States energy requirements, and that Our agricultural surpluses can be eliminated through using biamass calls, therefore, for the necessary initiatives to be taken at European level, to develop the use of Biamass". 20 per cent may be on the high side, but I am very glad that the Councll of Ministers in Brussels, has at last achoted a Blamass Energy progranme - albelt, however, olly for https://www.w3.org/1998/Math/MathML"> 20 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mCU against 60 ELU demanded by the European Parlidment https://www.w3.org/1998/Math/MathML"> 2 1 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> years ago, when I was Rapponteur for a 5 year international programe in biomass energy. This conference is ideally timed to make suggestions for inoorporation in that programne. The European Parllament reallses that Blomass must come of age. It can no longer be a futuristic, hypothetical technology. It mast fight in the market place on equal terms with other technologies. We have to convince the authorties and the farmers that they can make a Iiving out of energy croos. But a Blamass energy source which https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sultable for ane reglon, or climate may not be suttable for another. That https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> why I am deltghted that this conference https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> drawing contributions from so many different countries. In partlcular, the Mediterranean, Scandinavia, Ztmbabme, Canada, Florida and China. Furthemore. dufferent BLomass enviromments are discussed. Arable, industrial, aquatic and forests. The basic problem, however, is not technology, it is econcantes it is MONEY. That is why there will be no massive swing into Biomass Energy, until the price of Hydrocarbons goes up again. For that moment. Basically, it is far better to use avallable land in the EEC and the Third World to produce energy crops that we need, rather than food surpluses which we don't need, and that we have to sell off to the Russians and others at a substantial Ioss. It is costing the EEC something like https://www.w3.org/1998/Math/MathML"> 7 B n E C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a year - just to get rid of the surplus food on World markets, and in free Food Atd. It must be sensible to replace this costly food surplus, with energy crops, if it can be done wlthout costing more than it does now. 2. MOTOR AND TRACTOR FUET The biggest prize in Biamass Energy at the moment is fuel for cars and tractors. But I understand that cost estimates for producing Agricultural Alcohol are still far too high. An ofl company told me that while conventional Motor spirit costs only 350 ECU a tonne, grain alcohol costs between 795 and 875 meU per tonne to proauce; sugar beet alcohol costs https://www.w3.org/1998/Math/MathML"> 675 E C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per tonne. I have no figure for artichoke alcohol. So one vital area of research is to find ways to make Agricultural Fuel Alcohol cheaper and more competitive with fossil fuel. I don't believe we are anywhere near the end of the road in this sort of research. 3. RESEARCH IN SOUTH AFRICA In South AFrica, whth I visited recently, the Government are hoping eventually to derive https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of their liquid fuel requirements for cars and tractors from agricultural alcohol and plant ofls. Since 50: of their fuel goes into Farm Tractors, they tend to concentrate on tractor fuel. 3.I Ravmo and Purchase of Durban University Agricultural Energy Institute, declded that the main obstacle to Ethanol in notor Spirt.t, or tractor fuel, is the high cost of the raw materials, which is 658 of the total cost. They are dolng meaningful experiments to cerive Aloohol directly Irca Bagasse. which otherwise accumulates as waste, and can be obtained very cheaply. Now maybe cane sugar bagasse is of little interest to Europeans, but https://www.w3.org/1998/Math/MathML"> 1 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> certainly shoula be to the developing nations. The process seems to be to hydeollse the hemicellulose camponent, which is https://www.w3.org/1998/Math/MathML"> 35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the waste by dilute https://www.w3.org/1998/Math/MathML"> H 2 S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to Xylose, leaving a residue of cellulose and lignin. Xylose can then be fermented to alcohol The balance of Bagasse Cellulose is converted to glucose by enzymes. One third of the carbor of the Bagasse then rematns as burnable. In this process https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the Bagasse, which costs only https://www.w3.org/1998/Math/MathML"> E 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a tonne, is made fermentable, meaning that the raw material for alcohol costs not much more than El5 a tonne. So that could be one way to cheapen Bio-ethanol. 3.2 The Department of Agricultural Engineering in Natal University at pletermarttzberg have been blending diesel with up to 158 Ethanol (mark you South Africa has a warmer climate than ours). They store the ingredients separately to avoid phase separation. They do use Nitrates as CEIANE inprovers from the Ethyl Corporation, Baton Rouge, U.S.A. The Econcimics of mixing Ethanol with Diesel depends very much on the price charged by the Government for SASOL diesel. This research work is important strategically in case south Africa's surply of imorted otl is cut off. 3.3 Thirdly, many of those present will be aware of the successful work done in the Agricultural Engineering division of the Department of Agriculture in Pretoria by Fuls and others, on using degumed sumflower oil esterified by Ethyl Alcohol with a sodtum Hydroxide catalyst in a airect injection compression ignitition engine. Fuls is convinced that many different plant ofls (incluating non-food plant ofls), could be used in the same way to ditive Third world tractors, and this lends interest to Untlever's new Palm of1 clones, which yleld https://www.w3.org/1998/Math/MathML"> 30 o https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> more ofl than traditional strains. 4. THE ADVANIAGES OF BIO-EIHANOL The world needs an alternative transportable motor fuel to mineral oil. It may ane day be hydrogen, generated by nuclear energy, but ethanol has so many econonic and political advantages.

I Firstly, it provides a solution to the problem of farm food surpluses, and be sune these surpluses are going to tncrease every year due to the march of agriculture science, in selective breeding, growth regulation, hormone management, tissue culture and better fertilisation.

4.2 secondly, ethanol offers import savings to the EFC and Third World countries, who have to spend most of their own export earnings just to pay for their fossil fuel truports. 4.3 Thirdly, the higher value of the dollar has made inported crude oil much more expensive than it was, compared with altemative indigenous fuels. 4.4 Ethanol offers an altemative to lead in petrol, as an octane boorteer 4.5 Fifthly, ethanol offers an environmental improvement by replacIng hydrocarbons contatning sulphur, which pollutes the urban atr we breathe. If ethanol can be cheapened, and if it's bad effect on cold starting and the motor octane number can be resolved, it is bound to be used more and more. The practical problem with Ethanol lies in the reluctance of the International ofl majors to using agricultural oxygenates. And after all, they are the people we have to persuade. They, and the motor manufacturers, have to take the action - they have to adapt their refining processes and engine designs to accormodate ethanol and methanol in their fuel. They have to be persuaded that their balance sheets at the end of the year will not suffer. How can this be done? This is an ideal job for the ERC Commission. The Camission should launch a research programe to provide answers to the specific objections ralsed 5. OBJECRIONS TO OXYGENATES 6. 5.1 The first objection. I have heard that there is 7. OBJECTIONS TO OXYGENATES ton of bicmass residues, which on 8 million hectares, would give us 32 million tonnes of ethanol per year. With 90 mt.1liton tonnes of gasolene consumed per year In the https://www.w3.org/1998/Math/MathML"> E x B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 358 could theoretically come in the form of Ethanol from the land which at present 1 s procucing the unwanted food surpluses. In fact, with Ethanol likely to be limited in the EEC to 5 of of motor fuel at present, we would have 7 times more land than we need. So don't lets hear any more about the limitation of avallable land. 5.2 The second objection is - "How can you talk about converting good cereals into fuel alcohol, when these cereals are needed by the starving millions in Ethiopla and the Sahel?" Firstly, the ENC 1 s planntng to send 2.5 million tonnes per annum of cereals to Ethiopla and the Sahel. But the production surplus over requiremants https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> more like 20 million tonnes a year. Most of this is sold abroad at World prices, which are temporarily htgh - due to the high value of the Amertcan dollar. This may not last. In which case the cost of restitution, when we sell Surplus cereals abroad, will go up again. If, and when, World cereal prices fall back agatn, it wIII beoome more difficult and more expenstre to sel. cereals on the World market and more wIll then be avallable for conversion into fuel alcohol. In any case, 1t would be quite wrang to regard Europe as the permanent granary for the starving worla. To provide Emergency supplies in a crisis is a good humantarian act. To plan to permanently dump our surplus food on the Third world would be quite wrong. We must help them to beccome self-sufficient in Food. In their own interest, we must help them to butld up their agriculture and infrastructure by tnvesting and giving them technological help. So I don't see at all that the argument against using our surplus cereals for fuel alcohol instead of food has any validity at all. The third objection is technical. It is that Ethanol as a substitute for lead is only a partial answer. If you have a high or medium compression engine, as we have in europe, Ethanol w111 not eltminate htgh speed knock. There must be a research answer to this. Furthermore, for each 18 of ethanol added, you only get 1/5 th of an octane number improvement. This means you would need https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol to gain the improvement of 5 octane numbers needed to replace the 0.4 grams/litre of lead which is currently in use in the EEC. You would need about 10 of ethanol to replace the future level of lead of . 15 grams/11tre. This would be permissible in the U.S.A.; but in the EEC, the camission has been more cautious and wants to limit ethanol to 58 . So the current thinking in Europe is that https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> methanol derived from hydrocarbons is acceptable with 5 othanol as a cosolvent. The question is whether Ethanol has yet been proved to be an adequate cosolvent. If it is, the Farmers and the C.A.P. have a good outlet for https://www.w3.org/1998/Math/MathML"> 5 m i l l i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes of ethanol per year on over a 8. OBJECTIONS TO OXYGENATES (Continued) 5.3 million hectares. If it is not, oil companies may prefer to use T.B.A., as a cosolvent, or M.T.B.E., an as an actane booster, nelther of which would come cheaply fram Biamass. 5.4 The fourth main objection https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the one about Energy Balance. It says that you have to put noze energy in to Ethanol proauctian than you get out of it. I don't consider this a valid argument. Cars and aeroplanes cannot run on coal or nuclear power. They need a liquid transportable fuel. What the Brazllians have done is to convert solid raw material - cane sugar into a convenient Iiquia transportable fuel aloohol. Provided the energy imbalance ls not unxeasonable, Gasohol proculution from sugar is a sensible replacemant for petrol. The Swedes fn their Blostil plant at Skaraborg, sacchar1fy, ferment and distill surplus wheat in a continuous process which https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> engineereci for maximum heat regeneration, which should greatly improve the energy balance of ethanol production from cereals. 5.5 A fifth objection to Blo Ethanol production for motor fuel ts that the surplus subsidised ethanol might campete with the potable spirit industry. Clearly, the production process must be adapted to make the product undrinkable. 5.6 But the real objection by the oil majors is the Economic one. And the corridors of power in the Carmission in Brussels and in Bonn and Parls, are buzzıng wlth this controversy. For a 5 와 ethanol as cosolvent for methanol in motor fuel, we need about https://www.w3.org/1998/Math/MathML"> 5 m t l l i c n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes of agricultural ethanol. I calculate that this alone would need a subsidy of well over I Bn ECU per year. As I said earlier, the production cost of 100 of DRY ethanol from Beet Sugar 1s about 675 ECU per tonne and from cereals between 795-875 ECU per tonne. The oil compantes don't want to pay more than about https://www.w3.org/1998/Math/MathML"> 250 B C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per tonne for dry ethanol. Thls seems an unfairly low figure when petrol. costs https://www.w3.org/1998/Math/MathML"> 350 E C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per tonne to produce. At this rate, a subsidy of https://www.w3.org/1998/Math/MathML"> 425 E C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per tonne of Dry sugar beet alcohol, or https://www.w3.org/1998/Math/MathML"> 545 E C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per tonne of Dry wheat alcohol, (cmpared with the proposed https://www.w3.org/1998/Math/MathML"> 700 E C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per tonne subsidy for wine alcohol), would be necessary. At the moment due to the high dollar, very little restitution - perhaps https://www.w3.org/1998/Math/MathML"> 25 E C U / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Tonne - has to be pata by the EEC on cereals sold on the Norld market, which Indicates that it is much cheaper at present to sell as much cereal as possible on the world market with only a https://www.w3.org/1998/Math/MathML"> 25 E C U / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonne subsidy, than convert 1t into ethanol with a 545 ECU/Tonne subsidy! This may change, however, and the dollar may fall agatn, and then world cereal prices w1ll fall. Then the cost of restitution will increase, and a large subsidy on cereal alcohol for motor fuel will not look so out of line. Nor must we forget that the matn altemative for ofl companies is to change the oil refining process and Invest in expensive reformers in order to reach the necessary octane number. This will consume more crude ofl and cost more. 6. CONCLUSION Europe is getting increasingly excited about Bio-alcohol, as a substitute for lead in petrol. There are still a lot of hurdles to cross before 1 t becanes a commerclal reality. But there is a lot going for 1 t. (a) Bio-Ethanol is environmentally more acceptable than lead, or Hydrocarbons. (b) Bio-Ethanol production would help to solve the problem of cereal surpluses. (c) Bio-Ethanol would help to reduce our excessive dependence on imported ofl. (d) Bio-ethanol, is infinitely renewable, whereas liquid and gaseous fossil fuel reserves have only about 70 years to ru. In Lts new Blamass proganme, or a separate one, the cominission must take each objection to the adoption in the EEC, and the Developing World, of Bio Ethanol and vegetable ofls as fuels, analyse them and research for solutions, together with all interested parties. A new programe mist bring together experts from the oil conpanies, the motor manufacturers and the famers, to sponsor joint research to determine the facts, and finally come up with the solutions to these urgent problems. I am sure they can count on the full support of the European Parliament, if they do this. The Schleicher Resolution 1349/84 advocating Bio ethanol in motor vehtcles for environmental reasons has wide support in the Christian Democrat Conservatives and other Grours in the Parlitament. The sooner we can adopt renewable motor and tractor fuels, the socner wIll energy supplies for transport for future generations be assured. I look forward to the day, when, like Braz1l, we have cars running on pure Alcohol. Meanwhile, I have one other quite different suggestion, whtch I want to make to the conference. It concerns the use of biotechnology for energy conservation. After all energy saving has been described as the fifth fuel. I think that the biomass programe should take under Its wing the whole cuestion of energy conservation, in foor production by economising in the use of fertilisers, in the cost of fuel In horticulture, in selectibe breeding, or blotechnology, to accelerate growth rates and reduce the heat and energy needed to achieve fully grown plants, flowers and vegetables. Blological energy conservation is a whole technology which should become part of the biomass energy programme.

THE OBJECTIVES OF THE 1981 NAT IONAL ENERGY PLAN IN THE BIOMASS SECTOR

AVENIR DE L 'AGRICULTURE EUROPEENNE ET VALORISATION DE LA BIOMASSE L. PERRIN Président de I'Assemblée Permanente des Chambres d'Agriculture Abstract C'est avec plaisir que j'ai accepte de participer a l'ouverture du troisième congrès sur la valorisation énergétique de Ia biomasse. Je remercie les organisateurs de m'avoir invité à cette conférence, me permettant ainsi d'exprimer le sentiment d'un agriculteur francais sur l'avenir de l'agriculture et sur le role que peut y jouer la biomesse. Si vous le permettez, je ferai un rapide bilan de l'évolution de notre qgriculture et des perspectives envisageables. Ceci pour vous expliquer l'impression de désarroi que notrs ressentons mais aussi la volonte de réfléchir a notre avenir, de trouver des orientations qui permettent de faire vivre les agriculteurs et les campagnes. Les objectifs assionés à la p. A.C. par le traité de ROME étajent : - I'indépendance alimentaire;

Ia satisfaction des besoins des consommateurs;

une amélioration de la productivité

une augmentation du revenu des agriculteurs. Ces objectifs, en tous cas, les trois premiers, ont été atteints avec un Jarge succès.

. En 1982-1983, le taux d'auto-suffisance était de 147 of pour le sucre, 125 of pour Ie vin, 118 % pour les prodults lattiers, 117 % pour les ceréales et 100 % pour l' ensemble des viandes. La valeur de la production agricole de la Communauté a augmenté de 18 of en termes réels, dans les dix dernieres années, alors que la maind'oeuvre agricole diminuajt, elie, de https://www.w3.org/1998/Math/MathML"> 32 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; peu de secteurs économiques ont realise de tels progress de productivite. Les proprès prévisibles en oénétique et technique de production permettent de penser que cette évolution est loin d' etre terminée. Mais alors que 1'Agriculture a encore un potentiel de production considerable :

la demande de produjts alimentaires dans la communauté tend è stagner ; - sur les marchés mondiaux, les perspectives de débouchés solvables sont limités et la concurrence tres dure.

Un autre facteur qui nous préoccupe est celui de lívolution de la pyramide des ages des agriculteurs. Si nous prenons l exemple de la France, on constate que deux agriculteurs sur cinq ont aujourd'huj plus de 55 ans et permi ceux-ci, les https://www.w3.org/1998/Math/MathML"> 2 / 3 n ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ont pas de successeur pour leur exploitation ; ceci est vrai pour d' autres pays européens. Si on lajsse faire, cette évolution se traduira sans doute par une double tendance

concentration des productions dans certaines régions avec accroissement de productivité:

THE COMMON AGRICULTURAL POLICY AND BIOMASS ENERGY John SCULLY Directorate-General for Agriculture Commission of the European Communities Throughout history biomass has been used by man to provide enerove either directly by the combustion of fuelwood or indirectly by animal trac- tion. Industrial development in the 18 th and 19 th centuries depended prin- cipally on the use of fuelwood. In the https://www.w3.org/1998/Math/MathML"> 20 t h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> century, the use of fossil resources came to the fore. It seemed likely that man would break away from the use of biomass. But the successive crises of the https://www.w3.org/1998/Math/MathML"> 70   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> showed that fossil energy resour- ces were not unlimited and that an alternative had to be found. Attention was once again focussed on agricultural and forest biomass. But. compared with previous uses of biomass, some major changes were introduced in the conversion processes and techniques. It is now ten years since biomass con- version processes have been a subject of research and the Commission of the European Communities has been funding studies and demonstration projects in this area. The main impetus has come form two Directorates-General: the Directorate- General for Science, Research and Development (DG XII) and the Directorate- General for Energy (DG XVII). I would like to congratulate them for the work they have done, Other Directorates-General have been involved as well, especially the Directorate-General for Environment, which has funded research on anaerobic digestion, in the context of depollution and the Directorate- General for Regional Policy, which has been studying prospects for short- rotation coppicing in less-favoured areas of the Community. In 1984, the Directorate-General for Agriculture (DG VI), which I ain representing at this Congress, also launched a research programme on the subject. The conversion of biomass to energy thus has a long history as well as contemporary relevance. Recent developments fall into three phases:

the first phase ran from 1975 to 1979 , when pioneering work consisted in

identifying the problems and exploring the main fields of interest.

the second phase, which ran from 1979 to 1983 , witnessed the proliferation

of ideas and the first results. The media seized on the promises and brought them to public's attention. This was a difficult but enriching period. The difficulties stemmed from the fact that the widespread publi- city raised high hopes among policy-makers in agriculture and other bran- ches of the economy.

the third phase is the present one. Things have quietened down, research

findings are being analysed with more caltaness of mind and new projects are being launched The Directorate-General for Agriculture has taken the opportunity to launch a programme of research on biomass conversion to energy. And it has the benefit of previous experience from which a number of lessons can be drawn.

The problems presented by fossil fuel supplies seem to be less crucial today than some years previously. But resources are undeniably limited.

Furthermore, price forecasts for conventional fuel in the long term ( to the year 2000-2030) point to a significant increase in fuel prices. There is even some talk of 80 dollars a barrel. So oil prices will

There has already been a number of scientific publications on the con-

VIII. - conversion of dry agricultural residues, such as straw, walnut - IX. - advisory services to farmers, with the making of a film and advisory brochures: the invitation to tender is planned for the end of 1985 ; X. - economic aspects, which are being studied with a view to an invitation to tender towards the end of 1985 ; This is the general picture of our research programme. There is still room for discussions and proposals to the officials in charge of the programme in the Directorate-General for Agriculture, whom you are invited to consult for any further information. In conclusion, it seems clear that the conversion of biomass to energy is not something very new. On the basis of previous and present experience, we can plan our work for the immediate and more distant future, for which the targets of research and application will be different. It also seems clear that, despite economic problems, interest in the subject is still significant although certain factors are taking on new importance. In the case of environment, priorities in Northern and Southern Europe diverge or even confiict with each. The importance of linking up with agricultural policies and industrial policies is indisputable. For the developing countries, which we have not mentioned until now, ideas are already being formulated and it is important to take part. Some projects are under way at the initiative of the Directorate-General for Development (DG VIII). Attention is focused in particular on the economical use of biomass, 1imited consumption of fuelwood, introduction of new types of cooking appliance, and so on. But, for the developing countries where biomass is already used in large quantities for energy, there are plans to replant trees in village areas to prevent desertification. For this part of the world, the problem is more complex than it seems and much work remains to be done. My concluding words, as far as Europe is concerned, may seem rather severe but nonetheless realistic. It is important not to be too hasty in evaluating ambitious projects, but rather to wait until techniques are properly operational and economic viability is assured. KURZFRISIIGE VERFÜGBARKEIT VON FORSILICHER BIOMASSE IN DER A.F. WEISMANN Ministerialrat und Beauftragter für nachwachsende Rohstoffe im Bun- desministerium für Ernährung, Landwirtschaft und Forsten, Bonn ZUSAMMENFASSUNG: Die Entwicklung der Energiemärkte seit 1973 und die agrarische Uberschuß-Produktion in der EG führten zur Frage nach Nutzungsalternativen. Die Erwartungen richten sich auf die verstärkte Verwendung der Stoffgruppen Stärke, Zucker, Öle/Fette außerhalb des Food-Sektors. Auch die Erschließung der Potentiale von Lignocellulose könnte angesichts des geringen Selbstversorgungsgrades bei Holz für bessere Nutzung der Ressourcen beitragen. Es folgt die Darstellung der Ausgangssituation und Rahmenbedingungen einschließlich der Risiken, die aus den neuartigen waldschäden resultieren. Anschließend werden die nutzbaren Potentiale forstlicher Biomasse mit Hinweisen auf die Wettbewerbsfähigkeit von wald-Restholz quantifiziert. Als zusätzliche Quelle wird der Anbau schnellwachsender Baumarten in der Feldflur und auf Waldflächen diskutiert; das Potential könnte mittelfristig an das Aufkommen von Industrierestholz heranreichen. Das Fazit hebt hervor, daß die Probleme auf den Agrarmärkten keinen Aufschub dulden und Lignocellulose in den etablierten Verwendungsbereichen onne Konkurrenz für agrarische Rohstoffe eingesetzt werden kann. Land- und Forstwirtschaft bedürfen bei ihren Anstrengungen der weiteren Untersetzung durch verstärkte Förderung von Forschung und Entwicklung sowie durch Anpassung der Rahmenbedingungen, wenn die Entwicklung in der EG nicht Schaden nehmen soll. 9. EINFUHRUNG Von Wald und Holz in der Bundesrepublik Deutschland soll die Rede sein; beide Begriffe sind in der deutschen Sprache einsi.lbige wörter und Bezeichnungen für Naturphänomene, die auch heute noch voller Wunder und Rätsel sind, und zwar trotz des gebrauchs durch die Menschen seit Beginn ihrer Geschichte sowie trotz intensiver Erforschung während der letzten Jahrhunderte. Dagegen ist das Thema praktisch, nüchtern, nicht von gleicher Faszination wie das Naturphänomen wald, aber mit Risiken und unwägbarkeiten behaftet. Die bekannte Entwicklung auf den Energiemärkten seit der 1. Hälfte der https://www.w3.org/1998/Math/MathML"> 70 e r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Jahre und die wachsende Überschuß-Problematik auf den wichtigen Agrarmärkten der Europäischen Gemeinschaft haben die Frage nach Nutzungsalternativen außerhalb des food-Bereiches in das politische Rampenlicht gerückt. Die Erwartungen der politisch Verantwortlichen, ferner der un itre Existenz besorgten Landwirte und waldbesitzer sind groß und hochgespannt; kaum geringer sind aber auch die Schwierigkeiten, die Wettbewerbskraft nachwachsender Rohstoffe für geeignete Produktlinien durch Züchtung, durch Optimierung der Bereitstellung und Konversionsverfahren in der gebotenen Zeit so zu verbessern, daß ausgewählte Nutzungsmöglichkeiten in die Praxis umgesetzt werden können. Hoffnungen verbinden sich nicht nur mit den Stoffgruppen Stärke, Zucker, pflanzlichen Ölen und Fetten, sondern auch mit den Lignocellulosen und ihren Komponenten Cellulose, Hemicellulose und Lignin. Die Ausführungen beschränken sich auf Holz, auch wenn das in den landwirtschaftlichen Betrieben nicht benötigte Stroh in einer Menge von ca. 5 Mill. t jährlich ein beachtliches Potential an technisch verwertbarer Cellulose darstellt. Die weitere Einschränkung auf die in der Bundesrepublik Deutschland k u https://www.w3.org/1998/Math/MathML"> r   z   fr   is   tig https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> verfugbare Holz-Biomasse wirft die naheliegende Frage nach den weltweiten Relationen und der Aussagekraft der Betrachtungen auf. Wenn von der gesamten Waldfläche der Erde mit ca. 4,1 Mrd. Hektar (ha) nur 0,85 of auf die Europaische Gemeinschaft entfallen und die Waldfläche in der Bundesrepublik nur etwa 22 of der Waldfläche in der EG der 10 Staaten ausmacht, so können Sie die bescheidene Größe des hier in Frage stehenden Mosaiksteinchens aus globaler Sicht ermessen. Aus der Nähe unter einem anderen Blickwinkel betrachtet, stellt sich die Bedeutung anders dar:

In der stark mittelständisch geprägten Holzwirtschaft der Bundesrepublik Deutschland sind gegenwärtig 680.000 Mitarbeiter beschäftigt. Dieser Bereich erzielte 1983 einen Umsatz von über 92 Mrd. DM. Nicht mitgerechnet ist der Produktionswert der Forstwirtschaft, der rund 3 Mrd. DM ausmachte und von etwa 100.000 festen Beschäftigten und einer vielfachen Anzahl von Saisonarbeitskräften erzielt wurde. Einschließlich der Angehörigen der Beschäftigten gründet sich die unmittelbare Existenz einiger Millionen Menschen auf die Tätigkeit der beiden Sektoren.

Voraussetzungen dafür sind die Rohstoff- und Warenströme, wie sie sich in der nachstehenden Übersicht "Bilanz fur Holz und waren auf der Basis Holz in Rohholzäquivalenten" niederschlagen:

Die Datenübersicht spiegelt die potentiellen Nutzungsmöglichkeiten für forstliche Biomasse aber nur unvollständig wieder; darauf wird noch näher einzugehen sein. 10. AUSGANGSSITUATION, RAHMENBEDINGUNGEN 11. 1. die Position des waldes in der Rechtsordnung:

Elemente der Forststruktur sowie Merkmale der waldnutzung und Holzverwendung;

natürliche Kalamitäten und neuartige Waldschäden als ökologische und ökonomische Störfaktoren; 4. strukturelle Überschüsse auf wichtigen EG-Agrarmärkten; Konsequen-

12. Ad 1): Welche ökologischen und Ökonomischen Funktionen werden vom Teilnehmer und Interessenten, die nicht aus dein deutschen Sprachraum kommen, werden nicht so ohne weiteres mit den Rechtsnormen vertraut sein, die sich in Mitteleuropa seit Beginn einer planmäßigen Forstwirtschaft für den Wald als Ökosystem und Rechtsobjekt, aber auch für die waldeigentümer in zunehmend strengerer Ausprägung ergeben haben. Sowohl das Bundeswaldgesetz von 1975 als auch die Forstgesetze der Iänder bestimmen unter anderem: 1.1 Der Wald ist wegen seines wirtschaftlichen Nutzens und wegen seiner Bedeutung für die Umwelt, insbesondere für die dauernde Leistungsfähigkeit des Naturhaushaltes, für das Klima, den Wasserhaushalt, die Bodenfruchtbarkeit, die Agrar- und Infrastruktur und für die Erholung der Bevölkerung zu erhalten, erforderlichenfalls zu mehren. 1.2 Die ordnungsgemäße Bewirtschaftung des Waldes ist nachhaltig zu sichern. 1.3 Es bedarf des Ausgleichs zwischen dem Interesse der Allgemeinheit und den Belangen der Waldbesitzer. 1.4 Die gesetzlich verankecten Funktionen des waldes sind von den Behörden bei allen Planungen und MaBnahmen angemessen zu berücksichtigen, sofern diese eine Inanspruchnahme von Waldflächen vorsehen oder in ihren Auswirkungen Waldflächen betreffen kön nen. 1.5 Wald darf nur mit behördlicher Genehmigung gerodet oder in eine andere Nutzungsart umgewandelt werden. 1.6 Die Waldbesitzer sind verpflichtet, kahlgeschlagene waldflächen oder verlichtete Waldbestände wieder aufzuforsten oder die Bestockung zu ergänzen. 1.7 Wald kann mit weitergehenden Auflagen zu Schutzwald erklärt werden, wenn es zur Abwehr oder Verhütung von Gefahren erforderlich ist. Anders ausgedrückt: Raubbau am Wald ist im Allgemeininteresse untersagt. Neben den ökonamischen Funktionen konmt den Ökologischen Funktionen ein hoher Rang zu. Das die Bewirtschaftung des Waldes dominierende und von den Waldbesitzern längst akzeptierte Prinzip der "Nachhaltigkeit" führt im Ergebnis dazu, daß die planmäßige Nutzung den Zuwachs an Holz nicht uberschreiten darf und daß die waldflächen nicht beliebig einer anderen Nutzungsart zugeführt werden können. Ad 2): Elemente der Forst- und Agrarstruktur sowie Merkmale der Waldnutzung und Holzverwendung Der Waldanteil an der Fläche des Bundesgebietes beträgt https://www.w3.org/1998/Math/MathML"> 29,5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , d.s. über https://www.w3.org/1998/Math/MathML"> 7,3 M i l l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . ha; davon sind 31 of mit Laubholz und 69 of mit Nadelholz bestockt. Eigentumsverteilung: 56 of Bund, Länder, Gemeinden, öffentl. Anstalten und Stiftungen: 44 of Private. Zahl der Betriebe mit wald: 473.000 (ohne 0,44 Mill. ha waldfläche https://www.w3.org/1998/Math/MathML"> < 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha), davon 372.000 landwirtschaftliche Betriebe mit 23,5 of der Waldfläche und 101.000 Forstbetriebe mit 76,5 o des Waldes. Daraus erhellt dreierlei:

I Die starke betriebliche Verflechtung von Land- und Forstwirtschaft bei etwa der Hälfte der landwirtschaftlichen Betriebe mit durchschnittlich geringer Flächengröße des zugehörigen Waldes https://www.w3.org/1998/Math/MathML"> ( 4,40 h a ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Dieser Sachverhalt legt nahe, eine lokale und regionale uberbetriebliche Kooperation - onne Verlust des Eigentums und der Dispositionsgewalt - in Forstlichen Zusarmenschlüssen zu suchen. Nach einer älteren zählung haben sich vor Jahren über 150.000 waldbesitzer mit mehr als 1,5 Mill. ha Wald zu Kooperationen zusarmengeschlossen.

2.2 Die durchschnittliche Flächenausstattung ist bei den Forstbetrieben mit 51,8 ha erheblich größer; dabei ist zu berücksichtigen, https://www.w3.org/1998/Math/MathML"> d a B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> die Größenklasse über 1000 ha mit über 1000 Betrieben vertreten ist (bei den landw. Betrieben sind es nur 18). Eine ähnliche Relation besteht in der Größenklasse darunter mit 200 - 1000 ha. 2.3 In beiden Hauptproduktionsrichtungen dominieren der zahl nach die Betriebe mit Wald unter 20 ha. Diese kleinteilige Struktur ist sozioökonomisch sicherlich vorteilhaft, läßt aber wegen der lokalen Gemengelage der verschiedenen Besitzgrößen eine optimale Waldbewirtschaftung nicht zu. Das https://www.w3.org/1998/Math/MathML">   Aufkomen an Rohholz   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> aus dem Inland - bereits in der ersten Übersicht eingangs erwähnt - beträgt im mehrjährigen Durchschnitt knapp 29 Mill. https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ohne Rinde. Nebenbei bemerkt: Das bei der Be- und Verarbeitung anfallende Industrierestholz wird nahezu vollständig als Rohstoff oder energetisch genutzt; seine Menge ist mit 30-35 of des Rohholzaufkomens eine ökonomisch interessante Größe. Der Selbstversorgungsgrad bei Holz, d.h. eigene Erzeugung in 8 des inländischen Verbrauchs an Holz und Holzprodukten, beträgt rund 47 o; einschließlich Altpapier-Recycling 63 o. Überschüsse wie auf den Agrarmärkten sind also nicht zu erwarten. Die Abhängigkeit der Bundesrepublik Deutschland von Importen im Bereich Rohholz und bei ausgewählten Produkten auf der Basis Holz ist entsprechend grob. So beträgt die Netto-Importquote, https://www.w3.org/1998/Math/MathML"> d . h . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Netto-Import in 8 der im Inland verfügbaren Mengen, z.B, bei https://www.w3.org/1998/Math/MathML">   - Papierzellstoff     rund   798   - Sperrholz     rund   558   - Holzschliff     knapp   58   - Furniere     rund   178   - Papier und Pappe     rund   16 %   - Faserplatten     rund   378   - Schnittholz und     - Spanplatten     nur   48   Schwellen   28 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Die beispielhaften Daten und die vorerwähnten Sachverhalte verdeut-

die Produktionsstrukturen der Forstwirtschaft, aber auch der Holz-

die starke Importabhängigkeit bei Holz und Holzerzeugnissen.

Diese Hinweise ergeben bestenfalls eine unscharfe Momentaufnahme. Alle genannten Elemente müssen aber auch in ihrer zeitlichen Dimension und Wechselwirkung gesehen werden, um falsche Schlußfol- Ad 3): Natürliche Kalamitäten und neuartige Waldschäden als ökologische und ökonomische Storfaktoren Naturkatastrophen und weniger elementare natürliche Kalamitäten beeinträchtigen die wallder und deren Nutzung seit Menschengedenken imner wieder auf's Neue. Das ist keine nationale Spezialität, ebensowenig wie die seit Jahren deutlicher in Erscheinung tretenden neuartigen Waldschäden, die nach überwiegender Auffassung primär durch zu hohe Schadstoffimmissionen ausgelöst werden und auch in anderen Ländern Europas noch unübersehbare Gefahren hervorrufen. Durch Wind und Sturm verursachter Anfall von Holz in großen Mengen - so z.B. in den 70er Jahren über 14. Mill. https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in einem Jahr oder 1984 über 9 Mill. https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - schädigt anhaltend den waldaufbau und Außerdem gefährden die neuartigen Waldschäden 150 of der Waldflache sind - betroffen) zunehmend eine nachhaltige Produktion sowie die gleichmäßige Belieferung der Holzwirtschaft. Für die Arbeitsplätze zeichnen sich Risiken ab, wenn es nicht gelingen sollte, z.B. durch den Anbau schnellwachsender Baumarten Einbußen zu mildern. Die ökologische und ökonomische Brisanz des Prozesses wird im politischen Raum nach meiner Einschätzung vielfach noch nicht im vollen Ausmaße erkannt. 13. Ad 4): Zur Überschuß-Situation auf wichtigen Agrarmärkten der EG-Kon- Strukturelle Überschüsse auf EG-Agrarmärkten exfordern kurz- una mittelfristig ökonomisch und ökologisch akzeptable Alternativen der Nutzung landwirtschaftlicher Böden. Eine spürbare Reduktion der gesamtwirtschaftlichen Kosten zur Beseitigung der Überschüsse wird nur durch ein Bündel von Maßnahmen gemeinschaftlich zu erreichen sein. lichen skizzenhaft wirtschaft; gerungen zu vermeiden. stört die Märkte. sequenzen? Abstract Die Verwendung von Agrarprodukten für Energieträger und industrielle Grundstoffe kann in einigen Jahren einen Beitrag dazu leisten. Auch der Anbau schnellwachsender Baumarten komt dafür in Frage. III. NUTZBARE POIENFIALE FORSTLICHER BIOMASSE Nach der Skizzierung der Ausgangssituation und wesentlicher Rahmenbedingungen lautet die Frage: Welche Arten von forstlicher Biomasse könnten mit welchen Potentialen kurzfristig verfugbar sein und wie konkurrieren sie hinsichtlich der verschiedenen Verwendungsmöglichkeiten als Rohstoff oder als Energieträger miteinander? Es soll hier zunächst von Restholz die Rede sein, also von jenem Anteil des Rohstoffes Holz, der in den verschiedenen Be- und Verarbeitungsstufen, d.h. von der Holzernte bis zur herstellung der Produkte, anfällt. Außerhalb der Betrachtung bleiben noch ungenutzte Mengen von Altpapier und Reststroh aus dem Getreideanbau. Demnach geht es um folgende Reststoff-Arten

Industrierestholz:

Altholz aus Recycling;

Waldrestholz.

Als eine zusätzliche Quelle steht zur Diskussion:

Holz aus dem Anbau schnellwachsender Baumarten.

14. Ad 1): Industrierestholz (IR) Sägerestholz + Verarbeitungsabfälle gelten als preiswerte Rohstoffe mit festen Absatzwegen und werden zum geringeren Teil als Energieträger genutzt. Obgleich freiwerdende Mengen nicht in Sicht sind, bedarf IR wegen seiner preislichen Schlüsselfunktion der Berücksichtigung. 15. Ad 2): Altholz aus Recycling Das potential wird auf knapp 1 Mill. t pro Jahr geschätzt; der Markt nime aber bisher nur da. 0,15 Mill. t auf. 16. Ad 3): Waldrestholz (WR) Die Ernterückstände betragen knapp die Hälfte eines Baumes. Dazu kommen noch aus Pflegeeingriffen ganze ungenutzte Bäume. Das nutzbare Potential wird auf 4 Mill. t atro pro Jahr geschätzt. Weitere 3,5 Mill. t pro Jahr wären bei Durchforstungen als Schwachholz verfügbar. Ein Markt feh.lt noch. Eine Mobilisierung, z.B. in Form von Hackschnitzeln (HS), scheiterte bisher an den relativ hohen Kosten. Die Verwendung beschränkt sich bisher local auf energetische Nutzung. Nur Rohstoffengpässe könnten bei gegenwärtigem Kosten-Niveau für WR den Markt öffnen. 17. Ad 4): Holz schnellwachsender Baumarten Die Möglichkeiten, durch den Anbau schnellwachsender Baumarten ein zusätzliches Potential zu gewinnen, werden in Europa und Amerika seit Jahrzehnten erforscht und erprobt, und zwar vornehmlich als Alternative zur landwirtschaftlichen Nutzung von "Grenzertragsböden" (marginale Böden). Die Potentiale und Verfügbarkeit des Materials sind noch ungewiß. Geht man aber davon aus, daß a) in den nächsten Jahren zunehmend landwirtschaftliche Flächen nicht mehr für die Food-Produktion verwendet werden können - die Berechnungen ergeben fur Deutschland mittelfristig bis zu 1,2 Mill. ha https://www.w3.org/1998/Math/MathML"> ( = 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 8), für die EG (10) ein Vielfaches dieser Zahl b) nach https://www.w3.org/1998/Math/MathML"> 1990 z . B . 500.000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha für die Anpflanzung schnellwachsender Baumarten zur Verfügung stehen, so könnte bei einer Bionasse-Produktion von 12 t atro pro Jahr und ha ein Potential von 6 Mill. t atrola zusätzlich verfïgbar werden. Zum Vergleich. Eine solche Menge würde in der Größenordnung dem gesanten Industrierestholz nahekormen. Schnellwachsende Baumarten können 1. im Kurzumtrieb oder 2. im mittleren Umtrieb bewirtschaftet werden. Für den Kurzumtrieb zeigen erste Ergebnisse und Kalkulationen, daß die preisliche Wettbewerbsfähigkeit der gewinnbaren Hackschnitzel gegenüber IR oder anderen Energieträgern nicht höchste Massenerträge voraussetzt. Es ist vielmehr nötig, die gesamtkosten zu optimieren. Die ootimierung der In-/Output-Relation wird auch darüber entscheiden, ob eine solche Landnutzung gegenüber bestimmten landwirtschaftlichen Nutzungsarten wettbewerbsfähig sein kann, vorausgesetzt, daß man in Bezug auf Subventionen nicht ungleich verfährt. Mittlere Umtriebszeiten für schnellwachsende Baumarten dürften zu einer Senkung der Produktionskosten je Einheit führen und die Palette der Verwendungsmöglichkeiten vergrößern, z.B. fur die Produktion von Zellstoff. Modellrechnungen zeigen, da\beta bei teilweiser Umwidmung von EG-Marktordnungs-Ausgaben die Erzeugung von Industrieholz als Alternative zur bisherigen Flächennutzung für den Food-Sektor in Betracht komin. Diese Möglichkeit, die Holzerzeugung innerhalb kürzerer zeitrauume zu steigern, würde bei engagiertem Vorgehen die Basis für die Produktion von vielseitig verwendbaren industriellen Rohstoffen verbreitern. Dies könnte auch dazu beitragen, entsprechende Produktionsstätten zu erhalten oder neu zu schaffen. Das Flächenpotential ist angesichts der Agrarmarkt-überschüsse in der EG vorhanden. Der Anbau schnellwachsender Baumarten, wie z.B. Aspen, Birken, Roteichen, und die Bewirtschaftung im mittleren Umtrieb in der Feldflur und auf waldflächen wird aus zwei Gründen zu überdenken sein. Erstens: Wenn die neuartigen Waldschäden weiter zunehrnen und dadurch bedingter Mehranfa1l an waldholz als Vorgriff auf zukünftige Nutzungen die spätere Belieferung der Industrie reduziert, könnten Erträge aus solchen Anbauten helfen, teilweise auszugleichen. Zweitens: Sollten schadensbedingte Kahlflächen im Wald unvermeidlich werden, könnte der Anbau einen ökonomisch und waldbaulich interessanten Vorwald für die reguläre Wiederaufforstung ergeben. Die Natur hat nach der Eiszeit in Europa das Vorbild bei der natürlichen Ausbreitung des Waldes geliefert. 18. FAZIT

Die Probleme auf den Agrarmärkten der EG dulden keinen Aufschub. Abhilfe darf nicht nur innerhalb des Agrarsektors gesucht werden. Die alternative Flächennutzung durch annuelle Rohstoffpflanzen der Stoffgruppen Zucker, Stärke, Öle/Fette stößt bei der Züchtung, bei der Bereitstellung, bei der Konversion zu marktfähigen Produkten und bei deren Einführung in den Markt auf kaum geringere Schwierigkeiten als der Anbau und die Verwertung forstlicher Biomasse.

Lignocellulose könnte in industriell bereits etablierten Verwendungsbereichen eingesetzt werden und den Selbstversorgungsgrad zu Gunsten der volkswirtschaftlichen Bilanz erhöhen. Den landwirtschaftlichen Rohstoffpflanzen würde zusätzliche forstliche Biomasse keine Konkurrenz auf den Produktenmärkten bereiten.

Die Schwestern der Urproduktion - Land- und Forstwirtschaft - sind aufgerufen, zur Bewältigung ihrer drängenden Probleme die erforderlichen Anstrengungen unverzüglich zu unternehmen. Dazu bedarf es auch der Kooperation mit den verschiedenen Industriesektoren.

Auf der Ebene der Gemeinschaft und national muß die Politik die Forschung und Entwicklung weiterhin fördern und gezielt vorwärtstreiben. Außerdem müssen die Rahmenbedingungen in der Agrarpolitik und in anderen Politikbereichen unverzüglich Schritt für Schritt an die Erfordernisse angepaßt werden. Die Europäische Gemeinschaft muis sich auch auf diesem Feld bewahren, sonst werden das vertrauen der Bürger und die Entwicklung der Gemeinschaft Schaden nehmen.

Ich schließe mit einem Zitat von Ernst Curtius: "Ohne den UnsterbIichkeitsgedanken wären wir nichts als armselige Tagelöhner, durch ihn erhält alles, was wir beginnen, Bedeutung und Zusammenhang." LA BIOMASSE, SOURCE DE SUBSTITUTS AU PETROLE DANS LE SECTEUR DES TRANSPORTS P. LEPRINCE et J.P. ARLIE Institut Français du Pétrole 19. RESUME Les analyses de conjoncture mettent toutes 1 'accent sur I'impor- tance des transports dans le développement futur du monde. Ce sec- teur a connu en moins d'un siècle une expansion rapide grâce aux qualités exceptionnelles des hydrocarbures pétroliers, à leur fai- ble coût de production et à l'abondance des réserves en place. On peut cependant s'interroger sur leur remplacement pour deux rai- sons:

la premierre est économique: le nouveau pétrole est de plus en

plus couteux a extraire,

Ia seconde est stratégique : dans tous les pays les transports

sont un secteur vital pour l'approvisionnement duquel il peut être judicieux de faire appel aux ressources nationales. L'exposé se propose d'examiner at plan technique et áconomiale l'aptitude des produits de la biomasse à se substituer au pétrole. Les aspects suivants seront étudiés: qualités des produits, res- sources, implantation des installations, scénarios de pénétration, évolution de Ia compétitivité économique par rapport au pétrole. En conclusion, on présente les orientations possibles de la recher- che et du développement, principalement en ce qui concerne les nouvelles technologies et leur impact. 20. INTRODUCTION Depuis 1973, date de la premiere crise pétroliêre, la situation énergétique du monde s'est transformée : diminution de la demande, croissance de l https://www.w3.org/1998/Math/MathML">   t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> offre, développement de nouvelles énergies. Dans beaucoup de secteurs, la consommation énergétique a été profondément transformée par les nouvelles techniques économisant l'énergie ou par l'apparition de nouvelles sources d'énergie. Le secteur des transports est resté plus stable : les nouvelles sources d'énergie pour la propulsion des moteurs, comme 1 'hydrogène ou l'électricité, n'ont pas réussi à s'imposer et ne semblent pas en mesure de déplacer les carburants líquides, à haute densité énergétique. Ce secteur, dépendant aujourd'hui en quasi totalité des hydrocarbures liquides, est ainsi particulierrement sensible à la situation pétroliere mondiale qui se modifie dans ses données économiques et stratégiques par la découverte et la mise en exploitation de nouveaux gisements. Dans cette conjoncture il peut etre décisif de recourir à de nouveaux types de carburants et en particulier a ceux qui proviennent de la biomasse. L'IMPORTANCE ECONOMIQUE ET SOCIALE DU SECTEUR DES TRANSPORTS ROUTIERS Dans la CEE, le chiffre d'affaires total du secteur des transports peut être estimé à 170 milliards de dollars : 2/3 correspondent à la production des automobiles et 1/3 au transport des marchandises et des personnes. Les effectifs travaillant dans l'orbite de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> automobile re- 51 TABLEAU II USINE$ DE PRDDUCTION DE BUTANOL-ACETONE Fit DE PRODUT BLE : https://www.w3.org/1998/Math/MathML"> B 09 x / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha - PAILLE : 2,7 tha - TAUX D'0CCUPATION : 0,5 CAPACITE t/a 50000 100000 150000 MATIERES PREMIERES 8LE PAILLE BLE PAILLE BLE PAILLE CHARGE DE CAPITAL MAIM-0'OEUVAE COLLECTE TRANSPOPT 1520 2940 1190 2170 1010 2080 DIBTANCE DE COLLECTE (km) 14 30 20 41 25 52 TABLEAUH HI DOMNEES ECONOMIQUES (FA) EQUIVALENCE LITRE/LITRE ENERGETIQUE SUPERCARBURANT 1,08 1,38 METHANOL 1,05 2,10 ETHANOL ANHYDAE 2,50-3,00 3,90-4,50 ETHANOL SS % 2,10-2,40 3,30-3,80 MELANGES E https://www.w3.org/1998/Math/MathML">   5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TBA https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2,40-2,70 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> M3 MBA2 2,10 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> E5 MBA2 2,80-3,20 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> E3 M3 1,80-2,00 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> % Volume éthanol Fig. 1 Plantes sucriéres (F/t) https://www.w3.org/1998/Math/MathML"> 100   150 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig. 2. Compuses oxygenés de fermentation des plastes sucrieres Fig.3. Substitution par le methanal SESSION I THE EUROPEAN SCENE Trees and Wood as an Energy Source in the Nordic Countries G. Wilhelmsen Biomass Availability and Use in the Industrial Regions of the EC A. Strehler Ressources en biomasses utilisables a des fins énergétiques en milieu agricole - cas de https://www.w3.org/1998/Math/MathML"> 1 † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> europe des 10 - C. Gosse Biomass for Heating and Fuels in Austria - a Case Study for Europe? - A.F. J. Woh1meyer TREES AND WOOD AS ENERGY SOURCE IN THE NORDIC COUNTRIES G. WILHELMSEN Research Director The Agricultural Research Council of Norway Summary The anticipated use of wood fuels the last two years has been somewhat greater than the existing market, particularly in Sweden, In some countries this has lead to a certain overcapacity in fuel production. The optimistic expectation was due partly to an underestimation of the use of electricity in district heating plants and the replacement of oil burners with electroboilers and partly to a slower development that expected in the regional plans for district heating systems in general. The initial phase of aggressive optimism is therefore being replaced by a reflecting, sound phase of consolidation. This will hopefully result in a stronger market structure with respect to both economy and organization Socioeconomic motives, such as employment, energy security, over- production in agriculture, etc. seem today to be much more important in marketing wood fuels in the Nordic countries than previous energy motives, such as lack of energy, renewable vs.fossile energy sources,etc. In spite of some drawbacks, more and more people heat their houses with wood, and biofuels seem to be increasing their market-share in all countries. In Norway, https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the private households regard wood as the cheapest and most important fuel. The consumption has increased every year, from 190.000 toe in 1973 to 420.000 toe in 1984. However, a broadening of the market in the Nordic countries will very much depend on the success of upgrading wood as fuel, and the result of establish- ing confidence between seller and buyer through a strong reliable marketing organization. 1. INTRODUCTION The surrounding world of ten looks upon the Nordic countries as a harmonic and homogeneous unit. In many cases this is true and co-operative work between Nordic countries has been successful in many fields. In the energy field, however, there are gaps with regard to both energy production and energy consumption. A certain amount of background information is therefore needed to fully understand the use or lack of tase of wood fuels in these countries. The wood fuel market is most likely dependent on both the supply and price of alternative energy sources, such as coal, electricity and oil, and to what degree each country politically emphasizes socio-economic benefits using domestic and renewable energy sources.

HYDROPOWER, COAL AND OIL

The share of hydropower in the energy supply of the world is overall quite small, but Finland and especially Norway and Sweden have the advantage of good hydropower resources. The very few district heating plants in Norway are partly due to cheap and easily available hydropower. Denmark used to depend almost entirely on oil-based thermal power, but has in recent years partly switched to thermal power based on coal. A smaller part of Sweden's electricity supply is also covered by thermal power, based mainly on oil, but today oil has been replaced by nuclear power to a large extent. Both Norway and Sweden have a fairly low electricity price today and offer financi.al stpport to install electro boilers for those using surplus power. This has in a negative way seriously influenced the wood fuel markets in recent years. Tab. 1 Production of primary energy, 1982 (PJ) https://www.w3.org/1998/Math/MathML">   Tab.1     Production of primary enerby,     Country     Solid     fuels     Crude     oil etc.     Gases     power     Nuclear     power     Hydro     power     Sum     Denmark   7 70   Finland   175 173 55 403   Norway   41 1091 1040 394 2566   Sweden   129 1 421 233 784 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while the other countries have to import all their coal. The consumption of coal is decreasing in all countries except Finland, where it has stabi1ized. The competition from coal is noticeable in all countries except Norway, due to the few district heating plants. Oil is the predominant energy source in Denmark, Finland and Sweden, but is also of great importance in Norway's energy consumption. Essential in this connection are the important discoveries of oil and gas in recent years along the Norwegian coast. The extractable quantities are calculated to amount to about 529 mill. tons of oil and 360.000 mill Sm https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of gas fields which are in production, under development or for which development has been decided as per Dec. 31.1983. It is obvious that this production of gas and oil influences goals and strategies in the wood fuel programme of Norway. For example Norway has very few opportunities for financing wood fuel combustion plants or other incentives to cut back oil consumption. In Denmark, Finland and Sweden, several financial opportunities have been introduced by the governments as a facet of their over-all energy policy. This can also work to other way around, as in Denmark, where the authorities want to ensure and develop the natural gas market and the construction of pipe lines. This has slowed down the financial support to the wood fuel market at the present time. 2. THE WOOD FUEL SUPPLY Wood fuels in the Nordic countries still come from traditional forestry as hard-woods, first thinnings and forest residues, along with wood-residues from the forest industries. The total wood for combustion is at present https://www.w3.org/1998/Math/MathML"> 50 m i l l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . cu.m solid wood or 8.765.000 toe, (Denmark 1,5%, Finland 40, 8%, Swe- The coal supplies in Svalbard cover part of Norway's coal consumption, den https://www.w3.org/1998/Math/MathML"> 49,7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and Norway https://www.w3.org/1998/Math/MathML"> 8,0 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Tab. 2 Background information https://www.w3.org/1998/Math/MathML">   DENMARK     FINLAND     NORWAY     SWEDEN     Land area   k m 2 43000 337000 325900 411600   Population (mill)   5.1 4.7 4.1 8.3   GNP per capita 1981 (USD)   13120 10680 14060 14870   Production forest area     (mill ha)   0.41 19.7 6.7 23.4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Tab. 3 Energy use of wood in industry, district heat and space heating in 1983 DENMARK FINLAND NORWAY SWEDEN 1000 toe % 1000 toe % 1000 toe % 1000 toe % Black and sulphite liqueors https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0 1590 44.4 245 35.0 2732 62.7 Industrial waste wood 59 44.7 780 21.8 88 12.6 512 11.8 Space heating 64 48.5 1140 31.9 367 52.4 939 21.6 District heating 9 6.8 69 1.9 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0 171 3.9 Sum 132 100.0 3579 100.0 700 100.0 4354 100.0 Energy plantations based on root shoots harvested at a few years intervals and on stock with life expectancies of up to 30 years at present can be said to be at the research stage in several respects. There are at least in Sweden laxge-scale pilot trials in order to establish an adequate requirement of continuous research and development work, but it is not possible to day to assess the energy contribution, economics or environmental effects of these energy plantations.

WOOD FUEL MARKET

The wood fuel market is still very much dependent on the fact that the energy producers are the same persons or companies as the energy consumers - in other words no "market" in the traditional meaning of the word. The forest industry itself is today the biggest producer and consumer, as it burns its own waste material in kiln dryers or burns waste liquor. Next to the forest industry come the forest owners using their own wood or wood chips for heating purposes. In Norway we figure that about 2.5 mill. m of wood https://www.w3.org/1998/Math/MathML"> ( 430.000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> toe) is used for heating in private households. About https://www.w3.org/1998/Math/MathML"> 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of this wood is cut and handled by the consumer himself. Together with industrial waste this "market" part accounts for about https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total consumption. There is a general feeling in all the Nordic countries that this "market" will level off very soon. Any expansion must be based on a tradi- 3. PELLETS AND BRIQUETTES 4. DISTRICT HEATING/WASTE DISPOSAL significant contribution to the direct replacement of large nuclear fuel or fossile power stations. 5. SOCIO-BCONOMIC GROUNDS In most countries one would like to see that public funds in gratt forn are viewed as an exceptional measure in the case of energy investments that are well justified on socio-economíc grounds, but not viable on strictly economic terms. In many ways wood energy projects have been regarded as such, with a strongdriving force for rural development. Important key issues are:

Contribution to the creation of jobs in rural areas

Ensuring energy security

Environmental aspects

Relieving overproduction in some agricultural sectors.

Recent years have been regarded as a transition period to initiate and accelerate the desired investment activity. Some hope that the need for subsidies will be reduced and eventually phased out as the required investments are sufficiently supported by initial grants. Others want to continue this use of public funds to be able to direct the development with respect to the socio-economic grounds already mentioned. These views vary from one country to another and depend very much on the political system involved. It seems that Finland and Sweden emphasize socio-economic grounds more than the other countries. 6. RESEARCH AND DEVELOPMENT Five to six years ago strong energymotivated forces initiated and financed bioenergy research programs in all the Nordic countries. The R & budgets increased dramatically and have been kept at a fairly high level since. At the moment this initial phase of aggressíve optimism seems to have been replaced by a more reflective attitude. The R & D budgets have stabilized and in some countries been reduced. The socio-economic motives mentioned seem to be as important as previous energy motives such as 1 ack of energy, renewable vs. fossile fuels etc. This has in some countries restlted in substantial financial support from "non-energy" sources e.g. agriculture. Tab. 4 Government Funds for Bioenergy Research and Development (1983) USD per year Total mill. Per capita Denmark 1.0 0.20 Finland 4.2 0.89 Norway 0.8 0.20 Sweden 21.3 2.57 Total/Average https://www.w3.org/1998/Math/MathML">   ㄴ  https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 94.1 0.31 Total/average for 10 countries participating in the IEA Forestry Energy Agreement The time since 1979 has in many ways been a pioneer period. In the last few years many bioenergy projects have been turned down and also some products and companies have disappeared. For the time being, the strategy seems to be of strengthening basic competance in bioenergy research, more seriously analyzing market barriers and focussing on a few promising products. This has been necessary and natura1, but in some ways quite painfu1, development. 7. INFORMATION ABOUT THE NORDIC COUNTRIES Finally, I would like to advertize a directory called "Energy Research and Development Projects in the Nordíc Countries" that is published yearly. In addition all information on published 1iterature and research in progress is included in the computerized system NEI (Nordic Energy Index). Further efforts have been taken this year by the Nordic Council of Ministers to strengthen the basic competence and teaching facilities in bio-energy at university level. The Council has recently decided to offer two professorships and six fellowships in the area of bioenergy from 1986. 8. REFERENCES (1) GILLIUSON, R. (1984). National R & D programmes in member countries of the IEA Forestry Energy Agreement area "Harvesting, on-site processing and transport https://www.w3.org/1998/Math/MathML">   11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (2) Yearbook of Nordic Statistics 1983. (Nordic Council and Nordic Statistical secretariat). (3) Energy Research and Development Projects in the Nordic Countries. - Directory 1984 (Nordic Council of Ministers, 1984). (4) Energy Research Development and Demonstration in the IEA countries. 1983 Review of National Programes (OECD Paris, 1984). BIOMASS AVAILABILITY AND USE IN THE INDUSTRIAL REGIONS OF THE EC Dr. A. Strehler Technische Universität München Bayer. Landesanstalt fü Landtechnik D- 8050 Freising 9. Summary Many options to replace fuel oil are in discussion. One of the most impor- tant energy resource is to be seen in biomass as residues from agriculture. forestry, human waste and from energy plantations. The advantages of waste and residues are manifold; less environmental load, cost reduction, saving of devices. The energy plantation is a good option to reduce the problems in financing the EC agricultural market and to guarantee the fuel supply in the future Biomass is also used in industrial regions ike the Federal Republic of Germany, in rural and municipal areas. In some areas household, heat demand can be covered up to 100 of from biomass. It is mainly used asa solid fuel for heat generation. There are options for conversion to liquid fuel for powersupply in vehicles. The biomass energy of FRG, including ener- gy plantations on surplus areas, can supply up to 8 of total demand. To- day this supply mainly consists of woodwaste in the range of 1 o. It is ne- cessary to improve the combustion quality of most types of furnaces to get less emission of tar and smell. For use of biomass from energy plantations dens ification systems for fuel have to be improved, like briquetting, cut- ting, milling, thermal conversion, ethanol and plantoilproduction. biomass avajlability EC https://www.w3.org/1998/Math/MathML"> ∣   residues   23.5   findustrial region FRG   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mesidues https://www.w3.org/1998/Math/MathML"> 6.2 M t O E ∣   energy     mant     https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> industrial region FRGlresidues 6.2 MtOE https://www.w3.org/1998/Math/MathML"> ∣ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> plant. https://www.w3.org/1998/Math/MathML"> ( 1.6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Mio ha https://www.w3.org/1998/Math/MathML"> ) + 6.4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Mt\capE https://www.w3.org/1998/Math/MathML"> = 12.6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 10. INTRODUCTION The total energy consumntion of the EC is about 1 Mrd. tOE (OE = 0il equivalent). Agriculture utilizes directTy 18.5 Mio. toe as energy products. The percent usage in agriculture is very different depending on the region. Estimations of the potential of energy from biomass which could be utilized in agriculture run from 1 to https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the primary energy demand. Agricultu- ral countries have a relatively higher biomass contribution to the total energy consumption than industrial countries because industrial countries have a higher total energy consumption. However, the absolute quantity of energy from biomass in industrial countries is even higher than that in aqri- cultural regions because the population density is related to biomass waste. The 1 to https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> energy from biomass seems to be a low contribution to the to- tal energy consumption. But one should keep in mind the additional effects from utilization of biomass for energy generation as:

Disposal of combustable waste

National economic effect by diminishing the import of energy

Possibilities to diminish problems of agricultural market of the EC.

The importance of different resources for biomass is widespread. Further, the awareness of which different resources allow an effective economical usage is to be attained, employing mature technologies. Therefore there will As the problems of the agricultural market are very serious and the responsible people have not had great success in finding alternatives, the option of producing energy substitutes shall be treated especially in the following considerations.

ESTIMATION OF THE ENERGY POTENTIAL FROM WASTE

2.1 ENERGY POTENTIAL FROM ANIMAL WASTE Due to the waste quantity available, only swine, cattle and chickens will be in consideration. 11. 2. 1.1 WASTE POTENTIAL FROM SWINE From the number of animals, waste for different countries has been calculated. For economical and technical reasons only https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the resources can be utilized considering current technical standards and energy prices. The energy potential for Germany is https://www.w3.org/1998/Math/MathML"> 2.02 M t O E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , for Europe https://www.w3.org/1998/Math/MathML"> 0.094 M t O E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 11.0.1. ENERGY POTENTIAL FROM CATTLE WASTE Depending to the number of animals and the restriction of https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> effective use the energy potential for FRG is about 0.15 MtOE, for the EC 0.64 MtOE. 11.0.2. ENERGY POTENTIAL FROM CHICKEN DUNG For the FRG there are https://www.w3.org/1998/Math/MathML"> 0.01 M t O E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , for the EC https://www.w3.org/1998/Math/MathML"> 0.06 M t O E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 11.0.3. COMPARISON OF ENERGY POTENTIALS FROM THE DIFFERENT TYPES OF ANIMALS 12. FOR EUROPE AND FRG As Table I shows, there is a potential for a 113 types of animals from 0.79 MtOE for the EC and 0.15 MtOE for the FRG. With technical progress there could be a higher potential than only https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the resources. The economic effective utilization also depends on the price of alternative energy sources. Table I: Available energy from manure of swine, cattle and poultry animal energy in the produced gas https://www.w3.org/1998/Math/MathML"> 1000 G J / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Moil equivalent) column 1 usable energy (5% of potential) GJ/a MtOE EC MtOE FRG swine 79.1 3 4 6 cattle 534.3 1.3 3.9 0.09 poultry 50.0 12.7 0.64 0.120 663.4 1.2 2.5 0.001 columns https://www.w3.org/1998/Math/MathML"> 2 - 5 E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , column 6 FRG 13. 2.2 ENERGY FROM PLANT WASTE 13.1. CEREAL STRAW Since there are special straw combustion units on the market, strawcan be utilized as an energy source when there is not a better local utilization like animal bedding, animal food, fertilizer or raw material for industrial purposes. In many regions, especially with large cereal farms, little Tivestock and low rainfall, straw can be utilized with no or low costs from the field. The cereal straw obtained depends to the local situation and there are big differences even in sma]l areas. A total estimation of cereal straw yield could be done and the potential availability is set at https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total yield. In this case the 124 Mio t total yield of straw in Europe would deliver an oil equivalent to https://www.w3.org/1998/Math/MathML"> 8.4 M t O E / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In Germany the equivalent would be https://www.w3.org/1998/Math/MathML"> 1.56 M t O E / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In small regions there is an avallability of straw up to https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total. In special research work (1) to determine the availability of straw assuming a perfect technique of conversion, farmers would be ready to deliver https://www.w3.org/1998/Math/MathML"> 34 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of their total straw; that would be 9.4 MtOE/a from a total yield from 27 Mt in FRG. This quantity of energy corresponds to the current consumption of diesel fuel and fuel oil in the agriculture of FRG. Table II shows the total yield and energy potential from straw in the different countries of the EC. TabTe II: Energy potential from straw in the countries of the EC (1983) country straw total https://www.w3.org/1998/Math/MathML"> 1000 t / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> energy in straw https://www.w3.org/1998/Math/MathML"> 106 G J / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> energy in straw MtOE energy from straw with 20 availability NtOE column 1 2 3 4 5 FRG 23011 325.7 7.78 1.56 F 46605 661.8 15.76 3.15 I 17817 253.0 6.02 1.20 NL 1308 18.6 0.44 0.09 B 1877 26.6 0.63 0.13 LU 68 1.0 0.02 0.004 UK 21307 302.5 7.20 1.44 IR 1948 27.7 0.66 0.13 DK 6380 90.6 2.16 0.43 GR 4425 62.8 1.49 0.30 EC 124746 1771.3 42.16 8.43 13.1.1. ENERGY FROM GREEN PLANT RESIDUES The main source is from potatoes, sugar beets and vegetables. Refering to PALZ (2) there is an energy potential via biogas production from 0.64 MtOE for FRG and 3.13 MtOE for EC. 2.2.3 WOODY WASTE FROM AGRICULTURE AND HORTICULTURE The main resources are from wineyards and orchards; for Europe https://www.w3.org/1998/Math/MathML"> 2.7 M t O E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> via combustion are calculated. 2.2.4 RESIDUES FROM PROCESSING OF AGRICULTURAL PRODUCTS There is wet waste from slaughter-houses, wine production, processing of vegetables and fruits and there is dry waste from seed cleaning and rice https://www.w3.org/1998/Math/MathML"> m i 11   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These types of waste have only local importance. For example, in Italy in the Po region there is a potential of 70000 t of rice halls. Also high amounts of local importance have been found in fruit and wine processing. The total yield is low and not considered further. 13.2. ENERGY FROM WASTE OF FORESTS AND WOOD PROCESSING Europe has about 32 Mio ha, the FRG 7.2 Mio ha. That is https://www.w3.org/1998/Math/MathML"> 22 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the EC wood area. For the Community there is a fire-wood potential (2) of https://www.w3.org/1998/Math/MathML"> 17 M t O E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , in FRG fire-wood can be estimated in the range of 2.4 MtOE including waste from processing. 2.4 ENERGY FROM COMMUNAL WASTE (HOUSEHOLDS) For the EC a potential of https://www.w3.org/1998/Math/MathML"> 15 M t O E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is calculated and 4 MtOE for the FRG. 2.5 SUMMARY OF THE ENERGY POTENTIAL OF WASTE Literature from PALZ (2) and our calculations show a potential of 31.02 MEDE for the EC and 8.2 MtOE for the FRG. Table III shows the totals of the energy potential from biomass in Europe and FRG. Table III: Estimation from energy potential of biomass in EC and FRG (MtOE) 14. ENERGY POTENTIAL FROM THE NECESSARY FUTURE PRODUCTION OF ENERGY SOURCES The EC is not able to finance the agricultural market further on without restrictions. One possibility is to be seen in the production of energy sources instead of surplus food products. The most discussed options are: BASIC PLANT ENERGY SOURCE ANNUAL YIELD in t/ha ENERGY in t OE https://www.w3.org/1998/Math/MathML"> / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha plants with starch and sugar content ethanol 3-5 2.5-3.5 short-rotation forestry woodchips 10-20 3-7 oil plants oil straw 4-8 1.5-3.0 oil plants, sum of oil and straw https://www.w3.org/1998/Math/MathML"> - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.5-5.0 Having a surplus area of agricultural production in 1986 of 8 Mio ha in the EC (3), energy sources could be produced with an energy content of 32 MtOE annually. This energy potential would be https://www.w3.org/1998/Math/MathML"> 3.2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the actual EC energy consumption. For the FRG with 1.6 Mio ha surplus, 6.04 MtOE could be produced. 15. TOTAL POTENTIAL OF ENERGY FROM WASTE AND PRODUCTION OF ENERGY SOURCES MUOE from AREA RESIDUES (WASTE) ENERGY SOURCE TOTAL FRG 6.2 6.4 12.6 EC 23.5 32.0 55.5

POSSIBILITIES TO UTILIZE RESIDUES AND ENERGY SOURCES IN RELATION TO THE ACTUAL TECHNIQUES OF CONVERSION

5.1 ANIMAL RESIDUES AND GREEN PLANTS ARE TO BE CONVERTED VIA BIOGAS If https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the animal waste in the FRG would be utilized, 8500 biogas plants with https://www.w3.org/1998/Math/MathML"> 60 G V https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (animal weight units) each could produce 0.146 MtOE. The biogas technology is not ready within the next years to utilize residues from green plants. Actual biogas production in FRG: about 80 biogas plants are working in agriculture today and they are able to produce 1000 toe annually. 15.1. POSSIBILITIES OF UTILIZATION, POTENTIAL AND ACTUAL UTILIZATION OF STRAW The resources of residues from straw and wood are 12 Mio t with an energy equivalent to 4 Mio t OE. These resources can be utilized for heat and power generation. Heat production is of more importance because it is cheaper to replace oil this way. But in some cases power generation is more economical. The technical standard of systems is as follows: Power via heat generation via combustion in cylinder Steam piston engine x×xx Steam turbine x×xx Sterling motor 0 Hot-gas turbine x×x Thermal gas ifier, updraft Therma] gasifier, downdraft xx FTuidized bed TechnicaT standard: https://www.w3.org/1998/Math/MathML"> x × x × = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> high; x= low; 0= in development stage Aside of the technical standard, the total costs are important. They are in the range of 0.15 to https://www.w3.org/1998/Math/MathML"> 0.70 D M / k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Furnaces are delivered in a broad variety, 80 manufacturers deliver furnaces for wood and 20 from them for straw. The furnaces are produced with discontinuous and continuous charging, with small and large-sized combustion chambers and partly as pre-furnaces (especially for wood chips). Most success had following system: bottom-burning boilers with discontinuous charging in connection with heat stores, boilers and pre-furnaces with continuous chargingwith movable grates. Table IV shows the most important types of furnaces, the number of utilized plants and the market potential to utilize the available residues from straw and wood. Basis for the use of the big energy potential especially of straw is the availability of cheap, technical perfect furnaces with low critical emission and high efficiency and comfort. The important sponsorship of CEC, Gen. Dir. XII and BMFT Bonn for research was the basical start. Further research is necessary. The potential of residues and the production of energy crops is shown in Figure 1: Comparison of convenient usable biomass energy potential with the at present used potential in the FRG REFERENCES: (1) PETERS, A.: Das Energiepotent.v.Biom. i. Kreisen BRD,1983, ISSN-0303-2493 (2) PALZ, W.; Ph. CHARTIER:Energy f. Biom.i. Europe (1980) ISBN 0-85334-934-7 (3) SCHAFER, R. ; E. HEIDRICH: Einfluß u. Nutzung V. Biom. als Energieträger, TUM - Landt.-Weihenstephan, CEC Gen. Dir. XII, Study RESSOURCES EN BIOHASSES UTILISABLES A DES FIHS ENERGETIQUES EN MLLIEU AGRICOLE - CAS DE L' EUROPE DES 10 Ghislain gosse

Institut National de la Recherche Agronomique

Station de Bioclimatologie 78850 THIVERVAL-GRIGNON Abstract La surface agricole utlle de leurope des 10 est de 102 M dtheotares soit 60 or du territoire. La situation geographique et climatique de l' Europe ainsi que l' histoire différente des systemes agricoles ont condult a une tres grande variabillté des productions aussi bien en quantite qu'en quallte. Nous nous efforcerons de degager les grandes caracteristiques de cette production de biomasse et de l' 1llustrer par des exemples précis au détriment d" une analyse exhaustive de la ressource. Cette notion de ressource utilisable à des fins énergétiques dojt être a chaque instant sltuée par rapport aux utilisations concurrentes ou complémentaires (alimentaires, industrielles. .) et Svaluée en fonction de ltetat des connatssances des diférentes filieres de production d' Énergle. LES COMPOSANTES DU GISEMENT POUR UNE PRODUCTION DONNEE Il est possible dtexprimer la ressource potentielle en biomasse d un territoire donné par le produit d"un rendement agricole par la surface occupée par la production envisagée, cette ressource potentielle est alors fonction de deux coefficients:

un coefficient d'occupation, caracterisant la 3urface occupes, quí dépend de facteurg pédoclimatiques et économiques

un coefficient dit mtechnique", caractérisant le rendement agricole, qui est fonction des facteurs pédoclimatiques, des techniques de production, du niveau de technicite des exploftants et des structures de production.

Cette notion de ressource potentielie est tres insuffisante pour Elaborer un scénario d ut111sation de la b1omasse, elle peut être utilement completee par les notions de gisement disponible et de gisement utilise. Chacune de ces notions se traduit par li introduction d un coefficient de réduction, soit: - un coefficient de disponibillte tradulsant les concurrences entre techniques de la filiere,

un coefficient d'utilisation traduisant la mise en oeuvre du gisement, ce dernier coefficient 1llustre les concurrences avec les Energies fossiles, les concurrences au niveau de l'usage des facteurs de production et aussi le poids des facteurs humains dans la décision économique.

Par la suite, nous choisirons des exemples pour illustrer cette cascade de potentiels en soulignant les points faisant obstacle au développement de la biomasse comme source d' énergie. LES SOUS-PRODUITS D https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ORIGINE AGRICOLE : Les sous-prodults dºrigine agricole sont classiquement subdivisés en residus secs, residus humides et residus díelevage. Les ressidus secs représentent un gisement potentiel https://www.w3.org/1998/Math/MathML"> 1 m p o r t a n t   p o u r   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1"Europe des 10, de https://www.w3.org/1998/Math/MathML"> 1 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ordre de 85 MT de matiere seche (Cf FIgure 1 ) avec une contribution de 80 o pour les pallles de cereales, a ce titre nous developperons plus en détatl le gisement que représente ces pailles qui sont pour 90 des pailles de blé et d" orge. Au niveau europeen, le coefflcient d" occupation des sols est stable depuis 15 ans, une diminuation des surfaces en orge est compensese par une augmentation des surfaces en ble (CF F1gure 2); Il reste néanmoins difficile de falre des projections dans le futur de ces observations et surtout didentifier les zones pouvant faire liobjet de variations 1mportantes. L* Evolution du rendement en paille par unite de surface est une fonction du rendement en grain ; en effet, la selection a essentiellement porte sur ltaugmentation du rapport Epi/paille sans augmentation signifloative de la matiere seche totale solt une tendance a une decroissance du rendement en paille. Des travaux récents visent a augmenter la biomasse totale tout en gardant un rapport Epl/paille Intéressant, so1t une inversion de la tendance pour le rendement en 1nterere Le coefficient de disponibilite de la pallle pour un usage energet1que est essentiellement fonction des concurrences entre les diffénent usages finals (11tiere, alimentation animale, papier. .). Le tableau 1 lllustre pour 5 des pays producteurs europeens la destination de ces pailles de côréales:

60 wes pallles sont recoltees et 90 des pailles recoltees sont alors utilisées pour la litiere et l^ alimentation animale ; dans ces pays, 1'usage de la pallle comme source d" energie ne represente actuellement qui un total de 500 a 700000 " de MS.

40 des pallles ne sont pas récoltées, elles sont enfoules ou brulées sur le champ; a partir de ce gisement et en satisfaisant les besoins en matiere organfque des sols, notamment en enfou1ssant les résidus humides de la rotation ou les eultures dérobées (engrals vert) Il sembleralt possible d' estimer un gisement disponible au niveau européen d'une valeur de 18 a 20 MI de MS (Cf POSter de V. REQUILLART).

Pourquol me utilisation de la paille aussi falble et pourquol un developpement aussi lent a quelques exceptions pres (cas du Danemark) ? Ces questions paraissent fondamentales, elles sont largement développeres au niveau de posterg spétalisés : nesanmoins, ll semble important d'identifier les obstacles de type technique (bilan humique des sols, collecte et faisabillte technique de la transformation, ..), de type macro et microeconomique (concurrence avec les energies fossiles, concurrence au niveau de l" usage des facteuns de production), et de type humain ou sociologique. Les residus hunides et les dejections animales, on peut définir un gisement potentiel comme precedemment pour ces sous-produtts (Cf Figures 3 et 4 ) mais le probleme determinant est au niveau de la transformation par méthanisation de ces résidus. Pour les rés1dus humides de oulture, Il semble plus interessant de les valoriser sous forme de matiere organique enfoule afin https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> améliorer le coefficient d' exportation de la paille tout en maintenant un bon équilibre humique a l'échelle d' une rotation. L'utilisation de la méthanisation peut condulre a une valorisation sur trois points : une production d' énergle (blogaz), un effet bénéfique sur l' environnement (odeurs, teneur en mo des effluents) Source OCDE et EUROSTAT Fig. 1: Résidus Secs-EUR10 (78-82) Gisement PotentieI Fig. 3: Résidus Humides-EUR10 Gisement Potentie1 (78-82) Source OCDE Fig. 4: Déjections Animales-EUR10 Gisement Potentiel Fig. 5: Evolution de la matière sèche aéricure produite en fonction du rayonnement interceptế et du cycle métabolique. BIOMASS FOR HEATING AND FUELS IN AUSTRIA A CASE STUDY FOR EUROPE? A.F.J. WOHLMEYER, Austrian Association for Agricultural Research, Vienna 16. Summary Austria with her diversity in climate, geological formation and re- lief as well as with her ecological and economic situation can serve as a comprenensible case study for the present situation and the strategies, which have to be taken up. The wider context of the pre- sent ecological situation and the long term economic needs ask for a dramatic change. Covering the energy and raw materiat needs as far as possible within the circuit systems of nature in a decentralized style is the necessary answer. The potential of possible biomass pro- duction for energy and raw material uses is usually underestimated. The analysis shows that a doubling of agricultural and forestrial production can be foreseen. Since at the present state of producti- vity food, feed and export needs can be fully met, the increase in productivity per hectare can be dedicated to cover energy and raw material needs. Primary energy consumption being about 920 pl and biomass production amounting at present to about 1.000 PJ, biomass has the potential to cover all present primary energy needs. Accor- ding to the structure of energy consumption the use of biomass for producing heat and fuels for combustion engines is the most reason- able pathway. 17. Introduction The ecological situation asks for a new assessment for energy for biomass. Short term micro-and macroeconomic analysis within the traditi- onal framework of thinking is no longer satisfactory. The ecological si- tuation and the nightmare of structural unemployment as well as the danger of dying forests along with a substantial decline of the number of active farmsteads (which will aggravate the ecological and economic situation) strongly recommend a dramatic change. There are limitations of higher value which overrun the aim of a maximum of short term profit in micro- and macroeconomic models. If we want to ensure to the soil, to plants, animals and to ourselves a state of biological well-being, we must not take out of the ecosystem more organic substances than can be reintegrated. In other words, we have to live within the recycling system of nature in order to survive. The compensatory potential of many species is already overcharged and the worldwide ecological situation can be compared with a full pot. Any additional immission causes overflowing. This is to say that we are in the phase of breakdown, because the cumulative effect of the stressors can no longer be compensated by living organisms - especially by plants having a longer life time, because in their organisms the cumulative effect is much larger. We have to become aware of the fact that in one year's time we con- sume an amount of fossile biomass which nature has produced within at least 500.000 years and by doing so, we are overstressing the ecosystem, which is not allowed the time necessary to adapt to the rapidly altering environmen- tal conditions (including ionizing radiation for which nature has so far not even developed a sense-organ, which could warn living beings in case of danger). Theres is a growing gap between the reality of the slowly changing biological information and the rapid anthropogenous environmental changes. The answer can only be that we have to practice a more cautious energy- and raw material management in line with nature and not against her. The principles of precaution provision and responsibility have to be an irrevocable part of national and international energy politics. Finally, we are not allowed to plunder this earth, which is entrusted to us. We have the obligation to render it to succeeding generations in the best possible state. 18. The underlying situation 2.1. Austria has on the one hand a lack of fossile energy resources and has legally banned the nuclear option lwhich is rather vulnerable in case of war). On the other hand, she has a surplus of biomass and is well endowed with water power. Those federal provinces, where the governments had foresight to invest in water power, although this was more expensive in the days of fossile energy avatlable, are now in a favourable position, having relatively cheap energy available especially for industrial uses. Austria as a whole is in danger so lack the analogous foresight concerning organic primary energy sources. Her fossile energy resources may last for a maximum of 20 years only. although imports amount already to 90 % approx. of total fossile energy consumption. 2.2. Austria is one of the two permanently neutral members of the international commity. Thus her constitutional obligation to a maximum of self-reliance in case of conflict or restricted supplies is in its practical outcome very similar to what Europe as a whole should do in order not to be involved in international conflicts for energy reasons. Since about https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the population live in communities not larger than 5.000 inhabitants and since in industry smaller enterprises dominate also, Austria has a realistic chance to open the thermal market for biomass without inadequate direct transport costs and logistics as well as expensive investments in a new infrastructure for the transport of biomass. Austria also can step gradually into the market of fuels for motor vehicles since she has a great tradition in fermentation techniques (production and equimment), an evident need to find an outlet for lowgrade crops (due to climatic risks) and an industrial infrastructure with which production facilities can be easily associated. 2.5. Forestrial resources (wood): Approx. 40 of Austria's area are covered with forests. Therefore, wood has to be an essential resource. This proportion is fortified by the following facts: The last thinning report shows a thinning deficit of https://www.w3.org/1998/Math/MathML"> 28,5 m i 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . c.m. of stock. The proper use of thinning wood is direct combustion in the form of wood chips. If the power of resistance to infections is impaired by immissions, forestrial hygiene becomes more important. Thus, the use of thinning wood has also a sanitary aspect. Forestrial plant breeding was a stepchild up to the last decade. The genetic potential is thus underused. The selection of species is still far from being the best. https://www.w3.org/1998/Math/MathML"> 64 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the population of trees are spruce. The native spruce as a postglacial The additional volume of production, which can be achieved,

An adequate strategy for the use of domestic biomass

3.1. Genera1 considerations: If we recall, that according to the quantitative nature of light we can apply the Carnot-formula in order to estimate the proportion of useful work light can in principle be converted into, we find https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ! Having an influx of solar radiation of https://www.w3.org/1998/Math/MathML"> 40.000 K W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> approx. per inhabitant, of which https://www.w3.org/1998/Math/MathML"> 20.000 K W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reach the surface of the earth and an average Euronean energy consumntion of about 4 . https://www.w3.org/1998/Math/MathML"> K O O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the use of solar energy is not a question of the potential as it is often said - but of the best pathways to be chosen. We certainly have to further develop the solar thermal and the solar electric options. In both cases we have an energy storage problem, which is widely unsolved. The solar chemical option is so far practicable in the field of biomass only. Biomass has the advantage of a solved storage problem and of the possibility to work within the gentle pathways nature has developed for us. 3.2. Sensible pathways: 3.2.1. Teleheating systems for small communities: Larger boilers can be better equipped, they cause less emissions and have a higher efficiency (up to https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In addition, they bring more convenience to rural communities. According to the state of technique, optimal straw combustion demands a dust burning system. As a consequence, boilers smaller than I MW are too expensive. Thus small teleheating systems should be given preference. 3.2.2. Individual heating: If cooperative heating is not pos sible - e.g. in scattered farm houses - individual heating systems are justified. According to the state of technique retorts and stockers fired with fine wood chips are the most convenient and least emissive choice. The good old tiled stove also compares favourably. 3.2.3. Substitution of electric heating: Water power suffices for the electric power needs of Austria (light, telecomminication, EDP and electrodynamik use). Electricity for heating purposes is mainly produced by thermal power stations. They have an efficiency of https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> approx. and are used only when the weather is cold. Thus it is reasonable to build up cheaper biomass firing systems instead of investing into electric power plants. 3.2.4. Industrial heating systems: Especially for enterprises in rural areas biomass is an apt source of energy. By coupling heat and electrictty production (which can also be done in local teleheating systems) they can contribute to both forms of energy. 3.2.5. Biomass as a fuel for combustion engines: 3.2.5.1. Ethanol ("Biosprit R "): Rising productivity and a rising surplus of grain (at present 800.000 tons/ a year) as well as the necessity to find an outlet for low grade crops (especially from regions at a disadvantage) make an ethanol programme a sensible task. 19. Energy from biomass and biotechnology Energy from biomass and biotechnology are twins. They are enhancing each other. Considering at the energetic characteristics of biotechnologica processes are normally low temperature and low energy input because the pathways of nature are those of a minimum of entropy - the energy from a biomass programme also has an indirect energy saving effect which should not be neglected. In principle, petrochemistry can be substituted by biochemistry and this will be the future, because the end of the fossile period is foreseeable It is therefore hard to understand that except for Japan (which again shows the proverbial foresight), European governments - Austriamakes no exception - are so reluctant to engage in biomass-technology. If they spent only one tenth of the funds which have gone into atomic power research (and which have not been repaid) for research in biomass-technology, the necessary progress could be financed easily: There is not much time to lose: The development of high technology on an industrial scale usually takes three generations of industrial investment. This is to say 30 years approx.! But this is just the space of time for which we still have fossile resources for our present style of living. 5. Energy and raw materials from biomass for the sake of nature and man About 200 years ago, agriculture and industry began to go separated ways; the "age of fossile energy" began. Evidently, it is not an "age" but a mere episode in the history of earth. The exhaustion of fossile reserves will be the main problem of our children and the extreme use of fossile energy is detrimental to living beings, which need integrated systems. However, one major effect of the past development is usually forgotten: The nearly exclusive use of cheap fossile energy on the one hand led to industrial accumulations in areas, where fossite energy is easily available and on the other hand local enterprises were ruined and rural areas depopulated. Besides our ruinous style of covering our energy and raw material needs, these large accumulations of people and industries are the main ecological and social problem of our time In order to communicate, we need no longer to dwell next to our neighbours https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> door and to settle in large accumulations. We have developed telecommunication and traffic to such an extent that we can afford a decentralized style of living without losing information, culture and civitization. What we need is a style of living, respecting the proportions of man and nature, i.e. we have to cover our energy and raw material needs in line with and not against nature (within the biosystem) and we have the obligation to respect the human right for a sheltering and surveyable community Why do we not start environmental protection at the roots instead of during symptoms by expensive investments? The overall profitableness and the wellbeing of nature and man call for the utilization of biomass. 20. References:

Biomass for Energy https://www.w3.org/1998/Math/MathML"> ( 1984 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , OECD.

Bolhar-Nordenkampf, H. (1984). Faktorenanalyse des "Waldsterbens' aus pflanzenphysiologischer Sicht. Institute of plant physiology, University of Vienna.

Eccles, J.C. and Zeier, H. (1980). Biologische Erkenntnisse über Vorgeschichte, Wesen und Zukunft des Menschen. Kindler Verlag, Munich, p. 119.

Energiebericht und Energiekonzept 1984 der Österr. Bundesregierung. Federal Ministry for Trade and industry, yienna (1985).

Austrian Forest Stock-Taking 1961/1970-1971/1980. Federal Ministry of Agriculture.

Systemstudie Ottenschlag (1983). Austrian Association for Agricultural Research, Vienna

E. Broda (1981). Solar energy in the nineteen eighties, expanded version of a lecture given at the international Atomic Energy Agency, Vienna, in June 1979 p. 19 a.f.

Oosterr. Forschungszentrum Seibersdorf (ÖFZS), (1984). Energie aus Biomasse - Energiebilanzstudie.

SESSION II TECHNICAL SESSION Zur Agrarpolitischen Bedeutung der Ethanolproduktion in der Bundesrepublik Deutschland - K. Meinhold and H. Kögl The Use of Forests as a Source of Biomass Energy - F. C. Hummell The Availability of Wastes and Residues as a Source of Energy - G. Pellizzi The Potential of Natural Vegetation as a Source of Biomass Energy - T. V. Callaghan, G. J. Lawson and R. Scott Photobiology - the Scientific Basis of Biological Energy Conversion - M. C. W. Evans The Biomass to Synthesis Gas Pilot Programme of the CEC: a First Evaluation of its Results - A. A. C. M. Beenackers and W. P. M. van Swaaij Biomethanation, the Paradox of a Mature Technology E-J. Nyns, M. Demuynck and H. Naveau Novel Methods and New Feedstocks for Alcohol from Biomass U. Ringblom Use of Algal Systems as a Source of Fue1 and Chemicals E. Bonalberti ZUR AGRARPOLITISCHEN BEDEUTUNG DER ETHANOLPRODUKTION IN DER BUNDESREPUBLIK DEUTSCHLAND K. MEINHOLD und H. KOGL Institut für Betriebswirtschaft der Bundesforschungsanstalt für Landwirtschaft Bundesallee 50, D-3300 Braunschweig Bundesrepublik Deutschland 21. Summary

Adjustment of agricultural product prices to world market prices and reduction of sugar quotas according to domestic demand are not only favourable from a macroeconomic point of view but also important conditions for the economic viability of renewable resources.

In order to minimize the cost of renewable resources compared with fossil substitutes special crops with high yields and efficient technologies of conversion and use are needed.

If these conditions are fulfilled, the future development of world market prices of agricultural comodities and energy will decide wether agricultural resources should be diverted into the production of renewable resources.

Furthermore, to assess completely advantages and disadvantages of the ethanol production from biomass, one has to analyse too effects on other parts of the economy, on foreign trade as well as on the quality of the environment. 22. PROBLEMSTELLUNG Die Umlenkung von landwirtschaftlichen Ressourcen aus der Nahrungsmittelproduktion in die Produktion von Energieträgern und industrie1len Rohstoffen kann weder lösgelöst vom Hintergrund der EG-Agrarpolitik gesehen werden noch stellen einzelwirtschaftliche Rentabilitätsargumente hinreichende Kriterien für ihre sachgerechte Beurteilung als agrarpolitische A1ternative dar. Da die augenblick1iche Problemlage der Agrarpolitik der Europäischen Gemeinschaft sowie die Ursachen dafur hinreichend bekannt sind, erubrigt sich zur Begründung dieser These eine Aufzählung aller einzelnen Punkte. Es sollen aber im folgenden diejenigen Gründe genannt werden, die eine Beibehaltung der bisherigen Politik als kaum wahrscheinlich erscheinen lassen, auch wenn dies aus der Sicht einzelner Nationalstaaten unterschiedlich beurteilt wird.

Eine Anpassung von Angebot und Nachfrage nach Agrarprodukten innerhalb der EG kann bei herrschenden Preis-Kosten-Relationen nicht erreicht werden.

Ein weiterhin um https://www.w3.org/1998/Math/MathML"> 20 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . pro Jahr steigender Finanzbedarf für den https://www.w3.org/1998/Math/MathML"> E G - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Agrarhaushalt steht im Widerspruch zu den Bemühungen, die nationalen Haushalte zu konsolidieren

Steigende Agrarüberschüsse traditioneller Agrarexportstaaten erschweren es der EG, weitere Überschüsse am Weltmarkt unterzubringen.

Für die Politiker aller Parteien wird es zunehmend schwieriger, ihre Wähler davon zu überzeugen, daß Aufwand und Ertrag der Europapolitik unter diesen Bedingungen in einem zufriedenstellenden Verhältnis zueinander stehen.

Es ist deshalb nach Lösungen zu suchen, die die vorhandenen und auch weiterhin wachsenden Agrarüberschüsse volkswirtschaftlich so nutzen, daß die gesamtwirtschaftlichen Kosten ihrer Verwertung minimiert werden. Die Verwendung von Agrarprodukten für Energieträger und industrie1le Grundstoffe kann zukünftig ein erfolgversprechender Weg in diese Richtung sein. Denn sowohl im Bereich der Energieträger als auch anderer industrieller Grundstoffe ist - im Gegensatz zum aktuellen Geschehen - wieder mit steigenden Knappheiten und damit steigenden Kosten zu rechnen. 23. ZIELSETZUNG DER VORLIEGENDEN ARBEIT Im Gegensatz zu anderen Lösungsvorschlägen für die Anpassung von Angebot und Nachfrage bei Agrarprodukten weist der von uns vorgeschlagene Weg den Vorteil auf, daβ

weder der Dirigismus in der Landwirtschaft erhöht wird (Besteuerung von Betriebsmitteln, Erhöhung des Außenhandelsschutzes bei Futtermitteln, Beschränkung der Produktionsmengen, Stillegung von Produktionsfaktoren)

noch die Marktkräfte zum alleinigen Mechanismus der Preisbildung werden, wenigstens solange nicht, wie eine alternative Verwendung landwirtschaftlicher Produktionsfaktoren in anderen Wirtschaftsbereichen wenig Aussicht auf Erfolg hat.

In unsere Oberlegungen nicht einbezogen sind solche Maßnahmen, die durch direkte Einkommensübertragungen oder andere sozialpolitisch wirksame Instrumente den Strukturwandel beschleunigen wollen. Die konkrete Frageste1lung dieser Arbeit ist vielmehr, herauszuarbeiten, in welchem Maße Produktpreise und Preisrelationen zu verändern und Produktions- und verarbeitungstechnologien zu entwickeln sind, damit folgende Ziele erreicht werden:

Wettbewerbsfähigkeit der Rohstoffproduktion gegenüber der Nahrungsmittelproduktion auf betrieblicher Ebene

Minimierung des Wettbewerbsabstands gegenüber fossilen Substituten

Berücksichtigung des Einkommenszieles der Landwirtschaft

Versorgungssicherheit bei Nahrungsmitteln

Keine Erhöhung der gesamtwirtschaftlichen Kosten der Agrarpolitik

BESCHREIBUNG DES VERWENDETEN MODELLS UND DER ZUGRUNDELIEGENDEN ANNAHMEN Für unsere Uberlegungen zur Wettbewerbsfähigkeit der Produktion von nachwachsenden Rohstoffen benutzen wir eine Kette von Modellansätzen, angefangen von der einzelbetrieblichen Analyse über die Regionalanalyse bis hin zum sektoralen Ansatz einschließlich eines Modells der deutschen Mineralölwirtschaft. An dieser Stelle wird, da die agrarpolitische Perspektive im Vordergrund steht, ausschließlich der sektorale Ansatz zur Diskussion gestellt. Dabei beschränken wir uns auf die Betrachtung von Ethanol als nachwachsenden Rohstoff, da eine vergleichbare Datenbasis für die anderen Rohstofflinien bisher noch nicht vollständig erarbeitet werden konnte. In diesem Modell ist der Sektor Landwirtschaft nicht deckungsgleich mit dem in der volkswirtschaftlichen Gesamtrechnung verwendeten Begriff, da einzelne Teile entweder ausgeschlossen sind (Sonderkulturen) oder vor- und nachgelagerte Wirtschaftssektoren vollstandig oder teilweise einbezogen sind (Herstellung von Mischfuttermitteln, Verarbeitung vom Agrarprodukt zu Nahrungsmitteln). Dieses Mode 11 stellt einen Optimierungsansatz dar, bei dem Anpassungen an veränderte Rahmenbedingungen ohne Zeitverzögerungen erfaßt werden und selbst marginale Differenzen ausreichen, um eine Reaktion herbeizuführen. Mit Hilfe dieses Mode11s wollen wir die folgenden Frageste11ungen beantworten:

Beschreibung der heutigen Situation (Basis 1984 )

Fortschreibung der heutigen Situation bei anhaltendem technischen Fortschritt bis hin zum Jahr 1990 (0-Variante)

Bestimmung von Preisniveau und Preisrelationen zwischen Nahmungsmitteln und Nichtnahrungsmitteln für das Jahr 1990 , bei denen die Ethanolproduktion eine wettbewerbsfähige Produktionsalternative wird (1. und 2 . Variante

Im folgenden sollen stichwortartig die wichtigsten Annahmen genannt werden, ohne die das Verständnis der Modellergebnisse unvollständig bleiben muß.

Fortschreibung der naturalen Erträge entsprechend dem Trend (s. Anhang Obersicht 5)

Annahme einer "normalen Preisentwicklung" auf den Weltmärkten für Agrarprodukte und Energie, einer realen Verteuerung von industriellen Vorleistungen und einer marktorientierten EG-Agrarpreispolitik (s. Anhang Übersicht 6)

Konstante Nachfrage nach im Inland erzeugten Nahrungsmitteln

Beibeha1tung der bisherigen Handelsbeziehungen mit Agrarprodukten zwischen der Bundesrepublik Deutschland und anderen EG-Mitgliedsstaaten

Marktordnungskosten definiert als Differenz zwischen Interventionspreis und Weltmarktpreis.

ERGEBNISSE

Die Fortsetzung der bisherigen Preispolitik führt bei steigenden Erträgen, trotz steigender Betriebsmittelpreise, zu einer erheblichen Steigerung der Getreideproduktion (siehe Ubersicht 1 und 2, Basis 1984 und 0Variante). Diese Tendenz drückt sich in einer Zunahme der Weltmarktexporte von Getreide un https://www.w3.org/1998/Math/MathML"> + 179 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . bzw. einer Steigerung des Selbstversorgungsgrades der Bundesrepublik auf https://www.w3.org/1998/Math/MathML"> 120 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . aus. Das Sektoreinkommen steigt ebenfalls an, und zwar hauptsächlich verursacht durch Ausdehnung der Exporttätigkeit (+ 39 v.H.) sowie Einsparung bei den Vorleistungen infolge effizienterer Produktionstechnik. Damit geht ein Anstieg der Marktordnungsausgaben für Getreide um https://www.w3.org/1998/Math/MathML"> + 177 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . einher, von https://www.w3.org/1998/Math/MathML"> + 22 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> v.H. bei Milch (sinkende Magermilchverfüterung) und von + 28 v.H. bei den olsaaten (Produktionsausdehnung). Insgesamt erhöhen sich die Marktordnungsausgaben bei dieser Variante um + 68 v.H. gegenüber der Basis 1984, wogegen das sektorale Einkommen lediglich um https://www.w3.org/1998/Math/MathML"> + 15 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> v.H. ansteigt. Die Schlußfolgerungen aus dieser Entwicklung sind folgende: sowohl die Getreidepreise als auch die Ölsaatenpreise und die Quoten für Zucker sind der künftigen Marktlage besser anzupassen als dies heute der Fall ist. Dieser Ansicht hat sich auch die Kommission der EG angeschlossen, indem sie bei Oberschreiten bestimnter Zielmengen für Getreide und ơlsaaten eine nominale Preissenkung für diese Produkte festgelegt hat. In Analogie dazu haben wir für das Jahr 1990 folgende Annahmen über Agrarpreise, Quoten und Produktionstechnik getroffen (s. Anhang Üersicht 6):

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Reduzierung des interventionspreises für Raps auf 85 v.H. des heutigen Niveaus

Kürzung der A- und B-Quote für Zucker auf das Niveau des heutigen Inlandverbrauches

Beibehaltung der derzeitigen Preis- und Mengenregulierungen bei Milchund Rindfleisch

Annahme, daß Kostensenkungen in der Schweinemast, der Geflüge1- und Eierproduktion, verursacht durch verminderte Getreidepreise, in den Erzeugerpreisen zumindest teilweise weitergegeben werden

Bereitstellung von Produktionsverfahren zur Biomasseproduktion Diese Annahmen führen bei unveränderten sonstigen Nebenbedingungen und zunächst ohne die Möglichkeit der Ethanolproduktion zu folgenden Ergebnissen (s. Obersicht 1 u. 2, 1. Variante). Der sektorale Deckungsbeitrag sinkt gegenüber der 0-Variante ab und erreicht fast das Ausgangsniveau des Jahres 1984 . Der Produktionswert der am In1andsmarkt absetzbaren Güter vermindert sich um https://www.w3.org/1998/Math/MathML"> 5 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , gegenüber der Basis 1984 . Dies bedeutet trotz Erhöhung des Selbstversorgungsgrades bei Schweinefleisch von 87 auf https://www.w3.org/1998/Math/MathML"> 95 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . nichts anderes als eine Entlastung der Verbraucher. Der Getreideexport geht auf https://www.w3.org/1998/Math/MathML"> 65 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . der 0-Variante zurück und beträgt, gemessen in Flächenäquivalenten, nur noch 736.000 ha. Die Marktordnungskosten sinken infolge des Wegfa11s der Zuckerüberschüsse und der verminderten Preisstützung bei Getreide sogar unter das Niveau der Ausgangssituation von 1984. Die Einführung der Produktion von nachwachsenden Rohstoffen, hier dem Ethano1, wird auf folgende Weise vorgenommen: Bei den getroffenen Annahmen uber Produktpreise, Produktionsquote und Konversionstechnologie reicht ein Verkaufspreis von https://www.w3.org/1998/Math/MathML"> 1,00 D M / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ethano 1 aus, um eine Produktionsmenge von https://www.w3.org/1998/Math/MathML"> 890.000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ethanol bereitzustellen (s. Obersicht 3 ). Dies entspricht 5 v.H. des 1983 in der Bundesrepublik verkauften Superbenzins. Insgesamt steigt der Deckungsbeitrag um 13 Mio DM an, was in bezug auf die produzierte Menge Ethanol nur eine marginale Veränderung darstellt. Deutlichere Veränderungen ergeben sich bei den Vorleistungen, die um https://www.w3.org/1998/Math/MathML"> + 415 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Mio DM ansteigen, und beim inländischen Produktionswert (+ 890 Mio DM). Da die Ethanolproduktion ausschließlich Getreide verdrängt, das bisher auf den We1tmarkt exportiert wurde, sinken auch die Marktordnungskosten für Getreide, und zwar um 72 Mio DM. Das sind, bezogen auf den Hektar Rohstofffläche, 343 DM bzW. 81 DM je produzierten Kubikmeters Ethano1. Werden diese eingesparten Marktordnungskosten für die Preisstuttzung von Ethanol verwendet, so betragen die Nettoherstellkosten https://www.w3.org/1998/Math/MathML"> 919 D M / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Bei den getroffenen Annahmen uber die Weltmarktpreise für Getreide und Energie hängt die relative Vorzüglichkeit gegenüber einer exportorientierten Getreidepolitik weitgehend vom Substitutionswert des Ethanols ab. Da dieser Wert seinerseits weitgehend unternehmensspezifisch determiniert ist, sind hier drei Varianten aufgeführt und hinsichtlich ihrer haushaltswirksamen Konsequenzen mit dem Export von 0berschußgetreide verglichen (Ubersicht 4). https://www.w3.org/1998/Math/MathML">   21 )   g e s e t h a t z e   P r o i s   E t h a n d = P r e s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

SCHLUSSBETRACHTUNG

Die bisher berichteten Ergebrisse aus den Modellkalkulationen lassen sich aus gesamtwirtschaftlicher Sicht wie folgt zusammenfassen: Geht man davon aus, daß die Preise für Energieträger langfristig schneller steigen als es bei den Agrarprodukten der Fa11 ist, so ist es eine Frage der Zeit, bis die Wettbewerbsfähigkeit der Ethanolproduktion erreicht ist. Für die Finanzierung der bis dahin erforderlichen Stützungsbeträge von hier 52 bis 109 Mio DM pro Jahr wären folgende Denkansatze möglich:

Durch die Landwirtschaft: Beispielsweise mit einer Abgabe in Hơhe von 0,34 bis https://www.w3.org/1998/Math/MathML"> 0,71 D M / d t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> auf den bisher unverändert gelassenen Preis von https://www.w3.org/1998/Math/MathML"> 11,13 D M / d t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Rüben innerha1b der A- und B-Quote. Das würde gleichzeitig auch eine bessere Anpassung der Preisrelation gegenuber Getreide bedeuten.

Durch den Finanzminister: Mittels Steuerminderung für ethanolhaltige Kraftstoffgemische, die geringer sein könnte als es dem verminderten Heizwert entspricht. Dem stehen zusätzliche Steuereinnahmen aus einer verstärkten Nachfrage nach gewerblichen Vorleistungen in Höhe von 415 Mio DM, das sind rund 2.000 DM/ha Rohstofffläche, gegenüber. Der Saldo aus beiden Positionen entspricht der effektiven Steuerveränderung, dessen genaue Ermittlung an dieser Stelle noch nicht möglich ist.

Durch den Konsumenten: Durch eine Preiserhöhung von 0,42 bis https://www.w3.org/1998/Math/MathML"> 0,75 P f / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Kraftstoffgemisch bei https://www.w3.org/1998/Math/MathML"> 5 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Mischungsantei1. Da Ethanol sauberer verbrennt als Kohlenwasserstoffe, wäre auch hier ein Gegenwert vorhanden, dessen Ouantifizierung bekanntermaßen nicht leicht fällt.

Eine über die eingesparten Marktordnungskosten hinausgehende Verwendungsbeihilfe für Ethanol wäre im Rahmen des vorgestellten Modelles bereits 1990 nicht mehr erforderlich, wenn entweder das weltmarktpreisniveau für Getreide auf ca. https://www.w3.org/1998/Math/MathML"> 80 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . der hier unterstellten Annahmen absinkt oder aber ein ausreichend hoher Substitutionswert für Ethanol erzielt werden könnte. Weiterhin muß daran erinnert werden, daß Marktordnungskosten hier lediglich Exporterstattungen umfassen. Bei Einbeziehung a1ler anderen Marktordnungskosten, vorausgesetzt sie wären eindeutig zuordenbar, würde sich das ausgewiesene wettbewerbsdefizit noch verringern. ANHANG

Durchschnitt der Jahre https://www.w3.org/1998/Math/MathML"> 1977 - 1983   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2) https://www.w3.org/1998/Math/MathML"> 90 ∨ . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> H. des Weizenpreises unterstel1t

https://www.w3.org/1998/Math/MathML"> 80 v . H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . des Weizenpreises unterstelit 4 geschătzt 5 ) Dumehschnitt der

Jahre 1980-1983 6) Preisarnahtne infolge sinkender EG-Getreldeprefse https://www.w3.org/1998/Math/MathML">   Ubergicht 5: Entwicklung von Ertragen In der Bundesrepublik Deutschland   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Trendschatzung basierend auf den Janren 1949-1983 baW.

geschatita

Ubersicht 6: Annahme uber Entwicklung wichtiger Preise im Sektor Landwirtschaft THE USE OF FORESTS AS A SOURCE OF BIOMASS ENERGY HUMMEL, F.C. Associate Senior Fellow, Centre for European policy Studies (CEPS), Brussels 24. Summary In Western Europe and in industrialized countries in general, the main source of forest biomass for energy continues to be the residues from https://www.w3.org/1998/Math/MathML">   c o n v e n t i o n a l   l o m e t r e   f o r   b e s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which there are no other markets. Crucial to making such operations viable economically is the development of markets very close to the Viable economically ls the development of markets very close to the costs, forest biomass being a bulky commodity of low unit value. Short rotation biomass plantations on bare land are still largely at the experimental stage, at any rate in Europe. Progress has been greater than opponents had predicted, but siower than enthusiasts would Wish. The two main lines of development are, first single stem plantations on rotations of 20-30 years which combine timber production with biomass production for energy, and secondly the coppice crops which are usually managed on verv short motations of 2-6 years. In the European Community, our main interest lies in technoloby that permits viable small scale operations. This is partly for environmental reasons and partly because of the fragmentation of land ownership. The most urgent need in the world for more forest biomass for energy exists in the developing countries where almost half of the world's population continues to depend on wood fuel for cooking and heating and where rising pooulations have led to an over exploitation of the forest resource which in turn has caused wood shortages and soil erosion. While more research is needed, especially in arid regions, the main emphasis must be on the application of existing knowledge as an integral part of rural development. 25. INTRODUCTION Wood was at one time man's main soluree of energy. It not only provided the fuel for cooking and domestic heating, but also for many industrial purposes such as the smelting of metals, the burning of bricks, the manuf'acture of glass and the refining of salt. For these industrial uses, wood has been replaced almost completely, by fossil fuels as well as by hydroelectric and nuclear power. In the home wood has also largely been replaced in most developed countries, but in the developing countries some 2000 mIllion people, that is nearly half of the world https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> population, still depend almost entirely on wood to cook food and keep warm. The present status and future potential of wood as a source of energy, and the priorities for future research and development work in this field, depend not only on technological and economic factors but also on social considerations. Deep-seated human emotions and interests are involved. The blomass left in the forest consists in the first place of trees of small dumensions or inferion quality for which there are no markets or Sinall dinensions or infertor quality for which there are no markets or Which do not repay the cost of harvest because of distance to the markets. Transport costs loom large in all forestry operations and they are a decisive factor for material of low unit value m" removal of these trees decisive factor for material of low lnit value. The removal of these trees would also benefit timber production, because the removal of inferior trees reduces competition for the better tres which then orow faster. Where theme ane no pood trees as in some https://www.w3.org/1998/Math/MathML"> 6 m i l l i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha of nemlected coppice in the EC, the harvest of this biomass for energy would at least recoup part of the cost of clearance for replanting. The second component of the unutilized forest biomass are the residues from conventional logging. This logging is generally confined to the stemwood, leavine toos, branches, stumps and roots in the forest and sometimes also the bark, depending on whether logs are debarked in the forest or at the sawmill or other wood-processing plant. There is now a crenenal consensus in the cc that stumps and noots should not be extracted. general conserisus in the bo that stumps and roots should hot be extracted; the risks of damage to the soll are too great. Phere is therefore no polnt in pursuing that line of development. On the other hand, there are many sites where the remora] of a sionificant proportion of the biomass in tops, branches and bark is unlikely to cause a reduction in soil fertility or deterioration in soil stmucture. The main efforts have therefore been directed towards hanvesting this part of the biomass. The remova? of too much foliage with tops and branches would be harmful because of its high nutrient content. In extreme cases, the drain of nutrients might have to be remedied by the application of fertilizers. The technology of biomass hanvest in the forest has followed two main Iines. The first is whole tree chipping carried out in the forest. This method is usesd for trees of small dimensions for which there are no better markets. Considerable advances have been made in recent years in the develoment of suitable machines of various sizes and of logeing systems to go with them. Of particular interst to us in the EC, for further research and development, are the smaller chippers, especially those powered by a farm tractor. This is becatise our forests are rarely large and the ownership in these forests is often fragmented. Small operations are therefore the rule and farmers doing this type of work part time are important in some countries. The lareer machines too have a role to play In some of our forests but countries with much larger forest resources than countries of the EC are in a better position to take the lead. Two more restricted linessf development must also be mentioned; one is almed at speeding up the preparation of conventional fuel wood billets for domestic use by appropriate combinations of sawing and splitting mechanisms, the other is the conversion of residues into briquettes for ease of handling. The second main line of biomass harvest in the forest is to combine it In some way with conventional logsing. One approach has been to load the trees with their tops and branches onto lorries equipped with a device which enables the load to be compressed. Topping, delimbing and debarking is then carried out at the pulpmill, which pulps the sternwood. The biomass that is left is converted into energy for the mill's own use or for sale either as it is or after conversion to electricity. The other approach is to separate the stemwood from the biomass already in the forest. The first approach is less labour intensive, but is generally suitable only for large logging operations of the type that pulpmills undertake. The second approach is better suited to the woodland owner who selis what he can to industry and converts the rest into biomass for energy if there is a local market for it or if he himself can utilize it, e.g. on a farm or other at least 15 tonnes of dry matter/ha/year are necessary to make energy plantations an economically viable proposition; but these estimates do not take into account that the opportunity cost of such plantations may be very low if they are on land now used for highly subsidized surplus production of milk and meat. It also seems probable that research will not only lead to an increase in yields but also to a reduction in costs. Research on energy plantations has followed two main lines. First there are the very short rotation plantations managed on a z-6 year rotation. They usually consist of broadleaved species which coppice li.e. regrow from the stumps after being cut over). Then there are the single stem plantations which may be of either coniferous or broadleaved species; they are generally regenerated by planting and managed on 20 - 30 year rotations. Present indications are that there is a future for both types of energy crops. The longer rotation crops have the following advantages:

the technology is already better developed; that applies particularly to the harvesting and conversion to energy, but also in some measure to the silviculture:

part of the produce can be used for sawmilling or pulping as well as for energy: this improves the income from these plantations because industrial wood, especially sawlogs, generally fetch a higher price than fuelwood;

In some areas they are considered preferable on environmental grounds - more pleasing in the landscape, less need for fertilizers, better habitats for wildlife etc.

If the alarming dying of old forest stands in Germany and elsewhere continues, there will be an urgent need to plant fast growing timber trees to ensure future supplies.

The main advantage of the very short rotation crops on the other hand lies in the fact that the time interval between establishment and harvest is so much shorter. The early harvest is especially important for farmers who wish to switch part of their land to the production of energy for use on the farms. They are rarely willing or able to forego income from their land for more than a very limited period; moreover, the cultivation of very short rotation tree crops is more closely related to farm practices than more conventional forestry, am important consideration in countries where there is no forestry tradition among farmers. In this context the proposal by the EC Commission must be warmly welcomed, that farmers who embark on forestry should receive for a number of years a subsidy to replace the subsidies which would have been payable under agricultural use of the land. It would obviously be premature to set any targets for wood energy production from afforestation, but even a very modest achievement of an annual production in the EC of 5-10 million tonnes of oil equivalent, would double the amount available from forest residues and would make a major impact on the economies of the rural areas where this production would be concentrated. 3.2 Selection and Breeding The selection of species and the selection and breeding of clones Within species has made considerable progress in recent years and has been boosted by the cooperation that has developed between research workers from different countries. This cooperation has been encouraged by intemnational different countries. This cooperation has been encouraged by international organisations including, apart from the EC, the IEA, FAO and IUFRO. MOSt of the research has been emplrical but research on the use of advanced techinologies, such as propagation by tissue culture, is on the increase There appears to be a need at this stage to support the existing effort With more fundamental research, taking advantage as far as possible of work already done on plants other than trees, e.g. on problems of photobiology. Most of the work on very short rotation coppice crops has been concentrated on the genera Salix and Populus. The genus Alnus has been found useful on some wet and nutrient-poon sotas (NOT peates) but its verv capacity for nitrogen fixation diverts energy from production. Where climatic conditions have been suitable, genera such as Eucalyptus have also recelved some attention. Some very promising clones for particular sites have been identified, but experience has already shown that some clones do not keep their early promise and that they are too site specific. Good progress has also been made with testing for disease resistance. The testing of new clones for resistance to bacterial canker in poplar is now done on a coordinated basis in the EC, in a programame launched with financial support from the EC Commission. Some conifers such as Picea sitchensis, when planted at very high densities and cut over on a 2-6 year cycle, have also given high yields of biomass comparable to those of the broadleaved species, but the cost is high and the disadvantage that conifers do not coppice is accentuated on these very short rotations and lt seems doubtful whether there should be much further effort in this direction. For single stem plantations on rotations of 20-30 years, the choice of species is somewhat wider. Broadleaved genera, such as Betula and Prunus deserve mention as well as some species of conifers. In Ireland for example, high ylelds are achieved with Picea sitchensis which is also an excellent timber tree, and with some provenances of Pinus contorta which regenerates naturally on some sites. 26. 3 Management and Harvesting Very short rotation coppice stands resemble agricultural crops rather than forest plantations in their high demands on site, need for fertilizers and drainage, suppression of weeds and intensive capital and labour input. The spacing of the crop too is very important so as to make best use of the site while at the same time permitting access to the machines used for the various tending operations and the final harvest. Much progress has been made on these questions in recent years and, while much research remains to be done, sufficient is now known to embark on substantial pilot operations as an essential IInk between research and practice and also in order to provide the basis for testing harvesting machinery. Apart from some short term problems, such as weed control and uncertainties which can only be resolved in the longer term such as the longevity of coppice stools under very short rotations, by far the most serious problem is presented by the harvesting of the biomass. As far as I know, there are as yet no satisfactory machines for larger scale harvesting operations. The main efforts to solve this problem are being made in North America. In the EC our main interest lies in the improvement of intermediate technology suitable for smaller scale operations. "Excessive wood removals, fuelwood and charcoal mostly for (i) Making better use of the fuelwood by promoting the introduction of more efficient stoves. This can Immediately cut fuelwood consumption to less than one half. Some good designs have been developed which are inexpensive, can be made locally and are adapted to local customs. What is now needed is to make these designs more widely known and used. (11) The protection of the remaining forest areas - often open savanna or scrub - against avoidable destruction by uncontrolled grazing, fire etc. This is only possible with the full cooperation of the inhabitants. This cooperation can only be expected in the broader context of the introduction of better farm practices including, where appropriate, various systems of agro- forestry. THE AVAILABILITY OF WASTES AND RESIDUES AS SOURCES OF ENERGY G. PELLIZZI Institute of Agricultural Engineering Unfversity of Milan Sumary The report lo organlzed in three sections. The first section contains an exhatistive analysis of the actual avatlability of rural (agriculture, forestry, food technology industries and clvil) byproducts and residues of the EEC Countries (some 90 m1111on tons/y-TS). The second sectlon discusses an energy evaluation procedure based on the calculation of the residue https://www.w3.org/1998/Math/MathML">   4 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> energy return in relationship to the conventional technologles to be replaced (25 Mtoe/y). The third section https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a review of the existing mechanization chains for collection, load1ng, conveyance and prentreatement of byproducts and of the problems to be solved for an effective utillzation of such by products and residues for energy purposes. Two annexes follow. 27. INTRODUCTION The subject matter of this report had been discussed at the lst EC Conference on Energy from Biomass (Brighton, Nov. 1980 ), where some significant methodologlcal contributions were made. Later, a rather exhaustive book by Palz and Chartier was published. Thus, dealing further with this toplc mlght appear redtudant, especially since additlonal research has been carried out in the past four years on the available and recoverable amounts, chiefiy of cereal straw. Nevertheless:

The sources do not agree on speciflc (t of total sollds -TS- per ha or per head of livestock) and total amounts, nor on the actual amounts recoverable for energy conversion after deducting what is currently belng used for other purposes;

A clearcut evaluation methodology is as yet lacking; Scanty data are avallable on agricultural and non-agricultural byproducts other than cereal straw;

In the meantime, modern recovery and energy conversion techniques and technologies having been developed, the actual energy contribution of the various byproducts can be assessed more accurately;

The structural characteristics of the various crops evolve continuously (suffice to recall that the height of soft wheat has dropped by some https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tn 30 yeers)

Alternative uses are being developed for vegetal byproducts (treating straw with NAOH or NH and use of maize stalks for fodder etc.);

There 1s growlng demand for biomass (chlefly straw and wood residues) energy conversion technologies.

In 1983 for instance, some 300,000 straw burners were in operation in Denmark, 3,500 in France and barely some 20 in Italy; by late 1984, the situation changed and a few thousand straw burners are now operating in 28. MAIN REFERENCES TABLE 1 - TOTAL AVAILABLE VEGETABLE BY PRODUCTS AND NET ENERGY OUTPUT KEC COUNTRIES (1983) TABLEE 2 - TOTAL, AVAILABLE ANIMLL WASTE AND NET ENERGY OUTPUT, ERC COUNTRIES (1983) (1) Calculaced as obtained by anserobic digestion *t) Calculated as obtainect by direct combugtion (12) DEVANEL A., MERIKDJIAN C., (1984), Chafne de production, de stockage et de transformation énergétlque de la Canne de Provence - Proc. IO Eh Int. Congress of Agrıcultural Engineering, Budapest, 9. (13) DOBIE et A1., (1973), Systems for hand1ing and ut111zlng rice straw Transactions of ASAE, 16. (14) FARGET M.A., (1983), Valorisation énérgétique de la blomasse d'origine agricole - Sérles FAST n.I5 - EUR 8666 FR. (15) FIALA M., (1985), La combustione della biomassa: una tecnologla economicamente valıda - L. Infomatore Agrar1o, 5. (16) GEO PAUL N. (1980), Some methods for the utilization of waste from fibre crops and flbre wastes from other crops - Agricultural Wastes, 4. (17) GIEROBA J., NOWAK I., (1984), Hay and straw harvesting technologles applied in Poland - Rivista di Ingegneria Agrar1a, 2. (18) GUARELLA P., (1984), Raccolta e condizionamento 1 n balle di residul d1 potatura d1 vite e ollvo - LInformatore Agrario, 39. (19) HAVE H., (1979), Regional analys1s of potentlal energy production from agricultural wastes - Inst.of. Agric.Engineering Paper. (20) HJORTSHOJ-NTETSEN A. (1980), The energy demand of Dantsh agriculture and its potential role as producer of alternative energy - Compte rendus - Colloque Intern. du CENECA, Paris, 2. (21) LARKIN S.B.C... MORRIS R.M., NOBLE D.H., RADLEY R.A., (1980), PLOdUCtion, distribution and energy content of agricultural wastes and residues In the U.K. - Energy from blomass lst E.C. Conference, Braghton, 11. (22) LUCAS N., (1978), Whole crop harvesting - Power Farming, 8-10. (23) KASTROLL H.J., (1984), Aktuelle Probleme der Energıeproduktion und Energieanwendung in der Landwirtschaft - Proc. https://www.w3.org/1998/Math/MathML"> 10 th   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Int.Congress of Agricultural Engineering, Budapest, 9. (24) KUMAR K., BAT S. OJHA T.P., (1984), Fuel characterist1cs of agri- (25) NATALICCHIO E., SEMENZA C., (1981), Production, recovery techniques, present and alternative uses of agricultural byproducts - Report CNR https://www.w3.org/1998/Math/MathML"> n ∘ 23,10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (26) PALZ W., CHARTIER P., (1980), Energy from biomass in Europe - Applied Science Pubbl. (27) PELLIZZI G., https://www.w3.org/1998/Math/MathML"> ( 1980 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , New and renewable energy in agriculture - FAO Report, 4. (28) PELLIZZI G., (1984), Prlme analisi comparative di difeerenti processi d1 conversione energetica delle biomasse - Rivista di Ingegneria Agraria, 2 . (29) PELLIZZI G., (1984), Energy ut111zation of biomass - Proc. https://www.w3.org/1998/Math/MathML"> 10 th   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Inter. Congress of Agricultural Engineering, Budapest, 9. (30) PELLIZZI G., (1985), La legna fonte di energla rinnovabile - L'Informatore Agrarto, 5 (31) PETTERSON I., (1982), Halm som energikö1la - Pikon Energikonsu1t, Orbyhus. (32) POSSELIUS J.H., STOUT B.A., (1980), Crop residues avallability for fuel - Proceedings of "Bioenergy 80 "' Congress, Atlanta, 4 . (33) REQUILLART V., (1982), La fillére paille granulée; analyse économique - Etude comes-INRA. (34) REQUILLART V., (1984), Upgrading straw in Europe - Blomass News Intern, 1 . (35) REXEN F.P., https://www.w3.org/1998/Math/MathML"> ( 1980 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Straw and animal residues avallable for energy Energy from biomass lst E.C. Conference, Brighton, 11. (36) SATEK J., https://www.w3.org/1998/Math/MathML"> ( 1968 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Czech three-stage cereal harvesting - Power Farm1ng, 1. (37) STANIFORTH A.R., (I979), Cereal straw - Clarendon Press. (38) STANIFORTH A.R., (1982), Straw for fuel, feed or fertiliser? - Farming Press Ltd (39) STREHLER A., (1984), Energlegewinnung atis BIo-Masse - Proc. 10 Lh Int. Congress of Agricultural Engineering, Budapest, 9. https://www.w3.org/1998/Math/MathML"> ( 40 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TESIC M., https://www.w3.org/1998/Math/MathML"> ( 1984 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Die Bewertung der Maisstrohernterverfahren in Jugoslavien - Proc. https://www.w3.org/1998/Math/MathML"> 10 Eh   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Int.Congress of Agricultural Engineering, Budapest, 9. (41) VOLPI R., VATTERONI G., (1982), L' apporto della biomassa al sistema energetico nazlonale - Atti Conf. Int. Energia da Biomasse, Venezia, 3. (42) WILTON B.s (1978), Whole crop cereals: harvesting, drylng and separation - The Agricult. Engin. 1. ANNEX 1

The calculation procedure used to determine the actual availability of vegetal byproducts for energy conversion is based on the following equation:

https://www.w3.org/1998/Math/MathML"> TS = Σ [ A ⋅ y ⋅ α ⋅ δ ( 1 - M ) ⋅ ( 1 - AL ) ⌋   ( t / y ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> whereTS https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> T S = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> total solids avallable for energy converston (t./y) A= Earmed surface per crop (ha) https://www.w3.org/1998/Math/MathML"> y = m a i n ⁡ c r o p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yield https://www.w3.org/1998/Math/MathML"> ( t / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha y) α= byproduct/tain crop ratio, for the byproduct actually recoverable with δ= surface reduction coefficient, to account for small, 1 solated plots and generally for those plots where byproducts are difficult to collect M= moisture content of byproduct as collected https://www.w3.org/1998/Math/MathML"> % H 2 O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> A L = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> byproducts for alternative tises (%). 2. ANNEX 2 Anima1 equ1- Excreta TS VS Livestock valent (AE) (kg/t on the hoof) (% TS) Cattle 450 8.5 73 Swine 100 6.0 75 Broilers 0.8 13.0 70 Hens 1.7 13.0 70 THE POTENTIAL OF NATURAL VEGETATION AS A SOURCE OF BIOMASS ENERGY Summary

INTRODUCTION

3. THE WORID VEGETATION RESOURCE The International Biologloal Programme has enebled reasonably accurate egtumetog of plant productlvity in the worlata mejor eoperstems to bo compiled https://www.w3.org/1998/Math/MathML"> ( 5,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Around 133 Pg (bilition tonnes) of terrestral biomass is estimated to be producad annuelly from a world standing crop of 1244 Pa. However, as lıttle as https://www.w3.org/1998/Math/MathML"> 11.3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of this total production is from cultivated areas (occupyıng https://www.w3.org/1998/Math/MathML"> 10.7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the land surface), and only https://www.w3.org/1998/Math/MathML"> 1.1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 1.3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of agricultural and forest production are used by man in the form of food or timber (7). A theoretical study of the climatic and soil limits to serioultural production hes estimated thet 3419 million hectares of land are potentially cultivable in the world, and this extent could maximally oroduce 49.8 billion tonnes of grain equivalent (8). This compares with a produce 49.8 bil.1jon tonnes of grain equivalent (8). Whis compares with a current world production of 1.57 billion tonnes (9). However, this theoretical study could account neither for the social, economic and political constraints to an expansion of cultivation, nor did it consider the many practical reasons for sub-optlmal harvests of grain. At a more practicat Ievel, the Fan prediot that the nroportion of potentiel arable land which is actually cropped will increase from https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at present to only https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by the end of the century. Thus, https://www.w3.org/1998/Math/MathML"> 72 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the extra food necessary by 2000 must be met by an Lncrease in productivity (10). Yet such an increase wi.l depend on energy intensive practices such as fertilisation or irrigation. Also, breeding for higher grain yields at the expense of total biomass, and more complete harvesting nethods, will, reduce the residues available for soll fertilisation or utilisation as an energy source. Yields In the developed world appear to be approaching a ceiling (11), and large surpluses for export cannot be relied upon. Thus the FAO conclude that ith many developing countries. Iarge scale production of biomass for energy, if it is to be undertaken at all, will, need to come mainly from the land areas which are not devoted to agriculture and from marginal agricultural land" https://www.w3.org/1998/Math/MathML"> ( 10 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Here then is the role for natural vegetation, and in developed countries too it is likely that energy farming will make most impact on marginal lands, at least in the immediate future. 4. THE PRODUCTIVITY OF NATURAL VEGETATION Comparisons of managed and unmanaged vegetation In Germany and N. America have demonstrated little overall difference in yield between the two systems, but emphasised that agricultural yields were achieved on the best Iand, and with considerable inputs of fertiliser (12). Many native plants have recorded high yields, which often exceed those of crop species selected for food or timber production rather than for maximal biomass (7). The following section explores the reasons why many native species can fully exploit existing environments, and the folly, in many circumstances, of seeking to alter the environment to suit the requirements of crop plants. As stated in the planning of the International BIological Progremme: nThe natural communities present us with a basic yardstick, since they exhibit the level of productive effectiveness that has been brought into being by natural selection operating over geologlcal periods of time (13). In short, bad weeds possess most of the attributes necessary for good energy crops. 5. GHARACTERISTICS OF NATURAL VEGETATION ENERGY SYSTEAS 5.1. Greater diversity of cropping sites If energy cropping is to take place principally on uncultivated areas, as suggested by the FAO, then a major role will be played by natural vegetatIon which is already adipted to the various extremes of arialty, salinlty, expostre, erosion, innurdation, toxicity, or grazing pressure. 4.1.1 Arid Iands. These areas already support a wealth of native species which can potentially be used for the production of food, feed, fibre and fuel. These inciuce, cresote bush (iarrea tridentata), mesquite Prosopis spp. guinoe (Chenopodium spe), guffalo gourd (Cucurbita foetidissima), saltbrush (Atriplex spp.), Russian thistle (Salsola kali), carob (Ceratonia siliqua, pinyon (Pinus sembroides), Yucca spp. and various cacti (14). North American plants studied as a source of hydrocarbons include rasweed (A.mbrosia trifida, milkweed (Asciepias spo.), pale indtan plantain (Cacalia atriplicifolia), tall (ASCI.OpIQS https://www.w3.org/1998/Math/MathML">   BPQ.     ( C A D O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tall boneset (Eupatorium altissimum), mole plant (euphorbia lathyrus), smooth sumed (Rhus glabra), sassafras (Sassafras albidital sow thistle (Sonchus arvensis) and iron weed (Vermonta spp.) (15). Hvdrocarbon plants do not have a maior role in curnent US Government programmes https://www.w3.org/1998/Math/MathML"> ( 16 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , largely through doubts over econorics (17). These constraints will, however, be less severe in third world countries, where fossil fuels consume most avajlable forejgn exchange. Native arid land plants, particularly those containing hydrocarbons, are in cultivation ior energy purposes in several countries such as Euphorbia spp. in Kenya https://www.w3.org/1998/Math/MathML"> ( 18 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , black quince (́ㅓdonia spp.) in Brazil (19) and guayule (Pqrthenium arginatum) in Mexico (20). Calotropis procera is under investigation in India (34). 4.1.2 Saline areas. Native species have evolved tolerance of saline conditions in deserts, and also in coastal saltmarshes. These areas suffer no competition from other land uses. Wxtreme examples of desert tolemance to salt encrustations are Saltbrush (Atriplex spo.) and some species of mesquite, such as tamarugo (prosopis tamarugo). Mesquite even grows in foreshore conditions. Cordgrass (Spartina anglica) has been investigated as en eneroy crop on ss. tmarshes in the UK, aiving an average yield over three years of 12 the hat in October and 5 that in January (21). Silt-grass (Psalpum vaginatum) would be an appropriate energy crop on tropical saltmarshes. 4.1.3 Exposed climates. Crop plants are not adapted to wind and exposure. Wative species, and trees, also grow slowly in these severe conditions, but pracken (Pteridium aquilinum) can sustain an average yield of 9 t ha yr for at least 4 years (21). Dwarf shrubs like heather could provide a small yield https://www.w3.org/1998/Math/MathML"> 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tha https://www.w3.org/1998/Math/MathML">   - 1 y r - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in combination with roor land manasement. 4.1.4 Eroded areas. Perennial natural vegetation is of particular use In stabilising eroded areas, and energy harvesting can be conducted with little or no cultivation. Prosopis chilensis, for example, is being spread naturally in the Sudan by feeding the fruits to goats. This type of species stebilises the sands and lnitiates the accumulation of organic matter in the soji. which crop species can then utilise. Another example is Kudzu vine (Pueria lobata), which was extensively planted in United States after the great depression. It is now regarded as a major weed because it outgrows trees and pasture. However, the needless costs of spraying could be avoided by exploiting the value of Kudzu for energy cropping, land restoration, feed production, and even paper making (22). https://www.w3.org/1998/Math/MathML"> 4.1 . 5   I n u n d a t e d   a n e o s o   N a t u r e l   n q u a t i o   c o m m u n i t i e s   c a n   g i v e   y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ranging from 8 to 60 t he yr , with minimal management effort (7). 200 Mhs of gwamps and mershes exist in the world and, although this is 200 Hha https://www.w3.org/1998/Math/MathML">   H   S   B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> only 1.3 of the land alea, it estimated to produce 5.5% of g-obal plant production. Catail (Typha latifolia), reed (Phragmites australis) and giant reed (Arundo donax) have been thoroughly investigated as energy crops in Minnesota (23), Sweden (24) and France, the last in strip-intercrops with corn and sunflower, https://www.w3.org/1998/Math/MathML"> ( 25 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> These species are reported to yield up to 43, 37 and 59 tha yr , respectively, although such ylelds are not likely to be sustained in extensive energy plantations. Papyrus (Cyperus papyrus) has been suggested as an energy crop for Rwanda https://www.w3.org/1998/Math/MathML"> ( 26 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and its maximum productivity, meastred in India, is 78 t ha https://www.w3.org/1998/Math/MathML">   yr - 1 ( 27 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Water hyacinth has attracted considerable attention (28), but many other emergent macrophytes remain to be studied. One drawback of aquatic energy crops, however, is their low energy content of around https://www.w3.org/1998/Math/MathML"> 13   k J   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , compared with the average for all vegetation of 18.3 https://www.w3.org/1998/Math/MathML"> k J g - 1 ( 7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This is largely due to a high ash content. Much money and effort is devoted to the eradication of potentialiy useful weeds. Water hyacinth is perhaps the best example, and sl million is spent annually on its conrol in the Sudan alone (29). In two states of the united States the cost of control was https://www.w3.org/1998/Math/MathML"> $ 15 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million in 1976 ( 30 ). Yet water hyacinth can grow with astonishing rapidity, 10 plants increasing to 600,000 within a period of 8 months, and giving yields in laboratory conditions in excess of https://www.w3.org/1998/Math/MathML"> 100 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> he https://www.w3.org/1998/Math/MathML">   - 1 y r - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (31). In addition to being used for anaerobic digestion, water hyacinth can operate as a biological filter for sewage, taking up heavy metals and pathogens (28). Many Wetland species with potential for use as energy crops can serve similar multiple purposes https://www.w3.org/1998/Math/MathML"> ( 32 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . It is sad therefore that these most productive areas of the world are being drained and destroyeds yet the crops which relace them are far Iess productive and exploit, rather than create, the fertility of the soil. 4.1.6 Toxic and waste Iands. Native weeds of waste ground are Invasive and resilient in nature, making them suíted to repeated harvesting. The perennial species of Japanese and giant knotweed https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Reynoutria R. Sachalinense) have yielded around 15 t ha yr on unfavourable sites in the UK, and several other species such as nettle (Urtica dioica, Gunnera manicata, willowherb (Epilobium hirsutum), himalayan balsam (Impatiens Elandulifera) and gorse (Ulex europea) have been suggested for areas not suitable to agriculture or forestry (33). Productive indigenous weeds ocour in all countries. In India for example, species such as Saccharum munja, Camera lanata, and Bougainvillea are reported as having higher yields than nearby agricultural crops, without the aid of irrigation (34). Supplementing the value of these spectos as bloftels are their uses for anial feod, rope and furniture chemicals. The area of waste land in India is estimated to be 43.7 itha, with 2.7 Wha occurring around the periphery of farms (35). 6. CONCLUSIONS This paper has not considered the soclal. economtc or technologlcal aspects of biomess production and biofuel conversion from natural vegetation https://www.w3.org/1998/Math/MathML"> ( 7,21,29 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , but we would neverthelegs stress the importance of uging local technolory to explojt native plantg and cropoing systems. Slmple methods of briquetting (51), charcoal making (52) and protein extraction (53) bear special mention. AIthough the food versug fuel argument expresses valld fears about existing ethanol production schemes https://www.w3.org/1998/Math/MathML"> ( 54 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the conflict need not exist if the Lmperative were followed of Integrating biofuel production with agriculture and foregtry. Neglected specles and uncultivated land can thereby be brought carefully into production. 7. REFERENCES (1) WESTHOWF,W. https://www.w3.org/1998/Math/MathML"> ( 1983 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Man's att1tude towards vegetation. In: 'Man's 1mpact on vegetation. W.Holzner et al. (Eds). Junk. The Hague. 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Wastes 9:155-57 (53) OKE, O.L. https://www.w3.org/1998/Math/MathML"> ( 1974 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Leaf protein for better nutrition. App. Technol 1:11-12. (54) BROWN, L. (1980). The energy cropping dilema. Ceres Nov-Dec: 28-32. PHOTOBIOLOGY - THE SCIENTIFIC BASIS OF BIOLOGICAL ENERGY CONVERSION M.C.W. EVANS Department of Botany and Microbiology University College London Summary All systems designed to obtain energy from biomass are ultimately dependent on the growth of plants or photosynthetic microorganisms and therefore an understanding of the biology of these organisms is essential. Many of the systems to be discussed at this meeting have developed from agricultural and forestry techniques, and much of their development in the near future will depend on classical techniques of plant selection and breeding Other systems, notably those dependent on algal culture, have developed from laboratory studies of the photobiology of the organisms now used for mass culture. In the long term the development and viability of biomass systems will depend on the efficiency of solar collection and conversion to useful energy. In order to overcome many of the limits to efficiency a detailed understanding of the mechanism of photosynthesis at all levels from the whole plant to the primary reactions in the chloroplast membranes will be required. In the more distant future the selection, or synthesis by genetic modification, of organisms with the ability to synthesise directly products which currently have to be made by secondary processing of biomass may revolutionise both mass energy production and the photobiological production of high value products. All systems designed to obtain energy from biomass, whether from new biomass grown specifically for energy or from waste materials, are ultimately dependent on the growth of plants or photosynthetic microorganisms. They are therefore ultimately solar energy systems dependent on photosynthesis. Optimisation of these systems will require a thorough knowledge of the biology of the organisms involved and particularly of their photosynthetic and energy metabolism. Many of the systems to be discussed at this meeting have developed from classical agricultural and forestry techniques coupled to secondary processing systems developed from waste disposal niques coupled to secondary processing systems developed from waste disposal bably depend on classical techniques of plant selection and breeding. However the growth of plants in agricultural and forestry systems is very inefficient in terms of solar energy conversion, with yields rarely exceeding https://www.w3.org/1998/Math/MathML"> 1 - 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while the introduction of secondary processing reduces the yield further. This may be acceptable if the biomass used would otherwise be waste, for example from food production, but greatly improved yields will be required if biomass production for energy is to develop on a large scale. Systems which can function on non-agricultural land will also be essential. One solution to this problem may be the use of novel or genetically modified organisms, for example the development of algal culture. With a small number of exceptions the culture of microalgae has been developed in the laboratory as a technique for studying algal photoblology. One of the results of this work has been the demonstration that algae can be grown in the laboratory with an efficiency in conversion of light energy to biomass energy approaching https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , close to the theoretical limit of photosynthesis (1). This can of course only be achieved under very carefully controlled conditions, but it does suggest that it should be possible to greatly improve the yields obtained from more normal photosynthetic growth. Photosynthesis is normally limited by a very wide range of interna! and environmental factors. Photobiology attempts to understand the mechanism of photosynthesis and provide the knowledge which will enable internal limitations to be overcome and also may eventually permit the more direct conversion of light to useful fuels. This knowledge will come from many different sources and application of the results will combine genetic information with the results of biochemical and biophysical investigation to allow the control and modification of specific photosynthetic activities. Perhaps the most immediately obvious problem where large gains in productivity might be made is photorespiration (2). Losses due to the oxygenase activity of ribulose-bis-phosphate carboxylase may rise to twenty or thirty per cent of fixed carbon dioxide. This problem is the subject of major research effort at the present time. The immediate objectives being to understand the chemical reaction catalysed by the enzyme to understand why oxygenation occurs as well as carboxylation. The determination of the struture of the enzyme and elucidation of the active site, both from the amino acid sequence determined from gene sequences, and from X-ray crystal structure analysis combined with knowledge of the enzyme mechanism may eventually allow modification of the enzyme to a more effective form. The function of photorespiration must also be investigated since it would clearly be pointless to "cure" it if it is essential to the growth of the plant. Other limitations on photosynthetic efficiency lie in the earlier events of photosynthesis, the collection of light, the operation of the photochemical reaction centre, the oxidation of water, electron transport to NADPH and the synthesis of ATP (3). Light harvesting involves the absorption of light by a bed of chlorophyll molecules and transfer of the energy to the reaction centre of photosystem 1 and 2. The distribution of energy between the photosystem is the first control point of photosynthesis. In higher plants a complex control system has developed (4), sensitive to the redox state of the plastoquinone pool of the intermediary electron acceptor chain, and operating through the phosphorylation of chloroplast membrane components controlling the grana structure and protein distribution in the chloroplast membrane Following energy transfer to the reaction centre the photochemica charge separation occurs with high efficiency but forward electron transfer is subject to control both by environmental factors and the efficiency of the electron transport chain. The electron acceptor side of photosystem 2 is particularly sensitive to control and also to damage. Electron transport through the photosystem 2 acceptor complex requires the presence of https://www.w3.org/1998/Math/MathML"> C O 2 ( 5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the absence of https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> electron transport is inhibited. Photoinhibition of electron transport at high light intensities is localised on the protein which binds https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the electron acceptors of photosystem 2 (6). It occurs at high light intensities when https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> limitation prevents electron flow damaging the reaction centre. Apart from crop damage https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> control of this site may significantly affect attempts to operate semi-artificial systems for hydrogen production or dye reduction. This protein is also the binding site for many herbicides. Its amino acid structure has been determined and there is considerable homology with a bacterial reaction centre protein. X-ray structure analysis of the bacterial reaction centre (7) may therefore contribute to knowledge of its structure. Genetic modification can result in herbicide resistance; it may be possible to produce modification to give independence from https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and resistance to photoinhibition. The mechanism of water oxidation remains the least understood part of the photosynthetic electron transport chaint it is known to involve manganese and a mechanism to accumulate four oxidising equivalents, the details remain almost comoletely obscure; it is clearly one of the main areas for besic research in photosynthsis where the limitation and control for basic research in photosynthsis where the limitation and control mechanisms cannot be characterised until the basic system is understood (8). Many other enzyme systems are involved in the overall photosynthetic growth of a plant or alga, in the control of electron transport between the photosystems, in the control of coupling of ATP synthesis to electron transport, in the distribution of ATP and NADPH between carbon fixation, nitrate reduction and protein synthesis. All of these systems have evolved to optimise the reproductive growth of the plant, to divert the products of photosynthesis to desirable energy products will require that all of these be controlled. If the biochemistry can be understood means will have to be developed to introduce permanent modification into the strain to be used, involving to introduce permanent modification into the strain to be used, involving complex genetic manipulation https://www.w3.org/1998/Math/MathML"> ( 9 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Rapid advances are being made in under-standing the genetics of photosynthesis, much of the chloroplast genome has been characterised, identification of nuclear genes involved in photohas been characterised, identification of nuclear genes involved in photosynthesis and the developmental control is however only just beginning. Techniques for permanent genetic modification of plants or algae using a variety of different vectors are being investigated but none have yet reached a practical stage. If such techniques can be developed the biomass for energy programme may be able to move from the present emphasis on separate production and processing systems to direct production of high value products. It may already be possible to select algae which excrete useful products and to obtain mutants with enhanced production. In the future gene insertion might be used to divert photosynthates. For example in theory photosynthates could be diverted to ethanol by insertion of only two enzymes. However such diversion would result in major changes in the energy balance of the cell and is unlikely to occur on a large scale unless all the control mechanisms involved can be understood and manipulated. However the possibility that an alga which diverted https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of its photosynthate to for example ethanol or glycerol while growing with https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> efficiency of energy conversion might be developed would make the research effort worthwhile. It is essential if the biomass programme is to develop to its full potential that applied research should be supported by basic research in photosynthesis. 8. REFERENCES (1) GOEDHEER, J.C. and HAMMANS, J.W.K. (1975). Nature 256, 333-335. (2) OGREN, W.L. and CHOLLET, R. (1983). In: Photosynthesis Vol. 2, pp. 191-230 Ed. by GOVINDJEE, Academic Press, New York. (3) HAEHNEL, W. (1984). Ann. Rev. Plant Physiol. 35,475-503 (4) ALLEN, J.F. (1983). Trends in Biochem. Sci. 8, 369-373. (5) VERMASS, W.F.J. and GOVINDJE (1983). In: Photosynthesis Vol. 2 , pp. 541-558. Ed. by GOVINDJEE, Academic Press, New York. (6) KYLE, D.J., OHAD, I. and ARNTZEN, C.J. (1984). Proc. Natl. Acad. Sci. (USA), 81,4070-4074 (7) DEISENHOFFER, J., EPP, O., MIKI, K., HUBER, R. and MICHEL, H. (1984). J. Molec. Biol. 180, 385-398. (8) AMESZ, J. (1983). Biochim. Biophys. Acta https://www.w3.org/1998/Math/MathML"> 726 _ , 1 - 12 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (9) WHITFIELD, P.R. and BOTTOMLEY, W. (1983). Ann. Rev. Plant Physiol. 34, 279-326. 9. Summary and Concluslons Four p11ot plant projects alming at the production of synthesis gas guitable for methanol manufacturing were supported by the Commission of the European Commun1ties during a three year programme lasting from January 1982 to the end of 1984 . This paper gives a first evaluation of 1ts results. It is a personal view of the authors only. The most Lmportant properties of the four p1lot plants, which ranged in design capacity from 4.8-12 tons dry wood/day, are given in Table iv. For each of these projects a checklist has been worked out with the more 1mportant and/or critical development 1tems. The results have been condensed in Table VIL. From the most successful projects synthesis gas was actually converted to methanol in a methanol pilot unit of Lurgl The Creusot Lolre plant was able to run for more than 24 hrs on the CEC-bonus cond1t1ons given in Table III. Pog1tive polnts of the process https://www.w3.org/1998/Math/MathML">   C E C   b o n t r o   c o n d u t l o n g   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> conversion of blomass, high hydrocarbon conversion and good prospectg for presgurized operation. a pressurlzed p1lot plant of 60 ton dry wood/day https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to be constructed at Clamecy. Uncertainties lay https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the area of heat recovery from the product gas (1f des1red) and possibly removal of entrained ash wh1le the high oxygen consumption https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a disadvantage. The Lurg1 Clrculating Bed pllot plant also operated satisfactorily for more than 24 hrg nearly at cec-bonus cond1tions. Only the methane content was a bit too high due to the relatively low operation temperature. Positive polnts of the process are high specific un1t capactty: large operation flextbility, a relatively simple single bed gystem with proven scallng-up abl1ities in other areas. Due to the lower than antlcipated bed temperature the unit capacity was lower than foregeen and the methane content of the product gas a bit too high. Unfortunately no data at higher temperature have been published yet and stable operation at these cond1tions remains to be proven. Heat recovery from the product gas was not p1loted in this project. A digadvantage lg the use of oxygen which w111 gt111 Increase a bit https://www.w3.org/1998/Math/MathML"> 1 f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> synthesis gas according to the CEC bonus cond1tions 18 to be produced. The John Brown Wellman ODG p1lot plant made a longest testrun of 9.5 hrs but the gas composltion was st111 far away from the CEC bonus cond1tions due to the high methane content. It https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> not completely sure that the product gas was produced via the complex chemical mechanisms on which the process is based; possibly part of https://www.w3.org/1998/Math/MathML"> 1 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was produced by other

Groningen University, Laboratory for Chemical Engineering, N1jenborgh 16,9747 AG Gron1ngen, The Netherlands

Twente Un1veralty of Technology, Laboratory for Chemical Reaction Engineering and Industrial Processes, P.O. Box 217,7500 AE Enschede, The Netherlands

Figure 1 Methanol synthesis loop Pigure 2 simplified scheme of a possible methanol synthesis from wood 10. THE PILOT PLANT PROGRAMME SUPPORTED BY THB C.E.C. Table III. Bonus conditions in the CEC pilot plant programme Nine proposals were submitted to the Commission and discussed during the EC Workshop of 22 October 1981 in Brussels https://www.w3.org/1998/Math/MathML"> [ 10 ] . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Shortly thereafter four proposalo were selected on basto of optlmal development potential. It meant the actual start of a three year development program of which the final reports have been published recently. The contractors involved in the programme, the process principles and the pllot plant characteristics are all surnarized in Table IV. 2.1.1 Reactor types chosen As can be seen from Table IV all p1lot plants are based on one or two Eluid bed reactors thus providing the feedstock flexibility required to Elutd bed reactors thus providing the feedstock flexibility required to to handle In other type of reactors, specially on a large scale of operation. Moving bed reactors would requlre gevere feedstock preselection and/or complex and costly feedstock preparation steps. Powder flame reactors would require a costly milling step as discussed elsewhere [2]. Nevertheless, the apoondary gactfter of the Creusot lotre plant and to a certaln extent the Lurgi Circulating Bed plant have incorporated powder flame reactor characteristics. 2.1.2 Gasifying agent The processes of both Lurgi and Creusot Lolre use mixtures of steam and oxygen to gasify the wood. Aglp/Italenergle basically uses steam and alr but still needs oxygen in the secondary gasifier. Due to the special features of the John Brown/Wellman process, only air (and posstbly a small amount of ateam) reportediy will he required for this procesc. Tt should be realized, however, that for the latter process it has not been demonstrated yet that complete gasification to synthesis gas can indeed be effected without using any oxygen because, at the present state of development, the product gas still contains substantial amounts of methane and other pyrolysis products. Therefore, major process improvements stlll have to be realized before a secondary (oxygen consuming) gasification or a steam reforming step safely can be skipped from a technically feasible design. 2.1.3 Scale of operation The proven scale of operation (see table IV) https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dlfferent for each of the four pllot projects but ls always large enough to get all main technical problems at least ldentified. Nevertheless, none of them ls probably large enough to allow for a safe extrapolation to the commerclal scale unless additional experience from a similar reactor in a related application ls avallable. For the Creusot Lolre process a much larger pilot plant will be bullt In the near future. In this pllot plant also pressurized operation will be tested ( https://www.w3.org/1998/Math/MathML"> ± 15 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bar). TABLE IV Maln characteristics of the four https://www.w3.org/1998/Math/MathML"> C E C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> supported gasifieation pllot plant projects In series are requtred.

Calculated by the authors from mass and heat balances assuming watershiftreaction at equillbrium and assuming https://www.w3.org/1998/Math/MathML"> C H 4 + H C + N 2 a s 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> experiments

Assumed to be equal to experimental datae. Bntralnaent of ash and char particlesUsually a substantial fraction of the char produced from the wood in thegasifier will be entrained with the fluldizlng gas together with the ash. Inmost cases these solids w111 have to be recovered from the gas and at leastpartialiy be recycled. Another solution may be secondary gasification. Ashalways will have to be recovered somewhere https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the system and this ash shouldpreferably contain minor amounts of char only.

g. Safe and effective separation between gasifier and combustor (for double Figure 3 The Creusot Loire process Figure 4 Lurgi's circulating fluidized bed gasifier Fiaure 5 The Oxygen Donor Process of John Brown/wellman Fiaure 6 The Italenergie/AGIP S. D.A. process will still be whether gas clean up from tar and particles will be sufficient for these cases. 10.1. Additional p1lot projects Two additional pilot projects have been incorporated in the present p11ot programme of the CEC:

The AVSA fluid bed Combustor-Gasiffer Project

The Twente University of Technology project on hydrogen recovery.

2.6.1 The AVSA fluid bed Combustor-Gasifler Project (University of BrugseIs) In this project https://www.w3.org/1998/Math/MathML"> [ 16 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a double fluld bed gasifier has been developed with a simple but ingeneous system of solids circulation (see figure 7 ). To cira clmple but lingl https://www.w3.org/1998/Math/MathML">   t h e o u https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> transported from a fluid bed with a lower gas velocity (and therefore higher density) via a hole or slit to a fluid bed with a higher gas velocity (and density) via l hole or slit to a flutd bed with a higher gas velocity (and pressure on both sides of the holes. Both the gasifier and the combustor each consist of two beds geparated by a wall, one wth a relatively high the consist of two beds separated by a wall, one with a relatively high, the other with a relatively low gas velocity. Solids are transported from the bed with a high gas velocity to the bed with a low gas velocity by flowing over the top of the vall separating these two sections. Very high solids transport rates can be obtalned (up to https://www.w3.org/1998/Math/MathML"> 1000   k g / p e r m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> transport hole area). Also the Important problem of sufflciently large biomass solids circulation and segregation has been studied and solved. A pilot unit has been constructed, but up to now only the combustion section has been tested successfully. Present problems are the gas exchange rate between gasiffer and combuetor which fa to high https://www.w3.org/1998/Math/MathML"> ( 20 - 40 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and more development w111 be required to reduce this quantity. Another problem will certainly be the high hydrocarbon content of the product gas (as can be derfued from gmall goale expertments). For methanol production thts Important disadvantage but for many other applications it will often be acceptable, provided the tar content ls low. On the latter aspect, no reliable data are available yet. Char conversion can be relatively high in a double bed gasifler due to the combustion section but tar/char/ash dust mixtures entrained whth the product gas may still form a difflcult problem if a clean gas is desired. Nevertheless, the project forms an interesting addition to the CEC program, extending the value and belng complementary to the John Brown/Wellman and the Italenergie/AGIP projects. 10.1.1. The Twente University of Technology project on hydrogen recovery This profect https://www.w3.org/1998/Math/MathML"> [ 17 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> aims at the selective absorption of hydrogen at low partial pressures typical for low Joule producer gas obtained from simple atmospheric alr gasiflcation of wood. With slurries containing finely dispersed hydridible metals it is nossfble to recover the hydrogen continuously and get it avallable in a pure form at increased pressures. Because continuous processes to recover co already exist, 1t should be posslble this way to produce presgurlzed synthesis gas e.g. for methanol production from low Joule gases obtained from slmple air gasification. By steam shifting of all CO to https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tt https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> also possible to produce hydrogen only, which then could be CO to 14 it 2 for hydrogenation or htomass liquefaction. Presently, only small scale laboratory tests are available but they look quite promising. Also a continuous pilot plant (fig. 8) including the hydrogen absorber and desorber has been constructed and is being started up at this moment. Important development ttems are prevention of polsoning of the metal alloy slurry and possibly still increasing the volumetric absorption rate. The process could 143 Figure 8 Experimental hydrogen separation and recovery unit (Twente University of Technology)

U1lmann's Encyclopa'die der technischen Chemie, https://www.w3.org/1998/Math/MathML"> 4 t h E d ⋅ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Band 16 (1978)

H. Hiller, Co-production of methanol and higher alcohols for automotive uses, E. supp, European Methano1 Conf., Dec. 1984.

M.E. Frank, in: Proc. Intersoc. Energy Conversion Eng. Conf. 15th (2) (1980) 1567 .

D.M. Brown, in: ISCRE-8, The Inst. Chem. Engrs Symp. Ser. no 87 (1984) 699.

Call for tenders, Publikatie blad van de Europese Gemeenschappen https://www.w3.org/1998/Math/MathML"> N r C 18 / 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d.d. 27-1-1981.

W. Palz and G. Grassi (eds.), Energy from Biomass, Vol 2, Proceedings of the Workshop on Blomass PIlot Projects on Methanol Productlon and Algae, held 1n Brussels, 22 october 1981, Reide1, Dordrecht (1982).

Contribution of Creusot Loire (Framatome) to final project report (to be published).

Contribution of Lurgi GmbH to final project report (to be published).

P. Mehring, pers. communication.

Contribution of John Brown/Wellman to final project report (to be published).

Contribution of Italenergie/AGIP S.p.A. to final project report (to be published).

Contribution of University of Brussels to final project report (to be published).

Contribution of Twente University of Technology to finsl project report (to be published). E.-J. NYNS, M. DEMUYNCK and H. NAVEAU Unit of Bioengineering, University of Louvain, 1/9, Place Croix du Sud, P-1348 Louvain-la-Neuve, Relgium

11. Summary Bromethanation is an anaerobic biological energy-yielding and depolluting process by which organic matter (among which residues and wastewaters) is bioconverted in methane-rich biogas. Five hundred fif ty biogas plants have been identified in Europe and were scrutinized by a team of twelve experts. The results of this vast inquiry reveal that biomethanation is definitely a mature technology Yet its implementation cannot be called a success. Why is this paradox ? Biogas plants on family farms can be economical but seldom are so. Either the investment cost has been too high or satisfactory performances of the process could not be maintained over long periods of time. Biogas plants in agro-industries are just becoming well-established environmental biotechnologies. Landfills are more and more looked at as economically attractive sources of biogas. Biogas refineries, that is large-scale industrial biogas plants, are being seriously thought of. Biogas from energy crops remains of socio-economical interest. The latter five propositions are substantiated in the present paper. 12. INTRODUCTION Methanogenesis is a process by which a vast number of microbial species -up to 20 - organize themselves in a dominant and, hence, very stable microbial community and degrade almost any organic compound all the way down to methane, https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and inorganic carbon, namely carbon dioxide, https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which escapes with the methane as biogas, and hydrogenocarbonate, https://www.w3.org/1998/Math/MathML"> H O O 3 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which remains in the liquid effluent. The process of methanogenesis still rises a number of questions of great scientific interest but its understanding is nowadays largely sufficient to allow the process to be mastered in a reliable biotechnology (Winfrey (1), Daniels et al. (2)). A large variety of methane reactor designs, well appropriate to the methanogenic processes, are presently at hand to biomethanize almost any biomass substrate, whether a wastewater, a slurry or a solid residue in a reliable, performant and hence economically attractive way (Kirshop (3), Sahm (4), van den Berg (5)). Still, the implementation of biomethanation, a mature biotechnology, in Europe, in the industrial world as well as in the developing countries cannot yet be called a success. Why is this paradox ?

A SURVEY COMMISSIONED FOR THE DIRECTORATE GENERAL FOR SCIENCE, RESEARCH AND DEVELOPMENT (DG XII) OF THE COMMISSION OF THE EUROPEAN COMMUNITIES WITHIN THE FRAMEWORK OF ITS SOLAR ENERGY R AND D PROGRAMME

An assessment of "Biogas Plants in Europe" was realized between mid 1981 and early 1984 by a team of 12 experts. Each of them Identified, visited and scrutinized almost every methane digester existing in his home country, following a common format. By 1983 , a total of 546 methane digesters, were built in the European Community and in Switzerland. A synthesis of the survey has been published as a book intended to give guidance on the state-of-the-art and possible future developments (Demuynck et al. (6)). Individual results and national papers have been gathered in a three-volume compendium (Demuynck and Nyms (7)). For the economic analysis, The Financial Model Processor perfected as a processing tool by schepens was used. This model not only allows the calculation of the Simple Pay Back periods but also of the Net Present Values and the Internal Rates of Return. 13. BIOGAS PLANTS ON FAMILY FARMS By 1983,420 biogas plants, anong which 378 full-scale plants and 42 pilot-scale plants, were treating agricultural wastes. The total digestion working volume was https://www.w3.org/1998/Math/MathML"> 95000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Two hundred ninety one biogas plants were treating liquid or semi-solid wastes, mainly cattle and pig manure. Fourty five biogas plants were treating solid wastes, mainly manure with bedding. Seventy seven biogas plants were treating mixed agricultural wastes, mainly mixtures of manures. Biogas plants on farm can be economical, but this is seldom the case. There are two major reasons for this : too high an investment cost or too low performances. Among the 32 biogas plants for which enough data 'were available for a valuable economic analysis, only 6 were found profitable. Among these were 3 out the 5 Do-It-Yourself biogas plants. Their Simple Pay Back periods lie between 3 and 4 years and their Internal Rates of Return are higher than https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which in turn is higher than the capital cost of https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Although they have a low daily biogas production, below https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas per m of digester working volume, they are still profitable because their investment cost lie between 100 and 160 ECU per https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester working volume. Three biogas plants, constructed on a turn-key basis by companies, among which one includes an electricity generator, are profitable with Simple Pay Back periods of 5 to 6 years and Internal Rates of Return higher than https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . An average complete biogas plant on farm includes the methane digester itself, the system of gas storage and utilization and the system of influent and effluent storage and/or treatment, if any. The methane digester itself is of the continuous, completely-mixed type without recycle. The threshold value of the investment cost for a complete biogas plant on farm for profitability was found to lie between 400 and https://www.w3.org/1998/Math/MathML"> 450 E C U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (value 1983) per m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> working volume of the methane digester. When the investment costs were analyzed as a function of the scale of the methane digester, it appeared that the price per https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester working volume decreased with increasing scale, up to https://www.w3.org/1998/Math/MathML"> 100   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , when the investment cost per https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> became more or less stable. Whenever the investment cost is too high, nothing can be done afterwards to cure the problem. For profitability, the performance of an average biogas plant on farm must be at least equal to https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas, containing 1/2 to https://www.w3.org/1998/Math/MathML"> 2 / 3 m e - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> thane, per https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester working volume and per day. This performance must be maintained over most of the year. As a general result from the survey, it appears that each existing biogas plant on farm has suffered during its present lifetime an average of 2 major and 4 minor problems. Major problems result in the temporary shut down of the biogas plant. Major problems were encountered as well with the loading device (mainly failure of the feedstock pump) as with the methane digester itself (mainly gas leakage, insufficient mixing or heat transfer) as with the gas collection storage and utilization (mainly with the biogas compressor, the engine running on biogas, and the waste heat recovery sys tem). Major problems were not only encountered with the equipment but also with the operation of biogas plants. Upstream of the methane digester, settlement during storage, foreign water entry and scum formation, blockage of loading pipes and operational problems with heating of feed, during digestion, settlement in the reactor and scum formation were among the principal causes of failure. Gas metering was an often encountered major problem. A wide variety of other phenomena caused major problems in few cases and numerous minor problems. These problems were mainly encountered during the two first years of operation of a biogas plant. Quite often, the treshold of performance was reached thereafter, so that the present impression of lack of profitability must be taken with a grain of salt. Why do these two reasons apply so of ten ? First, many is not most existing methane digesters are each the first one if not the only one constructed by either its owner or a small entreprise. The know-how of methane digestor construction and operation exists but is not well widespread. In as much that the same basic errors have been made over and over again. Secondly, methane digesters are often poorly integrated in the farm : not enough agricultural waste upstream, ill-studied end-uses for the produced biogas. As a consequence, the implementation of new biogas plants on farm presently suffers from adverse publicity by owners of existing biogas plants. 14. BTOGAS PLANTS IN AGRO-INDUSTRIES OR IN VERY LARGE ANIMAL BREEDING By 1983,89 biogas plants, among which 69 full-scale plants and 20 pilot-scale plants were treating industrial wastes or wastewaters. The total digestion working volume was https://www.w3.org/1998/Math/MathML"> 174000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Twenty one different types of industrial wastewaters and 2 different types of industrial wastes served as substrate biomass or load for biomethanation in industry. Most wastes originated from agro-industries although a few wastewaters originated from the leather, wooden plates or paper industries. Continuous, completely-mixed systems were only used for the bionethanation of animal manures from large scale animal breeding units. Upflow anaerobic sludge beds and fixed-film systems competed as mature full-scale biotechnologies. Fluidized beds exist as experimental fullscale plants. The investment cost for an industrial biogas plant per https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas produced was about the same as that for a biogas plant on farm. Its performance is however 1 to 5 times better. Its investment cost per https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> working volume appears therefore larger than that of a biogas plant on farm. However, the cost of the methane reactor itself in an agricultural biogas plant amounts usually to around 30 to https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the overall cost. The cost of the methane reactor itself in an industrial biogas plant amounts usually to around https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the overall cost. The reason for this difference is that industrial requirements for efficiency and reliability are more severe and, hence, require extra-ancillary equipment. Often also up. Besides energy production which is still a too often neglected end-use, pollution control is the major target. The fringe benefit of depollution is more evident for industrial biogas plants than for biogas plants on family farms. A few constructors possess sufficient know-how to warrant safe investment cost and reliability of the biogas plant. As a result of all this, the anaerobic biological wastewater treatment has become quite competitive with aerobic biological wastewater treatment. Both technologies appear equal in the two following aspects : mean hydraulic residence times, θ H, which even tend to become lower in anaerobic systems (less than 1 day down to a few hours), and cost for the maintenance of the equipment (a yearly average of https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the investment cost). Anaerobic wastewater treatment systems offer the following advantages over aerobic systems : lower investment cost and lower production of excess sludge which is furthermore already stabilized. Aerobic wastewater treatment systems offer the following advantages over anaerobic systems : better performances (conversion, N-treatment), larger array of applications (including cold and low-strength wastewaters) and a still better-reputed reliability with time. Aerobic wastewater treatment is energy-costly : https://www.w3.org/1998/Math/MathML"> ± 1.8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> electric https://www.w3.org/1998/Math/MathML"> M J k g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> removed cop. Anaerobic wastewater treatment is energy-yielding : https://www.w3.org/1998/Math/MathML"> + 12 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> thermal https://www.w3.org/1998/Math/MathML"> M J k g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> removed COD. Safely constructed, well managed existing industrial biogas plants offer positive support for new industrial decision making. Industrialists and certainly agro-industrialists, as well as Water Authorities must nowadays at least take into consideration both anaerobic and aerobic treatment systems on a comparative basis when seaking a solution leading to environmental control. 15. EXTRACTION OF BIOGAS FROM LANDFILLS Domestic waste represents a permanent source of organic matter of the order of magnitude of https://www.w3.org/1998/Math/MathML"> 0.5 - 1   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per inhabitant per day. Individual landfills, where millions of tons of domestic waste are disposed off, are natural biogas plants from which vast quantities of biogas may or might be extracted over long periods of time. 1 ton of domestic waste, as it comes, can produce 5 to https://www.w3.org/1998/Math/MathML"> 10   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas per year during 10 to 20 years. Hence, an average landfill of 10 million tons domestic refuse will produce yearly between 50 to 100 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas which is equivalent to 800 to 1600 trucks of 25 tons of fuel each year. Whereas 2 sites only, where biogas was being extracted, were identified in Europe in 1980,36 sites were identified in 1983 and this number is expected to grow rapidly. In as much that the commission of the European cormunities intends to undertake a special inquiry to update the know-how and know-where of landfills for biogas extraction. Spreading of biogas extraction from domestic wastes will thus most probably follow up the spreading of industrial biogas plants as a second successfull wave. The following technical developments may be expected in the 5-10 year term : improvement of technologies for biogas collection, organisation of new landfills specially for biogas collection, namely recovery of the leachate and its treatment in a separate biogas plant. But some industrialists are already thinking in terms of biogas refineries where domestic waste would be industrially treated by advanced biogas plants. Reliable continuous reactors made to handle solid biomass substrates remain the present bottleneck. 16. BIOMETHANATION OF ENERGY CROPS The growth and harvest of energy crops as a potential biomass substrate for biogas production remains at present in the R and D state at least in Europe. When energy production is the sole output, the process is not economically attractive. But, when besides, depollution becomes a major target, as is the case in the lagoon of Venice, or when the digested mixed liquor can be valorized for agricultural use because of its fertilizer value or its compost-like properties, as was planned in the Lamezia project (Asinari et al., (8)), the process may become of socioeconomical interest. Further development could be promoted if energy crops were to replace excess food crops and financial aids for the latter used as incentives for the former. 17. THE WAY AHEAD First and foremost, a European network of selected biogas plants should be monitored and made to contribute to a substantial popularization effort of biomethanation to create on farms and develop in indus tries, a confident market. Basic research should aim at improved performances on a larger array of substrate compounds and provide energy yielding molecules other than methane. Research on engineering should aim at cheaper, more reliable, as well as second-generation, highly perfor mant methane digesters. Appropriate integration of biogas plants on farms remains a major target. Upgrading of side-products will add fringe profits. Adequate legislation as regard safety as well as sales practices, should help implementation. This is the message on which the 12 experts of the CEC inquiry on "Biogas Plants in Europe" unanimously agreed. 18. REFERENCES (1) WINFREY, M.R. https://www.w3.org/1998/Math/MathML"> ( 1984 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Microbial production of methane. In "Petroleum Microblology" (R.M. ATLAS, ed.) McMillan, New York, https://www.w3.org/1998/Math/MathML"> N . Y . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 153-219. (2) DANIELS, L., SPARLING, R. and DENNIS SPROTT, G. (1984). The bioenergetics of methanogenesis. Biochim. Biophys. Acta 768 , 113-163. (3) KIRSOP, B.H. (1984). Methanogenesis. CRC Crit. Rev. Biotech. 1 (2), 109∼159. (4) SAHM, H. (1984). Anaerobic wastewater treatment. Adv. Biochem. Engin. Biotech. 29,83-115. (5) van den BERG, L. (1984). Developments in methanogenesis from industrial wastewater. Can. J. Microbiol., 30,975-990. (6) DEMUYNCK, M., NYNS, E.-J. and PALZ, W. (1984). "Biogas Plants in Europe : A Practical Handbook". Reidel Publ. Co., Dordrecht, Neth. (7) DEMUNCK, M. and NYNS, E.-J. (1984). Biogas Plants in Europe. Compendium of Original Formats and National Papers. Vol. 1. F.R. Germany, Dermark and Netherlands. Vol. 2. United Kingdom, Ireland, Belgium and Switzerland. Vol. 3. France, Italy and Greece. Publ. EUR 9096 of the CEC. To be obtained from the authors at their affiliation. (8) ASINARI dI SAN MARZANO, C.-M., LEGROS, A., NAVEAU, H.P. and NYNS, E.-J. (1983). Biomethanation of the marine algae Tetraselmis. Int. J. Solar Energy 1, 263-272. (In collaboration with R. MATERASSI, Firenze, Italy). 19. Abstract Sweden, where the climate favours cereal production, has a steadily Increasing grain surplus. At the same time the country is an lmporter of proteln feeds as well as of all petroleum products. Along with the national schemes for cenewable energy resources, the Swedish Farmers' Coop has built the first fuel alcohol plant utllizing excess grain. The 20 o00 1/day plant was commissioned in late 1983 in the county of Skaraborg and demonstrates, at Swedish conditions, the feaslbllity for ethanol blended gasol1ne and coproduced high protein antmal feed. The Skaraborg plant ls based on a truly continuous fermentation process, which allows the use of concentrated feedstocks and avolds the effluent problem. Commercial Biostil plants, using molasses and concentrated cane fulce, are already https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> operation ln e.g. Brazll. The application of the process to gralns Involved the solution of challenging separation problems as well as the thermal integration of the distillation and animal feed drying sections of the plant. The technical conslderations are discussed together with the economical aspects of fuel alcohol production. 20. INTRODUCTION Sweden has a fertlie soll and a fatr climate which favour cereal production. The highly rationalized agriculture glves steadily larger crops and an 1ncreasing grain surplus. Most of tt is currently exported to the world market, although at prices lower than those guaranteed to the Swedlsh farmers. Having no mineral oll resources Sweden lmports all lts petroleum products. The country is also a net 1 mporter of proteln feeds. Along with several other national schemes alming to find efficient use of renewable energy resources, the Swedish Farmers" Coop bullt the flrst fuel alcohol plant which utilizes excess gralns tn 1983. The skaraborg plant produces 20 ooo l/day of anhydrous alcohol from feed grade wheat. The alcohol ls marketed as a https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gasoltne blend. Coproducts are protein-rich feed of unusualiy high quality, bran and carbondioxide. The anlmal feed https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> used by the Farmers https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Coop in the cattle feed mix where it partly replaces imported soy proteln. The con is liquefied and used in the beverage industry. The skaraborg plant is based on a truly continuous fermentation system. In this unique system, using the Biostil concept, the fermenter is fully integrated with the primary distlilation, which leads to signiflcantly reduced effluent volumes. Furthermore the problems with bacterial Infections, which often plague continuous fermentation systems, are avolded. The process was initially developed for clean substrates. Two plants are in operation on cane and beet molasses and four more plants are scheduled to come on stream in 1985. 21. PLANT DESIGN Apart from the application of the process to grain feestocks, the Skaraborg plant has demonstrated a number of other "firsts". The plant is first to apply yeast recycle to a continuous whole grain mash fermentation and to utilise part of the disltilation heat to dry the anlmal feed product. The stillage dryer was destgned to work at a low temperature level to ensure good digestibility of the dried protein-rich feed. A basic feature of the fermentation concept is the ability to accept very concentrated feedstocks, which is explotted also in the applicatton to grains. In the Skaraborg plant, every ton of wheat processed requires only 0.5 ton of process water. This dramatic reduction https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> process water requirement permits the recovery of a dried animal feed product in a very simple process which avolds the need for separation and evaporation of a grain solubles fraction. The plant produces no llquid effluents. Typical product pattern from Swedish wheat is shown below: https://www.w3.org/1998/Math/MathML"> 2.8   k g   wheat   ⟶   ⟶ 0.8   k g   CO     ⟶ 11   Ethano   199.8 %   wt     ⟶ 0.3   k g   bran     ⟶ 0.8   k g   protein-rich feed   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 22. PROCESS SECTIONS The baslc process sectlons are illustrated in flg. I. The fermentation section is a key feature of the skaraborg plant and it influences the deslgn of all the other process sections. In mid l984 the plant was extended with a process 11ne for A-starch recovery. The effluent from the starch line is routed to the fermentation section. 23. Fermentation Contrary to clear substrates, 1t was soon reallzed that whole-grain feedstocks would require considerable mod1fication of the basic Biostil concept tn order to be able to handle the ingoluble fraction of grafne A flrst approach was to separate the lnsolubles from the saccharlfied feedstock prior to fermentation. However, the cost of making such a separation was prohtbitive if excessive sugar losses were to be avolded. The finally accepted solutlon was to separate flbre and proteln within the recycle 1oop. Such an approach has two slgnigicant advantages.

Viscosity after fermentation is relatively low, thereby facilitating separation.

The fermenter llquld contalns only resldual sugar concentrations which eliminates significant sugar losses. The practical implementation of the flbre and proteln separation is lilustrated in flgure 2. Unlike in the clear substrate substrate system, the stream leaving the fermenter cannot be pumped straight to the yeast centrifuge. The flbre is flrst separated on a bent sleve and the flbre-free phase transferred to the centrifuge, where yeast https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> separated and recycled to the fermenter. The fibre phase is further washed in a rotating steve to remove residual. yeast, which is subsequently recycled to the fermenter. The stream entering the yeast centrifuge contains both yeast and grain proteins and it is essentlal that a separation be made between these two components if an execcive bulld up of protein in the fermenter is to be avolded. Fortunately, yeast is slightly more dense than grain proteln and, uder the steady state conditions prevailing ln the process, it is possible to separate more than https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the yeast togehter with only a small amount of grain protein. The bulk of the grain protein leaves the separator in the light phase and is transferred to the mash colum. The protelns leave the system as a component of the stlllage. The slngle fermenter works at constant conditions chosen as to glve optimum operation. Since all condıtions are steady the operation is easy to control. The fermenter temperature is kept at https://www.w3.org/1998/Math/MathML"> 32 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and pH at 4.5. The alcohol content is https://www.w3.org/1998/Math/MathML"> 6.5 - 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> voland the residual sugar level around 0.1 % wt. The concentration of vital yeast cells in the fermenter is around 300 A remarkable feature of the Blostil fermentation system is that it sldesteps the otherwise common problems of bacterial infectlon. Thls experience from operatlon of molasses and cane fulce plants located in tropical countries, has been reaffirmed in the skaraborg grain plant. The fermentation was inoculated with a yeast slurry in November-83 and no new inoculation has been required due to infections since then, despite a number of routine production stops and holiday shut downs. This microblologlcal stab111ty does not mean that bacteria do not grow 1n a Biost11 fermenter, but to balance this bacterial growth the recycle of the fermenter liquid through the primary distl11ation column ensures a very effective destruction of bactertal cells. At equillbrium only very low levels of bacteria are present in the fermenter. The Iow pH and low sugar concentration in the fermenter also help to suppress bacterial growth. m1111ons per mI. 1. Miling and starch conversion The short residence time in the fermenter requires that the starch be saccharified prior to fermentation, as 111 ustrated in fig. 2. The dry milled wheat, from which a certain amount of bran has been separated, https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mixed with weak beer, process water and enzymes to efect starch 11quefaction at around https://www.w3.org/1998/Math/MathML"> 90 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . After flash cooling the https://www.w3.org/1998/Math/MathML"> 11 quefied https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> substrate is saccharified using glucoamylase enzyme. 2. Distillation The distillation system is destgned to produce anhydrous industrial alcoholof min https://www.w3.org/1998/Math/MathML"> 99.8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wt quallty. Distillation is achieved in four columns: mash column, rectlfication column, dehydratlon column and a regeneration column, which recovers the cyclohexane entrainer. Efficient use of energy is achleved by operating the rectiffer under elevated pressure and condensing the rectlfied vapour in the reboller of the mash column. Subsequently the top vapours from the mash column provlde the reboll heat for the dehydration column. The mash column is split lnto two sections, as 1s typlcal of the Blostl1 system. Stillage leaving the mash column has a very high dry sollds concentration, usually above https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and ls transferred to the drying section without dewatering. A significant proportion of the heat utilized in distillation is recovered and used for drying the pelleted stillage. 3. Stillage Drying In Sweden, the price obtalned for the DDG depends upon its nutritional quality. A stillage drylng system was developed for the skaraborg plant to utilize very gentle conditlons (fig. 3). The pelleted product, containlng 35 percent molsture, is dried against https://www.w3.org/1998/Math/MathML"> 70 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> alr in a two stage grain dryer. The molsture content of the wet pellets is adjusted by recycling milled dried pellets and mixing this dry material with stillage from the mash column prior to pelleting. After some lnitial trimming of the dryer conditlons, the dried anlmal feed product (of https://www.w3.org/1998/Math/MathML"> 85 - 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DS) demonstrates a very high digestibility, as indicated by a pepsine solubllity in exess of https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The protein content is usually https://www.w3.org/1998/Math/MathML"> 35 - 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wt (on DS). 4. OPERATING EXPERIENCE Preceeded by extensive pllot plant work the Skaraborg plant was brought on stream, despite the many novel features, with only minor adjustments. During this first year of operation the plant has proven the realiablitty of the process but, more important, lt has demonstrated the feaslbllity to utillae all products obtalned from surplus wheat. Some operating data: In fermentation the ethanol yields are https://www.w3.org/1998/Math/MathML"> 92 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of theoretical (G.L.). Despite the relatively sma11 capacity of the plant, which did not justify maximum energy savings, the stean consumption of the entire plant lncluding dryer ls https://www.w3.org/1998/Math/MathML"> 3.7   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per litre of anhydrous ethanol. 5. ETHANOL AS FUEL Fig 1. Skaraborg plant process sections Fig 2. Biostil section Fig 3. Skaraborg stillage dryer Fig 4. Economics for ethanol production from wheat USE OF ALGAL SYSTEMS AS A SOURCE OF FUEL AND CHEMICALS 6. SUMMARY Micro-and macroalgal systems are examined for their direct uses or upon chemical transformations as a sources of power, food, and chemicals in diverse anthropic, farming, and industrial activities. 7. ALGAL SYSTEMS Algal systems, which are present on the planet in staggering amounts with rapid reproduction features, may play an important role in the fields of energy (in the broad meaning, stich as fuels and foods) and of chemicals(chemical elements collected from the environment and collected or synthesized compounds). This stems also from the realization that many non-renewable energy and mater resources of the planet are progressively and rapidly dwindling and the human population is increasing exponentialiy together with its living standard, which require a carefully planned environment management. As is known, algal systems are made up by autotrophic organisms belon ging to thallophyta cryptogams. Algae vary widely in size and structure They may be either microscopic or tens of meters long with mono- or pluricellular structure. They may grow in either fresh or salty water, on rocks, on humid soil or tree bark either alone or in symbiosis with other organi https://www.w3.org/1998/Math/MathML"> 3   m s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Algae are coated by a cell membrane that generally contains mucilage, si licic, or calcareors substances The plastids contain chlorophyll and often other pigments (chlorophyll, phycoerithrine, phycoyanine, phycophaeine, xanthophyl1)wich allow algae to develop and grow by photosynthesis under different environmental illumination conditions. Reproduction occurs by scission in monocellular algae by theans of spo res in polycellmlar algae. The main limiting factors of algal growth in sufficiently deep water are temperature, presence of nutrients, low content of poisonous substances, and 1i.ght availability . In the lower part of macroalgal colonies in deep waters light is drastically reduced, causing the system to cease growing in thickness so that sta tionary conditions are reached. When part of the material is removed from such colonies, its replenishment at the stationary level is iapid. Whereas in open water algal systems keep on growing, in lagoon, lake, or river basins, the size of the system reaches a limiting value which varies With seasonal conditions. For example, the Venice Lagoon system (550 square km ) has a stationary presence of wet macroalgae (ulva lactuga, ulva ri - gida, gracilaria confervoides, chetomorpha aerea, valonia agropila) of ca. million tons in warm months and of 0.5 million tons in cold months. When al gal collection is carried out in such a basin in warm months (April-September), the material is regenerated in abott 3-5 days. Therefore, by partial collection (about 3/4 of the algae present, in order to mantein the original algal productivity) programmed at 3-5 day intervals, a total availabi lity of ca. 68 million tons might be effected in 6 months, which is about 34 times the residing stationary amount. Algal systems in water basins are generally able to extract and concentrate substances from the waters, so that they can exert remarkable purifying action as far as pollution is concerned. Mono- and polycellular algae make up phytoplankton and are the first step of food chain in natural or artificial reproduction (aquiculture) of fish, crustacea, and mollus ca. Some algae are used in the production of feeding mixtures and also in hu man feeding, especially those rich in hígh-value proteins. The aerobic fermentation of algal biomass yields biogas as a fuel, which is one of the topics of this symposium. Some particular algae yield chemi cals, whereas díatomaceots earth is extracted from fossil siliceous algae deposits converted into rocks. Deposits of microalgae are the source of organic substances from which oil and natural gas were developed in ages. In symbiotic associations between algae and fungi (lichens) algae provide a photosynthetic biomass for the fungus, which in turn collects by its hyphae the water and mineral salts making them avajlable also for the alga. Lichens grow on tree bark and rocks. They are quite common in alpine and ar ctic regions (steppes, tundras, northern sea coasts). They can also thrive in place where life would be impossible for both algae and fungi. alone. They survive in extremely low temperature and play a major role in the formation of farming soil since they crush rocks by their excretion productus and lea ve organic debris for the settling of other plants. Some lichens also yield chemicals of industrial interest. 8. FUEL FROM ALGAL SYSTEMS 2.1. INTRODUCTION - The energy crisis has shorn the opportunity to use renewable energy sotrces as an alterative to non-renewable ones, such as fos sil and fissile fuels which are dramatically dwindling. Such renewable energy sources are essentially related to solar energy flux, geothermal energy and to the mechanical energy flux (tides) dive to the gravitational attrac tion of other heavenly bodies. As for the solar energy flux, an important ro le is related to the photosynthetic production of biomass. Any energy source is exploitable if it meets the requirement that the energy expenditure for extraction and use is lower than the energy produced. Algal systems of water basins appear to satisfy this requirement since the material is located at the surface and easily collected and there are several means of tapping the energy stored in then. 2.2. COMBUSTION OF ALGAE - Microalgae are not usually emp1oyed for combustion, due to the large amounts of water they contain, the difficult collection, and the other better uses that they lend themselves to. Combustion of macroalgae requires their prior drying which is easy to carry out,due to the state of this biomass, but which is energy constuming. Drying can be carried out from June to September under sunlight on soils that are not used for farming in such period. The dried material is fit for combustion even in pul verized form, but further experimenting is in order. 2.3. THERMAL TREATMENT OF ALGAE - Microalgae are not used in this fields for mich the same reasons detailed under 2.2 Thermal treatments of macrofor much the same reasoths detailed under https://www.w3.org/1998/Math/MathML"> 2.2 .   T h e r m a l   t r e a t m e n t s   o f   m a c r o https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bons and derivatives ), and gaseous fuels (hydrocarbons and derivatives),be sides chemicals of interest as such, related under 4 Macroalgal biomasses previously dried, can be "pyrolyzed", that is, thermally "decomposed" in the absence of air in a proper reactor heated by combustion of part of gaseous products. Alternatively, algae can be subjected to "gassification"by heating with a limited amount of air, or better, oxygen, with formation of the gaseous fuel carbon monoxide. If the biomass is only partially dried, the water also takes part in the reacting system to yield large amounts of hydrogen, another gaseous fuel. Both pyrolysis and gassification are still under experimental study at CSARE-Venice. 2.4. BIOGAS FROM ALGAL BIOMASS - Production of biogas (methane and carbon dioxide) from algal biomass by anaerobic fermentation in aqueous me dium has been the subjest of intensive study in some countries under both mesophilic and thermophilic conditions. The fermentation take place in two consecutive stages: methanogenic and acidic. The main studies in Italy, mostly supported by cee funding, are the folLowing. a) Mi.croalgae: at the Autotrophic Microorganism Center-C.N.R. University of Florence (prof. G.Florenzano) in collaboration with the Biophysics Dept., Technical University, Aachen (prof K. Wagener) and with the Unite de Geñie Biologique, Louvain (prof.E.T.Nyns and H. Naveau). These studies are being carried out at Lamezia Terme (Southern Italy), using the microalga tetraselmis in see water in shallow basins located along the coast 1 ine and having a high growth rate (doubling of biomass in ca. 2 days) Microalgae are separated from the liquid phase and subjected to anaerobic mesophilic fermentation to yield biogas. b) Macroalgae: at CSARE-Venice, in collaboration with AGIP NUCIEARE (ENI) and at C.T, Padua in collaboration with ISTITUTO CTR-C.N.R.- Padua. The macroalgae ulva, gracilaria and valonia are collected from the venice lagoon basin by means of appropriate boats and subjected to anaerobic mesophilic fermentation. It is noteworthy that biogas production does not entail energy expense for biomass drying since fermentation requires the presence of water anyway and the biogas separates out spontaneously through physical phase change. Anaerobic biomass fermentation also produces small amounts of hydrogen sul - fide in the biogas due to the presence of sulfur-containing proteins in the algae and to reduction of sulfates present in the algae through transfer from sea water. CSARE and C.T. studies have defined the separation conditions from the biogas of methane, carbon dioxide and hydrogen sulfide to yield a better Euel (pure methane). A remarkable advance in anaerobic fermentation technology has been achie ved by grinding and pressing the macroalgal biomass, collecting and filte ring the pressing liquid and percolating it on anaerobic fermentation bacte tial colonies immobilized on solid bodies. Owing to the homogeneous features of the liquid material to be fermented and to the higher concentration of bacteria, the kinetics is ca. 25 times faster than when operating on wet macroalgae as such.This entails the notable benefit that size and cost of the plant are reduced by ca. 25 times, other things being equal. This technology has been applied jointly by CSARE and AGIP NUCLEARE to ul va and by C.T. to valonia. Abstract As for the use of methane on biogas as an energy source, its combustion can yield thermal energy, electric power, or a mixed power production, depending on energy use demands. In Italy the use of power plants ifoTEM" using a FIAT 127 car engine have proven quite satisfactory. 3. FOODS FROM ALGAL SYSTEMS

MICROALGAE AS FOOD FOR ZOOPLANKTON AND AQULCULTURE LARVAE - Reproduc tion and raising of fish, mollusca and crustacea is known to start up with the animals larvae which require microalgae-based food, i. phytoplank ton (e.g. artemia salina), followed by subsequent feeding on mícrofauna (e. g. rotifers), to end up in the adult stage with macroflora and macrofauna or artificial feeding. In natural water basins phytoplankton reproduces and grows in fertilized environments, like all autotrophic plants. Zooplankton, on the contrary, being etherotrophic, reproduces and grows by feeding on phy toplankton or on other zooplankton. Finally, for the initial stage in fish, crustacea and mollusca aquiculture, the larval plankton food is produced in appropriate phytoplankton rearings in fertilized and lightened waters: part of this phytoplankton is also used to produce and feed the zooplankton necessary as the subsequent plankton food. This technology is now widely applied in many countries such as Italy.

Abstract 3.2. MICROALGAE FOR HUMAN FEEDING - Some microalgae are particulariy sui ted for human feeding due to their high growth rate and chemical composiz tion. Worthy of mention is spirulina, which grows in waters rich in alkali carbonates that yield most of the carbon dioxide for photosynthesis. Its protein content is quite high (up to https://www.w3.org/1998/Math/MathML"> 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). This alga is present in lake Ciad, Africa, and in salty lakes of Mexico, where it has represented in remote ti mes and still partly represents today the main food through the preparation of pies for those poor populations. Studies on the cultivation of such algae in artificial water basins rich in alkali carbonates are being carried out in Italy in warm months at the Autotrophic Center-C.N.R. University of of Florence (prof. G. Florenzano) https://www.w3.org/1998/Math/MathML">   L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Other microalgae used are Chlorellae. 3.3. MACROALGAE FOR ANIMAL AND HUMAN FEEDING - Particular macroaIgae are used for animal and even human feeding. These studies in various countries are still in progress, especially as far as ease of digestion and salt conLent of algal biomass from sea water are concerned. The ease of digestion is favoured by the almost total absence of lignin. As for salt content, the use of algae for goat feeding appears promising. Macroalgae are food for fish (e.g. herbivorous carp). Lichens are the only wintertime food for arctic animals (reindeer). The use of macroslgae in natural basins as food pluays entaila the riok of the presence of poisonous pollutants (heavy metals) of industrial, farming or urban origin, so that sanitary control of the material is needed. 9. CHEMICALS FROM ALGAL SYSTEMS 4.1 PROTEINS, POLYPEPTIDES AND AMINOACIDS FROM MICROALGAE - Spirulina, a 1 reasy mentioned under 3.2, is a source of proteic material that yields proteins, polypeptides and aminoacids. 4.2. FOSSIL MATERIALS FROM MICROALGAE - The formation in remote ages of huge deposits of dead mono- and polyce https://www.w3.org/1998/Math/MathML"> 11 u 1 ar https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> microalgae forming the phytoplankton together with dead zooplankton, trapped in layers of inorganic se- diments, has provided the biomass which originated oil and natural gas by ingphthogenes ictur The dead monocellular microalgae diatomeae, present in all the planet's waters and having a siliceous membrane forming a rigid shell, upon sedimen https://www.w3.org/1998/Math/MathML">   W a t e r s   a n d   h a v i n g   a   s i l i c e o u s   m e m b r a n e   f o r m i n g   a   r i g i d a r i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which have evolved into a very porous, light, pale yellow sedimentary rock which has several industrial applications. As a dust it is used as a light abrasive; it is employed in the manufacturing of dynamite by soaking with the explosive liquid nitroglycerine in order to decrease mechanical sensiti vity to shock explosion. It is also used in the manufacture of refractory brick. Another material akin to fossil flour is tripoli, made up by cell walls of diatomeae and radiolaria. Owing obviously to their long genesis, these materials are all classified as non-renewable. 4.3. CHEMICALS FROM ALGAE - Macroalgae, on account of their ability to absorb many water-dissolved materials, will extract some chemical elements, often in a highly selective fashion. An industrial exploitation is represen ted by the extraction of iodine from sea water by some macroalgae, the ashes of which, commercially named"kelp"or" varec" contain potassium iodide from which iodine is extracted chemícally. Various metal elements in waters are trapped onto algae. In general, howe ver, their concentration in algal biomass is only scanty (at ppm level) and cannot exploited for industrıal purposes. In contrast, noteworthy is the use of algae in purifyring processes involving polluted waters. 4.4. MUCTT ACE CHEMTCATS FROM MACROATGAE - Some sea macroaloae are used to produce agar-agar. In Ireland gelidium is employed, whereas gracilaria is used in Italy. In particular, the Venice lagoon yields large amounts of gracilaria. Agar-agar is a polymer of galactose, soluble in warm water, which is used to prepare gels, drug excipients, laxatives and bacterial culture me dia. Furcellaran, akin to agar-agar, is extracted from algae in Denmark. Chondrus crispus, which grows along the Northern Atlantic coast lines, yields carragenine, a polysaccharid produced in France and Britain, which is used in food industry. Laminaria, ascophyllum and fucaloides of Ireland and Britain (the former two also in France) yield alginates, salts of alginic acid, whích are used in food, paper, fiber, dye, ink, cosmetic, and paint industry. 4.5. CHEMICALS FOR DYE INDUSTRY FROM MACROALGAE - Purple and carmine are extracted from the lichen rochilla tintoria. 4.6. CHEMICALS FOR PERFUME INDUSTRY FROM MACROALGAE - Everna furfuracea, ramalina calicaris and fulmonaria sticta yield oaken mus, which is used in perfumery as essence or as a fixer for other perfumes. 4.7. LABORATORY CHEMICALS FROM MACROALGAE - The lichens lecanora and variolaria yield litmus, a pH indicator. 4.8. CHEMICALS FOR AGRICULTURE FROM MACROALGAE - Macroalgae can be used as farming soil fertilizers. Furthermore, wet algae, mixed with biological sludges from water purifica tion or algae biogas production, and subjected to aerobic fermentation yield humus of which farming soils are lacking. SESSION III IMPLEMENTATION L.E.B.E.N. - Large European Bioenergy Project, Abruzzo, Italy G. Grassi, U. Miranda, C. Baldel1i and F, Gheri The Production and Use of Fue1 Alcohol in Zimbabwe - C. M. Wenman Canada's Energy from the Forest Programme - R. P. Overend Integrated Food-Energy Production Systems - E. L. La Rovere The Use of Wastes as a Source of Energy in the U.K. - R. Price The Southern U.S. Biomass Energy Programs with Emphasis on Florida - W. H. Smith Biomass Energy Utilisation and its Technologies in China Rural Areas - W.Wu G. Grass1, U. Miranda, Commission of the European Communities (DG's XIL and I respectively), Brussels, Belglum C. Baldelli, Cassa per 1l Mezzogiorno, Roma, Italy F. Gheri, Regione Abruzzo, Pescara, Italy 10. SUMMARY Present concepts of optimized b1o-energy schemes represent a new field of integrated activities which open perspectives of such large dimensions, not only for Europe, which justify the intensive world-wide R&D and demonstration programmes actually being carried out. Large blo-energy schemes can give a substantial contribution to general reglonal development, especially for the more disadvantaged internal agricultural districts, through the upgrading of properly converted non-explofted resources (resldues, wastes, biomass from marginal land and eventual agricultural surpluses). The multi-disclplinary aspect of this type of project will glve vast opportunities for new jobs in rural communities. The LEBEN project, already https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the prellminary phase of lmplementation In the Abruzzo Region of Italy, wIll be the first large European BIo-energy prolect. This profect is based on the exploftation of about 450.000 t/year of biomass. It will utl1ize a divers1fled harvesting, collection and chlpping system, a network of dispersed pyrolytic conversion units and an ethanol factory https://www.w3.org/1998/Math/MathML"> ( 150 - 200 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> t/day). The pyrolytic products will be fired in the Avezzano power station (27 MWe). Waste heat will be recovered for alcohol distillation and for heating greenhouses (20 ha). A laboratory unit for the "in-vitro" fast reproduction of plants will supply greenhouses with the plants needed for the reglonal energy crop programme and for other particular forestation programmes. An educational, training and maintenance centre for about 200 young people per year will be operational in 1986. A second sector of activity will be production of electricity by the construction of 12 small hydro-electrlc power statıons for a total installed power of https://www.w3.org/1998/Math/MathML"> 22 M W . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A third sector of activity w111 be the exploitation of a group of agro-industries for processing local products. The LEBEN project will be technically supervized jointly by the Commission of the European Communities (DG XII and DG XVII in cooperation with DG V, DG XI and DG XVI), the Italian Authority for the development of South Italy (CASMEZ), the Abruzzo Regional Authority, and the Organization for the agricultural development of the Abruzzo Region (E.R.S.A.). It Is cons1dered of great strateglc lmportance for demongtrating, for Europe and other countrles in a similar situation : - the economic feaslbility of energy-orlented Innovative and complete blomass schemes;

the high socio-economic impact and benefit resulting from the wide penetration of pyrolysis conversion processes and alcohol conversion processes, eventually in combination with the new concept of energy

The total budget foreseen for the 1mplementation of the LEBEN project is approximately https://www.w3.org/1998/Math/MathML"> 230   m 1111 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on ECU https://www.w3.org/1998/Math/MathML"> ; 120   m 111 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on ECU* https://www.w3.org/1998/Math/MathML"> ( 52 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total) ts needed for the bio-energy activitles. Completion is scheduled for 5 years https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> time. 11. INTRODUCTION At the Commission of the European Communtties, after eight years of exploratory Research and Development activities (as significant as the pllot- projects and the demonstration programmes of DG XII and DG XVII), it is cons1dered that the modest technical risk, stlla present in some areas of biomass prodtiction, harvesting and conversion, now allows for the lmplementation of large bio-energy (or "agro-energy") schemes, which are absolutely necessary to demonstrate the full potential interest of exploiting the large amount of blomass available in many countries https://www.w3.org/1998/Math/MathML"> ( 85 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million t.o.e./year of net energy for the Communlty in the year 2000). Only In this way, we shall be able to prove the validity of the strategic European blomass isstes, which are outlined below :

technical and economical vlabllıty for the massive, fast and rapl.d thermochemical conversion of agricultural and forestry wastes into fuel products (for local heat and electricity production), especially for the Inland districts of the Medlterranean region of the Community - about 20 m1111on t/year in the short-term, about 40 million t/year in the medium term.

Technlcal viability and social interest for alcohol production as Ingredients for motor fuels from unwanted agricultural surpluses avallable in all regions of the Community (cereals: 30 million ton/year - sugar: 4 million t/y - wine: 3 million t/y in 1984), to reverse the past 10 year situation.

technical viab1lity and economic viab1lity (at a later stage) for ethanol production from energy crops (100 million t/year of blomass could be available in the European Community from short rotation forestry, catch crops... In the year 2000) for car fuel application.

SCOPE OF THE LEBEN PROJECT/ABRUZZO The LEBEN - Project Is consldered particularly fmportant for the verification of the above-mentloned strategic option https://www.w3.org/1998/Math/MathML"> n ∘ 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The Abruzzo Reglon is a part of the "Mezzogiorno" of Italy where the Inbalance between energy (electricity) production and consumption is * 1 ECU https://www.w3.org/1998/Math/MathML"> = 1.382 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Lire (March 1985) 12. OBJECTIVES OF THE LEBEN PROJECT/ABRUZZO 13. The main objectives of the LEBEN project are the following: 14. DESCRIPTION OF THE LEBEN PROJECT 15. Bio-energy sector, which is based on :

At present the total amount avallable 18 3. 500.000 ton, of which 1.800.000 ton for energy utl11satlon and which could be recovered in a 15 years' perfod. The actual productivity is about https://www.w3.org/1998/Math/MathML"> 2.34 t / h a . y . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Furthermore, an amount of about 10.000.000 t/year of sugar-beet will be avallable https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the surroundlng area of the Avezzano power station (production cost - 1984 - 120 ECU/ton; market value = https://www.w3.org/1998/Math/MathML"> 185 E C U / t o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> )

b) A diversified blomass harvesting-collection-chipping Bystem : Up to now only prellminary tests on several harvesting machines have been carried out. The harvesting technology and methodology Is currently under examination. c) A network https://www.w3.org/1998/Math/MathML"> ( 20 - 50 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dispersed pyrolytic conversion units for the thermochemical conversion of blomass into fuel. Such untts w111 be of a "fluidized-bed" type and of a modular design. showing enough flexibllity to match their conversion capacity to the biomass accumulation in different sites. Their energy-conversion efflciency https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> about https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The average fuel production (from 1 ton of dry blomass) ls the following:

gases : https://www.w3.org/1998/Math/MathML"> 300   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (heatıng power https://www.w3.org/1998/Math/MathML"> 900 K c a l / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ); part of: the gas will be supplied to a 70 KWe motorgenerator and to a blomass drylng unit the gas will be supplied to a 70 KWe motgenerator and to a blomass drylng unft

charcoal: https://www.w3.org/1998/Math/MathML"> 250   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (heating power https://www.w3.org/1998/Math/MathML"> 7000 K c a l / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) - blo-oll : https://www.w3.org/1998/Math/MathML"> 200   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (heating power https://www.w3.org/1998/Math/MathML"> 5000 K c a l / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> )

d) A 27 MWe power station. The existing ( 3 sections) of1-operated Avezzano power station will be modified for an optimum utilisation of pyrolytic products. Two solutions are now under study :

Installation of charcoal/bio-oll gasiflers (nr. 3) direct firing in the bollers of a "biomo11/charcoal powder/water/fuel-emulsion".

The waste-heat from the power station will be recovered:

to supply heat to the "green-house" system: - to supply heat to the distillation of alcoho1;

e) A unit for the preparation of the emulsion to be fired into the bollers, should this approach be adopted; f) A system of "green-houses" (for a total covered area of https://www.w3.org/1998/Math/MathML"> 20 h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) situated near to the power station for the production of early fruits and vegetables and the temporary planting (10-12 months) of fruit and forestry trees to be transplanted or to be exported. g) A laboratory for "In-vitro" fast reproduction of plants having a capacity of 8-10 million plants/year. h) Ethano1 factory (total capacity : https://www.w3.org/1998/Math/MathML"> 40.000 - 50.000 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (eth.)/year) will replace an existing sugar factory. A surrounding area of 20.000 ha will supply the raw material (sugar-beet, sorghum..). The ethanol will eventually be ut https://www.w3.org/1998/Math/MathML"> 111 zed https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as "octane-booster" in unleaded-gasoline for motors. 1) an educational and training centre https://www.w3.org/1998/Math/MathML"> S = 8.000   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for a total maximum capacity of 200 young people and open to other Italian regions, other Member States of the EC and also to developling countries. Maln subjects of training w111 be : the production, harvesting, collection and storage of biomass, premtreatment and conversion technologles, utillsation of conversion products. j) a maintenance centre to Insure correct and regular operation of ail sub-systems of this very complex and diversified project.

ELECTRICITY PRODUCTION SECTOR (by hydraulic power stations). A total number of 12 stations are foreseen for a total electric power of 22 MWe and an electricity production of https://www.w3.org/1998/Math/MathML"> 107 m i l l i o n K W h / y e a r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

AGRO-INDUSTRIES SECTOR A group of 8 agro-1ndustries for processing several types of agricultural products grown in the Abruzzo Region. These processes require large amounts of thermal power and electriclty (processing, drying, liophilisation, cold storage, freezing...)

TIME SCHEDULE OF THE LEBEN-PROJECT/ABRUZZO Completion is scheduled within 5 years, starting June 1985 as shown here below: blo-energy sector 1985 1986 1987 1988 electro-hydraulic sector agro-industries sector Activities already under way :

General design and special assessment studles on the potentlal ofbiomass potentlal harvesting and conversion technologles, blomass potential harvesting and conversion technologles, elaboration of a socio-economical model on computer

Intensive testing of the pyrolytic process (pilot-plant in operation since 1983)

Group of conversion units under construction

Preliminary experimental tests by forest harvesting machines.

ECONOMIC EVALUATION Here below we present the main economical data : A. Investments https://www.w3.org/1998/Math/MathML">   MECU   9,2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 28,2 8,3 21,7 38,5 6,5 6,8 119,2 24,0 70,5 13,3 227,0 https://www.w3.org/1998/Math/MathML"> = = = = m = = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 16. SOCIAL BENEFITS The LEBEN Project/Abruzzo Is estimated to be capable of creating many new job opportunities. A preliminary evaluation gives the following figures : 17. INTERNATIONAL COOPERATION The results of the LEBEN project and the expertence drawn from it are of high interest for cooperation with third countrles, namely developing countries. The LEBEN project applies an integrated approach to agroenergy on a regional basis and, for this reason, is well suited for many developlng countries whose economy https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> based on agrlculture. It is also Lmportant to note that this project has an lmportant social. Impact on the population of such countries. The development of local energy resources In an Integrated scheme, factlitates the soctal life of the country and reduces the need for urbanisation. Cooperation with developlng countries can be foreseen at different Levels, starting with a transfer of expertise to feasibllity studies or operational projects. Training programmes can also be set up for personnel coming from thlrd countries, as well as the participation of specialists in the programme preparation and/or in its implementation. As far as flnanclal aspects are concerned a large spectrum of possibillties exists dependlng on the type of cooperation under which the project 1 s to be implemented. 18. Conclusions To conclude, the 1mplementation of large agro-energy schemes w\perp11 demonstrate:

the possibility for agricultural and forestry activities to enter the energy market which has, for ofl importing countries, the attraction of a non-saturable market.

The LEBEN project in particular, by the exploitation of a stgnificant amount of the blomass potential of the Abruzzo Reg1on (about 450.000 t/year of agricultural and forestry residues), will demonstrate : THE PRODUCTION AND USE OF FUEL ALCOHOL IN ZIMBABWE. TECHNICAL DIRECTOR, TRIANGLE LIMITED, https://www.w3.org/1998/Math/MathML">   TRIANGLE, ZIMBABWE.     TRIMENMAN   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 19. SUMMARY. A plant to produce https://www.w3.org/1998/Math/MathML"> 40 m i l l i o n   & https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of absolute alcohol per annum was built in 1980 in Triangle, Zimbabwe, adjacent to an existing Sugar Mill. This plant has run successfully since that time and operating experiences to date are discussed. The rationale for building the plant and specific difficulties encountered during this phase of the project are probably relevant to many developing nations today. Al1 the alcohol produced is blended with petrol and distributed throughout Zimbabwe. This https://www.w3.org/1998/Math/MathML"> 12 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> alcohol/petrol blend is the only fuel available in the country for spark-ígnited engines. Minor difficulties experienced during introduction of this fuel are discussed. In 1978 sugar production in Zimbabwe was 309500 tons, of which 108500 tons was consumed within the country, the balance being exponted. At that time, the export price of sugar was approximately us.$100. per ton whilst transport costs of US.$20. per ton further reduced the amount received by the producers. Two producers of roughly equal size accounted for the total sugar production in Zimbabwe. With a production cost of some US. https://www.w3.org/1998/Math/MathML"> $ 130 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . per ton, my Company Triangle Limited, decided to pursue the possibility of converting part of its sugar exports into ethanol. From a national point of view, local fuel production would reduce the amount of imported hydrocarbon fuel, thus reducing foreign currency expenditure and high transport costs to our land-locked country. Strategically, the production of a liquid fuel Within the country made very good sense, particularly at that time when a war situation existed in Zimbabwe prior to the country gaining its independence. Against this background, Triangle Limited's proposal to produce ethanol and market it solely through the Government's Oil Procurement Company made good economic, political and strategic sense and readily gained the approval of Government Authorities for its implementation. Notwithstanding the attractive nature of the project to the national economy, a very strict limit was put on the amount of foreign currency allocated to the project. This is a situation not uncommon in most Third World countries today. Having received Government and Company Board approval to proceed, a number of technical decisions had to be made, the most critical of Which was the choice of plant to be installed. The criteria which were set in making this choice were as follows:

Minimal foreign currency content. The plant should be constructed as much as possible within the country with a minimum imported content.

In a developing country it was necessary to design and build a plant appropriate to the abilities of the people who were to run it. Therefore a large amount of automatic control and sophisticated equipment had to be discarded in favour of simpler manual processes.

The conversion yield on the plant should be of an acceptably high level to ensure that in sacrificing sugar production for ethanol the Company was not making an economically retrogressive step. This was particulariv important as it must be emphasised that the project was conceived and implemented entirely by private enterprise without Government assistance or subsidies.

To meet the above criteria numerous processes were considered and the decision made to build a straight-forward batch fermentation plant to produce dehydrated alcohol. This plant was designed by Gebr. Herrmann, now part of the Buchauwolf Group. The agreement reached with the designers was that the design only would be bought from them and that all construction would be carried out in Zimbabwe with the proviso that the critical aspect of building the distillation columns would be overseen in the initial stages by a Construction Supervisor sent out by the designers, and once the building was completed, pre-commissioning checks and ultimately commissioning would be carried out by a team sent out from Germany. To undertake the construction, a Project Team was set up in Triangle to translate the specifications recelved from the designers into equipment available within Zimbabwe, or, where necessary, to be imported from outside the country. In this category such items as plate heat exchangers, air blower and certain dairy-standard pumps had to be imported, as well as basic essential instrumentation. Material in the form of stainless steel plate, piping and certain specialised valves were also imported for fabrication and assembly within the country. The major aspect of fabrication which was undertaken was the construction of the distillation columns. These measure some 2 metres in diameter and 30 metres in height with perforated trays, up to fifty five in number, supported internally. The levelness and symetry of these distillation trays was the most critical aspect of their construction which had to be monitored and controlled continuously during fabrication. To undertake this, a Local Inspection Authority was appointed with standards being set by the German Construction Supervisor. \begin{abstract}Construction of the buildings and structures and assembly of all components had to be done to a very high standard, and to achieve this, semi-skilled local welders were put through a short training course in a school specifically set up to ensure that their work met an acceptable standard. Periodically during construction, spot checks were made on welds and welders not maintaining an acceptable standard lost their Quality Bonus and nad to undergo re-training before being allowed back on the construction site. In this way a very high standard was maintained and on commissioning, virtually no weld faults were detected. Construction of the plant started in March 1978 and it was commissioned in May 1980. The final cost of the total project, including integration with the sugar mill, was some US. https://www.w3.org/1998/Math/MathML"> $ 6 m i l l i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (at the rate of exchange applicable at that time). The plant was positioned as close as was practical to the existing sugar mill in order to take advantage of facilities already existing in the mill. The feedstock to be used - although potentially crystal sugar - was to be bled as liquid from the sugar mill at an appropriate point. This point could vary from, immediately after the raw juice was expressed from the sugar cane and prior to any clarification or evaporation had taken place, to as far down the sugar manufacturing process as "B" molasses. It is normal practice to further exhaust the molasses in a third or "'C" process but the decision was taken to dispense with this stage. The reasons for this were twofold:

Additional energy was required to extract this final amount of sugar which was unnecessary.

In laboratory tests it had been determined that molasses produced after three boilings was considerably less fermentable than after one or two boilings.

Steam savings achieved by cutting out the third boiling stage and by taking juice directly from the sugar mill without evaporating it, equalled the amount of steam required for distillation. Thus it was unnecessary to build additional boilers and a low pressure steam supply was taken from the existing Power Station directly to the distillery. The operation and management of the distillery was integrated into the duties of the existing sugar mill staff, which could be achieved as less attention was required in the sugar mill due to the decreased emphasis on molasses exhaustion. Maintenance staff were similarly redeployed and no increase in staff was required. The plant is designed to produce 120000 & per day. With a https://www.w3.org/1998/Math/MathML"> 96 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> time efficiency and operating for fifty weeks of the year it can produce 40 million l per year. During the first year of operation, the plant ran for some nine months, and since that time annual production has not quite reached 40 million l, although it is hoped to achieve this figure by the end of the current year ending March 31, 1985.\end{abstract} PERFORMANCE OVER PAST FIVE YEARS. During the last two years, expanded milling capacity has been available, and as a result, far less sugar juice has been consumed as more molasses is now available from the Factory. This has resulted in a slightly less efficient utilisation of steam, as water has to be evaporated from the sugar juice during the production of molasses which is then re-diluted prior to fermentation. In reviewing the past five seasons' performances it can be seen that the conversion yield of sugar to ethanol has steadily decreased. Coincidentally the proportion of molasses in feedstock has increased and this is one of the main reasons why the yield has dropped off. In analysing for total sugars, the traditional method used in a sugar factory is the Lane and Eynon titration method which in fact analyses for total reducing substances, not sugars. This over-estimates sugars and increasing errors are therefore introduced with increased molasses usage. To overcome this, we will introduce from the forthcoming year chromatographic analyses for sugars which will give a much more accurate measure of the total sugars being used. In an attempt to further improve yield, we have now purchased a yeast centrifuge which it is hoped will enable us to dispense with the pre-fermentation stage by recycling yeast directly from a fermented batch back to a newly prepared one. In this way all sugars will be used in the production of ethanol with a minimal amount being used to produce yeast. Maintenance problems so far have been few. The most serious one related to incorrect specification of circulating pumps on the main fermentation tanks which resulted in their premature failure. These have now been correctly sized and normal life expectancy is being achieved. To save foreign currency during initial constmution, the main fermentation tanks were made from 6 mm mild steel plate and severe corrosion is now being detected on the heat-affected zones at all the welds. These are being re-welded and the interior of the tanks protected with epoxy paint which appears to have stood up well during a oneyear test programme. From the operating point of view, one of the major long-term problems is the disposal of stillage. The initial plan was for this to be diluted 40:1 with irrigation water and used to irrigate some 100 ha of cane fields. This has proved successful in that a larke saving in fertiliser has been achieved. However, the stage is now being reached Where there is an over-application of minerals to these fields and the stillage is now being applied to a further 1 200 ha to increase the dilution factor. Although the fertiliser value of the stillage more than pays for the cost of application and maintenance of equipment, the long-term effect on the fields has yet to be established. Furthermore, Inevitably, mis-application of the irrigation water results in diluted stillage running directly into water courses causing pollution of the environment. It is therefore felt necessary to investigate and pursue other disposal methods in the longer term. In this regard, the best solution with minimal operating cost and maximum recovery, appears to be anaerobic digestion, but this is very costly. Certainly cheaper, and possibly more applicable in a country where land is not at a premium, would be lagooning or aerobic digestion of the stillage. However, this is not very efficient in reducing pollution levels and no energy recovery is possible. Concentration and subsequent incineration has also been considered, but at best this alternative is only energy self-sufficient and would again be costly in All the alcohol produced at Triangle is used as a motor fuel by blending with petrol. As Zimbabwe has no natural oil deposits, all its petrol and diesel fuel is brought into the country in a refined form and blending takes place at numerous centres around the country. The main reason for having various blending points is to have separate storage of petrol and ethanol until they are loaded into road tankers for distribution to retail outlets. By keeping these products separate, fire fighting procedures can be simplified as different foams and fire fighting techniques are required for the two products. The overall blend of alcohol in petrol now stands at https://www.w3.org/1998/Math/MathML"> 12 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> having been reduced from an initial blend of https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as a result of increased fuel consumption and static production facilities. During the initial stages of the introduction of the blend fuel, numerous vehicle faults were attributed to it, ranging from broken fan belts to intoxicated drivers !! However, on investigation there appeared to be only two faults which could in fact be substantiated. The solubility of certain plastic components - particularly in one brand of car - in the blended fuel. The solvent properties of the alcohol also affected glass fibre fuel tanks such as were fitted to some motor boats. These problems soon manifested themselves and were remedied by replacing the affected item by a non-soluble one. foreign currency. These were: - The effect of alcohol on certain acrylic enamels which were mainly used during the repair of motor vehicles. Many cars throughout the country could be seen with strips of paint taken off the bodywork from the petrol filler to the ground. This problem has been minimised by liaison with fuel retailers who have instructed their Forecourt Attendants to dilute with water any spill at the fuel filler. Liaison with automotive paint suppliers in the country has also resulted in the withdrawal of alcohol-soluble paints from the market so that the problem should disappear in time. Milling capacity has been increased in the past two years and as a result of this, sufficient feedstock is available to double the capacity of the distillery. By increasing the capacity, proportionately less molasses can be used and advantage can once more be taken of the energy savings inherent in sending cane juice directly to fermentation. It is anticipated that by utilising yeast recycling no major increase would be required to the size of the fermentation plant to supply fermented beer to a second distillery. Even if production were doubled to 80 million l per year, this would represent, at today's petrol consumption within the country, a blend of some https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The option, however, remains to introduce vehicles powered by pure alcohol engines so that increased production up to twice our present capacity could easily be accommodated. Talks are currently underway with Government to finalise arrangements for the building of a second plant and it is expected that this will become a reality in the not too distant future. 20. Summary In 1978 Canada implemented 2 programs to encourage the development of bloenergy as a reliable and economic substitute for fosstl fuels. The bloenergy as a rellable and economic substitute for fossil fuels. The FIRE program, a capltal incentive program, will have stimulated almost https://www.w3.org/1998/Math/MathML"> 370 P J / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of additional biomass fueled capacity when all projects are completed. The ENFOR program, the subject of this paper, has played a significant role in the provision of technical support for commercial and developmental work in forest energy applications. The ENFOR program has established a forest biomass inventory, and developed new harvesting machines to provide increasing quantities of biomass for bioenergy, while at the same time contributing to improved forest regeneration practice. Other achievements are the development of a large scale simulation of forest nutrient dynamlas, and improvemente the the mechanization of Short Rotation Intenglue Cutare (SRTC) On the conversion slde of the ENFOR program, contributions to materials handling and combustion technology have been made. MJV gasiffortion has been scaled up to https://www.w3.org/1998/Math/MathML"> 10 t h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> throughout in a pilot installation and direct Ilquefaction has been taken to the PDU scale. A major project completed under ENFOR converslon was a technoeconomic assessment of commercial and near term technologies as well as of the more futuristic proposals. This wi11 serve as a basis for the implementation of bioenergy options through to the year 2000 when it is expected that the contribution will be around 1000 PJ as against today's 545 PJ (1978, 380 PJ). 21. INTRODUCTION Following the first of the https://www.w3.org/1998/Math/MathML"> 1970 ' s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of 1 shocks a review of the Canadian terrestrial biomass energy potentlal was undertaken in order to establish the pollcy actions necessary to access this source of renewable energy (l). Due to the northern and continental nature of Canada, almost https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the land mass is terrain which is relatively non- productive. An additional https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ls able to support forestry and https://www.w3.org/1998/Math/MathML"> 6 - 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> supports agriculture; the balance is freshwater and urban areas. The preliminary study identified a major energy potential in the use of m.11 and process residues from the forest Industries, with the possible export of fuels from that sector ln the form of solid, liquid and gaseous fuels. To encourage the development of this potential energy source, the Federal government instituted two programs during 1978: FIRE and ENFOR. The former https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a capltal investment assistance program to bring about the celluloslcs and the subsequent processing of the hemlcellulose, cellulose and 1 ignin-derived fractions.

ENFOR PROGRAM RESULTS

The appendix to this paper contains a serial list of ENFOR projects and reports for the period throtgh to April 1984 which was the final period of the ENFOR program before it split into the two separate fractions. The https://www.w3.org/1998/Math/MathML">   o f   t h e   t h i t e d   p r o g r a m   b e f o r e   i t   s p l i t   i n t o   t h e   t w o   t e p a r a t e   f r a c t i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ces no report is available since the project served to furnish raw, unprocessed data for other work. Due to the fact that all project proposals were numbered serially and were not all supported, the number sequence 1 s not complete. The missing numbers represent proposals that were not accepted elther for monetary, technical or mandate reasons. The reports list does not include the activities engaged in under the Canadian participation In the Porestry Energy Agreement of the International Energy Agency, which was supported under the ENFOR program by the CFS. 2.1 ENFOR Production Program For the purpose of analysts the 14.5 MS, 142 Individual contracted elements of the production program are grouped and analysed according to the 4 major activities shown in Table I below. In the space available it will only be possible to discuss some of the major findlngs and highlights of each of the areas of activity. Table I. "Production program data for dollar and sub-program distribution." Research Area % Do1lars Spent of all Projects B1omass Avallability 33 39 Harvesting Technology 20 12 Environmental Impacts 100 100 Short Rotation Intensive Culture TOTAL 100 2.1.1 Biomass Availability The major concern of this program was the total avallability of the forest blomass for all purposes and the share that mlght be avallable for energy. Prior to the ENFOR program, the basis for such estimates was the Inventory data for the merchantable species and the application of factors of poor reliability relating the merchantable volume to that of unmerchantable trees and the ratio of other tree components to the merchantable volume. A further consideration https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the accessibllity of forest stands; since the economic avallability is a direct function of the access to roads and other transportation inks. The information for the stated aim, "to determine the quantity, form and location of biomass in Canadian forests", was obtained through the acquisition of data on the blomass of tree components and the development of biomass equations, in comblnation wlth the computer based system of national inventory which was developed in parallel by the Forestry Statistics and Systems Branch (FSSB) of the CFS. The FSSB had already prepared the national inventory "Canada" sorest Inventory 1981 " 3 ) under this system known as the Canad1an Forest Resource Data System (CFRDS) which captive user, the mill site, there is the possibility of well. integrated economic operations. 21.0.1. Environmental Impacts The impacts of bioenergy use on the forest can be on the flora, fauna and on the human populations. The main concern, however, has been the risk of damage to the blosphere itself in terms of eroslon and nutrient deplem tion which has led to the development of a an ecosystem-based forest management model and simtilation program called FORCYTE-10. This model examines the the long term consequences of intensive forest management on slte nutrient capital and biomass production, and allows the evaluation of the economic performance and energy efficiency of alternative management scenarios. A forest manager can model the consequences of variations th the rotation length, regeneration delays, species selection, initlal stocking density, spacing, utl11zation level and final harvest. It is possible to run through 300 years of forest management in https://www.w3.org/1998/Math/MathML"> 10 m i n u t e s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of stmulator time The model was lnitially developed around the nitrogen budget but now Includes several nutrients. Presently there is on-golng work to validate the model and to extend the number of biomes to which lt can be applied. 21.0.2. Short Rotation Intensive Culture (SRIC) SRIC has as its basis the tise of species that are high yielding ln short rotations. Using hybrid poplar as an example it is possible to obtain yields of 60-70 t/ha in a rotation period of lo-12 years rather than the equivalent yleld obtained in 80 years in the natural forest. Most studies have been tndertaken on the Alnus, Populus and Salix genera. Much of this work has been shared whth the International Energy Agency's Foredtry knergy Agreement under whtoh there have heen exphanges of experience in the management and harvest of short rotation energy plantations. Because of the rapid response of short rotatlon species thls area has also served as the testing ground for studies of mycorrhiza and actlnorhlza. The former symbiont assists in the tptake of nutrients and its study has led to inproved strains and innoculation procedures, while the latter has been studied with a vlew to transfer the nitrogen fixing abllity of Frankie assoclated with Alders to other species. 21.1. ENFOR Conversion Program Unlike the production program which by definltion is restricted to the Canadian biome, the conversion program was more general in scope and had to recognise the existence of large programs outside of Canada under the auspices of the EEC and the USDOE. Thus, to some degree the program consisted of elements to enable Canadians to follow work golng on elsewhere, a Watching Brief so to speak, on areas in which Canada had a unique requirement or qualification. The proportion of the 77 contracts and of the total of https://www.w3.org/1998/Math/MathML"> 1.4 . 5 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> $ expenditures in the 5 key areas of the program are shown in Table II. There is no category for the impacts of this progran since the environmental and social impacts tended to be evaluated as an Integral part of each project. Table II. "The Conversion program distribution of effort." 21.1.1. Feedstock Preparation Analysis of the conversion chain from receiving the feedstock through to the final product shows that an appreciable part of the investment is in the front end materials handling. Projects ranged from dewatering technology, the preparation of pelletized and water resistant prepared fuels, to the assessment of sensors available for the on-line determination of fuel molsture. A very succesful component of the effort was in studies of storage bin design and materials transfer facilities, this work origlnally at BC Research, one of Canada https://www.w3.org/1998/Math/MathML">   ⊤ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> s provincial research councils, is now belng commercialised in the forest products Industries. Though much work was done in this area, there still exists a need for the demonstration of the best technology to ensure 1ts adoption. 22. 2.2.2 Direct Combustion The inftial program directlon assumed that this area would need little Input since it was the basls of the already extensive bioenergy contribut1on. However, there were 2 areas in particular that required attention. The first was in the direct use of wood and residues to fire lime kilns in kraft pulp mills, Elsewhere most needs can be satisfled either by hot gases or more probably by steam generated ln hog fuel and recovery bollers. The second area was in the efficiency and emmissions characteristlcs of the https://www.w3.org/1998/Math/MathML"> 1 t g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in use. A gurvey of mills chowed that in the matoritys the combustion of wood residues required inordinately large quantities of fossil fuels to enable load following and to compensate for the variations of the molsture content of the feedstock. A boller test program was established to investigate this and to identify the means by which fossil fuel use could be minimised or e11minated. Three major avenues were followed in the substitution of oil in the Iime kiln: the use of hot combustion gases; mixing wood chips with the lime mud; and finally the firing of clean ptelverised fuels. The hot gas and the wood chip addition projects were targeted at the partial replacement of oil In the kiln. In both 1nstances, the projects c-14 and c-l23 were carried to a succesful conclusion. Commercial adoption ts a function of local economics and with declining oil prices has not yet been implemented. The pulverised clean dry fuel option is more expensive, yet has been already adopted at one mill in Sweden. The boller test program has examined the performance of 4 bollers with steam capacities in excess of https://www.w3.org/1998/Math/MathML"> 90 t h ( 200,0001   h / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Each of the boilers Was considered to be of a type likely to be replicated in the future in Canada. The test procedure involved "tuning" the botler and by operating Canada. The test procedure involved tuntarg the botler and by operating at various loads the thermal and eminisions performance was evaluated. Foz each test it was established that with minor adjustments and modifications the boller concerned could signfflcantly reduce fossil fuel consumption whetle otily meetlng https://www.w3.org/1998/Math/MathML"> 100 d   a n d   e m m i s s i o n s   c r t t e r t a   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to provide guldance to the Industry and could result in appreciable reductions in the use of fossil fuels in existing installations while at the same time lead to a better deslgn basis for new units. 2.2.3 Thermochemical Conversion By excluding combustion as such, this category covered pyrolysis, gasiflcation and direct liquefaction of wood. Each area involved basic research, process development and in some instances the evaluation of near commercial unlts. The classification of projects was primarily in terms of the primary product: gas, char or a liquid. 23. 2.2.3.1 Gasification The three end uses envisaged in Canada are: fuel gas for bollers and processes; gasifier/heat englne combinations for remote community and possibly grid-connected electricity generation; and the production of synthesis gas for the production of liquid fuels such as methanol. Projects were undertaken in all of these areas, partly through the lmportation of World War il derived European gasifiers and by the development of indigenous expertise In fluidised bed gasification. Electricity generation https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a country with a large hydro and nuclear potential is not very profttable unless it is for in plant use as in com generation or in remote community applications. Demonstration experiments showed that the labour requirement compared wlth the diesel competitor usually resulted in the gaslfler optlon belng unattractive. Current activa ity is targeted at a much larger scale than the 250 kW of the average remote community with an eye to export sales of multi-MW units. Most development was applled to the fluldised bed option on the basis of prior experience In INCO (C-12) and ECO-Research (C-68). This and other fundamental work has lead to the construction of a prototype pressurized fluidised bed gasifier at St.Juste, Québec under the aegis of a crown corporation. The BIOSYN project has a design rating of 10 th at https://www.w3.org/1998/Math/MathML"> 2 M P a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to produce a medium joule value gas for reforming to syngas and possible conver sion to methanol in a projected second phase of the project. 24. 2.2.3.2 Liquefaction Though longer term in nature than the gasification syngas route to 1iquid fuels, there was extensive research and fnternational collaboration on direct routes to liqutds. In part this was because of hoped for process slmplification and partly as a restlt of theoretical analysis that showed an efficiency advantage under conditions of lower severity than gasification. Projects ranged from pyrolysis https://www.w3.org/1998/Math/MathML"> - 28 , C - 223 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under rapid heating conditions to vacuum pyrolysis https://www.w3.org/1998/Math/MathML"> C - 33 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C - 326 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , through to classical liguefaction slmilar in process conditions to coal hydrogenation and liquefaction. https://www.w3.org/1998/Math/MathML"> ( C - 44 , c - 48 , C - 69 , C - 118 , C - 256 , c - 288 , C - 442 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The Canadian effort in this field was a contribution to a major IEA profect known as the IEA BLTF (Biomass Liquefaction Test Facility). This study in which the USA, Finland and Sweden, also participated was a complete survey of the performance of 25. REFERENCES ENFOR PROJECTS - PRODUCTION SERTES PITLE Energy from Newfoundland's Forest Blomass Fuelwood Consumption in Newfoundland Tree Biomass Equations for Ten Major Species in Cumberland County, N.S. Volume of Wood Residues for Energy Production at Parent, Quebec https://www.w3.org/1998/Math/MathML"> - 8 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Tabular Summary of Data from the Literature on the Biogeochemistry of Temperate Forest Ecosystems Forest Ut11ization for Energy and the Role of Nitrogen Fixation: A Literature Review Intensive Culture of Green Ash and Japanese Larch Plantations to Maximize Biomass Production Energy from Forest Biomass: Public Awareness Program Direct Assessment of Forest Blomass with a Radar Altimeter Complete Tree Ut111zation: An Analysis of the Literature https://www.w3.org/1998/Math/MathML"> ( 1970 - 78 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Part I-IV Growth of Forests in Canada - Part 2: A Quantative Description of the Land Base and the Mean Annusl Increment 26. CONTRACTOR/AUTHOR R.S. van Nostrand https://www.w3.org/1998/Math/MathML"> ( N - X - 180 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Northland Assoctates Ltd., St.John's, Nfld. M.F. Ker https://www.w3.org/1998/Math/MathML"> ( M - X - 108 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Blais, McNe11, Lussier Tremblay et Associés, and Dendrotik Inc. Dr. J.P. Kimmins Dr. A. Fortin Ontario Ministry of Natural Resources J.D. Coates GRW Resource Inventory Radar Ltd., Rescott, Ont. Dr. Robert W. Weldwood A. Blckerstaff, W.L. Wallace and F. Evert (PI-X-IF) P-19* Cost Estimates of Forest Biomass Delivered at the Energy https://www.w3.org/1998/Math/MathML"> p - 20 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Data Collection for Mature Softwood Biomass Conversion https://www.w3.org/1998/Math/MathML"> P - 21 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Blomass Inventory of Tolerant Hardwoods in Algoma, https://www.w3.org/1998/Math/MathML"> P - 22 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Blomass Productivity of Young Aspen Stands in Western https://www.w3.org/1998/Math/MathML"> P - 23 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Prediction of Forest Residues After Harvesting P25* Energy from Forest Biomass on Vancouver Island https://www.w3.org/1998/Math/MathML"> P - 28 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Inventory of Forest Blomass Left After Logging in Canada https://www.w3.org/1998/Math/MathML"> P - 30 ( 1 ) * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Biomass Yield Tables for Aspen in Ontario Biomass Potential of Aspen and White Birch in Ontario Development and Testing of a Ffeld Treatment System for Logging Residues Tree Blomass Equations for Seven Spectes in Southwestern New Brunswick Blomass Harvesting and Chipping in a Tolerant Hardwood Stand in Central New Brunswick P-40* Biomass and Nutrient Removals by Conventional and Whole-tree H.J. Hanson Biomass and Nutrient Removals by Conventional and Whole-treeClear-Cutting of a Red Spruce-Balsam Fir Stand in Central Nova Scotia N.A. Wiksten and P.G. Prins Horton Forestry Services Ltd., Stouffoflle, Ont. J.B. Thomas Western Ecological Services Edmonton, Alberta Tfmeriinn Ltd., Ste.Agathe des Monts, Quebec Paul H. Jones and Associates Ltd., Vancouver, B.C. Forest Engineering Research Institute of Canada. Polnte Claire, Quebec. K.W. Horton K.W. Horton K.J. Blakeney M.F. Ker https://www.w3.org/1998/Math/MathML"> ( M - X - 114 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   B e r e f   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> B.S. CRaalte Intensive Forest Harvest: A Review of Nutrient Budget Considerations Forest Blomass and Nutrient Studies in Central Nova Scotia https://www.w3.org/1998/Math/MathML"> P - 41 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Rate of Growth of Biomass in Young, Natura11y-Regenerated Stands https://www.w3.org/1998/Math/MathML"> - 51 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Upper Limites of Standing Crop Density and Growth Rates for Woody Species in the Prairie Provinces Implications of Fu11-Tree Harvesting for Biomass Recovery Energy Analysis of Energy from the Forest Options A Proposal to Develop a Comprehensive Forest Biomass Growth Mode Planting Macine for Mini-Rotation Poplar Field Research and Computer Simulation Modelilng of the Long-Term Consequences of Intensive Biomass Fertility and Intensive Culture of Plantations to Maximize Biomass Production Uses of Nitrogen Fixation and Other Root Symbioses for Biomass Production Biomass Equations for Ten Major Tree Species of the PrairieProvinces Rrovincer Evaluation of Potential Impacts of Forest Biomass Harvesting B. Freedman https://www.w3.org/1998/Math/MathML"> ( M - X - 121 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> B. Freedman (M-X-134) Dr. A.J. Kayl1 Western Ecologlcal Services Edmonton, Alta. Jean-Guy Routhfer M.J. Ash, P.C. Knoblock and M.J. Ash,N. Peters Dr. J.H.G. Smith and D.H. WLlliams HYD-Mech. Engineering Ltd. Woodstock, Ont. Dr. J.P. K1mmins Ontario Ministry of Natural Dr. A. Fortin T. Singh (NOR-X-242) Le Groupe Dryade Ltée, Que. https://www.w3.org/1998/Math/MathML"> P - 102 *   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> An Improved Stand Growth Model for Trembilng Aspen In the Prairie Provinces of Canada (2 Volumes) P-112 & 190* Biomass Equations for Six Tree Species in Central Newfoundland https://www.w3.org/1998/Math/MathML"> P - 115 *   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Whole Tree Chipping for Hogged Fuel in Newfoundland https://www.w3.org/1998/Math/MathML"> p - 121 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Effects of Spacing and NK Fertilizers on Dry Matter Accumulation and Nutrient Contents of Two-Year-01d Populus x euramericana cv. I-45/51 and cv. robusta DN17 https://www.w3.org/1998/Math/MathML"> P - 135 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Forest Blomass Energy in British Coumbla: Opportunities, Impacts and Constraints https://www.w3.org/1998/Math/MathML"> P - 138 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Macronutrient Content of Deciduous Tree and Shrub Samples from the Great Lakes-St. Lawrence Forest Region. P-139* Update of Canadian Activities In Poplar Blomass Production and Utilization P-140 Forest Blomass Inventory System https://www.w3.org/1998/Math/MathML">   M e t r c t e   s t a g l e m e e   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> P - 141 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Metric Single-Tree Weight Tables for the Yukon Territory P-142* Development of a system to Estimate Quantity of Biomass Standish Following Logging in British Columbla Forests to Specified Recovery Criteria P-143* Integrated Logging for Production of Pulpwood and Hog Fuel https://www.w3.org/1998/Math/MathML"> P - 144 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Manual of Data Collection and Processing for the Development of Forest Biomass Relationshfps Reforestation of Areas Harvested for Biomass https://www.w3.org/1998/Math/MathML"> P - 145 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Reforestation of Areas Harvested for Blomass K.0. Higginbothom, I.D. Heidt and T. Grabowski Northland Associates Ltd. St. John's, Newfoundland W.C. W11ton & W.P. Duffett George E. Ogar Nor thwest Soll Research Ltd. Edmonton, Alta. L. Zsuffa, D. Boufford and Statistics Canada, Ottawa Ontario G.H. Manning https://www.w3.org/1998/Math/MathML"> ( BC - X - 250 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> J.T. Stand sh W.C. Wilton I.S. Alamdag (PI-X-4) Price (Nfld) Pulp and Paper Ltd., Grand Falls, Nf1d P-146* Procedures for Estimating Newfoundland's Blomass Reserves P-148 Development and Pilot-Scale Demonstration of an Integrated Information and Mapping Capability for Forest Biomass Inventories in the Prafrie Provinces and the Northwest P-149* How C11mate Affects Tree Growth in the Boreal Forest https://www.w3.org/1998/Math/MathML"> P - 150 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Impact of Climatic Variation on Biomass Accumulation in the Boreal Forest Zone: Selected References https://www.w3.org/1998/Math/MathML"> P - 152 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Blomass Harvesting in Tolerant Hardwoods P-154 Hardwood Copplce Silviculture https://www.w3.org/1998/Math/MathML"> P - 155 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Postcut Impacts in Hardwood Stands Postcut Impacts in Hardwood Stands Prospects for the Use of Forest Biomass in Quebec. P-158* Tree Biomass Equations for Young Plantation Grow Red P1ne Ian Methven (P1nus Resinosa) in the Maritime Lowlands Ecoregion P-162* Analysis of Salvage Yarding Systems and Costs in Pacific Gagle Coast Forests Northland Assoctates Ltd. St.John https://www.w3.org/1998/Math/MathML">   ' s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Newfoundland Systemshouse Ltd. Systemshouse LtdOttawa, Ontario L.A. Jozsa, M.L. Parker, P.A. Bramhall & S.G. Johnson E.B. Peterson (NOR-X-254) Lake Superior Forestry Services, Sault Ste.Marie Ontario. Perreault, Larouche, Houde, et Associés, Québec, Quếbec Le Groupe Dryade Ltée, Québec, Québec L.J. Lussier (LAU-X-52) Ian Methven M.F. Ker https://www.w3.org/1998/Math/MathML"> ( M - X - 148 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> George S. Nagle P-157* Perspectives d'utilisation de la biomasse forestière au Québec. L.J. Lussier (LAU-X-52) P-159* Blomass Equations for Seven Major Maritimes Tree Species M.F. Ker M-X-148) P-163* Costs of Harvesting Aspen Stands for Energy Production P-164 Impact on W1dlife of Short-Rotation Management of Boreal Aspen ImpactStands P-169* Biomass Equations for Six Major Tree Species of the Northwest Territories P-170* Evaluation of Potential Interactions Between Forest Biomass Production and Canadian Wildiffe https://www.w3.org/1998/Math/MathML"> - 172 *   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A Pflot Study on the Peasibility of Establishing W111ow Energy Plantations in Newfoundland -179* Mass Equations and Merchantabl1ity Factors for Ontario Mass Equat

182* Homass Inventory of Tolerant Hardwoods in A1goma, Ontario

Further Development of Logging Residue Processing Systems The Harvesting and Processing of Residual Biomass in Hemlock-Cedar Stands in the B.C. Interior Wet Belt The Economics of Harvesting Fuelwood Under Four Different Stand Conditions on Prince Edward Island https://www.w3.org/1998/Math/MathML"> - 190 & 112 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Tree Welght Equations for Newfoundland Tree Mass Equations for Common Spectes https://www.w3.org/1998/Math/MathML"> - 191 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Harvesting Forest Blomags as an Alternative Fuel The Coban Institute Resource Management Consultants, Edmonton, Alberta D.A. Westworth and Assocs. Ltd., Edmonton, Alta. T. Singh (NOR-X-257) R. Coulombe & A.B. Lemay Alison Dyer I.S. Alemdag (PI-X-23) Dr. J.B. Thomas Forestal International Ltd K.A. Nelson D.C. Peters https://www.w3.org/1998/Math/MathML"> ( M - X - 139 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> M.B. Lavigne https://www.w3.org/1998/Math/MathML"> ( N - X - 313 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> M.B. Lavigne https://www.w3.org/1998/Math/MathML"> ( N - X - 313 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Bowater Newfoundland Ltd P-193 Regeneration Assessment Following Complete Tree Harvesting P-194 Alnus for Energy Production 2-197 Computer Modelling of Intensive Biomass Management Impacts Uses of Nitrogen Fixation and Other Root Symbloses for Biomass Production Impact of Harvesting Immature Trees by the Whole-tree Method on the Microbiology, Organic Matter Contents, and Nitrogen Transformation of a Forest Soll Design and Fabrication of a Bundle Typing Device for the Design and Fabrication of Impect on Wildiffe of Short-Rotation Management of Boreal Aspen Stands Determination of Blomass and Nutrient Content in Trees, Ground, Vegetation and Soll of Aspen Stands in the Prairie Provinces Development of an Integrated Harvesting and Processing System for Hardwood Sawmilling and Energy Production Development of the RECUFOR Logging Residue Processor (FERIC Proposal F-1) Preparation of Report on ENFOR Project P-152 Application of the RECUFOR Rotor to Comminution of Residues at Landings and Processing P1ants Ltée. Trois Rivières, Que. Pamper Inc. Dr. J.P. Kimmins Dr. A. Fortin Unflersity of Guelph, Guelph, Ontario Hovey and Assoclates (1979) Ltd., Ottawa, Ontario D.A. Westworth and Assoc. Edmonton, Alberta Alan Moss & Assoctates Ltd. Kelowna, B.C. Woodland Resource Services Edmonton, Alberga Forest Engineering Research Institute of Canada,Polnte Claire, Québec Polnte Claire, Québec Matcam Forestry Consultants Sault Ste.Marie, Ont. Forest Engineering Research Institute of Canada, Polnte Claire, Quebec P-216* Development and Testing of a Ro11 Splitter P-219 Survey of Biomass Estimation Projects https://www.w3.org/1998/Math/MathML"> P - 224 *   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Avallability and Cost of Forest B1omass in Canada P-225* Biomass Equations for Black Spruce Biomass in Quebec https://www.w3.org/1998/Math/MathML"> P - 226 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Potential Impacts of Intensive Forest Blomass Production on Reptile and Amphibian Populations of Southern Ontario and puebec https://www.w3.org/1998/Math/MathML"> P - 227 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Coordination of ENFOR Biomass Estimation Profects, and Development of Blomass Estimates Based on Provincial Timber Inventories Feasibility Study on the Conversion of an 011/Gas Heating Plant at CFB Borden to a Biomass Fuel Plant https://www.w3.org/1998/Math/MathML"> - 231 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Development of a Mechanized Brush Harvester https://www.w3.org/1998/Math/MathML"> - 232 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Transfer of Nigrogen Fixing Ability from Alder to Birch Energy Plantations and Soll Nutrients Levels https://www.w3.org/1998/Math/MathML"> 12 - 234 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Total Tree and Merchantable Stem Biomass Equations for Ontario Hardwoods https://www.w3.org/1998/Math/MathML"> P - 236 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Biomass Prediction Equations for Twelve Commercial species in Quebec Forest Engineering Research Institute of Canada and K.C. Jones & Assoc. T.M. Thomson & Assoc. Ltd. Intergroup Consulting Economists Ltd., Winnipeg Manitoba. D. Oue11et (LAU-X-6OE) The Environmental Applica- tions Group Ltd., Toronto Ontario T.M. Thomson & Assoctates Victoria, B,C. Charles Turner & Associates Don M118, Ontario ELMS Design Inc., Ancanster Ontario Université Laval, Ste.Foy Ontario Ministry of Natural Resources, Kemptville, Ont I.S. Alemdag (PI-X-46) D. Ouellet (LAU-X-62E) https://www.w3.org/1998/Math/MathML"> P - 237 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Modèle de simulation pour la récolte de et biomasse https://www.w3.org/1998/Math/MathML"> P - 238 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Trial Conversion of Conventional Inventory Data to Biomass https://www.w3.org/1998/Math/MathML"> - 240 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Pilot Trial of a Forest Biomass Inventory https://www.w3.org/1998/Math/MathML"> P - 242 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> P11ot Study for a Canada Biomass Inventory https://www.w3.org/1998/Math/MathML"> P - 243 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Optimization of the RECUFOR Rotor https://www.w3.org/1998/Math/MathML"> P - 245 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Review of the ENFOR Production Program P-246* Development of Blomass Prediction Equations for Yukon Tree Spectes https://www.w3.org/1998/Math/MathML"> P - 247 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Trial Conversion of Conventional Inventory Data to Biomass Data in Nova Scotla P-248 Land Application of an Industrial Sludge to Hybrid Poplarplantations Plantations https://www.w3.org/1998/Math/MathML"> P - 249 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Preparation of Report on ENFOR Project P-138 Processing Biomass in a Central Location with the Separator-shear system https://www.w3.org/1998/Math/MathML"> P - 251 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Recovery and Transport of Roadside Biomass in Mountainous Terrain J.G. Routhier (LAU-X-53) D. Fowler Northland Associates Ltd. St. John's, Newfoundland Northland Assoclates Ltd. St. John's, Newfoundland Forest Engineering Research Institute of CanadaPointe Claire, Quebe Rolnte Clatre, Quebec Dendron Resource Surveys Ottawa, Ontario M.R.C. Massie G.D. MacQuarrie Dupont Canada Inc. Maltland, Ontario Dr. I.R. Methven Frederscton, N.B. A.W.J. Sinclair (BC-X-255) A.W.J. Sinclair P-252* Residential Fuelwood Supply and Demand in Greater Victoria and Vancouver https://www.w3.org/1998/Math/MathML"> - 253 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Socioeconomic Impact of an Integrated Fuel and Fire Production and Merchandizing System for the British Columbia Coast https://www.w3.org/1998/Math/MathML"> - 255 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Green Volume (Basic) Specific Gravity of Tree Species in the Prairie Provinces https://www.w3.org/1998/Math/MathML"> - 256 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Determination of Avallable Heat of Combustion Data for Canadian Woody Species P-257* Silvicultural Treatments to Maximize Biomass Production in Aspen Stands https://www.w3.org/1998/Math/MathML"> P - 258 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ovendry Mass and Volume Equations for Canadian Species 3-262 Biomass Growth and Yield Models for the Major Forest Cover Types of the Maritimes P-263* Domestic Fuelwood Consumption in Newfoundland Calibration of FORCYTE Simulation Model for Newfoundland Forest Types Ce11 Access for the 1984 National Biomass Inventory Coordination of the National Forest Biomass Inventory Program Compliation of porest Biomass Inventories for New Brunswick Compilation of Forest Biomass Inventories in Nova Scotla T.M. Thomson & Assoclates Victorla, B.C. Nawitka Renewable Resource Consultants Ltd., Victoria, B.C. University of A1berta, Edmonton, A.berta John M. Kryla B.J. Horton L.R. Roy Woodlot Service (1978) Ltd Fredericton, N.B. Northland Assoclates Ltd. Northland Associates Ltd. St.John's, Newfoundland T.M. Thomson & Associates T.M. Thomson & Associates Ltd., Victoria, B.C. New Brunswick Dept. of Natural Resources, Fredericton, N.B. Nova Scotia Dept. of Lands and Forests, Truro, N.S. https://www.w3.org/1998/Math/MathML"> P - 270 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Compilation of Forest Biomass Inventories for Manitoba https://www.w3.org/1998/Math/MathML"> P - 271 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Compilation of Forest Blomass Inventories and Collection of https://www.w3.org/1998/Math/MathML"> p - 272 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Collection of Forest Biomase Data on Uneurveyed Forest Lands in ontario https://www.w3.org/1998/Math/MathML"> P - 273 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Collection of Forest Biomass Data for the Prairie Provinces and Northwest Territories https://www.w3.org/1998/Math/MathML"> P - 275 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Collection of Forest Biomass Data for the Yukon https://www.w3.org/1998/Math/MathML"> P - 276 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Production of National Forest Biomass Inventory Report https://www.w3.org/1998/Math/MathML"> P - 280 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Harvesting of Forest Blomass for Energy Terminology Study https://www.w3.org/1998/Math/MathML"> P - 283 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Collection of Forest Blomass Data for Québec P-284 Effect of Acid Rain in the Development of Mycorrhiza P-285 Refinement, Evaluation, and Testing of FORCYTE Simulation Models Calibration of FORCYIE Simulation Model for Application in Central Canada Impact of Intensive Forestry on Denftrification Kinetics in Forest Soils https://www.w3.org/1998/Math/MathML"> P - 288 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Assembly of a Base Collection of Canadian Alnus Seed Manitoba Data Services Winnipeg, Man1toba British Columbia Ministry of Forests, Victoria, B.C. Dendron Resource Surveys Ottawa, Ontario Woodland Resource Services Edmonton, Alberta Paciflc Forest Research Ctre Dendron Resource Surveys Ottawa, Ontario Thérèse Sicard-Lussier Le Groupe Dryade Ltée Québec, Québec Université Laval, Ste.Foy, Quêbec. Dr. A. Fortin Univ. of British Columbia Vancouver, B.C. Dr. J.P. Kimmins University of Toronto, Toronto, Ontario Unfversity of Windsor, Windsor, Ontario (various contractors) P-289 Poplars and W111ows - Their Socioeconomic Impact in Canada P-291* An Analysis of Two Trials of a Portable Shear-type Residue Processing Syste P-292 Bconomic Evaluation of Wood Chip Production Alternatives for P.E.I. Impact of Heavy Fuel 011 and Natural Gas Prices on the Value Review of Commercial and Industrial Wood/Peat Energy in Atlantic Canada, 1978-83 and Beyond Energy Biomass Yield by Selected Fu1.1-Tree Harvesting Methods in Frozen Conditions https://www.w3.org/1998/Math/MathML"> - 296 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Identification of Logging Waste in the Vancouver Forest Region P-297 Field Testing of the Experimental Prototype of the Roll Splitter https://www.w3.org/1998/Math/MathML"> p - 298 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Report on European Congress on Economics and Management of Baergy in Industry ENFOR PROJECTS - CONVERSION SERIES https://www.w3.org/1998/Math/MathML"> C - 2 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ageegament, Selection, and Commtestontng of a Sma11-Scale Assessment, selectio Great Lakes Forest Research Centre Boller Study: Wood Fired Boller Feasibility Study Poplar Council of Canada Philip 0akley https://www.w3.org/1998/Math/MathML"> & G ⋅ H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Manning https://www.w3.org/1998/Math/MathML"> ( B C - x - 249 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> IEA Consulting Group Ltd. Charlottetown, PEI Robinson Consulting & Assoc. Victoria, B.C. Northland Assoclates Ltd. St.John's, Newfoundland Forest Engineering Research Institute, Pointe Claire, Quebec. Nawitka Renewable Resource Consultants Ltd., Victoria, B.C. Forest Engineering Research Institute of Canada and the Tennessee Valley Authority Sandwe11 and Company Ltd. Vancouver, B.C. B.H, Levelton & Associates Vancouver, B.C. Sanwell & Company Ltd. Vancouver, B.C. Performance Monftoring and Thermal Efficiency Determination of C-5 Energy Self-Sufficiency through Total Residue Utilization by Conversion to Energy and Production of Marketable Fuel https://www.w3.org/1998/Math/MathML"> C - 6 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Design, Construction, and Testing of a Pilot Scale Continuous Dewatering Device Hog Fuel Availability in British Columbla Evaluation of Wood Gasifier at Hudson Bay, Sask. The Social, Environmental and Resource Impact of Wood Gasification on Isolated Northern Comnunities Evaluation of a Fixed Bed Wood Gasifier Using chipped Round Wood as Fue1 Application of Fluid Bed Technology to the Gasification of Waste Wood 011 Replacement on a Pulp Mill Lime KIln Using Hog Fuel in a Lamb Wet-cell Burner Rapid Gasification of Wood Waste A Study on the Rapid Devolatilization/Hydrogenation of Blomass Material The Flash Pyrolysis of Wood in a Bench Scale Fluidized Bed P1lot Plant Investigation of a Wood Gasifier for Generation of Electricity Catalytic Pyrolysis and Gasification of Lignocellulosic ADI Limited, Fredericton, New Brunswick. Stott Timber Corporation Sydney, N.S. Stake Technology Ltd. Ottawa, Ontario P.W. Appleby Saskatchewan Power Corp. Saskatchewan Power Corp. Manttoba Research Council A. Dalvi I.G. Rowe H.G. Brandstatter S.N. Basu; P.C. Stangeby D.S. Scott G.A. Weisserber E. Chornet Development of Techncial Basis for Assessing Wood Gas1fier Design and Operation https://www.w3.org/1998/Math/MathML"> c - 44 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Further Studies on Wood Liquefaction through Operation of a Fontinuous/Semi-continuous Wood Liquefaction Unit 27. https://www.w3.org/1998/Math/MathML"> C - 48 ( 1 ) * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Study of the Conversion of Lignocellulosic (Aspen) Materials to Lfautd Frels and Chemicals (Aspen) Materials Supercritical Gas Extraction of Chemicals from Forest 28. Products; Phases I-III Characterization of Tar Produced during Gasification of Wood App11cation of a F1uidized Bed Gasifier to Conversion of 29. Forest Biomass to an Energy Source Study on the Design and Optimization of Biomass Liquefaction Process Unite Biological Transformation of Waste Forest Blomass to Humus for Use as an Agricultural Sol1 Amendment Evaluation of Fuels for Operation of a Fixed-Bed Downdraft Commercial Gasifler Wood Waste Fuels Preparation and Hand11ng Cost Benefit Analyels of Systems Using Fuel Gas or steam for Drying of Wood Waste Feedstocks Development of a Motature Reatetant Denoffted Solfd Fuel from Forest Blomass 30. D.W. Bacon; J. Downie D.G. Boocock; D. Mackay J.M. Pepper; R.L. Eager J.M. Pepper; R.L. Eager J. Howard D.W. Duncan G. Gurnik; K. Luke SNC Inc., Montrea1, Quebec A. McNaughton; Forintek Canada Corp. B.H. Levelton & Assoc. Sandwell & Company Ltd. B.H. Levelton & Assoc. Blowass Material, Phase II 31. A Kinetic and Catalytic Study for the Optimization of the 32. Development and Small-Scale Demonstration of a Reliable on-line Monitor for the Continuous Measurement of Feedstock Molsture Content https://www.w3.org/1998/Math/MathML"> - 111 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Evaluation of Wood Waste Energy Conversion Systems, 1980 Edition Study on the Generation of Design Data for Blomass Liquefaction P11ot Plant 33. Wood Residues as Fuel Source for Lime Kilns Evaluation of Infrared Molsture Analyzers for Hog Fuel Bin and Stlo Destgn for Blomags Matertals Phase I Identification of Hydrocarbon Emfissions from Industrial Combustion of Forest Blomass/011 Mixtures A Study of Pyrolytic Explosion for Subdividing Wood Ultrapyrolysis of Cellulose and Wood Components Advanced Feedstock Preparation System for Large-Scale Hog Fuel Bollers Development and Demonstration of a Sma11-Scale Gasiffer for Wood Waste RF Transmission Line Method for Feedstock Moisture Content Determination 34. P.C. Stangeby; S.N. Basu Forintek Canada Corp. Ottawa, Ontarlo T.Y. Yung B.H. Levelton & Assoc. N.E. Cooke; J.M. Moffatt R.J. Ph11p; M.K. Azarnfouch S. Prahacs N. Brundalli; 0. Martinez Charles J. Wiesner John Stone & Assoc. Univ. of Western Ontario Industrial Process Heat Eng. Ltd., Vancouver, B.C. Industrial Process Heat Engineering Ltd. Carleton University Ottawa, Ontario C-235 Test Program on Bollers Burntng Wood Refuse C-240* Comparative Study of Laser Spectroscoplc Techniques for Analysis of Biomass Gasifier Products https://www.w3.org/1998/Math/MathML"> - 253 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The Development of Machinery for the Recovery and Preparation of Biomass Feedstocks for Conversion Systems at a Central Full Tree Processing Complex -254* Forces Exerted on Restraining Structures by Hog Fuel Piles https://www.w3.org/1998/Math/MathML"> C - 256 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Development of a Method for Characterizing Pyrolytic 011s Effect of Particle Size on Gross Heat of Combustion of Wood A Comparative Assessment of Porest Biomass Conversion to Bnergy Forms Status of Blomass Feeder Technology Development of a Dense Phase Pneumatic Conveying System for Biomass Materials Further Development of Processes for the Conversion of Wood to Liquid Fuels Through the Operation of a Continuous Semicont1nuous Liquefaction Unft -293* Research on Gasification of Wood in a Plasma Pyrolysis Unit https://www.w3.org/1998/Math/MathML"> C - 295 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Study of Blomass Feedstocks from Poplar Wood Using Supercritical Fluids C-299* Pretreatment Methods for Enhancing Conversion of Lignocellulosic Material to Liquid Fuel Canadian Boller Society & Environcon Eastern Ltd., Toronto, Ontarlo MPB Technologles Inc. Ste.Anne de Bellevue, Que. D.D. Hamilton W.C. Edwards H. Ménard; C. Roy J.M. Kryla Simons Resource Consultants B.H. Levelton & Assoc. Vancouver, B.C. B.H. Levelton & Assoc. B.C. Research Vancouver, B.C. D.G.B. Boocock; D. Mackay Resorption Canada Ltd. E. MCDona1d; J. Howard Forintek Canada Corp. INTEGRATED FOOD-ENERGY PRODUCTION SYSTEMS E.L. La Rovere FINEP - Financiadora de Estudos e Projetos Av. Rio Branco, 124 , Rio de Janeiro, 20042 , Brazi1 Summary The sharp increases of oil prices in the international market during the seventies put a heavy burden on the trade balances of oil importing developing countries. For those third world countries having large land availabilities and suitable climatic conditions, the domestic production of energy from biomass as a substitute for oil products is seens as a hopefu] alternative. However, if appropriate measures are not taken the production of bio-energy may be achieved at the expense of the agricultural performance related to its traditional goals: providing food, industrial feedstocks and export products Brazil was the world pioneer in launching an important national alcohol programme in 1975. Today more than 10 billion litres a year of alcohol are produced from sugarcane and more than one and a half million cars run on pure alcohol engines. Besides that, a11 the gasoline consumed in the country has an alcohol content of https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on average. However, the programme relies on capital-intensive big plantations with disruptive social and ecological effects. The best agricultural land, government capital funds and subsidies, as well as private savings, are being channelled into the production of alcohol from sugarcane aiming to reduce the oil import bill at the expense of the food production for the internal market. Integrated food-energy production systems offer a promising alternative of better utilisation of biomass resources, avoiding the potential risk of competition between fod and energy production. In Brazil, the need for establishing an alternative model of producing energy from biomass, in opposition to the way that alcohol production is being developed, led to an effort on research, development and demonstration for integrated food-energy production systems. A number of programmes and projects applying this concept are being sponsored by FINEP. Research and development in this field presents a wide range of possibilities for south-south cooperation. The main findings of an international seminar jointly organised by FINEP, UNESCO and the United Nations University, held in Brasilia (September 1984) indicate the large scope for scientific and technological cooperation on the food-energy nexus and related fields among third world countries. I. L'Interface Enérgie/Alimentation au Tiers Monde L'approvisionnement en 'énergie et aliments est une dimension absolument essentietle du développement socio-économique, ca la satisfaction de ces deux types de besoins est une condition sine qua non de la survie humaine. L'augmentation des prix du pétrole dans le marche international, qui s'est oroduite au cours des ann'. 70 a difficulté 1é] buation de la consommation renergétique des pays du Tiers Monde importateurs de petrole avec laggravation de la situation de leurs balances de paiements. La production interne d'énergie a partir de la biomasse, dans des pays a grande abondance de terres disponibles et conditions climatiques appropriees, a ete consideree comme une alternative prometteuse pour rendre viable ' expansion de la consommation energétique, en se substituant aux dérivés de pétrole. cependant, même dans des contextes avec abondance de terres disponibles, la production de bioenergie peut se fajr aux dépens de la performance agricole mesurée par rapport a ses objectifs traditionnels: production alimentaire, approvisionnement de l'industrie en matieres premieres et produits d'exportation. Le risque de compromettre l'augmentation de la production alimentaire merite une attention particuliere, en vue des niveaux precaires de consommation de calories e protéines de la population dans la plupart des regions du Tiers Monde. En plus, les petits producteurs, responsables d'un apport important à Ta production alimentaire, en général, se trouveront dans des conditions disavantageuses pour concurrencer les putssants interêts commerciaux de la production d'énergie (qui épargne des devises) dans 1 'approvisionnement en ressources essentielles comme intrants, credits, main dioeurre qualifié, facteurs de production rares dans ces pays. 1. Le Concept de Systèmes Intégrés Dans ce contexte la poursuite d'une integration entre la production d'énergie et d'aliments apparait comme un essai de concévoir des solutions technologiet d'aliments apparait comme un essai de cancevoir des solutions technologe propose une planification "ex-ante" de "utilisation du sol, des déechets agricoles, animaux et forestiers et des ressources aquatiques, mettant en valeur les complementarités possibles au lieu de la simple juxtaposition de grands projets intensifs en capital, si typiques des essais de modernisation de l'agriculture aux tropjques. Á travers la promotion de cultures associées. l'utilisation des résidus agricoles pour produire de l'énergie et réciproquement, la mise en valeur des résidus de la production energetique dans les activités agricoles, on cherche à obtenir un effet de sinergie. La productivité globale du systeme serait donc superieure a l adition des deux productions (énergétique et alimentaire) effectuees separemment avec ' 'emploi de la même quantité de ressources. De cette façon les impacts sur 1 'environnement seraient réduits a un niveau minimum et on pourrait rendre viable une décentralisation de la production avec les maximum d'impacts sociaux bénéfigues pour les petits producteurs. Le defi à ètre rélevé par la recherche consiste donc dans la conception, experimentation et mise a point de differents schémas technologiques appropries aux ecosystemes et contextes socioeconomiques divers, qui soient a la fois economiquement viables, socialement désirables et soutenables sur le plan écoloqique. 2. Explorant les Possibilitēs de Coopération Sud-Sud Pionnier au monde dans la mise en oeuvre d'un programme de production à grande échelle de combustibles liquides a partir de la biomasse, a travers le PIan National Alcool, le Brésil occupe aussi une place de relief dans la scene internationale par ses activités de recherche et développement de systemes de production intégrée d'aliments et energie. On peut mentionner, parmi d'autres les projets de systèmes d'auto-approvisionnement energetique developpes par l'EMBRA^ et le Programme des communautés Agro-Energétiques crée par la finep*\star Cet effort a attire l'attention de l Université des Nations Unies-UNU, qui a recemment lance, a la fin 1982, un programme d'etudes sur linterface energie/ alimentation (1). Ce programme, qui vise particulièrement à la promotion https://www.w3.org/1998/Math/MathML"> d ' un https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> échange scientifique et technologique au niveau international dans ce domaine, a soutenu la visite d'une mission bresilienne au senegal, en Inde et an Chine, réalisée en novembre-decembre 1983 . Son but a été celui de favoriser líchange d'informations, de résultats et d'approches de la recherche dans ce domaine parmi chercheurs et responsables de la planification de differents pays en voie de développement, qui doivent rélever des défis et contraintes du même genre. Evidemment, cet appui a la coopération scientifique et technologique internationale ne voulait pas promouvoir une simple transposition de 'experience brésilienne a la réalité africaine ou asiatique, et vice-versa, ce qui serait a 1 'opposé de T'approche mème de concévoir differéntes configurations technologiques de systemes integres selon les specificites de chaque contexte. Au contraire, le type d'échange sud-Sud a poursuivre, a notre avis, doit s"inscrire dans l esprit de la loi, ennoncee pour llistoire mais valable aussi pour l'analyse comparative internationale: "elle ne fournit jamais des modèles à suivre, mais seulement des anti-modèles à superer. Cet article présent quelques observations effectués pendant le voyage, d'une duration totale de cinq semaines (une semaine au sénéegal, deux en Inde et duex en Chine, grosso modo) https://www.w3.org/1998/Math/MathML"> ( 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Nous n'avons donc la pretension de traiter d'une facon systématique et rigoureuse un sujet si vaste et complexe comme celui de la réatité agróénergétique des regions diverses des pays visités. Nous nous bornerons ici a enregistrer quelques impressions recuillies au long de ce parcours, et qui donnent lieu a des reflexions sur les possibilités de coopération scientifique et technologique entre le Brési1 et les pays visités, dans le domaine de la recherche et developpement de systemes integrés de production d'énergie et aliments, et domaines liés. 3. Le Cas Brésitien 4. IV.i. Un bref bilan du Plan Alcool La conception de programmes de recherche et developpement de systemmes integres de production d'énergie et aliments au Brésil est nee de 1 'évaluation de la performance du Plan Alcool. Ses resultants sont indéniablement positifs en termes de l'augmentation de la capacite de production d'alcool dans des délais très courts: elle atteint aujourd'hui environ 8 milliards de litres par an, faisant rouler plus d'un million de voitures a f'alcool pur, et permettant un apport de plus de https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d alcool dans de melange carburant essence/a Tcool. Cependant, il existe certainement un énorme potentie" d'augmentation de la productivite du procedé d'obtention de /'alcool a partir de la canne a'sucre, soit au niveau agricole (production de la canne a'sucre) comme au niveau industriel (production de T'alcool dans les distitleries), a' travers introduction de procedes technologiques plus performants, ce qui permettrait d'améliorer l'éfficacité economique due Plan Alcool et de reduire son impact dans l'augmentation du niveau des prix.

Empresa Brasileira de Pesquisas Agropecuarias - l'entreprise de recherche agricole du Ministère de 1'Agriculture brésitien.

** Financiadora de Estudos e Projetos - 'agence pour le financement de orojets de recherche et dêveloppement technologique du Ministëre du Plan brésitien. La réussite des objectifs sociaux du Plan Alcool a eté fortement limitée par le modele adopté pour https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> expansion de la production d'alcool, basé sur https://www.w3.org/1998/Math/MathML"> 1 ' c t r o i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de facilites de financement pour i implantation de distilleries, de grande taille (120 mille litres par jour et plus) aux grands proprietaires de vastes monocultures de canne d sucre du genre "plantation" ou la main d"oeuvre est employee dans des condions tres precaires, aggravees par un chomage saisonnier. Duant à 'aspect ecologioue, il faul résoudre avec urgence le probleme de traitement des énormes volumes de vinasses résiduelles produites dans les distilleries (10 a 17 litres par litre d'alcool produit) et très polluantes des cours https://www.w3.org/1998/Math/MathML"> d ' eau https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a travers https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> emploi de procedés technologiques nouveaux qui réduisent le volume de ces résidus et rendent possible son utilisation économique (par exemple, la digestion anaérobie). Enfin, it faut rappeler que parallelement à 'augmentation de la production d'alcool on remarque une diminution de la production par tete des principaux produits alimentaires de base et une élévation du niveau des prix des aliments superieure meme aux taux d"jnflatjon, sans precedent dans l nistoire économique du pays, récemment enregistres. Sans approfondir la polemique sur le degré de resonsabilite du Plan Alcool dans la production de ces deux phenomenes, nous pouvons constater que fiexpansion de la surface cultivee avec canne a sucre a déjà commencé a deplacer des cultures alimentaires, au moins dans les régions à frontiēre agricole quasiment fermée, comme 1 'état de São Paulo (3). En tout cas, le risque potentiel de compétition avec la production https://www.w3.org/1998/Math/MathML"> d ' aliments https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> devra être pris en compte avec attention toujours croissante dans le futur, au fur et a mesure que la production d'energie de biomasse augmente, soit a' travers le Plan Alcool comme par d'autres programmes dont on examine la possibilite de creation (huiles végetales, alcool a partir d'autres matieres premières, etc.). 5. IV.ii. Lessystèmes intégrés_de_production_d'énergie_et_al liments.au Brésị Les premiers systèmes intégrés de production d'ênergie et aliments proposes par la communaute technico-scientifique bresilienne étaient centrés dans leur conception sur la combinaison delements divers autour d une microdistillerie d'alcool. Le renforcements divers autour d'une micro-distillerie d'alcool. Le renforcement du PTan Alcool a partir de l979 a eveille un grand interêt sur la possibilite de se decentraliser la production d'alcoo travers 1'implantation de micro et mini-distilleries (500 a 20.000 litres par jour), pour augmenter les bienfaits sociaux et ininimiser linpact ecologique du programme. Une polemique aigue sur la viabilite technoeconomique de la production d'alcool en petite eche le s'est alors instauree. Aujourd" hui, on semble s'orienter vers la conclusion que, meme isolee, la micro-distillerie est economiquement viable et se compare bien vis-a-vis de la production d'alcool en grande échelle (4). En 1981, 1'EMBRAPA a lancé, dans le cadre de son Programme National de Recherches sur https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Energie, une ligne de recherche et développement de systemes de production de bioenergie en milieu rural. La configuration de base des huit systèmes en operation dans les unites de terrain de l'EMBRAPA rassemble les élements suivants:

micro-distillerie d'alcool de canne a sucre et sorho doux fou manioc, beterrave)

élévage bovin sous stable

biodigesteur de déchets animaux (et/ou bagasse, vinasses)

Cette configuration de base, avec quetques variations, est aussi appellée par 1'EMBRAPA de systèmes d'Auto-Approvisionnement Energétique, dans la mesure où ils veulent essentiellement assurer ' auto-suffisance energétique au niveau de la proprieté rurale (5). Une configuration semblable, mais plus complète, incluant aussi la culture en milieu aquatique de jacynthes d'eau et l'élévage de poissons, est proposee dans le systeme Intégré de Production de Bioénergie et Proténe Animale. Ce systeme, Leste dans 'unite de terrain du secretariat a fingriculture de íetat de Rio Grande do Sul, a Capela de Santana, vise explicitement a la production d'un surnlus d'ónergie (sous la fome d'alcool) et d'aliments (grains de sorgho, viande de boeuf et poissons) pour la commercialisation. produit dans une micro-distillerie (500 litres / jour) a'partit de la canne a sucre (25 hectares) et du sorgho doux (41 hectares). Les feuilles et pointes de canne et de sorgho, et une partie de la production de grains de sorgho, sout utilisées dans l'alimentation de 80 têtes de bétail. Une partie des bagasses de canne et de sorgho, aussi bien que la proteine qu'on peut obtenir a partir de la jacynthe d'eau, peuvent etre testees avec le meme but. Le biodigesteur (100 metres cubes) produit, a partir des déchets animaux, du biofertilisant pour les champs de canne et sorgho et pour les bassins de poissons, en plus du biogaz qui peut être utilise pour la production de vapeur dans la micro-distillerie ou pour faire face aux besoins énergetiques de la population rurale, Une partie de la bagasse de canne et de sorgho se destine a la chaudiere de la micro-distillerie, et le surplus est disponible pour 1'utilisation a 'exterieur du systeme, comme matiere premiere de la fabrication de pate a papier ou comme combustible. La vinasse est utilisee pour la production de jacynthes d'eau et, ensuite, clarifiee, comme base de 1"activite de pisciculture ce qui évite la polution et contribue a l'obtention de protéine an imale et végetale (6). Une analyse préliminnaire de viabilite économique (7) indique que ce systeme intégre présente une rentabilite superieure a celle des distilleries d'alcool isolees (soit les micro comme les macro), meme sans prendre en compte dans le calcul quelques activites qui demandent encore à etre mieux eprouvees du point de vue technologique (utilisation de proteine obtenue a partir de jacynthes d'eau et de la bagasse dans 1 'alimentation du betail) ou commercial (exportation des sous-produits bagasse et biogaz a l'exterieur du système). Le programme de Communaùtes Agro-Energetiques propose par la FINEP (8) suggere la generalisation de l'approche qui mème de la micro-distillerie au système intégré, c'est a' dire: a partir de chaque contexte socio-économique et ecosysteme specifique, concevoir une configuration technologique approprię a la production integree d'energie et aliments, selon des critëres de viabilite economique, de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ampleur des bienfaits sociaux et de maitrise des impacts ecologiques a long terme. La methodologie pour concevoir le complexe agro-energétique doit partir du bilan des ressources naturelles disponibles et due diagnostic socio-economique etabli avec le maximum de participation de la communaute locale. Il est encore suggere que https://www.w3.org/1998/Math/MathML"> 1 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> implantation, le suivi et l'evaluation du systeme integre combinent un niveau de recherche et developpement avec un stade de demonstration, de facon a minimiser le risque technologique a etre supporte par les petits producteurs ruraux. Le degre de sophistication des options technologiques retenues doit etre compatible, ou bien rendu compatible par moyen https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> un processus pedagogique approprie, avec maximum d'autonomie au niveau local dans la fabrication, l'operation et le maintien de 1'equipement néecessaire. Enfin, deux orientations sont áviter: (a) la simple installation d'équipements chers et sophistiques pour la mise en valeur de sources non conventionnelles d'énergie (capteurs solaires, éoliennes, biodigesteurs) visant a la satisfaction des bésoins deméstiques en énergie de la population rurale, comme l'on peut remarquer dans quelques projets de ce genre. La cojugaison de la production energetique avec une activite agro-industrille, capable de fournir un surplus economique a' la communauté locale, est absolument essentielle si 1 on veut démontrer la viabilite économique de la généralisation de l'experfence pilote a d'autres communautes rurales. (b) la production d'un système intégré donné, "standard", dans des contextes divers à etre adaptés pour rendre possible son utilisation. Au contraires, les procédés technologiques et les formes d'organisation sociale associées aux systemes integrés doivent varier et constituer des configurations differentes selon les particularités de chaque cas. Un projet de recherche et développement d'une communaûté agro-énergétique dans la région de Tabuleiros de Valenca, au sud de Salvador (Bahia), a eté démarré par la CEPLAX https://www.w3.org/1998/Math/MathML"> ( * ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et le CEPED https://www.w3.org/1998/Math/MathML"> ( * * ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , avec soutien de la FINEP https://www.w3.org/1998/Math/MathML"> ( 9 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Son but est de concevoir et implanter un systeme integré de production d'energie et aliments basé sur le developpement de technologie appropriee pour liextraction d'huille de palme en petite échelle, avec la mise en valeur des sous-produits, et sur l'association des cultures d'haricots,mais, manioc, bananes, etc., avec les palmiers a huile, occupant les interstices de la plantation de palmiers (espacés de 10 en 10 metres). L'huile de palme produite peut être utilisée comme carburant, car elle se substitue tres bien au gazoil apress son craquage catalytique, déja testé avec succès dans les raffineries de PETROBÁS(***) et, au stade de laboratoire, par le CEPED (oū on a obtenu jusqu'a https://www.w3.org/1998/Math/MathML"> 720   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de "gazoil végetal" a' partir de 1 tonne d'huile de palme). L'extraction de https://www.w3.org/1998/Math/MathML"> 1 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> huile de palme dans une micro-usine ( 1.5 tonne/heure de matiere premiere) performante, avec la mise en valeur des sous-produits dans la production d'éneraie, fertilisant et matieres premieres industrilles, pernettrait de rendre viable sa production par une cooperative de petits paysans, gardant une tradition de polyculture qui éxiste deja dans la region. Du point de vue agronomique, en plus de l'augmentation de productivité des palmiers a huile, an cherche t travers tes cultures associées d'obtenir un degré plus éléve d'auto-suffisance alimentaire et d'augmenter les recettes de commercialisation de matieres preinieres pour la communauté locale. (*) Comissão Executiva para a Lavoura Cacaueira - agence du Ministere de 1'Agriculture responable, dans la région, de la culture du cacao et du développement agricole. https://www.w3.org/1998/Math/MathML"> ( * ⋆ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Centro de Pesquisa e Desenvolvimento - centre de recherche et développement technologique de l'etat de Bahia. (\star) Entreprise d'Etat pour l'exploration, production, raffinage, transport et distribution de petrole et ses dérivés. D'une facon génerale, 1'approche de développement de systèmes intégrés de production dínergie et a liments présente encore un grand potentiel à être exploité dans le cas du Brésil: on peut souligner son interèt particulierèment pour les zones d'expansion de la frontiere agricole, comme les savannes brésiliennes ("cerrados") et la région amazonienne. 6. References Sachs, Ignacy. The Food-Energy Nexus, Subprogram Proposa 1, United Nations University, Paris-Tokyo, October https://www.w3.org/1998/Math/MathML">   11 982 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> La Rovere, Emilio Libre: South-South Cooperation in the Framework of UNU's Food-Energy Nexus Subprogram. Report of the visit of a Brazilian team to Senega1, India and China, April 1984. Coordenadoria de Planejamento e Avalicao do IAA/PLANALSUCAR: A cultura da cana-de-acucar e a evolcuao do uso da terra em Sao Paulo, 1974 a 1979. CNPq: Avaliacao da Viabilidade Tecnico-Economica de Microdestilarias de Alcool, Brasilia, 1983.

Corgatti Netto, Agide: Yeganiantz, Levon: EMBRAPA's Food-Feed-Bio-Energy Production Systems, EMBRAPA, Brasilia, 1982 .

Porto, Rogerio Ortiz: Bio-Energy and Animal Protein Production System Capela de Santana; Resource Management and Optimisation, Vol.3, No.1, 1983.

Tolmasquim, Mauricio Tiomno: Avaliacao de Sistemas Integrados de Producao de Energia a Alimentos; these en elaboration pour la COPPE/ UFRJ.

Baiardi, Amilcar, La Rovere, Emilio Lebre: Food-Energy Integrated Development Schemes in Brazil: FINEP's Agro-Energy Communities Programme; Resource Management and Optimization, Vol.3, No.1, 1983 .

Aguiar Sergio Catao, 0liveira, Hermano Peixoto: Agro-Energy Community Tabuleiros de Valenca; Resource Management and Optimization, Vol.3, No. 1, 1983 . THE USE OF WASTES AS A SOURCE OF ENERGY FOR THE UK

DR R PRICE Energy Technology Support Unit, Harwe11, England Summary In the UK interest in biofuels is focussed on the use of wastes as a fuel rather than energy crops. This is mostly because of the pressure to use a restricted land area for producing higher value food and timber crops. However wastes are attractive in their own right as fuels particularly since there are often environmental benefits to be gained as well as fuel costs to be saved. The paper describes the UK programme of waste-as-fuel demonstration projects and some of the lessons which have been learned. 7. INTRODUCTION Biofuels are fuels which, directly or indirectly, have an organic origin, They include not only agricultural and forestry energy crops of various sorts, but also waste products derived originally from these sources. Wastes can come in a variety of types, shapes and sizes. Domestic rubbish ranges from teabags to bedsteads but commercial, industrial and farm wastes are fairly well defined. Paper, plastics and packaging make up the bulk of commercial and industr al waste, but in addition, there are residues of manufacturing processes. On farms, animal wastes, crop residues and straw are produced in large quantities. In developing a programme to research or promote the use of biofuels, each country will place a different emphasis on the relative importance of wastes to energy crops. The UK view is much influenced by our own particular national situation. We have a relatively densely populated country which is not self sufficient in food production Moreover we produce less than one tenth of our timber requirements. On the other hand we are in the fortunate position of being a net energy exporter. In addition we are relatively well endowed with fossil fuels, the most notable of which are known coal reserves amounting to at least 400 years supply at the current rate of use. Bearing in mind that both food and timber are of much higher value per kilogramme than energy crops, it becomes understandable why our first priority is to use our limited land area for the former more conventional uses. https://www.w3.org/1998/Math/MathML">   UK FOOD, TIMBER AND ENERGY PRODUCTION: TABLE   1   The UK produces:     -   63 %   of its food requirements (by value)     -   9 %   of its timber requirements     -   105 %   of its energy requirements   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Wastes, on the other hand cannot be ignored; if they are not exploited they have to be disposed of in some other way. In the UK, this includes burying large quantities of refuse in landfill sites, releasing treated industrial effluent into waterways and burning unwanted straw in the fields. Where organic wastes can be used as fuels, there are therefore often associated envirommental benefits. In many cases these can be translated directly into financial savings, through savings in waste disposal costs. The value of environmental benefits together with associated fuel savings can often therefore make the use of waste as fuel an attractive option. Work is now well advanced in the UK Department of Energy" https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> "Waste as Fuel Programme". Initially studies looked at the size of the resource of usable waste, determined its nature, and investigated where it could be used sensibly and economically. These showed that wastes totalling over 22 million tonnes of coal equivalent are technically available for use as fuel each year, and over a quarter of this amount could be used economically at today"'s energy prices. Technologies for handling, treating and burning wastes were also studied to determine how they should be developed further and what new techniques would be necessary to improve technical and economic viability. Many of these technologies are in principle available but there has been a reluctance to move towards using them because of fears about associated risks, high capital costs and reduced convenience. Our first priority has therefore been to move towards a comprehensive programme to demonstrate how and under what conditions it is sensible to use wastes as fuel. Under the Energy Efficiency Demonstration Scheme we are planning a total of 56 demonstrations of the use of domestic, industrial, commercial, agricultural and wet wastes. This will cost about els millions, of which the UK government will pay one quarter, but is expected to stimulate energy savings of around 1.8 million tonnes of coal equivalent per year in the longer term. 25 of these projects are now under way and some of them are described in this paper. UK WASTE-AS-FUEL DEMONSTRATION PLAN: TABLE 3 WASTE PROJECTS COST TO GOVT. Ek REPLICATION POTENTIAL 000 tce/y Domestic Industrial Agricultura1 Wet 31 9 1,905 2,785 812 560 514 482 761 240 TOTAL 8 6,263 1,786 There are several different ways of using waste as a fuel. Dry materials can be burnt directly to provide heat and even those with a higher moisture content may be suitable for combustion after some drying and processing Wastes too wet to burn can best he converted to fuel by anaerobic digestion, biological breakdown in the absence of oxygen, producing methane gas. The method adopted will depend on the nature of the waste, where it occurs and where it will be used as a fuel. These are the two techniques which are nearest to commercial use there are others, such as methods of conversion to liquid fuels which may offer some promise in the longer term if early research is successful and if conventional fuel prices continue to rise. 8. COMBUSTION The principle of burning waste to provide useful energy is not new. However in recent years, increases in the price of fuel coupled with technological improvements and a growing awareness of the need to find new ways of dealing with waste have renewed interests in combustion. It is now the most advanced technique available for utilising the energy content of waste. Even after separation from its non-combustible components, waste has different properties from more conventional fuels, and has to be burnt either in specially designed equipment or in modified coal-burning systems. Several technical options are available. It can be burnt with Iittle or no pre-treatment in large incinerators or purpose designed boilers, or it can be processed to a greater or lesser degree so that it can be used in a smaller, simpler and cheaper furnace. There is obviously a trade-off between the cost of processing and the cost of the furnace equipment. The system adopted will depend on the nature of the waste, the scale of operation and the pattern of heat use. 9. Domestic Waste Although most of the domestic waste in the UK goes directly to landfill, it is becoming more difficult in urban areas to dispose of it in this way. Suitable sites are becoming increasingly scarce and in many cases waste is transported considerable distances for disposal. Local Authorities are faced with rising transport costs and a growing reluctance of residents near disposal sites to accept other people's rubbish. Burning waste can provide useful heat; it also reduces the volume which must be dumped and improves the economics of disposal. Because domestic refuse consists of a wide range of materials, the cheaper alternative is to pretreat the refuse and then burn it in a smaller boiler. At the Great Coates Works of Courtaulds Ltd., in Grimsby, domestic waste and coal are used to feed two chain grate stokers, firing boilers which are each rated at https://www.w3.org/1998/Math/MathML"> 20,000   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , raising https://www.w3.org/1998/Math/MathML"> 70,0001   b / h o u r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of steam. They are normally coal fired, but have been adapted so that they can operate on a mixture of coal and shredded refuse Pulverised and screened waste is supplied to Courtaulds by Humberside County Council. The prepared waste is blown into the combustion space of the boilers, where it burns principally in suspension with a proportion landing on the moving grate where combustion is completed. The project has been supported by EEDS and has been monitored for two years to determine its effectiveness as an energy saving measure. Up to https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the coal can be replaced by refuse without seriously affecting the combustion efficiency. Such a system could prove attractive to sites where Iarge coal fired boilers are already installed and where cooperation with the Local Authority can be established. For smaller boilers, there are also advantages in making a preformed fuel out of domestic waste before it is burned. Refuse derived fuel (rdf), as it is known, is made up of hard pellets of compressed waste with calorific value of around https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of that of coal and with an ash content of around https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The pellets are made by shredding, sorting, compacting and then drying the refuse before pelletising it. Two EEDS projects aim to show that rdf is a cost-effective alternative method of waste disposal where direct landfill is not available, or where refuse disposal costs exceed around e10 per tonne. Merseyside County Council has set up a company, Merseyside Waste Derived Fuel, to manufacture rdf from the shredded waste output of its pulveriser plant at Huyton. The total output of this plant will be sold to Associated Heat services Ltd, who will burn the fuel in a multi-fuel fluidised bed boiler plant. These projects represent an important step forward in waste utilisation technology and are being carefully watched by other Local Authorities who have problems with waste disposal. Already the West Midlands County Council is installing similar equipment at its Castle Bromwich incinerator site. 10. Commercial and Industrial Waste Unlike domestic refuse, much of the waste produced from commercial and industrial activities is easier to segregate and use as a fuel. In addition there is normally a demand for heat (either process or plant heating) close to the place where the waste is produced. There are several technical options available and the most appropriate one for a particular site will depend on the amount of waste being produced, the heat demand and the type of boiler plant already installed. Broadly speaking there are two main approaches. The material can either be burned directly in an incinerator plant (which, because the waste can be preselected, will be simpler and cheaper than the incinerator used for domestic waste and so can be operated economically at a smaller scale), or it can be shredded and burned with or without coal in a boiler. To demonstrate the economics of burning the waste directly, Freemans (London) Ltd, a mail order company, have installed an incinerator at their Peterborough factory. This has been running since 1982 and results from the monitoring are now available. Basically the system consists of a starved air incinerator which is producing https://www.w3.org/1998/Math/MathML"> 1800   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as hot water for space heating, consuming 16 tonnes of waste packaging material each week. The waste is fed to a primary combustion chamber with a limited air supply so that it secondary chamber where sufficient air is introduced to complete the combustion. Energy savings of about 270 tonnes coal equivalent (tce) have been achieved, giving a payback time of around four years on a capital investment of https://www.w3.org/1998/Math/MathML"> E 143,000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . If the quantity of waste and the heat load were more closely matched, a payback of three years should be realistic. This shows that the economics of waste combustion are dependent on matching the size of the system to the size and nature of the demand. In another EEDS project, a retail store in Leeds city centre is being heated by the combustion of shredded waste. Schofields (Yorkshire) Ltd generates some 12-13 tonnes of general commercial waste each week. A waste Fired boiler rated at https://www.w3.org/1998/Math/MathML"> 1220   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has been installed which has a fixed bed above which the fuel is sprinkler fed. The design has a large furnace volume which appears to be highly suitable for waste burning and also incorporates auxiliary gas burners to allow total firing by gas if necessary. The reduced energy use achieved with this system is expected to save Schofields around e24, 000 per year. Taking into account lower electrical and disposal costs adds further savings of E15,000 per year. With an investment cost of 130,899 for the system this should give schofields a payback period of 3.3 years. Some industrial waste is peculiar to an industry. A demonstration project with a company that remotılds tyres fits into this category. At Colway Tyres Ltd., over 750,000 scrap tyres have to be disposed of each year. For many years this has presented the company with a major problem, costing them something like f65,000/year. They have now installed a shredder and controlled air incinerator which consumes about 24 tonnes of tyres esch week. The primary chamber of the incinerator rotates slowly to ensure complete combustion of the fuel, while the secondary chamber remains static. The exhaust gases are scrubbed of sulphur dioxide, to prevent the possibility of acid pollution. The waste heat boiler has an output of https://www.w3.org/1998/Math/MathML"> 1230   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and provides the total requirement for process steam, space heating and domestic hot water at the Eactory. Colway Tyres expects to save about f88,000 per year in fuel costs which, when added to the savings in the cost of disposal, give the company a payback time of just under two years for its investment of £269,053. 11. Farm Waste Every autumn, UK farmers are criticised for burning straw in the fields after harvesting. It is a simple and quíck means of disposal which clears the land and provides a fertilizer for the following year's crops. However, it is a nuisance which produces many complaints. Approximately https://www.w3.org/1998/Math/MathML"> 13.5 m i l l i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes of straw are produced at present each year in the UK. Of this, about half is used as animal food and bedding and the rest is either burnt in the field or ploughed in By developing the appropriate technology, it should be possible to extend its use as an economic fuel. According to figures produced recently, straw could make a cost- effective contribution of over 1.3 Mtce per year to the UK energy supply by 2000. Already many farmers have installed boilers that can burn straw for heating farm buildings. For them, it is cost-effective, a convenient means of disposal and incurs no transport costs. Today, approximately 166,000 tonnes of straw are used mainly for farmhouse heating. By 2000 , it is expected that farmers will be heating glasshouses, animal houses and crop drying units on a much larger scale and that 1 million tonnes of straw be used anuually in this way. fuel away from the farm, there are certain limiting factors which have to be taken into account It is bulky and expencive to transport and has a lower fuel content than conventional fuels which makes it uneconomic to transport far - at least in its original form. There are opportunities for using straw as a fuel in industry located in rural areas. Typical applications could include maltings, disti11eries, sugar beet processors, mineral processing industries etc. It has been estimated that a maximum of 4 million tonnes of straw could be used anntally in boilers and a further 0.4 million tonnes used in furnaces. Some o.3 million tonnes of this might be realised by 2000. EEDS is supporting a demonstration project in a chalk drying plant operated by Needham Chalks Ltd in Suffolk. A https://www.w3.org/1998/Math/MathML"> 7300 kW https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( 25 million Btu/hour) cyclone furnace which will be fired by straw is being installed at the plant. This will be the largest straw-fired combustor in the world and is eight times larger than anything built to date in the UK for this fuel. Baled straw Chopped straw Hot gases https://www.w3.org/1998/Math/MathML"> 7.3 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> straw burning cyclone furnace at Needham Chalks Ltd, Suffolk Straw might be used more widely as an industrial fuel if it is Abstract compacted. Various methods of making straw briquettes have been explored but none have yet been produced at a competitive price. Within the Departments Biofuels Programme R&D studies have been initiated which aim to reduce the manufacturing costs of briquettes and so make them attractive Anaerobic digestion is the process by which methane and other gases are produced when an organic waste product decays via bacterial action in the absence of oxygen. Anaerobic digestion has been identified as the most promising method of producing fuel from wastes with a moisture content of greater than https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The technique is already being used successfully in the treatment of domestic sewage and most sewage disposal plants are now equipped with anaerobic digesters which provide energy for use on-site. of the other possible applications, the closest to realisation concern landfill gas extraction and the treatment of industrial effluents. 3. ANAEROBIC DIGESTION Landfill At present, about https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of domestic, commercial and industrial waste boes to landfillo technique will continue to remain popular so long as suitable sites are available. Anaerobic digestion occurs spontaneously in landfill sites under certain conditions. Parameters such as the avallability of oxygen, water content and density of the refinse affect landfill aragroduction. If conditions are suitable, sites become what is termed tiologically active producing large volumes of methane gas. A study carried out in 1981 identified the 20-25 largest sites in the UK where landfill gas extraction schemes could be installed most effectively. Early work on landfill gas was carried out in R & D trials at the London Brick Company's premises at Stewartby. Here gas extracted from an adjacent landfill site was piped to fire brick kilns. Following on from this, there is now an EEDS project at the Thames Board Ltd works at Purfleet in Essex. Gas generated in a landfill site at Aveley is piped underground two and a half miles to the Thames Board works and then used as a base fuel on a https://www.w3.org/1998/Math/MathML"> 57,000   k W ( 200,000 l b / h o t r ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> steam-raising boiler. Initially one burner out of four was converted but this has proved so successful that the company has changed over another burner. The total cost of the demonstration was 2.24,000 and the energy savings in the first ftull operational year were 1,4,760 tce, representing a payback period of less than two years. Energy savings are likely to increase to 37,000 tce in succeeding years, making this project highly successful. More R & D is still needed to determine the best methods of extracting gas and to overcome other technical problems. Although it is theoretically possible to produce https://www.w3.org/1998/Math/MathML"> 400   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of gas for every tonne of refuse, yields of only https://www.w3.org/1998/Math/MathML"> 10 - 60   m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonne over a 10 -year life have so far been obtained. In the longer term, it may be possible to increase gas yields to https://www.w3.org/1998/Math/MathML"> 100   m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonne or more by optimising and conserving landfi1l gas production in new sites. New types of wells improved abstraction apparatus, methods of biologically activating sites, and techniques such as capping with polythene sheeting to carried out by London Brick Landeill Ltd in conjunction with the Harwell Waste Unit. 12. Industrial Effluent Some liquid effluents produced from industrial processes are suitable for anaerobic digestion. They are most common in the food and drink sector where large and fairly consistent streams of hot and easily degradable liquids are produced. There are estimated to be about 120 sites in the UK producing effluent of this type. Studies have shown that industrial digesters with a volume of https://www.w3.org/1998/Math/MathML"> 2,000 m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and above could produce sufficient biogas to be viable at current energy prices. A demonstration project at south Caernarvon Creameries (scc) near Pw11heli is expected to save 570 tce annually using this process. A total of https://www.w3.org/1998/Math/MathML"> 20,000 - 22,000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of whey are produced each year as a byproduct of the factory. A 2,400m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> high-rate hamworthy digester has been installed to digest the whey anaerobically and this is expected to produce https://www.w3.org/1998/Math/MathML"> 775,000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of biogas each year. The plant also reduces substantially scc's disposal costs. The cost of the plant is around f400,000 and the payback period is expected to be around six years. W.H. SMITH Center for Biomass Energy Systems University of Florida--IFAS Summary The Southern US is a warm humid region with abundant underutilized lands and waters. Much is forested with hardwoods with limited market potential. This "Sun Belt" region is rapidly growing in population and increasing its energy consumption. Plant growth is rapid in the terrestrial and aquatic sites in the region; thus, it is well-suited for biomass production. Abundant forest and agricultural residues exist in the region and several energy crops appear promising. Conversion technologies are also being advanced in order to economica11y produce usefu1 biofuels from the available feedstock. Progress in this region has been possible largely because of significant biomass program development by various federal agencies and 7 and-grant universities in the South. 1. INTRODUCTION The Southern US east of mid-Texas possesses a warm, humid climate with long growing seasons; considerable underutilized land and freshwater resources: and substantial marine coasts. These factors favor biomass production and create a substantial bioenergy potential. In this humid portion of the "Sun Belt" region, conditions also favor growth in the human porticution the "Sun Bett" region, conditions also favar grouth in the human population and energy demand. Thus, several biomass programs have emerged to explore biomass production and conversion to meet the need for alternatives in the future energy mix. The deliberate production of energy crops has not been a commodity objective in agriculture since the era of crops has not been a connodity objective in agriculture since the era of producing feed energy for draft animals. Forest and agricultural wastes and residues (including animal manures) have the potential for meeting certain on and off-farm energy needs, but, because of restraints on convertibility, seasonal availability, and unpredictability of supply, supplements with biomass from energy crops will be needed to sustain a biofuels industry. Present domestic crops in the us were developed over the past centuries to meet criteria important to food/feed/fiber crops. Thus, they cannot be expected to be desirable energy crops for energetic and economic reasons. Many domestic crops in the us are easily overproduced; thus, there is a need for new crops in demand and growable at a profit. Conversion technologies now available simiarly are not compatible with requirements of a bioenergy industry because they were mainly developed for the spirits and industrial chemicals industries and/or for waster disposal. That these technologies do not prove economical for energy production should not be a surprise. Several failures could be cited where attempts have been made to commercialize these inadequate conversion technologies. Most of the agricultural and forestry research including that pertaining to biomass is conducted at federal laboratories or at the state experiment stations located at land-grant universities. These universities have ties to the US Department of Agriculture through formula funding and special grant projects. State support either matches or exceeds the federal contribution. For example, in Florida federal formula support represents 16 percent of the state's research budget. Extra-mural support for research at the principal research performing institutions supplements in-house funds.

STATE EXPERIMENT STATIONS

Since 1980, about g5 biomass research projects have been initiated at the experiment stations in the southern US. Of these, 31 have dealt with biomass production while the remaining 54 have focused on conversion processes or utilizaton options. Of the 27 projects continuing past 1984, 16 are targeting conversion goals. Among the states, Florida has reported a total of 35 projects and Texas, 10 from 1980 to present. 0ther states reported fewer projects with only one state reporting no biomass research activity. The Texas and Florida programs will be discussed later in this paper. Several projects at land-grant universities also contribute to the programs described subsequently. 13. OAK RIDGE NATIONAL LABORATORY (ORNL) Tris agency manages a number of bs Department of Energy (DOE) biomass programs. These total about https://www.w3.org/1998/Math/MathML"> $ 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million annually. Nationally, the Short Rotation Woody crops Program includes 24 projects--9 in the Southern US. Four of the 9 projects evaluating the effects of whole tree harvesting on site quality are in the Southern US. Among the 7 Herbaceous Energy crops Program Projects, 2 are in this region. In addition, ORNL manages a winter rape project at USDA, Tifton, Georgia. In total, 16 projects have been conducted in the Southern US since 1978 in these programs. Present1y, they are focused on genetically improving productivity, testing operational crop trials with industry and evaluating nutrient demands on soils producing energy crops on or from which biomass energy has been harvested. Most of these projects have been conducted by land-grant universities and the forest products industry. Species showing the most promise and now receiving interest include eucalptus, slash pine, sycamore, sweetgum, cottonwood, black locust, sorghum, and winter rape. Economic evaluations of some species are nearing completion but increased use of tissue culture technologies are allowing expanded, more rapid progress on species improvement in productivity and site stress tolerance. Regional differences in nutrient removals and regrowth were determined between conventional and whole-tree harvests. The herbaceous program recently initiated has selected lignocellulosic grasses/legumes annuals or perennials showing adaptability to marginal lands. 14. U.S. DEPARTMENT OF AGRICULTURE (USDA) Agricultural Research Service: This agency manages the Southern Agricultural Energy Center (SAEC), Tifton, Georgia, established for research on the on-farm collection, storage and utilization of solar and wind energy and for the production, harvesting, processing/converting and utilization of biomass energy. This encompasses both crop residues and biomass which may be produced specifically for energy. The biomass programs of the SAEC receive primary funding from USDA, with supplemental funding from the DOE, Research programs are conducted at SAEC with satellite locations at Bushland, Texas and Ames, Iowa for wind energy research, and at Columbia, Missouri for research on anaerobic digestion of manure for methane. Partial funding was supplied for three years to Belle Glade, Florida for research on utilization of the biomass residue from sugarcane. At the peak of activity there were 65 projects, in addition to those at Tifton and the satellite locations, conducting research on renewable energy. Due primarily to the current excess supply of https://www.w3.org/1998/Math/MathML"> 0 i 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the interest in and support for renewable energy has diminished. Today there interest in and support for renewable energy has diminished. Today there are only 16 projects, plus those at fifton and the three satellite locations making up the research program. Last year, new funding was received from ORNL for vegetable ofl/diesel fuel research. The goal is to received from ORNL for vegetable oll/diesel fuel research. The goal is to develop methods and processes which will maximize the use of renewable energy for the production of food. Research is being conducted on the harvesting, storing, processing and utilization of crop residues, animal harvesting, storing, processing and utilization of crop residucs, animal manure, and nerbaceous crops produced for energy and wood. The processes of conversion/utilization being studied include direct combustion, gasification and pyrolysis, anaerobic digestion, small scale alcohol production and extraction of vegetable oils (peanuts and rapeseed) for diesel fuel substitutes. Forest Service: The Forest Service has both the Southern (west South) and Southeastern Experiment stations. Much of their research addresses biomass inventory, residue harvesting, handling and utilization schemes for biomass inventory, residue harvesting, handling and utilization schemes for been conducted by the Forest Inventory and Analysis Group. From their survey network state-by-state biomass inventories are emerging in Forest survey network state-by-state biomass inventories are energing in forest developing ways of measuring economic potential for using biomass, especially the residual from harvesting other timber products. They have developed the Total Biomass Cruise Program (TBCP), a computer-based program that uses conventional cruise data to provide simultaneous estimates of wood product weights and volumes as well as the total stand biomass. The wood product weights and volumes as well as the total stand bioniass. The Forests and by forest industries in the Southern US. In addition, the Southeastern Station has examined cost-effective shipping distances for wood fuel and developed a simulation model, Wood Residue Distribution Simulator (WORDS), to derive least-cost a1locations of wood fuels from supply sources to demand points. Under investigation, also, is the impact of biomass capture on the potential for nutrient depletion and ways to reduce wood moisture for improving burning efficiencies and energy yield. To date, nutrient depletion is not markedly affected and transpirational drying possesses potential for increasing energy recovery. The Southern Station projects mostly indirectly relate to biomass energy objectives. Results from projects in this station could benefit intensive culture techniques, prediction of biomass yield, harvesting and utilization. 15. TENNESSEE VALLEY AUTHORITY (TVA) TVA Biomass Fuels program is designed to develop information through research to assist industry in commercializing renewable energy resources. The TVA program managed by its office of Agricultural and Chemical Development in Muscle Shoals, Alabama has several integrated facets designed primarily for valley conditions; however, the technologies and designed primarily for valley conditions; however, the technologies and The program emphasizes use of the Tennessee Valley hardwood resource because of its abundance and current underutilization. Over 50 percent of the https://www.w3.org/1998/Math/MathML"> 23.6 × 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha of land in the valley is forested, and 80 percent of the forests is hardwoods. Foresters are updating the total support for these programs which is about https://www.w3.org/1998/Math/MathML"> $ 6.4 m i l l i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on annua https://www.w3.org/1998/Math/MathML"> 11 y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Production of alcohol from hardwood, which includes greater utiliztion of a 11 cellulosic components, is being studied in TVA laboratories. This involves two-stage hydrolysis of wood with short hydrolysis retention times, explosive release to physically disrupt the wood, and use of dilute acid to form solutions of predominantly five-carbon and six-carbon sugars, respectively, from the two stages. These sugars are available then for fermentation to ethanol. Design work is in progress, and equipment for a https://www.w3.org/1998/Math/MathML"> 0.9 M g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pilot-plant facility is being purchased at this time, DOE funded research at Purdue facility is being purchased at this tine. DOE funded research at Purdue University on the conversion of agricultural residues (such as corn stover and wheat straw) to ethanol by a concentrated acid hydrolysis process using low temperatures and pressures was encouraging. Commications between DOE, Purdue University and TVA resulted in the design of an experimental facility as a front-end modification of the existing https://www.w3.org/1998/Math/MathML"> 37.8 h r - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethano facility as a front-end modification of the existing 37.8 h hromethanol unit built by TVA in an earlier DOE sponsored program to obtain benchmark data on grains and alternative starch and sugar crops. Acid hydroiysis equipment to process https://www.w3.org/1998/Math/MathML"> 3.2 M g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day https://www.w3.org/1998/Math/MathML">   - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of non-woody biomass is installed and shakedown tests are being conducted. TVA also provides technical monitoring assistance for the DOE loan guarantee program. DOE wi11 guarantee loans for construction of privately owned plants to produce guarantee loans for construction of privately owned plants to producan yr - DOE incurs a liability only if the firms default on the loans; hence, technical assistance has been requested to ensure that the plants are properly constructed and effectively operated. The New Energy plant af South Bend, Indiana, is nearing completion; it is a https://www.w3.org/1998/Math/MathML"> 189 × 10 6 l y r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> facility, Tennol, Inc. has completed final preconstruction, requirements with DOE and is beginning construction of its https://www.w3.org/1998/Math/MathML"> 94 × 10 6 l y r - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> plant. The Southeastern Region Biomass Energy Program (SERBP) was established by DOE to promote effective use of regional biomass resources to meet regional energy needs. The focus is on information development/transfer and technoloy transfer for a broad range of biomass resources, conversion technologies, and end uses. Much of the effort in the 13 Southeastern States is carried out under competitive contracts selected with the assistance of key representatives of industry, academia, and government. TVA has another agreement with DOE to conduct activities to develop/improve technology for harvesting wood for energy. The focus is on equipment for harvesting short-rotation intensive tree crops and other small diameter energy wood (such as from rights of way and tree crowns from traditional forest harvest operations). This is a new project in cooperation with ORNL's Short Rotation Woody crops Program. 16. TEXAS A & M UNIVERSITY The program at this site includes various projects. One is directed toward fluidized bed gasification and cyclonic burner development. These were designed to primarily use cotton gin trash and similar agricultural residues for fuel. Gas clean-up has proven critical because of the corrosive properties of the ash upon the metal at high temperatures. Other projects have evaluated plant oils and animal fats as diesel fuel substitutes. Engine tests have shown that fully esterified cottonseed oils provide the best alternative fuel followed by beef tallow and a1kali refined cottonseed oil. Longer termed tests with more complex engines are in progress. Grain sorghum has been investigated as feedstock for ethanol. Research on grain treatment chemicals showed that some did not affect ethanol fermentations. Certain chemicals were destroyed in the process while others appeared in the stillage in levels of concern. Disposal problems associated with stillage have been investigated using recycling and nutrient recovery procedures. Sweet sorghum processing in preparation for ethanol fermentation has shown that fermenting chopped stalks yielded more ethanol than shredded sorghum or juice. In 1983 , Texas A & M initiated a cofunded program with the Gas Research Institute (GRI) to research sorghums for methane. This is a multidisciplinary research program to establish the technicat and economic feasibility of producing pipeline quality methane from sorghum. The overall objective is to develop an integrated system for methane production utilizing sorghum as the feedstock. Research emphasizes genetic manipulation, crop physiology and production systems, harvesting, storage, processing and conversion systems production systems, harvesting, storage, processing and conversion systems and economic and system analyses. First year results indicate that the proposed methane from sorghum system is in the realm of economic feasibility; storage and high-efficiency conversion are critical to the economics; and the system economics is improved if the grain and vegetative materials are harvested for separate purposes--food and energy. While crop management and genetic improvement fon methane production mesearch are in management and genetic inprovement for methane production research are in thefr early stages, results indicate that sorghum yields up to about https://www.w3.org/1998/Math/MathML"> 35 M g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha are possible with sweet sorghums. In these, the yield is mainly vegetafive. In the high-energy sorghums, yields ranged between 16 and 26 Mg ha with 45-51 percent of the yield as grain. Genetic manipulation of both lodging and chemical composition of the vegetative portion shows promise for improving the sorghum as a feedstock for methane.

UNIVERSITY OF FLORIDA--IFAS

In 1979 the Florida Legislature funded a low energy technology research program in the Institute of Food and Agricultural Sciences (IFAS), university of Florida. A substantial portion of the https://www.w3.org/1998/Math/MathML"> $ 6.4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million University of florida. A substantial portion of the https://www.w3.org/1998/Math/MathML"> $ 6.4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million mainly biomass. After redirection guidelines were met, the annual statewide biomass program was about https://www.w3.org/1998/Math/MathML"> $ 3.0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million subsequently funding statewide biomass program was about https://www.w3.org/1998/Math/MathML"> $ 3.0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million. Subsequentiy, funding from other agencies (e.g., GRI, DOE etc.) brought the annual effort to about https://www.w3.org/1998/Math/MathML"> $ 6.0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million. The program was reduced in response to revenue shortfalls and now stands at about https://www.w3.org/1998/Math/MathML"> $ 4.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million annually with the major portion contributing to the joint GRI program. Current research is conducted by about 50 faculty located throughout 13 academic departments on the Gainesville campus and 13 research centers dispersed throughout the state. The projects can be grouped into five major areas of investigation. Wastes and Residues: Projects in this area have focused on the inventory and capture of various wastes and residues. Major resources include wood (non-merchantable residual trees, tree parts not harvested, and mill processing wastes), sugarcane bagasse, vegetable culls, field crop residues and animal manures. Wastewood and bagasse appear to be the only feedstocks reliably available in adequate quantities. Unfortunately, the demand is for liquid and gaseous fuels, and wastewood and bagasse presently cannot be economically converted to these energy forms. Energy Crop Development: A large effort is underway to identify plants that have potential as biomass crops. Over 150 species ( 350 cultivars and varieties) have been field tested for their suitability as energy crops. Three species (water hyacinth, Eichhornia crassipes; Napiergrass, Pennisetum purpureum; and sorghum, Sorghum biocolor) have been chosen for intensive evaluation in the GRI/IFAS program. Annually, water hyacinth yields near https://www.w3.org/1998/Math/MathML"> 75 M g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha and Napiergrass more than https://www.w3.org/1998/Math/MathML"> 50 M g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha with low production inputs. Other promising species are being identified in the systematic process for further development as energy crops. This process involves conventional cultural and genetic improvement practices as well as advanced biotechnologies such as tissue culture and somatic hybridization by protoplast fusion. Plants of both Napiergrass and sweetpotato have been produced from somatic embryos. Gel-seeding of these plantlets appears promising. Thermochemical Gasification: The thrust has been on sma11-scale gasifiers to meet on-farm and other distributed energy needs (about https://www.w3.org/1998/Math/MathML"> 112 K W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or less). Project activities have focused on wood fuel improvement, fuel feeding, gasifier design, gas clean-up, microprocessor controls, supercharging in engine applications and gas utilization applications - commodity drying, space heating, electrical generation, pump engine powering etc. Alcohol Production: Research projects in this area have three thrusts: technology for small-scale alcohol production, physical/chemical treatments to hydrolyze lignocellulosics into fermentables, and genetic engineering of microorganisms to improve the efficiency of the alcohol engineering of microorganisms to improve the efficiency of the alcohol fermentation process. Research on smatl-scale operations optimized feedstocks, enzymes, and physical controls to manage the rate of alcohol production and produce beer with high alcohol concentrations. A gasifier production and produce beer with high alcohol concentrations. A gasifier was designed and adapted to provide the necessary heating to make lignocellulosics has been accomplished by a novel acid hydrolysis process using of the acid anhydride sulfur trioxide. NASA has assisted in designing a laboratory pilot plant, which they subsequently fabricated and sited in the IFAS Bioconversion Laboratory Licensees for the patented process assigned to the University of Florida are bejng sought. IFAS research is attempting to genetically engineer organizms that can tolerate higher temperatures, osmolarity and alcohol concentrations. Unconventiona? organisms (e.g., Zymomonas) for alcohol production are being researched to improve fermentation efficiency. Other work is designed to manipulate the organism in a way that substrate range is increased le ge ferment lactose as well as glucose). Transfer of important genes that control alcohol fermentation to E. coli (the best understood microorganism known) is being attempted. Methane Production: For anerobic digestion, one approach is off-the-shelf equipment for designing a low-cost system adaptable to low-solids waste streams that are typical of Florida animal confinements. Wood chips have been experimentally compared to several plastic media with different geometries as packing for fixed bed digesters. Wood chips cost about one-tenth as much as plastic media. The second strategy in concert with GRI is to design innovative digestion systems that will accommodate various highly productive biomass crops in the generation of pipeline quality methane. The process for this development activity invoives: (a) bioassay plant and plant parts for chemical properties relating to methane production; (b) improve microbial inocula; (c) develop ways to control the rates of the hydrolytic, volatile acid, and methanogenic processes; and (d) design low-cost, efficient digesters. Biotechnologies are exploited in improving the quality of the plant for methanogenesis, accelerating biological hydrolysis with cellulase enzymes, and improving the rate and efficiencies of the microorganisms active in volatiee acid conversions to methane. A recent development is the initiation of research with a new digester design that is multiphase in function and potentially capable of using multiple feedstocks. The GRI/IFAS program is presented in 3 other papers in this set. 17. ACKNOWLEDGEMENTS Information was provided by Dr, Robert Van Hook, ORNL, Oak Ridge, TN 37831 ; Dr. James Butler, USDA, SAEC, Tifton, GA 31794; Dr. Eldon Ross, USDA, Forest Service-southeastern Station, Ashville, NC 28804; Dr. Thomas Ellis, USDA, Forest Service--Southern Station, New Orleans, LA 70113 ; Or. Joe Roetheli, TVA, Muscle Shoals, AL 35660 ; and Dr. Edward Hiler, Texas A https://www.w3.org/1998/Math/MathML"> & https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> M University, College Station, TX 77843. Details on these programs are available from these sources. BIOMASS ENERGY UTILIZATION AND ITS TECHNOLOGIES IN CHINA RURAL AREAS Research Professor and Chairman of Scientific Council of Guangzhou Ingtitute of Energy conversion Chinese Academy of Sciences 18. Summary The energy situation in China rural area is first described with biomass energy as the major supply source. VaHious biomass supply sources (straws & stalks, firewoods, animal manures, industrial wastes) and their respective thods, such as traditional and improved cookstoves, bio gas, gasification and ethanol, employed now in china countryside, are discussed separately. Finally the trends of development of various biomass energies and their relavant technologies are presented.

BIOMASS ENERGY AS A MAJOR RURAL ENERGY SUPPLY

A survey in 1979 of 28 provinces and cities showed that the biomass energy contributed https://www.w3.org/1998/Math/MathML"> 68.6 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the tota. energy supply in China https://www.w3.org/1998/Math/MathML">   ∘ s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> rurel area https://www.w3.org/1998/Math/MathML"> ( 1 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The details of the energy supply are listed es in table 1. Table 1. Rural Energy Consumption in 1979 Item Energy Consumption Quantity 1 Biomass 2.25×108 TCE 2 Coal 0.572×108 3 Electricity 0.314×108 https://www.w3.org/1998/Math/MathML"> m C E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4 Diesel, gasoline https://www.w3.org/1998/Math/MathML"> 0.144 × 10 8 T C E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 17.45 & kerosine 4.57 38 Total https://www.w3.org/1998/Math/MathML"> 3.28 × 10 8 T C E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 100.00 Wren though the total amount of energy consumption of https://www.w3.org/1998/Math/MathML"> 3.28 × 10 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TCE is large, but the average individual energy consumption is rather low, which is https://www.w3.org/1998/Math/MathML"> 7791 k c a l / c a p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -day on account of rural population of https://www.w3.org/1998/Math/MathML"> 8.074 × 10 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in 1979 . The household portion of the total energy consumption https://www.w3.org/1998/Math/MathML"> 3.28 × 10 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TCE is https://www.w3.org/1998/Math/MathML"> 79.7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while the portion for agriculture production is https://www.w3.org/1998/Math/MathML"> 20.3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

BIOMASS ENERGY RESOURCES AND THEIR POTENTIALS

The amount of Biomass Energy supply of https://www.w3.org/1998/Math/MathML"> 2.25 × 10 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TCE of A. Research Needs and Resources for the Development of Biomass Energy B. Land Use, Food and Fuel Production C. Development and Environmental Issues D. Institutional Aspects of Biomass Production and Use ROUND TABLES by 0.0. Ha11 & J. CoombsBio-Services King's College, 68 Half Moon Lane, London, SE24 9JF, UK. Abstract A. Research needs and resources for the development of biomass energy Chairman: P. Chartier (France) Panel members: E. Teissier du cros (France) H. Naveau (Belgium) K. Kocsis (FAO, Italy) The main consideration on furthering biomass for energy at present is on the price of the biofuel and how it competes,and in the future with competing fossil and nuclear fuels. These factors are determining the current support for biofuels and the R, D& D which will be undertaken in the future. A major point of discussion was whether further field trials are necessary to establish the yield potential and economic yiability of dort rotation forestry. These have been underway for over 10 years in various parts of the world and some people consider that this is sufficient to launch much larger demonstration and commercial projects. However, others thought that we still lack good yield data and harvesting technology especially on diverse sites and because the trials have been small the economic data is a poor base from which to make large scale capital investments. It was also thought that we have too Tittle good data on multiple-use forestry which could make biomass fuel schemes more economically attractive. If we wished to take a longer term view of biomass energy, it is essential that we inprove productivity through basic research on breeding and physiology and we improve the efficiency of conversion, whether it be thermochemical or biological. A detailed analysis of the European biogas installations, mostly using manure, has shown disappointment in the number of problems which have arisen primarily as a result of inexpert construction and maintenance. However, the situation is now improving with more established firms doing good work and the integration of energy production with pollution control. The need for widely accepted standards in a 11 types of biomass conversion apparatus was stressed especially since biomass is mainly a local fuel being used in numerous conversion "machines". The necessity for R&D follow-up of apparatus for its improvement to ensure reliability, longevity and ease of operation, was repeatedly emphasised if biofuels were to be more widely accepted. The recently established European Network of Rural Energy Use attempts to provide collaboration on how applied research can help solve practical problems in biomass use. It acknowledges the diversity of expertise and experience available in Europe. Transferring such knowledge between regions is difficult and even more so to developing countries - although there are a number of regions in Europe which have levels of https://www.w3.org/1998/Math/MathML"> R , D & D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> close to those of many developing countries. The session conctuded with a discussion on the recently announced Call for Tenders by the Commission of the European Communities' Third Phase of Energy from Biomass R&D Programme. One part stresses field trials, improvement of productivity and improved harvesting techniques. The second part covers biological conversion to ethanol and some basic biological studies,plus thermochemical processes of conversion such as pyrolysis and gasification. B. Land use, food and fuel production https://www.w3.org/1998/Math/MathML">   Chairman: J.F.Molle (France)     Panel Members:     E. La Rovere (Brazi1)     H. Wohlmeyer (Austria)     J. Zubr (Denmark)   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A number of studies have concluded that the Commission of the European Communities (10) will have about https://www.w3.org/1998/Math/MathML"> 10 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hectares of "spare" land by 1995 which will have been released from agriculture due to changing social and economic circumstances. The large EC and national subsidies for agriculture which now approach 30 billion ECU per annum in the EC (10) distort land use and production. Any changes in subsidies and land use will undoubtedly affect biomass energy opportunities,as will any changes in the subsidies in other energy industries such as coal and nuclear. Within a country, the import and export of fuels, food and animal feed must be considered jointly before biomass energy schemes can be implemented. Local conditions and requirements are preeminent in determining any biofuels policy. The Brazilian example was discussed in some detail since over https://www.w3.org/1998/Math/MathML"> 1.3 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hectares of sugar plantations have been established there since 1976 to provide for the 11 billion litres of ethanol being produced now to run the 9 million cars. Much of this land has been converted to sugarcane from pastures but much food producing land (beans and maize) has also been converted. However, Brazil has simultaneously also greatly increased its food producing and cash crop (for export) producing areas, so that a simple competition between food and fuel is very difficult to discuss. There are moves in Brazil to encourage intercropping and rotation of food and fuel crops,and also to disperse sugar-alcohol projects (both large and small scale) throughout this vast country and not just to concentrate them in a few favourable regions. In Denmark an extensive 3-year trial on the optimum system for producing energy from biomass crops was discussed; 18 crops and various rotations within annual cycles have been studied to maximise the light-absorbing leaf area and thence productivity. The biomass is being used for biogas and ethanol production. The economics of such systems were discussed but it was agreed that insufficient data is yet available to make any longer term predictions as to their viability. A study in Austria has concluded that biomass energy production is feasible if it is combined with existing systems of agriculture such as the sugar and starch industries and foresty; starting with waste products then to byproducts and fina https://www.w3.org/1998/Math/MathML"> 11 y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to energy crops themselves. It was stressed that the social and economic needs of the farmers and the population are being considered when trying to formulate a food, feed and fuel programme. The year- to-year financial requirements of farmers were repeatedly stressed as being most important in trying to implement any biomass energy schemes - whatever the regime of subsidies and long term alternative requirements. 19. Development and Environmental Issues 20. Chairman: B. Bini Smaghi (EC) The major issue is the wood crisis in the developing countries, which is Tinked to the depletion of the world's forests and increasing desertification Discussions related to the contributions made by the EC to development of alternative energy resources from biomass, and the mechanics for dissemination of information in Africa in particular. Concern was exoressed by re https://www.w3.org/1998/Math/MathML">   t i o n   o f   f n f o r m a t i o n   i n f i n i c a   i n   p a r t i c u l a r .   C o n c e r n   w a s e x p r e s s e d   b y   r e m e n t e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> given, that technology was often inappropriate and that the emphasis (through government) should perhaps be changed so that EC funds could go more directly to projects under control of universities and NGOs. (non-governmenta) organisation? The current contributions made through DGVIII of the EC are financed by The current contributions made through DCUTII of the EC are financed by countries (ACP) through the Lome convention. However, such aid for biomass energy projects is relatively small and hence care is taken in choice of projects which are assessed on the basis of practical value and rational use of the available funds. In general the objective ts to demonstrate the suitability of proven technology which may be adapted to local needs in order to avoid technical failure or socio-cultural rejection. At the same time steps are taken to involve local research and training bodies in order to achieve success. Typical projects have included development of a gasifier fuelled with coconut husks in the Ivory Coast, supply of mobile gasifier/ generators in Guyana, production of gas and charcoal in Mali, etc. as well as studies of biomass resources and agricultural wastes, and setting up of blogas projects. Such projects are assessed and monitored in order to establish the best means of replication of a given technology throughout a region following initial demonstration. The size of the orogramme was criticised from the audience. However, it was pointed out that the major effort of EDF was in food. Dther critical remarks related to (i) the choice of technology coften large scale, e.g.s dams, rather than aimed at meeting rural and environmental needs); (it) funding of high profile projects; (iji) use of developing countries as a proving ground for untried technology; (iv) mestricting technology transfer by patents and licences, and so on. It was suggested that the EC funding should be directed in such a way that countries can solve their own problems. However, the chairman pointed out that governments were asked for their input in the setting of strategies and may in future insist on specific fields of action in order to complement projects being funded by the World Bank and other a id agencies. Larger projects were favoured since it is easier and more cost effective to fund one or two large projects than several hundred small ones. The discussion in general highlighted problems of energy, environment and food which lay beyond possibilities of being solved by the financial aid and resources available. The magnitude of the problem are such that there is no answer but on the other hand on a local basis the input of a well funded project can be of significance, especially where this can be replicated through education and dissemination of information. D. Institutional aspects of biomass production and use https://www.w3.org/1998/Math/MathML">   Chairman:   _ =   R.S. Dosik (World Bank) Panel Members:     U. Miranda (EC)     F. de Poli (Italy)     H. Quadflieg (France)   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Implementation of biomass energy programmes in both developed and developing countries denend on similar factors which are technical. political. social and economic. Much of previous RaD effort has centred on the technical aspects on the basis that oil orices would rise and fossil fuel supplies become significantly depleted. Hence, the emphasis was on oil substitution. However, the picture has now changed with the major problems facing Europe being ones of agricultural surpluses and the related problent of land use. Production of liquid fuels and/or octane enhancers from these surpluses could represent a short term answer. However, the fact that end use technology had been developed might not be a sufficient answer to the problems. This was already clear from results of large projects such as the Dendrothermal project in the Phillipines where lack of fuel wood trees had negated technically sound large scale electricity generation within the EC most countries had revised their energy laws, especialiy in relation to the sale of gas and electricity, during the last four or five years. This had led to numerous small scale generators based on biogas or direct combustion. However, these might not be economic in real terms unless other benefits were associated with them. Such benefits related in particular to pollution control, and as such depended on strict enforcement of relevant legislation. In the same way the empnasis on use of crop surpluses for production of fuel ethanol related to the need for an alternative octane booster once lead was removed from petrol at the end of this decade. Aga in ethanol was only one answer to a problem which could be solved by changes in the refining of oil to liquid fuels, by changes in car engines, or by changes in the oxygenate used. The move in any particular direction could be induced by institution of, or removal of tax in a particular sector, or by introduction of specific legislation. Such moves could upset economic logic. In general it was felt that the biomass programme in Europe, which had started as a response to energy shortages, was now justified in terms of energy efficiency, recycling of materials, use and avoidance of waste on the one hand, and regarded by some as the answer to problems of surpluses and the CAP by others. Many of the technical problems of enduse had now been solved. We were now in a position where both incentives and subsidies were needed if significant biomass energy programmes were to be implemented. Incentives were needed in order to establish an infrastructure to support economically sound energy programmes based on wastes and possibly short rotation forestry. At the same time financial inputs, in the form of tax relief or subsidies, were needed if agricultural products were to be used as a source of 1 iquid fuels. This analys is of the situation was felt to contrast with the current EC policy which supports extension of the land area which is used for agriculture at the expense of natural vegetation and the destruction of forests. The technology for greater use of biomass is now available, what is needed is the removal of institutional restraints. However, in most European countries biomass would probably contribute only a few percent of total energy needs and hence the incentives are not perceived at a national level, although they may be significant on a local basis, or within a particular sector. I. Biomass Resources II. Biological Conversion III. Research Priorities in Thermal Conversion Technology IV. Densification and Combustion 21. WORKSHOPS

Biomass Resources

C.P. Mitchel1, Aberdeen University, UK J.F. Molle, CEMARGREF, France The purpose of the workshop was, by discussion and verbal presentation of relevant poster papers, to identify critical areas for future R&D. An important constraint on development of biomass resources, particularly energy cropping, is the availability of suitable land. Rationalisation of the Common Agricultural Policy (CAP) in Europe will have the effect of releasing land from agricultural production for food. Studies of these effects indicate that by the mid 1990 s some 5-10 million hectares of land would have come out of agriculture. Land released from cereal production will more than likely be used for high grade pasture and that the land for energy production will be on the medium to poor pasture lands. However, what is lacking from these analyses is information on the detailed nature and location of this land. Such information would be very useful in designing a research strategy to optimize use of the available land for growing energy crops. The type and production of energy crops is very closely tied to site quality and location. Conventional crops can be used as a source of energy. Ethanol can be produced from sugar beet and cereals. Much valuable research has been undertaken on the improvement of production of sugar beet. Yields of sugar beet have increased dramatically over the last 50 years but the sugar content has declined. It is anticipated however, that with improvements gained from breeding, agronomy and better storage techniques the sugar yield can be increased from 9 to 10.7 percent during the https://www.w3.org/1998/Math/MathML"> 1990   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Agricultural residues represent a significant resource. Large quantities of cereal straw are generated each year within the Community, much of which has to be disposed of and which could be used as a source of energy. Where the potential market is some distance from the source then transport becomes a problem as straw, with its low bulk density, is expensive to move. Research on methods of compacting straw, possibly in the field, has a high priority if the resource is to be exploited. When looking at the potential of utilising 'new' biomass species it is important to note that there is relatively little variation in photosynthetic metabolism. It is the suitability of the species to the site, climate and cropping system which is of importance. In this regard information on biomass production between different parts of the plant(as influenced by treatment)is needed in order to manipulate the plant to provide the right quantity and quality of biomass. In ecological terms stands of mixed species, in which the canopy structure makes best use of the available light, are very productive. Evidence from several studies appears to indicate that high yielding natural stands do not grow well when managed intensively. Further, it is of ten not possible to maintain yields with repeated harvests. This, however, may be a

high energy inputs (such as fertilizer) can be beneficial;

overall system economics should be examined to optimize production practice;

selection and breeding can lead to improved biomass production;

data on type and location of land available should be collected in order to better direct the R&D effort. II. Biological Conversion Francesco Alfani, University of Naples, Italy. Emer Colleran, University College, Galway, Ireland. The following is a summary account of the proceedings of the workahop on biological conversion technologies for energy production from biomass. The purpose of the workshop was to provide a forum for in-depth discussion of key aspects of biological conversion, thereby supplementing the more formal morning sessions where time considerations limited both the ntimber of papers and the length of discussion. Biological conversion covers a wide variety of processing options and biological disciplines and includes anaerobic digestion, bioethanol, fermentation chemicals, enzymic saccharification of lignocellulosics, algal hydrocarbon production etc. In order to structure the discussion and in an attempt to equitably divide the workshop time between the various processing options, the session chairmen invited a number of experts to present short papers on topics likely to stimulate discussion. The cooperation of the following experts is gratefully acknowledged: Barry Rugg (USA); Francis Nativel (France); Peter Weiland (FRG); E.J. Nyns (Belgium); D. Verrier (France); A. Rozzi (Italy) and R. Materassi (Italy). Pretreatment and Hydrolysis of Lignocellulosic Materials Utilisation of cellulosic and lignocellulosic materials for ethanol or fermentation chemical production requires extensive pretreatment of the raw material followed by acid or enzymic hydrolysis of the cellulosic component. Contributors to the discussion emphasised the need to develop cost-effective methods which would enhance both the rate and the extent of cellulose hydrolysis. Current interest appears to be focussed on steam explosion of hardwood materials. However, a major limitation of this process is the large loss of the hemicellulose fraction due to degradation by the high steam temperature. A -promising alternative is freeze-explosion using liquid anhydrous ammonia insofar as the freezing temperature of the liquid ammonia e1iminates the problem of heat degradation of the carbohydrate components. Organosolv procedures are also considered to provide promising pretreatment methods and have the advantage of being applicable to both hardwoods and softwoods. In addition, these processes permit the utilisation of the three main components of the biomass - namely Iignin, cellulose and hemicellulose - and some contributors considered that all three components must be utilised in order to achieve cost efficiency. The point was clearly stressed too that no one pretreatment is ideal for al1 biomass types and that the optimal pretreatment or combination of pretreatment methods will have to be determined on an individual basis for each biomass substrate. No clear decision as to the optimal method for cellulose hydrolysis emerged Barry Rugg described a mild acid procedure at elevated temperatures currently being evaluated in New York for hydrolysis of paper pulp, twelve different agricultural residues and hardwood materials such as aspen and poplar. The necessity to maximize rates and yields and minimise sugar decomposition losses was emphasised. Hemicelluloses may be preferentially hydrolysed by a preliminary pass through at temperatures below 180 C, thereby minimising subsequent fermentation problems arising from the use of pentose/hexose mixtures. Increasing the sugar concentration in the hydrolysis 1iquor was also considered to be essential. Cold processes utilising concentrated acids, although generally achieving higher yields were regarded as costly because of the need for complex and capitalintensive plant which would allow recirculation of the large quantities of acid involved. The use of gaseous hydrogen fluoride appears promising, particularly if preceded by a mild pre-hydrolysis with dilute sulphuric acid to remove hemicellulose and other materials such as waxes, resins, organic acids etc. Discussion on enzymic methods of hydrolysis centred on the need to reduce enzyme costs by development of higher-yielding cellulase producers or by recirculation of the enzymes using ultrafiltration membrane reactors. Cellulose losses by adsorption of the enzymes onto undigested material were regarded as being significant. In practice, the cost and energy balance of any cellulose-based project requires very critical and careful analysis and the results of the two-year French study on enzymic hydrolysis of steat exploded biomass will be of value in assessing both of these factors. Alberto Rozzi stressed, in particular, the necessity for energy balance analysis with respect to processes with high steam input requirements. Ethanol and Fermentation Chemicals The feasibility of producing biofuels from surplus agricultural products and the potential role of such fuels in the new European fuel blend policy were discussed. Ciearly, production of ethanol from molasses, concentrated cane juice or whey is already an established commercial process. The data presented by Ulla Ringblom from Alia-Laval in Sweden show that ethanol production from surplus grain is also economically feasible provided byproduct use is ensured - i.e. utilisation of the milled wheat residue as an animal feed, production of liquefied https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> etc. Further research on the development of yeast strains with greater sugar and ethanol tolerance was seen as essential as was the development and scale-up of more novel fermentation systems such as the vacuferm method. Considerable interest was also expressed in solid-state fermentation methods for both ethanol and acetone-butanol-ethanol (ABE) production. For cellulosic substrates, the need to develop pentose - utilising strains capable of high ethanol yields was considered to be a priority. The recent studies by scheffers and co-workers in Delft on xylose fermenting Pichia sp. are of interest in this regard. With regard to fermentation chemicals and solvents, Professor Materassi outlined the wide variety of chemicals which can be produced by different fermenting strains. It was felt, however, that the choice between ABE and ethanol fermentation is likely to be dictated more by political than by technical considerations and depends largely on whether EC strategy opts for replacement of lead in petrol by https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> methanol and https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> co-solvents or promotes the use of https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol. Anaerobic Digestion With respect to the digestion of solid substrates, Peter Wieland of FAL, Braunschweig described a novel process for contintuous methanation of grass silage at high solids concentration and utilising a screw press system which dewatered effluent solids and returned the liquid to the fermenter. In a stimulating presentation, Jacques Nyns of Louvain-la-Neuve highlighted the importance of physico-chemical factors in determining the microbiology and hence the fermentation product composition obtained during digestion. This concept implies that, with detailed knowledge of the various physico-chemical factors involved, it should be possible to predict the fermentation products which would be obtained from a given substrate under various operating conditions. Such a concept is of particular interest in the context of two-phase anaerobic digestion processes since it implies that the first phase can be manipulated physicochemically to yield a feed of suitable and constant composition to the methanation reactor. It also has important implications with respect to the production of fermentation chemicals from biomass. Although it is now apparent that high-rate digesters such as the UASB, fixed-bed design or fluidised-bed system are making a significant impact at full-scale throughout the world for biomethanation of industrial and agricultural wastes, the workshop participants stressed the need for more fundamental microbiological and physicochemical research which would provide valid design criteria and establish optimum start-up and running conditions for retained biomass reactors. A very interesting contribution from Dominic Verrier of INRA highlighted the deficiencies in our knowledge of the factors/mechanisms involved in biofilm and granule formation. A distinction was made between adsorption and attachment of microorganisms to support material surfaces and the importance of adhesin, capsule and glycocalyx formation together with specific attachment mechanisms between individual organisms was stressed. General agreement was reached on the need for the following specific studies: identification and determination of the function of individual bacterial species in biofilms and granules; influence of substrate composition on excreted polymer production; characterisation of the role of methanogens in biofilm formation and cohesion; determination of the influence of the support materials characteristics on the initial adsorption phase: identification of the factors which determine the unusually high level of both exopolymer and endopolymer production by methanogens in grairules; modelling of biofilm thickening and substrate and product diffusion characteristics in both biofilms 'and granules. Such studies will require the development of immunological and autoradiographic techniques in order to identify the component microorganisms in the extremely complex ecosystems provided by fixed film and granules. The need for in-depth study of the known tolerance of retained biomass reactors to toxicants was emphasised by Alberto Rozzi as was detailed investigation of the mechanisms underlying microbial adaptation to toxicants. III. Research Priorities in Thermal Conversion Technology A.V. Bridgwater, Aston University, UK. A.A.C.M. Beenackers, The University of Groningen, The Netherlands.

INTRODUCTION

The interest 1n thermal converston technology, status and future ls reflected by the participation of 70 delegates in the Thermal Conversion Workshop. There was 11vely discussion throughout the meeting, and it is hoped that the range of views expressed In the meeting is reflected 1 . this report. The objectives of the Workshop were to discuss:

Current state of art,

Prospects for thermal conversion technology,

Identiflcation of problem areas,

Identification of research needs

In order to provide some recommendation and priorities for research and development in this area. The Workshop programme was dlvided into five sessions:

Gasification for 1iquid fuels production (large scale systems)

Gasification to glve low heating value gas/producer gas (small scale systems)

Conventional pyrolysls

Flash pyrolysis

Direct ilquefaction

Each Is described and discussed with particular reference to the objectives set out above. F1nally some concluslons and recommendations are presented.

GASIFICATION FOR LIQUID FUELS PRODUCTION Timutd fuele can be produced from blomass in a variety of ways (1) including:

1ndirectly by synthesis of liquid fuels from syngas, including methanol, fuel alcohol, gasoline and diesel (discussed here),

directly as pyrolysis liquids which require upgrading (see later discussion 1n sections 4 and 5),

directly by pressure liquefaction (see later discusslon In section 6)

The stgntficant constituents of syngas from blomass gasificatlon are co, https://www.w3.org/1998/Math/MathML"> H 2 , C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> together with a large number of mlnor components and contaminants. Nitrogen from an air gasification process, is conventionally considered to be unacceptable due to the complexity and cost of its removal. Most processes rely on elther steam and/or oxygen gasification to give a nitrogen free gas. Gas compos1tion and quality ls dependant on a wide range of factors relating particularly to feedstock characteristics, type of gasification reactor, and reaction parameters. The raw gas requires cleaning and conversion using state-of-art technology to give the final 1iquid product Each of these aspects is dfscussed below.

I Synthesis Gas Productions

The four EC sponsored demonstration projects for methanol production - AGIP/Italenergie, Creusot-Lolre (now framatome), John Brown/wellman, and Lurgi are described in detall in another paper (2). Other current work in Europe is belng carried out by Rhelnbraun, Studsvik Energietecknik, Twente University, and University of Brussels all of which are reported in these Wropeedthge Although extenslve research and develoment has heen perm formed on all the above processes, much work still remains to be carried out on optimisation and design studies. number of toplcs attracted special attention In the Workshop: Pressure: The economic and energetic advantages of a pressurised gasifier In reducfing compresgion cogts for methanol synthests or fmprovIng power production efflciency, must be set against the higher costs of feeding under pressure and greater operatting problems, particularly when using oxygen. The trade-off https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> not well understood and requires evaluation. Ash: 1.1.1. The low levels and relatively stable characteristics of wood ash cause few problems in gasiflcation except when very high temperatures are encountered In elther the primary or secondary reactors then using oxygen. Solid waste/refuse, however, glves rise to much more potentlally serious problems with ash unless the temperature Is carefully controlled. Other blomass feed https://www.w3.org/1998/Math/MathML">   t h e   t o p l e s   s u c h   a s   s t r a w   a n d   r y c e   h u l l e   a l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1ng to avold ash fusion in unwanted locations. The principle of slagging gasification of hlgh ash blomass materials has only successfully been applied to refuge, and is unlikely to be sultable for other high ash biomass fuels. These are an unwanted and almost Intractable byproduct of gas1fication, (although In sorne pyrolysis processes this fraction Is maximised as discussed later . The mechanism of formation and decomposition is not yet well understood, although some Interesting research is belng carried out and good gasifier deslgn will help to reduce tar production. The results obtained by Creusot Loire with thermal secondary The resulta obtalned by Creusot Lofremith thermall secondary both https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the primary gasifier and https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> secondary gasiflcation, have shown preliminary promising results in R&D work at Battelle Pacific North West and Studsvic Energietechnlk. The latter methods, 1f successfully developed to a commercial scale, may permit Iower operating temperatures and hence hlgher energy efficiencies for the process. This will provide a solution to possible ash melting problems in thermal secondary gasification These catalytic processes deserve attention tn other ongolng R&D work within the EC. Other alternatives might be found in separation of tars followed by elther recycling to the gasifier or by disposal. All these alternatives require evaluation in a total system concept. Feed1ng: The problems of controlled feeding of blomass to a gasifier are belng overcome, but the reliabllity of these systems remalns to be proved. Such problems are multiplied when pressurised systems are consldered when the feeding system can cost as much as, or more than, the gaslfler. Modelling: Thermodynamic modelling of ideal gasifier performance ls now well established with emplrical modiflcations to account for deviations from ideallty. Stagewise modelling of the various progressive steps in gaslfication wl11 enable more robust predictive models to be developed for system evaluation and feasibility studles, which are needed for economic and market evaluation. Kinetic modelling for commercial design purposes Is necessarily more complex and confidential, and will tend to be reactor-specific. Considerable scope exists for tmprovements in both areas, but rellable and robust data resources are necessary. The product gas from gasiflcation contalns particulates, tars, and contaminants such as https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , that are deleterious to downstream converston processes. It 18 necessary to clean the raw gas prior to compression for the conversion processes. Rellable hot gas cleaning and waste heat recovery systems are not yet widely available. While wet washing systems https://www.w3.org/1998/Math/MathML">   c o n   b e   d e s t a n e d   t o   g l u e   a d e q u a t e   c l e a n - u p   t h e r e   f o r m o n g e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be deblgned to glve adequate clean-up, there is no long term experience avallable nor information available of specific requirements for contaminant levels in feeds to compressors. There https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , therefore, an opportunity https://www.w3.org/1998/Math/MathML">   f o r   d e v e l o p m e n t   o f   h i g h   e f f l o l e n c y   g e r v h b e r s .   W h a t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for development of high efficiency scrubbers. The waste water containg dissolved organics and suspended tars, and constitutes a signiflcant disposal problem. While the tars may be separated and recycled to the gaslfler or burned as fuel (as discussed above), an environmental problem sti1l remains. This is a further area where useful R&D may be carried The orthodox view that syngas for methanol production should have as low a CH_ content as possible was challenged w1th a view that a secondary reformer in the synthesis loop or purge stream could be economically and energetically preferable to a more costly gasifier giving a low methane Although most attention has been paid to production of methanol. a range of other fuel and chemlcal products are also possible such as methane, gasoline, diesel, syncrude, ammonla, ethanol and mixed alcohols for fuel based on methanol. The more economically attractive products are currently methanol, methanol based fuel alcohol and ammonta. all of which have to be produced at a substantial scale of operation to take Which have to be produced at a substantial scale of operation to takeadvantage of the economies of scale. None, however, is competitive with advantage of the economies of scale. None, however, 1 s competitive with conventionally derived products https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Europe. Clrcumstances where any of these products could become economically viable need to be https://www.w3.org/1998/Math/MathML"> 1 dent 1 f 1 ed . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A signiflcant feature of these syngas producers 1 s that the product gas 1s of medium heating value https://www.w3.org/1998/Math/MathML"> 12 - 14 M J / N m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as it is nitrogen free. It may readily substitute for natural gas https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a retrof1tting mode wlthout requiring extensive, costly, and space consuming modifications to the burner system, as https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> required with low heatlng value gas from alr gaslficatıon the hlgher energy density of the gas w111 also benef1t electricity generation as a smaller englne is requtred which will also operate more efficiently. An evaluation is required of the costs and benefits of the hlgher quallty gas in order to 1dentify advantageous situations. Attention was drawn to a number of interesting new developments concerning modification of syngas composltion within the gaslficatlon

employlng a catalyst in the fluid bed (eg Battelle Columbus and Battelle PNL) to achleve equilibrium compositions of speciflc favourable reactions,

employing a secondary reformer or partial oxidation reactor downstream of the primary reactor for hydrocarbon decomposition and/or tar elimination. This may be a thermal system (eg Creusot Lolre) or catalytic (eg Studsvik"s MINO).

There are many opportuntties in this area for syngas compositlon adjustment 2.2 Gas Treatment and Convers1on out. product. This requires evaluation. 21.1. Products 21.2. Some New Developments Evaluate tar management in respect of degradation, recycling and d1sposal (2.1,2.2) - thls Is related to recommendation 9.

Develop more robust predictive gasifler models for system evaluatfon (2.1)

Establish a data base resource for model11ng https://www.w3.org/1998/Math/MathML"> ( 2.1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Develop hot gas cleaning and waste heat recovery systems (2.2)

Establish gas quality spectfications for englnes and turbines for power generatıon https://www.w3.org/1998/Math/MathML"> ( 2.2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Evaluate 1n-situ low methane gas productlon (related to recommendation 4) and methane reforming steps in downstream converston processes https://www.w3.org/1998/Math/MathML"> ( 2.2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Establish the possib111ties and circumstances of viable 11quid fuels production in Europe https://www.w3.org/1998/Math/MathML"> ( 2.3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

Evaluate the advantages of mediun heating gas in retrof1tting and power generation applications (2.3).

Examine the use of catalysts In gasification (2.4). This can affect tar and methane production (recommendation 4 and 9 ).

Examine and cont1nue work on secondary gasiflcation (partial oxidation/reforming) with either catalytic or thermal processing (2.4). This can affect both tar production (recommendatıon 4), and methane production (recommendation 9).

Examine the feasibllity and viabl11ty of very small scale liquld fuel production https://www.w3.org/1998/Math/MathML"> ( 2.4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 15) Develop and evaluate the production of methanol based fuel alcohols

Identify market opportun1ties for 1mplementatıon of European technology in blomass converslon in the world-wide market place (2.5)

22. GASIFICATION FOR LOW HEATING VALUE (PRODUCER) GAS Extenslve research, development and demonstration has been carried out on small scale alr gasiflers to produce fuel gas and power in the slae range https://www.w3.org/1998/Math/MathML"> 50 - 500   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biomass https://www.w3.org/1998/Math/MathML"> ( 50 - 500   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A1though a range of systems are installed In the field or as demonstration unlts, there ls still a surprising lack of operating experience avallable. Most problems appear to lie fn reliable feedtng systems and adequate economic gas clequ-up appear to lie fareliable feeding systems and adequate economic gas clean-up systems. In Europe, most installations are in France where some comparatlve assessment has been carrled out of gaslfiers manufactured by Creusot Lotre, Cemagref, Babcock, pl11ard, Everard, Duvant, Chevet, and Tut11ot, No general concluslons were derived. There https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> still https://www.w3.org/1998/Math/MathML"> 11 t t l e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> robust experlence of gaslflers operating in the field and a thorough appraisal of gastfiers operating in a real-llfe sttuation wowld be very valuable. Activity currently seems to be evenly split between fixed bed and fluld bed systems. The former are simpler to construct and operate, but have more spectfic feedotock limltationg: whye flutd beds are more vergat t1le for feedstocks but are more complex and costly. Specification of a suitable gasifier for a glven application is still dependent on the commerclal sk111s of the suppller rather than technlcal or economic performance of the gasifler. Operating experience and technical back-up are https://www.w3.org/1998/Math/MathML"> 1 m p o r t a n t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> conslderations. Most RED has been carried out on wood. Other feedstocks considered Include bark, agricultural residues, refuse derived fuel (loose and pellet1sed); and bagasse (loose and pelletised) and rice hulls for developing country applications. 3.1. Gasifiers 22.1. Feedstocks Refuse derived fuels offer a range of problems related to their diverse constituents. Aluminium causes jamming of feed screws with shredded feed, and glass softens and agglomerates. Pelleted feed ls easier to handle and feed, and glves more consistent gasification but has a significant cost penalty compared to shredded feed, of approximately double the https://www.w3.org/1998/Math/MathML"> c o s ⁡ t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 22.2. Gas Cleaning Heat recovery and gas cleaning were still seen by many members of the workshop as a difficult area, particularly for smaller gasiflers of less than https://www.w3.org/1998/Math/MathML"> 200   k g / h ( 200   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> For retrofitting or direct firing it is energetically advantageous to burn a hot gas, and efficient hot gas cleaning devices are not available. The performance requirement 1 s dependant in appllcation and raw gas quality For remote fuel gas use or use in an englne for power generation, two systems are avallable: dry and wet. Dry cleaning gives rise to heat exchange problems from fouling and difflculties in achieving an adequate degree of partlculate and tar removal. Bag f11ters were clalmed to be effective but little experience is available. High efficiency systems can be designed and installed, but are claimed to be too expensive. Tar is considered to be the biggest problem in handiing, cleaning and tislng fuel gas from btomass. The alternatives for tar management inside and outstde the gastfler were discussed above in section 2.1 and apply here also. Ash also causes problems with some feedstocks, such as the high level of potassium in Euphorbia, and the high silica content of rice hulls. Further work on ash characteristics and management is recommended. 22.3. App11cations There is growlng awareness by European engine manufacturers of the opportunities afforded by blomass to power applications throughout the world. Some engine manufacturers have acqulred considerable practical experlence both of engine performance and design, and fuel gas specificatlon. The relatively high cost of the resultant electricity makes for appllcatıons in remote areas where there is no utilities infrastructure. It was suggested that power costs from blomass gasification are 2 - 2\frac{1. } times that from gasoline. Retrofitting applications with low heating value gas give rise to a number of problems. Boilers are downrated by as much as https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dependant on the proportion of low heating value gas and destgn of boiler. In addition burner designs for this gas are relatively large and cumbersome, and hence expensive, and often need to be an addutional installation since co-combustion of natural gas and low heating value gas is not considered practicable. It is preferable to burn the gas when hot to avold loss of sencible hemt and an adequate hot gas cleantag system is therefore, desirable. In such applications, a low ash feedstock is advantageous. Examples include lime calcination and cement manufacture. It is claimed that the maln competitor to biomass gasification is combustion for heat and power applications. No work has been carried out on a comprrative economic assessment, although it is likely that an engine is preferred to a Rankine steam cycle for power generation for smaller scale applications of below abotit 5 MWe. For less developed countries, licensing agreements for local manufacture are a more acceptable way of implementing gasification. 22.4. New Developments The introduction of low cost oxygen enrichment technology means that

Examine viabl11ty of chemicals production (5.2)

Evaluate upgrading and utilisation of "oll" as for conventional pyrolys https://www.w3.org/1998/Math/MathML"> 1   s ( 5.2 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Research and developtnent in scale up is necessary, particularly with respect to heat transfer. Feas1bility should be demonstrated before pilot plant work https://www.w3.org/1998/Math/MathML"> ( 5.3 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Liquefaction has developed in parallel to flash pyrolysis and 1 s at about the same stage of development. The characterlstic reaction para- Low temperature : up to https://www.w3.org/1998/Math/MathML"> 350 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

high pressure : up to 300 bar

low heatlng rate and relatively long restdence time

possible addition of hydrogen, Co, and/or catalyst

ILquid phase processing.

he lower temperatures and heating rate offer the potential to overcome the disadvantages of scale-up noted above for flash pyrolysis, but at the expense of high pressure, a longer reaction time, and use of costly re- Analogies with coal liquefaction processes were noted, and a view as expressed that direct liquefaction technology may be more sultable for blomass conversion than coal converslon. It https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> interesting to note the favourable C:H ratıo but unfavourable C:0 ratio for biomass compared to coal. Slnce there are substantlal coal 1lquefaction facilities avallable, a direct comparison would be Interesting. Yields of liquids of up to https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by welght of feed have been reported. The llquid product is typlcally of low water content and low oxygenates and to more stable than pyrolysis "otl" Althowgh it is more easily upgraded than pyrolysls "oll" it costs conslderably more to produce. A recent IEA study 1nto the technoeconomic merits of flash pyrolysis and 11quefaction for production of a marketable fuel product is understood to have found that overall, there was relatively little difference in final product cost - in both cases the production cost was several times that of conventionel fuel costs. further feature is the low char yield, possibly due to the higher activity of biomass derived char, whlch fits the view above about coal and biomass liquefaction potential. The discussion relating to liquids upgrading and use from flash pyrolysis apply equally to liquefaction products; and there https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> considerably scope for experimentation, applications, and utllisation studies. A variety of other products have been reported such as phenolic oll. hydrocarbons, monosaccharides, hydroxylic and carboxyl1c acids. Little work has been carried out on product analysis or characterisation, which would be a useful addition to an R&D programme. Most experimentation has been carried out https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a batch mode. It 18 believed that scaling up liquefaction processes may present fewer techmical problems than flash pyrolysis wth less constraints on particle s1ze, residence time, and heating rate. Experience of coal processing will ald identification of problem areas. It will also be possible to draw on the practical experience gained with coal liquefactlon R&D, and the possibllitles of uslng biomass on a coal liquefaction pilot plant are quite Interesting. Particular problem lie in feeding and product separation, which will require special attention.

LIQUEFACTION meters are: grente

6.1 Product 6.2 Reactor Large quantities of straw and wood are available for heat generation. The combustion quality has to be improved to diminish the environmental impact of furnaces. Depending largely on local conditions, many farms can be heated via biomass combustion on a solid financial basis while being independent of imported fuel. Mr Brenndorfer, KTBL Darmstadt, gave a report about briquetting of straw in an on-farm-demonstration plant. According to present operation experience the operating reliability can be considered as good costs for producing the operating reliability can be considered as good. costs for producing briquettes depend on the rate of utilization, organisation and preparation At a utilization rate of about 1,000 hours/year the production costs amount very low emission (dust content), which are fully in accordance with the emission standards of the FRG. Mr Sturmer, TUM, FRG, spoke about, "Economics of High Pressure Densification" Three straw briquetting enterprises were compared, two on solid economical success, one without. In his summary, Sturmer stressed that it was the related circumstances that determined whether the results were positive or negative. Mrs Christel Benestad, Central Institute for Industrial Research, Oslo, Norway, gave a very interesting lesson about air pollution by combustion of wood and straw. Polycyclic aromatic hydrocarbons (PAH, some of which are known carcinogens, are formed by incomplete combustion of any carbonaceous materials. Recent1y, studies in Scandinavia showed that very high concentration of PAH could be found in emissions from combustion of biomass. These emissions have also been shown to contain large amounts of mutagenic materials, as detected by the Ames' Salmone https://www.w3.org/1998/Math/MathML"> 11 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mutagenicity assay. Results for different furnaces. Studies were done in https://www.w3.org/1998/Math/MathML"> 20 - 50   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> performance. Sma11 single stoves had the lowest combustion quality. While starting a cold furnace, pollution is worst. Stoves have to be improved in combustion quality. Straw as a fuel was near to wood. Mr Wilson from Foster Wheeler, UK, showed the technical possibilities of combustion and gasification of biomass in fluidized bed systems of the manufactuer, Foster Wheeler. Some information was presented about peat combustion. Mr Gautier, France, reported about cereal straw combustion for corn drying, harvesting and energetic valorization of corn cob. The rise of fossit energy price entails difficulties for the farmers and collector organisms which dry corn. Drying costs are high. The waste such as cereal straws or corn cobs, used by combustion, represent a solution. They allow organisms to control their fuel stock and to master its cost price better. From 1979, straw furnaces have been settled in farms, in the parisian area. Trials have been realised with this equipment, in relation with the constructors in order to determine their performance with a view to improve them. In 1984 , more than 30 straw furnaces were in operation. The equipment make the investment overcosts profitable from 3 to 4 years. At the same time, three establishments burned dried cobs in high powered furnaces in order to dry corn seeds. Some furnaces have high performances of up to https://www.w3.org/1998/Math/MathML"> 700   k W t h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Rotary grates and drump boilers were described. Dr Okken, NL, spoke about wood stoves in The Netherlands, including environmental and social aspects. In general wood stoves have too much heating capacity. As a consequence they must be operated with little air supply in order to temper the heat output. This has an adverse impact on air pollution; emissions of polycyclic aromatic compounds, particiles and carbon monoxide will rise. Mr B: Wilton, Univ. of Nottingham, UK, reported about fluidized bed combustion of both light and wet biomass. 1. The problem FTuidised bed combustion is a potentially desirable process for biomass; however, in practice one major problem is encountered, namely the air velocity required to fluidise the bed elutriates ijght biomass before it has a chance to burn complete. When this happens the bed temperature drops and the process becomes unstable. Densification of some biomass materials to make them resemble coal may overcome this problem, but if this operation could be avoided and a more generally applicable solution found, biomass would become a more attractive fuel. A particular problem outside the EEC is rice husks, which at the moment often causes environmental problems because they are disposed of by allowing large heaps to smoulder; another potential fuel is maize stover and there are several by-products for agriculture and forestry that are normally considered too wet to burn. 2. The_solution At the University of Nottingham a somewhat unusual fluidised bed combustor has been designed and is being built. It has three features that will encourage biomass to burn within the bed and a further two that will retain any elutriated material for a period Tong enough for combustion to be completed. Mr M. Hellwig, Chile, guest scientist at TU-Munich, Weihenstephan, FRG, presented a paper about "Fundamentals of the Combustion of Wood and Straw under Special Consideration of the Burden on the Environment". The direct combustion of wood and straw is the most important use of biomass in substitution oi1, since the technical equipment required is minimal. However, difficultires often arise with the combustion of biomass, which result in a serious burden to the environment. This work discusses the importance of the essential combustion characteristics of wood and straw and compares these to other fuels. Mr U. Kraus, TU-Weihenstephan, spoke about test results from pilot plants for firing wood and straw in the Federal Republic of Germany. In the FRG, the entire energy demand for agriculture could be met with regenerative energy sources. Forestry waste and straw deliver by far the largest portion. The combustion of these materials often leads to problems. Apart from a high combustion quality, practical applications require a high degree of automatisation of the plant. Plant for wood chips give very good results with regard to the combustion quality. The dust emissions are clearly below the values a 11 owed under FRG laws. Efficiency of https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and more can be reached with a moisture content of around https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for chips and when operating the boilers at near capacity. S1ag problems have not as yet appeared at any of the supervised plants. The firing of straw is accompanied by still larger problems. Even with dust filters, it is difficult to reduce the solid particle emissions in the flue gas to a value of https://www.w3.org/1998/Math/MathML"> 300 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as required by law. In addition, the formation of slag represents a problem, which however will be solved with the use of new grate systems. There were further discussions about: combustion quality, costs, regulations in different countries, availability of biomass, and test methods. CONTRIBUTED PAPERS I. RESOURCES (a) Trees (b) Crops (c) Algae and Aquatic Plants (d) Physiology 3. BIOMASS FROM SHORT ROTATION COPPICE WILLOW G H MCELROY AND W M DAWSON HORTICULTURAL CENTRE, LOUGHGALL, NORTHERN IRELAND 4. SUMARY This project began in 1973 with the objective of maximising the production of willow biomass on agriculturally marginal land as an alternative and renewable energy gource to focsil resources. After screening a range of species Salix x'Aquatica Gigantea' was identified as the most promising for this investigation. Plot work at both the Horticultural Centre and on the marginal surface water gley soils of County Fermanagh, the area identified as having the yreatest potential for biomass production in the United Kingdom, has shown that at the planting density of 20,000 ha-1 annual yield increments of 17 t oven dry matter ha-1 have been achieved from triennial harvesting cycles. Having established basic production criteria a development plot of 2. 0 ha was established in County Fermanagh to provide feed-stock for commercial end product evaluation. Initially two rautes were investigated vizz- (i) Chipping for direct burning. An automatic staker and boiler system has been operating for two seasons to heat a 200 m2 glass- house producing early tomatoes. Mean daily usage for the February to June period in 1983 , maintaining a daily minimum of https://www.w3.org/1998/Math/MathML"> 18 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a https://www.w3.org/1998/Math/MathML"> 2 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> night set-back was 292 kg willow biomass at 30-35 per cent moisture. (ii) Animal feed supplement. Chipped willow biomass has been further processed and evaluated with silaqe as an animel feed and has been shown to have the feeding value of cereal straw. New techniques for fractionating wood show promise for developing this use. 5. INTRODUCTION Northern Ireland's position as a relatively isolated part of the United Kingdom not having significant fossil energy resources led to an examination of the contribution that the large area of marqinal agricultural land in the west of the province could make to local energy requirements. In a basically agricultural economy with a low population density(in this area https://www.w3.org/1998/Math/MathML"> 27.5   k m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) it was envisacued that biomass could make a significant contribution. Following earlier work at the Horticultural Centre Loughgall trials began in 1975 in Co Fermanagh where most of the heavy surface water mineral qley soils are found. This area of County Fermanagh and west County Tyrone has been identified as the largest area (200,000 ha) of potentially suitiable land for biomass production in the United Kingdom (1) Trials carried out in 1973/74 identified willaw (Salix) as the most productive genera (2) (3) for biomass production in this area. Investigations centred on identifying the most suitable species planting densities, harvesting cycles and management techniques. 2. SPECIES AND SPACING Following screening trials (4) two species were selected for evaluation at a range of densities - Salix 'Aquatica Gigantea" and viminalis. Salix viminalis proved unsuitable because of lower yields and poor persistence under intensive harvesting cycles. From establishment (1975) nine annual harvests have been taken from Salix x 'Aquatica Gigantea https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the yields are given in Table I. TABLE I Yield data ( t ha-1) of Salix'Aquatica Gigantea' planted at eight densities and harvested annually. https://www.w3.org/1998/Math/MathML">   Spacing   ( m )   Fresh wt.     Dry wt.     Mean     Fresh wt.     Mean   1984 1984   Dry wt.*   1.0 × 0.25 44.0 19.4 38.7 17.0 1.5 × 0.25 37.1 16.3 30.6 13.5 2.0 × 0.25 35.9 15.8 26.5 11.7 3.0 × 0.25 24.2 10.6 20.6 9.1 1.0 × 0.50 33.2 14.6 30.7 13.5 1.5 × 0.50 32.5 14.3 27.9 12.3 2.0 × 0.50 33.1 14.6 24.1 10.6 3.0 × 0.50 25.7 11.3 20.1 8.8 * 1984 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> At the higher densities maximum yields are obtained generally within two years of establishment and have been maintained to date; there being no trend towards decreasing yields. The lowest densities show a sionificant reduction in yield indicating that the complete ground capture has not been obtained to date with annual harvesting. In addition at lower densities competition is reduced and so cane number per staol increases. Further evidence indicates that square planting (0.7 x 0. 7 m) may be more productive than rectangular plantings at the same density. However for our current harvesting operation a minimum of one metre is required between rows (5). Based on this information it was decided that a spacing of https://www.w3.org/1998/Math/MathML"> 1.0 × 0.5   m ( 20,000 h a - 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , had the best potential for optimising yield whilst at the same time minimising management problems.

HARVESTING CYCLES

A series of trials with Salix x 'Aquatica Gigantea' planted at a density of 20,000 ha-1 in 1976 was carried out to evaluate the effect of annual biennial and triennial harvesting cycles on yield. These trials were carried out on the surface water mineral gley soils of Co Fermanagh and the results obtained are recorded in Table II. TABLE II Yield data ( t ham 1) of Salix x 'Aquatica Gigantea / for three harvesting cycles (planting density 20,000 ha-1) Harvesting Mean annual yield https://www.w3.org/1998/Math/MathML">   Cycle   77 78 ' 79 80 181 82   increment   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   Annual   8.7 16.6 17.0 22.6 16.7 18.7 16.6 7.8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Biennial - - 36.5 - 66.3 - 51.0 25.6 12.0 Triennial - - - 82.3 - - https://www.w3.org/1998/Math/MathML">   -   97.3   29.9   14.6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> *Based on 1982 dry matter analysis. This data shows an increasing annual dry matter yield increment with increasing harvesting interval. The triennial harvest carried out in 1982 (see above) gave the highest total yield with a mean of 97.3 tha-1 fresh weight. At a dry matter content of 49 per cent at harvest this gives a yield increment of 15.9 tha-1 year-1 dry matter. With increasing annual yield increments being recorded from biennial and triennial harvesting cycles observational plots were established at Loughgall in 1979 to investigate yields after four, five and six year harvests. These longer cycles however have the disadvantage of a less attractive cash flow and will be much more difficult to harvest and handle mechanically. The most important concept underlying the production of biomass from short rotation coppice is to maximise the nett eneray gain both in production and utilisation. Early results showed a yield increase with added nitrogen and over a nine year period a mean yield increase of 1.2 t ha-1 dry matter has been recorded following an anntal application of 45 kg ha-1 nitrogen costing e17.50. Trials to determine the effect of further increasing nitrogen application up to https://www.w3.org/1998/Math/MathML"> 250   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> did not show economic yield resoonses. Calculations based on leaf litter analysis show that Salix x Aquatica Gigantea https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> contributes https://www.w3.org/1998/Math/MathML"> 130   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha-1 yr-1 and yields to date have been maintained by thjs level of fertilisation.

UTILISATION

Having established production technology for willow biomass on low grade mineral soils the emphasis of this project has been changed to investigate and evaluate the opportunities which exist for the utilisation of biomass in specific areas of Northern Ireland. Two main topics are currently under investigation - the use of biomass as a fuel for direct burning and as an animal feed supplement. To provide a feedstock for these investigations and to obtain yield data from a cormercial block of willow coppice a 2.0 ha plantation was established in County Fermanagh in 1982 and will provide its first three year harvest in the winter of 1985 . Direct burning: Since combustion technology using wood as a fuel is well established initial work has concentrated on the use of bionass as a fuel source for commercial purposes and to create self sufficiency in energy requirements on farms. Chipped willow rods were used as the energy source for the production of early tomatoes using a heating system incorporating an automatic stoker, gasifier and high output boiler (216 MJ hour-1). For this system it was necessary for the chipped willow biomass to have a minimum dry matter of 50 per cent up to a maximum of 75 per cent. Three year old willow has a dry matter of break the ligno-cellulosic bonding in wood and in so doing improve its overall digestibility to 65 per cent. The production of celiuloses Suitable for use in animal feeds would enhance the economic prospects for willow biomass utilisation. Salix x 'Aquatica Giqantea" rods have been processed in this way and up to 32 grams per litre glucose has been recovered where 55 grams per litre represents 100 per cent recovery Dther opportunities for the utilisation of willow biomass including the manufacture of charcoal, the production of chipboard and its use as a source of viscose for the textile industry are under consideration. 6. REFERENCES (1) STOTT, K. G. (1977). Coppice willow pulpwood - feasibility study. Report for Paper Industry Research Association. Leatherhead, Surrey, England. (2) STOIT, K.G..., McELROY, G.H., ABERNETHY, W. and HAYES, P. (1980). Coppice Willow for Biomass in the U.K. 198-209. In Energy from Biomass 1st E.C. Conference Brighton. (3) STOTT, K.G. PARFITI, R I MEEIROY, G. H. and ABERNETHY, W. (1982). Productivity of Coppice Willow in Biomass trials in the UK, 230 235 In Enerqy from Biomass. 2nd E.C. Conference Berlin. (4) STOT T, K.G. (1971). Check list of Long Ashton willows. Rep. Long Ashton Research Station, Bristol 1971. 143-249. (5) McLAIN, H.D. (1982). The development of a harvester for 2-3 year old Willow Coppice 225-229. In Energy from Biomass. 2nd E.C. Conference Berlin. (6) ANON. (1983) Annual Report The Horticultural Centre, Loughgal1, Northern Ireland. 96-98. (7) MeCULLOUGH, I. (1981). Evaluation of willow nuts as a feed for beef cattle. Internal Report. Department of Agriculture Northern Ireland. (8) WYLIE, A. (1984). The apparent digestibility of alkali-treated willow (Salixx 'Aquatica Gigantea') when fed to sheep. J.Sci. Food Agric. 35. 1174-1177. (9) ANON. (1984). Iotech Biomass Review. Iotech, Montreal Canada. BIOMASS GAINS IN COPPICING TREES FOR ENERGY https://www.w3.org/1998/Math/MathML">   CROPS   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> W. A. GEYER, G. G. NAUGHTON, and M, W. MELICHAR Department of Forestry, Kansas State University Manhattan, Kansas 66506 Summary Woody biomass is an appealing energy source. When grown under the short-rotation intensive culture (SRTC) system, fuelwood crops are harvested at a relatively young age. Subsequent crops are dependent upon coppice regrowth from established root systems. Use of species/clones that resprout profusely and consistently is crucial to the successful application of this concept. In 1968 a series of experiments were initiated to evaluate biomass yields in seedling and coppiced tree plantings. Several fastgrowing deciduous tree species and populus clones were tested using two- to four-year cutting cycles over several rotations. Survival was over 90 percent for seven species when first cut at two years. Firstcycle coppice yields were about 60 percent more than seedling yields. Some two-year sprouts at https://www.w3.org/1998/Math/MathML"> 0.3 × 1.2   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> spacing yielded 20 dry tonnes/ha. Acer sp. demonstrated the longest root system viability. Many Populus clones did not sprout when first cut at four years. Those sources from the central United States grew and sprouted best. The biomass yields and sprouting longevity observed in our studies indicate that several deciduots tree species and selected Populus clones have potential for succesive coppice harvest cuts in short-rotation energy forest plantations. 7. INTRODUCTION Use of wood as an energy resource has tripled in the United States since the 19608. In 1981 wood supplied about six percent of industrial and 10 percent of residential heating requirements nationwide (4). Forest plantations managed intensively for biomass production could contribute significantly to energy supplies. SRIC forestry is a silvicultural system that incorporates close spacing, intensive cultural techniques, and short cutting cycles. This system was first studied intensively in the United States in the mid-1960s (5). In 1978 a comprenensive national program was initiated by the united States Department of Energy. Successful coppice rotations are crucial to the SRIC concept. Time of harvest, stump height, age, and tree species affect stump survival and coppice response. Establishment and production costs are reduced substantially with high coppice yields (6). This report summarizes the results of numerous coppice experiments with several fast-growing deciduous tree species grown in the central Great Plains region of the United States. 8. 2. https://www.w3.org/1998/Math/MathML">   PRELIMINARY   1968 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> STUDIES 1/ One-half plots cut and weighed after https://www.w3.org/1998/Math/MathML"> 2 nd https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 3 rd https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> year; all cut at https://www.w3.org/1998/Math/MathML"> 4 t h , 5 t h , 6 t h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 8 t h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> year. https://www.w3.org/1998/Math/MathML"> 27 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Apacing https://www.w3.org/1998/Math/MathML"> - 1 0.3 × 0.3   m , 2 0.45 × 0.45   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 3 https://www.w3.org/1998/Math/MathML"> ) 0.6 × ( 6.6   m . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9. MULTI-SPECIES STUDIES Several additional species were studied for their coppice potential in subsequent trials and early results were reported (2) ind subsequent trials and early results were reported (2). sandy and loamy. Spacing within rows was 0.3,0.6, or 1.2 m. Plots (0.01 hectare) were set up for each spacing with 370,190 or 100 trees, respectively, per plot. Weeds were controlled by cultivation. Biennial harvest cuts were made during the dormant season. ANOVA tests (split split plot) revealed significant differences in annual growth rates for growing sites, spacing, harvest cycles, and spacing-harvest cycle interaction. Yields are presented in Table II. In general, the loamy site produced 50 percent more biomass than the sandy site; boxelder (Acer negundo) produced substantially less biomass than the other six species; closer spacing produced 10-25 percent greater yield than wider spacing; the first 2-year coppice harvest produced 60 percent greater yield than the first 2-year seedling harvest. The percentage growth increase was not as large at closer spacings as at wider spacings. Some species did not respond well to multiple cuttings, especially on the 3 andy site Sycamore (x)atanus occidentalis) sandbar willow (Salix exigua) and the male cottonwood (populus sp.) cultivar (siouxland) died 10. REFERENCES

D A ALCLAIR

Institut National de la Recherche Agronomique Station de Sylviculture d'Orléans S1.05-10 working party chairman 11. Summary The International Union of Forestry Research Organisations (I.U.F.R.O.) gathers approximately 200 scientific research units into six "divisions". The working party s1. 05-10, entitled "monospecific coppice stands in short rotation" includes forest scientists working worldwide on this subject, and mostly interested in biomass production. An enquiry has been sent to interested members of I.U.F.R.O. to com- pile available data, mainly concerning coppice biomass production in various experimental conditions. The present work summarizes the results of this enquiry, giving some information on the various existing experimental plots and on the research objectives. 12. INTRODUCTION The International Union of Forestry Research Organisations groups 10 ooo scientists belonging to 500 member organisations, coming from 90 countries. It is divided in 200 research units under 6 main divisions. In Division 1, "Forest Environment and Silviculture", the fifth Subject group https://www.w3.org/1998/Math/MathML"> ( S 1.05 - 00 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , "Stand establishment, treatment and amelionation", includes two working parties interested in coppice : st. O5-09, "Treatment and conversion of coppice stands", and https://www.w3.org/1998/Math/MathML"> S 1.05 - 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> "Monospecific coppice stands in short rotation". This last working party has received a new impulse with the growing interest for biomass production. At present sixty scientists coming from 18 countries have answered to an enquiry concerning their projects and their experimental plots. Countries most represented in this group are, inside Europe : France and Untted Kingdom, and outside EFC : Sweden, USA and Canade. The aim of the present paper is to outline the main characteristics common to the studies undertaken by members of IUFRO working party "Monospecific coppice stands in short rotation", after an enquiry sent out to those scientists which were registered in the IUFRO files. 13. TRADITIONAL COPPICE The IUFRO group most interested in traditional coppice is s1.05-09 "Treatment and conversion of coppice stands". The objective is mainly to study means of improving the quality of timber produced with this technique, mostly by conversion to coppice with standards or high forest. However, several scientists in France, Italy, UK, and Canada, have been interested in studying the quantity of biomass produced in these traditional coppice stands. In this respect they can provide precious information concerning the evolution after several rotations. Country Members 117111011112131581 SHORT ROTATION FORESTRY FOR ENERGY PRODUCTION M. Neenar An Foras Taluntais (Agricultural Research Council) Oak Park, Carlow, Ireland. Abstract Suminary The yield of short rotation forestry is determined by a number of factors such as species, spacing, length of growing cycle and soil fertility. All of the these factors interact with one another. A number of these variables have been tested in a series of field experiments begun in 1977. On soils of very low fertility only conifers, which will not resprout, will survive. On slightly more fertile soils the most promising species are salix, populus and Alnus. Yields of up to https://www.w3.org/1998/Math/MathML"> 18 t h a - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> annum https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dry matter have been obtained on a 3 or 4 year growth cycle. Most species so far tested suffer from some biological disadvantage. On wet soils, Salix aquatica gigantea outyields all other species. Alnus fixes nitrogen at rates of 105 to https://www.w3.org/1998/Math/MathML"> 212   k g h a - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> annum https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . However the species is slow to recover from harvesting. In the young stage, some Populus clones are prone to frost injury. There are indications that the clone Fritzi Pauley may not be tolerant of coppicing. 1. INTRODUCTION In this investigation, the objective is to utilise the methods of agricultural technology to produce an energy crop. Theoreticaliy, many species of plants can be used, but there are obvious advantages in using a crop which is relatively high in dry matter, and perennial in growth habit https://www.w3.org/1998/Math/MathML"> [ 1 ] [ 2 ] [ 3 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Short rotation or coppice forestry is one such crop. The efficiency of production depends very much in matching the species to the site. The availability of land is complicated by socjological and democratic factors; nevertheless it can be assumed that only land which is uncompetitive for agricultural production, will be devoted to forestry. Such land can be infertile in different ways e.g. poor soil cover, located at high elevations, or rendered infertile by poor drainage conditions. On very poor soils only coniferous species will survive. If planted at close spacings i. e. less than 1 mapart, these species will provide an acceptable yield on a 7 to 10 years cotation. Planting accounts for approximately 20 per cent of the cost of the fuel. Because of this, and the earlier return on investment [4] coppice forestry has certain economic advantages. From studies begun in 1977 , three main genera, Alnus, Populus and Salix, were chosen as having the best possibilities. 14. MATERTALS AND METHODS Beginning in 1977 , a series of species trials were carried out on different soils. Coppicing, spacing and other trials were carried out at 3 centres. A series of field and laboratory trials on Alnus was conducted by https://www.w3.org/1998/Math/MathML"> 0 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Neill [5] at Johnstown Castle Station, wexford. It will be seen that the yield of conpice is substantially higher than that of the primary growth, and that in some species this is being maintained in the second coppice. In 1982 a trial with 29 poplar clones was established on a peatbog. In the second year when the plants were under https://www.w3.org/1998/Math/MathML"> 2   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> high, many clones were severely damaged by a frost of https://www.w3.org/1998/Math/MathML"> - 5.0 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which occurred when the trees were atmost in full leaf. The most tolerant clones were TT32 Donk, and a German hybrid, P.maximowiczii x P.berolinsis (Table 1). It is believed however that this is only a problem at the establishment stages. Nevertheless, it is prudent to use only genetic material which comes from an appropriate climatic zone. The spacing of plants is a difficult problem because there is an interaction with the length of coppicing cycle. A spacing of 0.3. 1. Om gives high initial yields, but this is not sustained in some species such as poplar Fritzi Pauley which showed a high mortality at the second coppice (Fig.2). 15. DISCUSSION The most important consideration is the species. Of the 38 species of Alnus which exist, only four, A.glutinosa, A. incana, A.rubra and A.cordata have been tested on a range of soils. The species recovers slowly after cutting, and makes little growth in the first coppice year. A.rubra tends to die off to the extent of https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ater cutting. This is Believed due to genetic variation. 0 'Neill [5] found that these species fix nitrogen at rates varying from 105 to https://www.w3.org/1998/Math/MathML"> 212   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per annum, but exotic species were less efficient in this regard https://www.w3.org/1998/Math/MathML"> [ 6 ] . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In the case of salix, testing has so far been confined to European types of which about 300 species and many more hybrids and clones exist. It has been found that in wet soil conditions, the hybrid, Salix aquatica gigantea, outyields every other species, giving https://www.w3.org/1998/Math/MathML"> 18.00 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha annum of dry https://www.w3.org/1998/Math/MathML">   matter. It is also highly resistant to the leaf beetle phyllodecta     https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vulgatissima to which other salix species are sensitive. The species is however extreMely crooked and branched and therefore somewhat difficult to harvest. Another natural hybrid, S. dasyclados, is equaliy high yielding on reasonably good soil, but is prone to leaf beet?e attack. Only one clone of s.viminalis, an Irish one, was tested. This proved low yielding as did S. Smithiana. Two poplar hybrids, Rap and TT32, and P.trichocarpa Fritzi Pauley, were tested initiall1y. TT32 is not well adapted to adverse soil conditions. Al though Salix aquatica gigantea outyields all other species so far tested, there are indications that some of the European hybrid poplars may come very close to attaining the same yields. It has been shown [7] that species differ but slightly in calorific Value, but that bark has a higher heating value than wood. inis gives a slight advantage to small dimensional wood, provided it is allowed to dry out before burning. Harvesting small dimensional wood creates some problens but these appear to have been overcome in finland where more than one hundred wood fired plants ranging in size form 0.5 to 1.0 MW are now in operation [8]. Possibly one of the main obstacles to the commercialisation of fuel wood is the lack of standards and quality specifications [9]. This, however, is an institutional and administrative problem. 16. REFERENCES [1] NEENAN, M, (1980). The production of energy by photobiological methods. Energy. Commission of European Communities ESBN-92-825, 1982-1, p.141-167. [2] LAVOIE, G. and VALLEE, G. (1981). Inventory of species and cultivars potentially valuable for forest biomass production NE.1981-17. National Swedish Board for Energy Source Development Box 1103, S-16312 Spanga, 43 pages [3] KHALIL, M.A.K. and A.W. ROBERTSON (1984). Conifers for Biomass production. Vol.I and II. Forest Energy Program, Canadian Forestry Service and I. E.A. [4] NEENAN, M. and G. LYONS (1981). The production of energy from short rotation forestry. Energy from Biomass, Vol.1, Series E. Proc. Contractors Meeting, Copenhagen, 1981. p.47-51. [5] O'NEILL, P. (1984). Studies on the symbiotic performance of the nitrogen fixing tree species and microbiological aspects of the nitrogen fixing endophyte. Ph.D. thesis, National University of Ireland, 1984. [6] O 'NEILL, P. and P.M. MURPHY (1983). Nitrogen fixation and dry matter yield in Alder species. Research Report, Soils Division, 1983. An Foras Taluntais, p.23. [7] NEENAN, M. and K. STEINBECK (1979). Calorific values for young sprouts of nine hardwood species. Forest Sci. 25, No.3, pp.445-461. [8] HAKKILLA PENTTI (1984). Forest chips as fuel for heating plants in Finland. Folia Forestalia 586 , Finnish Forest Research Institute, Hel sinki [9] NEENAN, M. (1984). Biomass qualities for energy conversion with particular reference to the combustion of wood. Report No.2. Biomass growth and producion. International Energy Agency Forest Enerqy Agreement, Ministry of Natural Resources, Ontario, Canada. UNE PLANTE ENERGETIQUE A CYCLE COURT LE GENET : CYTISUS SCOPARIUS P. TABARD Laboratoire de Bioclimatologie I.N.R.A. Domaine de Crouelle 63039 Clermont-Ferrand-France 17. Summary Grazing areas of Central France (Auvergne) are composed of about 250000 hectares of moor land, waste land and low yield pastures. With the purpose of rehabiliting these areas, it would be possible to sow 20 to https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with broom as part of a rotation, as an energetic plant. Life duration of a broom canopy is about 12 years. Its evolution goes through several stages lasting 2 to 4 years each : setting of the plants, growth, decay, death and resowing. During maximal growth, toward the 7 th year and at 1 o00 m altitude, a dense population yields 50 Tons dry matter per hectare. With P.K fertilization, this crop may yield up to 15 Tons per hectare and year. The broom being a legume brings about https://www.w3.org/1998/Math/MathML"> 100   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of nitrogen/year/hectare, therefore it is an interesting rotation head. Broom which has a calorific power of about 4400 Kilocalories/kg of dry matter has long been used as fuel. A survey of biology, yield and possibilities of utilization has been undertaken to bring up conditions of a rationnal cultivation.

INTRODUCTION

Le mode de culture en moyenne montagne d'Auvergne a évolué sensiblement depuis le dêbut du siècle. Le systeme agro-pastoral ancestral s'est progres sivement modifié par suite de la desertification rurale avec une réduction sensible du trotpeau ovin d'oü, un envahissement progressif des prairies, pâturages et même terres de cultures par les broussailles et les genêts. Ces derniers sont souvent dominants et forment parfois une couverture to- tale sur des grandes étendues, spécialement dans les zones à statut collec- tif. Il est possible https://www.w3.org/1998/Math/MathML"> d t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> estimer ces surfaces a 10 % de la surface agricole totale soit 250000 hectares. Au dêbut du siècle, beaucoup de ces parcelles êtaient soumis au systême d https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> assolement suivant

semis de genêts avec pâturage pendant 4 à 5 ans,

culture de céréales pendant 3 ans.

Les genêts fournissaient un fourrage d https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> appoint pour le bêtail, du bois utilisé pour le chauffage des fours à pain et enfin un precedent cultural intêressant grâce à la fixation de 1" azote atmosphérique. Ces différentes constatations nous ont amené à rechercher un systeme rationnel de remise en valeur d'une partie de ces friches avec des cultures de genêts utilisées comme plantes productrices de bíomasse énergétique et cultures améliorantes. 2. BIOLOGIE : DESCRIPTION GENERAI.E Le genêt appartient à la famille des papillonacées, il se rencontre dans presque toute l'Europe spëcialement sur les sols acides (pH 5 à 6) sauf ceux humides en permanence. Sa durée de vie est de 10 à 12 ans, ă 1 êtat adulte il peut atteindre 2 à https://www.w3.org/1998/Math/MathML"> 3   m . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Il possède de nombreux rameaux chlorophylliens cannelés qui restent verts toute https://www.w3.org/1998/Math/MathML"> l ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> année. Les feuilles sont de deux types:

trifoliêes et pêtiolées à la partie inferrieure du rameau

simples et sessiles à 1'extrémité du rameau.

Elles axilent toutes un bourgeon. La floraison a lieu de mai a juillet suivant l'altitude et ne s'observe que sur des pieds đe 3 ans ou plus. Les fruits sont des gousses velues de 3 à https://www.w3.org/1998/Math/MathML"> 4   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de long contenant 8 à 10 graines. Ces gousses s'ouvrent par dêhiscence êlastique sous https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> action du soleil ce qui provoque la dispersion des graines. Ce phénomène pose d'ailleurs un problème pour Ia rëcolte. Si les graines semblent pouvoir se conserver très longtemps dans le sol. il est très difficile de les faire germer. A 1'état naturel, le renouvellement se fait le plus souvent à la suite de la destruction du vieux peuplement par le feu ou après un défrichement. Même dans ces conditions il faut au moins 2 ans pour obtenir une couverture totale. https://www.w3.org/1998/Math/MathML"> L ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> appareil racinaire est formé https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> un pivot de 20 à https://www.w3.org/1998/Math/MathML"> 25   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de 1 ong entouré d'un important chevelu sur lequel on observe des nodosites en quantité irmportante. Les mesures montrent que les genêts peuvent fixer environ loo kg d'azote atmosphêrique par an et par hectare (1).

ESSAIS CULTURAUX

1 Essais en conditions contrôlées.

. T Germination des graines.

Le pouvoir germinatif des graines est très faible et, comne dans le cas de nombreuses légumineuses, celles-ci semblent subir une inhibition tégumentaire très importante. Sans traitement la germination est toujours inférietre à https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ,aussi divers procédés ont-ils été expérimentés pour essayer d' https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> amëliorer cette capacíté germinative :

trempage des graines dans l'eau à différentes températures 50 - 80 et pendant 5 et https://www.w3.org/1998/Math/MathML"> 10 m n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ,

scarification,

10000

LIaitement à https://www.w3.org/1998/Math/MathML"> H 2 S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pur pendant 2-4 et 24 heures.

...2 Mesures de la photosynthése et bilan hydrique.

Des mesures de photosynthèse ont étế effectuées sur un couvert dense de genêts de l an (Fig. 1). La rëponse au rayonnement est largement supérieure â celle obtenue sur une culture de gramínées placée dans les mêmes conditions. Le bilan journalier atteint 50 grammes de https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> par m https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pour une radiation de https://www.w3.org/1998/Math/MathML"> 25 M . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> joules. La surface foliǻre, très élevêe (LAI https://www.w3.org/1998/Math/MathML"> > 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) ne parâtt avoix qu'une incidence limitée sur la photosynthêse. L'effet température est très important, on constate un palier dès que celle-ci atteint 23 à https://www.w3.org/1998/Math/MathML"> 25 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C. Par contre, par température inférieure à https://www.w3.org/1998/Math/MathML"> 0 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C la photosynthêse est loin d'être négligeable (6,5 g de con absorbê pour un rayonnement de https://www.w3.org/1998/Math/MathML"> 1,8 M . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> joule par jour). \begin{abstract}- récolte de la biomasse au maximum du développement - cultures fourrageres pendant 3 à 4 ans. Malgré ces aspects positifs le développement et 1 utilisation de cette biomasse ne peut https://www.w3.org/1998/Math/MathML"> s † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> envisager que dans un contexte de petites régions et dépendre de décisions prises au niveat local en fonction de critères êconomiques et socio-culturel. (1) ROUSSEAU S., LOISEAU P. (1982). Structure et cycle de développement des peuplements à Cytisus scoparius dans la Chaine des Dômes. Acta 0ecologie applica. Vol. https://www.w3.org/1998/Math/MathML"> 3 n ∘ 2,155 168 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (2) WILLIAMS P. (1981). Aspects of ecology of broom (Cytisus scoparius) in Canterbury, New Zeeland. New Zeeland journal of Botany, Vo1. 19, 31-43.\end{abstract}

REFERENCES

fig 1 - Relation entre le royonnement ef lassimilation nette. ENERGY AND BIOMASS OF PIEDMONT HARDWOODS Summary

INTRODUCTION

Venice, Italy. March 25-29,2985 2. THE HARDWOOD RESOURCE More than 1.1.3 million ha, roughly https://www.w3.org/1998/Math/MathML"> 64 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total land area in the southern Piedmont, is classified as commercial forest. (2) Of this area 6.8 million ha https://www.w3.org/1998/Math/MathML"> ( 599 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is allotted among three hardwood types--oak-pine https://www.w3.org/1998/Math/MathML">   u p l a n d   h a r d w o o d   a n d   b o t t o m l a n d   h a r d w o o d   a r d a r i o n t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> upland hardwood, and bottomland hardwood. Hardwood biomass distribution among forest types averages https://www.w3.org/1998/Math/MathML"> 62 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , with slightly greater values in the northern regions and lesser values to the south. Total green weight estimates of aboveground hardwood biomass is l. l8 billion metric tonnes. (2) The hardwood resource can be divided into two major categoriesthe Upland and the Bottomland forest site types. Upland sites are characteristically mesic and relatively low in fertility; common species include red oak (Quercus rubra), black oak (Q. velutina), white oak (Q. alba) red maple (Acer rubrum), and black cherry (Prunus serotina) Bottomland sites are more fertile, slightly more basic and hydric in nature. Bottomland sites have the highest productivity rates of any land in the southern piedmont and represent the best sites for hardwood growth. Typical species include sycamore (platanus occidentalis), willow oak (Q. phellos), water oak (Q. nigra), American elm (Ulmus americana), and green ash (Fraxinus pennsylvanica). Currently, hardwood growth exceeds harvest by about 2 to t. Much of this growth is in lower-quality species unsuitable for solid wood products. (3) POTENTIAL FOR BIOMASS AND ENERGY Many hardwood stands show the effects of repeated harvests and past neglect. https://www.w3.org/1998/Math/MathML"> ( 6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The harvesting of only pine, leaving understory hardwoods and residuals for the next rotation, has adversely affected quality and potential of many hardwood stands. One possible solution for stand rehabilitation is whole-tree harvesting and either replanting pine or allowing the stand to regenerate naturally. Whole-tree harvesting is an excellent method for utilizing low-arade timber and replacing or upgrading forests of poor quality. Harvesting degraded hardwood stands for biomass can be profitable but, when coupled with conventional harvesting regimes, the potential gains are substantial. Improved harvesting techniques can increase forest biomass yield by 30 to 57 in in conjunction with conventional practices. https://www.w3.org/1998/Math/MathML"> ( 7,9 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Increased mechanization and overall operability of hardwood sites in the southern Piedmont point to the future potential. of harvesting hardwoods for energy. Presently forest industry is the leader in the use of biomass and mill residues for energy needs and is moving toward energy selfwsufficiency. The forest industry is successful in using wood energy because of an established procurement system and a readily available supply. Small-scale biomass energy use and facilities, including certain governmental institutions or small manufacturing facilities, are becoming increasingly common.

SOUTHEASTERN HARDWOOD FOREST BIOMASS, ENERGY AND NUTRIENT STUDY Since 1979 the North Carolina State University Hardwood Research Cooperative, // in conjunction with the U. S. Forest Service, Southeastern Forest Experiment station, has been sampling natural stands of hardwoods

I/The North Carolina State University Hardwood Research Cooperative consists of 17 forest industries and public organizations which own or control lo million ha of land int he southeastern United States. in the southeast. Plots have been established in even-aged (lo-, 20-, 40- and https://www.w3.org/1998/Math/MathML"> 60 - year - old ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stands on various site types, inctuding bottomland and upland. Numerous plots and replications have been located throughout the three major provinces--Coastal plain, piedmont, and Cumberland Region west of the Blue Ridge. Area plots l. 04 -ha have been established, with all aboveground vegetation cut and weighed. Supplemental trees outside of area plots have also been sampled to develop prediction equations for measured parameters. Samples are used for determination of green and dry biomass, nutrient and energy content of total trees, components and understory vegetation. (8) Listed below are mean energy yields for major species from lo-yearold stands on Piedmont upland and bottomland site types (Table l). Table 1. Average energy yields for major species on lo-year-old upland and bottomland Piedmont sites, by component

Species bear-old Upland Site

Composite (Wood & Bark) Branch Foliage Black cherry 45922 47310 https://www.w3.org/1998/Math/MathML"> 4836 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lo-year-old Bottomland Site Branct Foliage Anerican https://www.w3.org/1998/Math/MathML"> 4561 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Numbers followed by the same letters are not significantly different at the .05 level.

The greatest variability in energy values for Piedmont hardwoods occurs within the foliage component (Table 1). All other comparisons between site types or among components within site types are nonsignifibetween site types or among components within site types are nonsignificant. Similar relationships have been reported for hardwoods growing in the Coastal Plain. (5) Currently, estimates are available for Coastal Plain forests. https://www.w3.org/1998/Math/MathML"> ( 4,8 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> piedmont samples are being analyzed and field sampling is complete for the Cumberland Region. Data compiled from these studies will comprise the most detailed biomass, nutrient and energy information available for southeastern hardwood forest. https://www.w3.org/1998/Math/MathML">   REFERENCES   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (3) BOYCE, S. G. and KNIGHT, H. A. (l980). Prospective ingrowth of southern hardwood beyond 1980. Res. Pap. SE-203. USDA FOF. Ser. SE FOr. Expt. Sta. 33pp. (4) GOWER, S. T., FREDERICK, D. J. and CLARK, A. (l984). Distribution of energy in different-aged bottomland forests. For. Ecol. Manage. 9:227-146. (5) GOWER, S. T., FREDERICK, D. J and CLARK, A. (1982). Caloric COntent estimation and distribution in seven bottomland haxdwood tree species growing in natural stands in the South. IN Proc., 4th Central Hdwd. Conf., Lexington, Ky. (6) KELLISON, R. C., FREDERICK, D. J., GARDNER, W. E. (l981) A guide for regenerating and managing natural stands of southern hardwoods. Bull. 483. N. C. State Univ., Ag. Expt. Sta. https://www.w3.org/1998/Math/MathML"> 24 p p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (7) KNIGHT, H. A. and MCCLURE, J. P. (l981). Multiresource inventories-forest biomass in south Carolina. Res. Pap. SE-230. USDA FOr. Ser. (8) MESSINA, M., GOWER, S. T., FREDERICK, D. J., CLARK, A. and PHILLIPS, D. R. (1983). Biomass, nutrient and energy content of southeastern wet land hardwood forests. Hdwd. Res. Co-op. Ser. #2. https://www.w3.org/1998/Math/MathML"> 28 p p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (9) WELCH, R. L. https://www.w3.org/1998/Math/MathML"> ( 1980 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Living residues in the South Atlantic states. For. Prod. J. https://www.w3.org/1998/Math/MathML"> 30 ( 6 ) : 37 - 39 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 18. COPPICED TREES AS ENERGY CROPS M. I. PEARCE Forestry Commission, Research & Development Division U.K. 19. Summary Foresters are only now beginning to evaluate wood production in terms of biomass" This project is collecting data from coppiced tree crops with the singular object of maximising production. The end product has no dimensional Bpecifications other than tonnes of fuelwood over a minimal harvest rotation. The system is remewable" - that Is several harvests from an initial crop planting. Early results indicate that production Levels will be dependent upon the chosen tree species and the Crop bpacing. It ls too early to determine the elfect upon production of the harvest rotation period. Highest levels of production so far attained from experimental plots are 23 tonnes (fresh) ha https://www.w3.org/1998/Math/MathML">   - 1 y x - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 20. INTRODUCTION A Beries of experimental plots are situated in Southern Britain to reflect broad environmental zones - hot/dry to cool/wet. Each experiment includes a range of tree species to match the site and have been established at two crop densities - https://www.w3.org/1998/Math/MathML"> 10,000 p l a n t s / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 2,500 plants/ha. The matrix of species and densities are further divided to test the effect of harvesting rotation upon levels of production - will the crop produce a better annual increment if left two or four years between successive harvests? An additional variable has arisen which was not designed into the experiment, and can crudely be described as the 'start-up' time for the production system. There has occurred variation in the time lapsed between the initial planting of the crop (as maiden trees) to the optimal time for the first coppice cut (when the single stem malden tree is cut off at ground level) to allow multiple coppice shoots to develop. The periods have ranced from 1 to 4 years, and the variation can be attributed to species, site nutrition and environmental factors such as annual precipitation and temperature. In the results which follow, the 'start-up' time is shown by the difference between stool age (i.8. planting date plus years to any particular harvest) and coppice age (i.e. interval between harvests). (Fig. I). Some data has been included for production during the 'start-up' period (described as 'Maiden" in Fíp I) but it must be remembered that this represents production from single stem maiden jrowth before coppicing has taken place. The hypothesis of this project, expects sustained production from coppiced trees to be Ereater than that from maiden trees. https://www.w3.org/1998/Math/MathML">   RESULTS   T + i   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> It Is far too early in the tife of these experiments to make any judgements about production levels, but the data availabie https://www.w3.org/1998/Math/MathML">   COPPICE BIOMASS PRODUCTION   - 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure I herii (ha 10 32 ) https://www.w3.org/1998/Math/MathML"> . 90 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> . 51 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) 28 ) 34 60 ) The first two horizontal columns are single plot(unreplicated)values, the remainder from replicated plots A11 values extrapolated from nett plot areas (excluding buffer rows) Eucalyptus values include leaves https://www.w3.org/1998/Math/MathML"> 10000 / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 2500 / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Populus 43.8 46.8 Salix 44.0 45.4 Eucalyptus 42.5 44.7 21. FAO'S ACTIVITIES ON INDUSTRIAL WOOD-BASED ENERGY M.A. TROSSERO Forest Industries Division - Forestry Department Food and Agriculture organization of the United Nations 22. Summary The paper analyses the activities of FAO on wood-based energy which are being implemented by the Forestry Deoartment since this subject has been stressed as a priority area for action in many international meetings such as the https://www.w3.org/1998/Math/MathML"> 21 st https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FAO Conference. The energy situation in developing countries and the role of wood energy is briefly described in order to accelerate the transition from non-commercial use of wood energy to commercial energy schemes specially through the promotion of wood-based energy systems in rural industries and village activities. Finally, the main FAO strategies for action implemented through the Regular Programme and Field Projects are briefly mentioned in order to reach the ambitious targets of the Nairobi Plan of Action. 23. INTRODUCTION Energy is one of the most important commodities required to satisfy the physical needs of mankind. Over the years, limits in the availability, technological changes, location, prices and use of certain fuets have necessitated the search for new energy alternatives. Furthermore, the growing population, the continuing industrialization and the economic growth of countries have led to an increasing demand for commercial sources of energy. The growth of energy consumption since 1860 has been essentialLy exponential and during the last forty years has grown at an annual rate of about 5 per cent. Developed countries, comprising only https://www.w3.org/1998/Math/MathML"> 28 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the world population, use https://www.w3.org/1998/Math/MathML"> 82 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total commercial energy, so that, the per caput consumption of energy is https://www.w3.org/1998/Math/MathML"> 11   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the USA, https://www.w3.org/1998/Math/MathML"> 5   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in Germany, while developing countries consume only https://www.w3.org/1998/Math/MathML"> 0,2   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Although fuelwood and charcoal provide only six per cent of the world's energy supply, around half of the world population depends on wood for its energy needs, which is mainly considered as a non-commercial source of energy. Traditionally fuelwood was considered a free good provided by nature. However, due to the expansion of agriculture and other reasons, fuelwood is becoming scarcer and people are forced to devote more time or money to obtain it. Fuelwood increasingly becomes an economic commodity with more and more people involved in its exploitation and trade. 24. THE WOOD ENERGY TRANSITION The economic difficulties that most countmies are facing, together with high oil prices, are bringing about a period of energy transition from an economy based primarily on hydrocarbons to one based increasingly on new renewable sources of energy, although it is expected that oil and gas will continue to dominate the market during this century. In some of the less developed countries woodfuels are covering about https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of their primary energy consumption which is obtained from their immediate environment without payment and is commercialized in non structured economic markets, so that, in areas where forest resources for energy use were previously plentiful they are now becoming scarse. In this situation, woodfuels increasingly become an economic commodity commercialized under well established rules of trade. If the economic circumstances are favourable or the prices of wood fuels are too high, the fuelwood consumers begin to use kerosene or bottled gas which means increased expenditure on imports. In these countries, which begin to have welt structured markets, the incentives for implementing tree plantations become economically feasible. If this happens on a sufficiently large scale, wood fuels' supply, instead of being based on a depleting resource, could be based on a planned and sustained resource which could be considered as a commercial source of energy.

THE ROLE OF WOOD ENERGY

Many technical solutions using new and renewable sources of energy are being tried in order to substitute fossil fuels. However, due to technical, economical and social reasons, forest biomass seems to be one of the most appropriate alternative sources of energy not only for domestic use but also for industrial purposes and a clear demonstration of this are the policies being imolemented. The role which trees can play in easing world energy problems is much broader than is generally realized. Fuelwood and charcoal have, until recently, been regarded simply as subsistance fuels but it is now clear that ENERGY FORESTRY RESEARCH IN BRITAIN Single Stem Short Rotation Systems C.P. MITCHELL Forestry Department, Aberdeen University, Aberdeen, U.K. AB9 2UU 25. SUMMARY Trials of eleven single stem short rotation forest energy plantations recently established in Britain are described. They were designed to provide, in the short term, information on the logistics and costs of establishment. In the Ionger term production curves can be established. The trials were established in four geographical regions and on three site types using ten commercially available tree species at one planting density https://www.w3.org/1998/Math/MathML"> ( 10,000 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hectare). Costs of operations for the first three years are detailed and discussed in relation to the financial viability of forest blomass production. Although more expensive than conventional forestry on a per hectare basis costs for initial establishment are similar on a per thousand tree basis. Good weed control, although costly, is considered essential. 26. INTRODUCTION Earlier studies (1) indicated that wood has a potential as an alternative source of fuel within the U.K. Various possible end-uses were postulated and detailed studies undertaken to establish the area and nature of land which might become avallable for the supply of wood for energy under a number of scenarios (2). Wood is now seen to have its major outlet as a fuel in the domestic, institutional and small-scale industrial combustion markets. Both coppice and single-stem short rotation energy plantations are appropriate; coppice in the more fertile and sheltered Iowlands, single stem on the less fertile and more exposed lowlands and sheltered uplands. The experimental programme to establish production curves for coppice is reported elsewhere in these proceedings (3). Machinery for harvesting short rotation coppice is being developed at Loughry college (4) The trial single stem energy plantations, with which this paper is mainly concerned, were established initially to examine the logistics and costs of growing trees on relatively small areas of land. The rationale being to see whether it was possible for farmers to grow trees for energy on the small areas of under-utilized land which occur on every farm. 27. METHOD A total of eleven trial single stem energy plantations have been established on three site types : marginal agricultural land, scrub woodland and existing young plantations. The trials are situated in four geographical regions of Britain (Table I). Three were planted in 1981, seven in 1982 and one in 1983. At each site two replicate plots of each species were planted at one by one metre spacing (ie. 10,000 per hectare). Ten tree species (Alder, Alnus glutinosa; Birch, Betula pendula: southern beech, Nothofagus procera; Sycamore, Acer pseudoplatanus; corsican pine, Pinus nigra var maritima; Scots pine, Pinus sylvestris; Douglas fir, Pseudotsuga menziesii; hybrid larch, Lafix x eurolepis: Sitka spruce, Picea sitchensis and western hem- lock, Tsuga heterophylla) as bare-rooted stock were obtained from commercial nurseries and planted on all sites. Forestry contracting companies were employed to carry out the work as it was felt that would be the course adopted by many farmers and landowners wishing to plant trees for energy on their land. 28. DESCRIPTION Detailed descriptions of the site and operations necessary to establish the trials have been given elsewhere (5); only a summary is given here. A. Craibstone - An area of marginal agricultural land planted in spring 1981. A polythene mulch was used initially to control weed growth but hand and chemical weeding was required in subsequent years. Most of the trees are growing well, particularly alder, sitka spmuce, lanch and Scots pine. Corsican pine, southern beech and birch are growing poorly and are not suited to the site. Table I LOCATION AND DESCRIPTION OF SINGLE STEM TRIALS B. Banchory - Originally covered with a sparse birch scrub the site was cleared and plowghed prior to planting weeding was not necessary until the second and subsequent years. All trees except corsican pine are successively established. C. Aldroughty - This young plantation was cleared and replanted in spring 1981. Weed control has been particularly difficult with woody and herbaceous weeds growing in profusion. Mechanical cleaning of the site forbaceous weeds growing in profusion. Most of the trees, except corsican pine and western hemiock, are well established. D. Marlefield - This area of marginal agricultural land was ploughed prior to planting. Survival of all species, except corsican pine and western hemlock, was good although the southern beech has suffered from frost damage. Control of weed growth has been necessary in each of the years following planting. The conifers, particularly Sitka spruce, hybrid larch and Scots pine, are now showing vigorous growth. E. Kilham - This dry and exposed site had a cover of sparse wood- land. Extensive drought in the two seasons following planting has had a devastating effect on survival and the few trees remaining are only growing slowly. F. Witney - Black polythene mulch was laid over this marginal agricultural site prior to planting to control weed growth. This was successful in the first season but in the following winter it was damaged by wind and had to be removed. Most species are successfully established but growth is poor - a possible micro-nutrient deficiency is being investigated. G. Tar Wood - An area of old mixed broadleaved woodland was cleared prior to planting. Growth of weeds has been extensive and difficult to control (hand and chemical). Most species are established but the survival and growth rate is poor. H. Longridge Wood - This site carried a young stand of European Iarch which was cleared prior to planting. There were some plant fatalities in the first vear: Corsican pine and western hemlock suffering badly. Weeding by hand has been necessary in each year. Growth of alder birch and southern beech has been particularly good. I. Crowcombe - A bracken covered area of marginal agricultural land was cleared using 'Asulox" and then planted. Survival and growth of all species is good but hand weeding of the bracken is still necessary. J. Queenhill - One hectare of old mixed broadleaved woodland was cleared prior to planting. Use of an antimammal smear was necessary to deter deer. All species are successfully established and growing well, notably birch and southern beech. K. Holmington - This area of young birch wood was cleared and planted later than the other sites. Plant survival is good but it is too early to judge growth. Control of weed growth is a potential problem. 29. RESULTS AND DISCUSSION The main initial aim of these studies was to study the establishment procedure and ascertain the likely costs of establishment. Costs of production as a percentage of total costs appear in Table II. The costs of initial establishment (ie. ground preparation, fencing, plants and piantm ing) are somewhat higher than for conventional forestry. The average cost for these trials was &3,700 compared with &987 for a conventional mixed plantation https://www.w3.org/1998/Math/MathML"> ( 20 - 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> broadleaved). However, the initial cost per thousand plants compares favourably; https://www.w3.org/1998/Math/MathML"> £ 370 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as compared with https://www.w3.org/1998/Math/MathML"> £ 375 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for conventional forestry https://www.w3.org/1998/Math/MathML"> ( 6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The major cost elements are fencing, plants and planting, and weeding The costs for fencing were higher than might be expected in practice as security of the trials was required. A farmer would probably make more extensive use of existing fences than was possible here. It would not be possible to reduce the cost of plants considerably unless large numbers were bought, say, by a cooperative. Planting costs may be reduced, as Indeed might all labour costs, by using surplus farm labour in slack periods although this may not always be possible. Weeding is an essential operation if good and speedy establishment is to be guaranteed. Polythene muleh however was not found to be cost effective (Table III). A question ofter raised is - is energy forestry a viable financial proposition?" Unfortunately, the 'experimental' nature of these trials and the lack of adequate data on yields and harvesting costs procludes a definitive answer. However, it is possible to gain a rough idea of the value wood for fuel would need to command 20 years hence if the operation is to breakeven These values have been determined for three sites, two discount rates (with and without grants) and at three assumed rates of Table II COSTS OF OPERATION PER HECTARE AS PERCENTAGE OF TOTAL Table III BREAKEVEN VALUES https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (£/tonne) 1 A price of https://www.w3.org/1998/Math/MathML"> £ 45 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after 20 years is equivalent to a present value of investment of &25 at https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A price of https://www.w3.org/1998/Math/MathML"> £ 66 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after 20 years is equivalent to a present value of investment of https://www.w3.org/1998/Math/MathML"> £ 25 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 3 Without polythene mulch. 30. FOREST BIOMASS. INRA'S PROGRAM E. TEISSIER-DU-CROS, coordinator Institut National de la Recherche Agronomique (INRA) Ardon 45160 OLIVET (France) 31. Summary There are two main parts to the biomass research programme conducted by the Forestry Department of Institut National de la Recherche Agronomique (INRA)

existing stands of coppice and coppice-with-standards which, for practical reasons, cannot be all converted into high forest stands. This resource is available for immediate use. Our research programme concerns the measurement of the productivity in terms of total biomass and the techniques which will increase productivity while maintaining site quality (e. g. mineral nutrition).

possibilities for future plantations on the numerous marginal forest and agricultural sites. Research in this area has long-term goals. It includes forest tree breeding for short term biomass production, optimization of silvicultural techniques, fertilization and use of nitrogene fixing species. We are also studying the insect and disease problems associated with short rotation intensive cultures. Studies in this area were begun in 1980 .

32. INTRODUCTION France, like several other countries of western Europe, has very little of its own energy resources. Several factors have led to greater interest in forests as a renewable energy source and have precipitated the initiation of new research programs:

a third (roughly 5 million hectares) of France's forests is presently unproductive due to lack of management. Part of it could produce wood for biomass if investments could bring short-term revenues

a second third of France's forests is under coppice or coppicewith-standard management. Even if most of these stands are converted into high forests, many of them will remain in their present status due to patchwork ownership patterns and its small size.

EEC economists forecast that between years 2000 and 2030, the European excess of agricultural land will be 3 to 7 million hectares, of which two thirds will be in France (1):

petroleum supplies are presently sufficient and prices have decreased, but a new shortage can be anticipated after years 1990-95 or earlier in case of war in the Middle East:

several national or regional organizations and many private landowners believe in the role of forests for energy production. Support for research in this area has been shown by direct funding of projects and by allowing use of private and state land;

public and private research organizations have started investigations on methods of harvesting and uses of forest biomass.

33. OBJECTIVES Research initiated by INRA and funded by the French Energy Agency (AFME), by the European Community and by Regional administrations have two majon themen

existing stands. Forest stands under coppice or coppice-withstandard management have not been harvested regularly since the l940's. mhese stands need to be inventonjed for curnent votume and growth These stands need to be inventoried for current volume amd growth. Techniques to increase production should be studied, as well as the impact of these techniques on the nutrient balance.

short rotation forestry. There are 3 objectives : (a) to choose appropriate species and improve them through genetic selection ; (b) to develop silvicultural techniques including olanting density, rotation period, fertilization, irrigation and weed control; (c) to evaluate the impact of insect pests and diseases on short-term biomass stands.

These two main themes have resulted in a series of research activities which I will briefly summarize. 1. MANAGEMENT OF EXISTING STANDS 3.1. Effect of rotation shortening on soil nutrient balance 3.1.1. Problem. One way to increase ooppice production is to shorten rotations length. But alter a few harvests this treatinent may result in decreased productivity due to nutrient depletion or deterioration of roots. In chestnut stands of central western France certain coppices have been harvested every 5 to 8 years for a long time. Studies of nutrient uptake in these stands will serve to develop models which will be applied later in short rotation intensive cultures. 3.1.2. Investigators. Jean BOUCHON, Laboratory of Silviculture and Production ; Claude NYS and Jacques RaNGár, Laboratory of Soil Science and Forest Fertilization (N*). 3.1.3. Approach. Six stands at an approximate age of 25 years have been sampled on sites of different fertilities. The analysis concerns biomass production and nutrient balance in relation to site fertility. A second series of stands at ages 5,9,15 and 19 years have been sampled to study biomass production, nutrient uptake and nutrient transfer between growth rings in relation to age. Finally, a third series of stands which were coppiced every 5 to 8 years have been sampled near stands which were coppiced every 25 years. The analysis will concern biomass production and nutrient balance in relation to length of rotation. 3.1.4. Preliminary results. Provisional results (2) show a slow but steady decrease of https://www.w3.org/1998/Math/MathML"> N , P , K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and Ca concentration in the wood with an increasing age The six coppices with rotation periods of 5 to 8 yeares showed productivities from 5.4 to https://www.w3.org/1998/Math/MathML"> 16.9   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yr https://www.w3.org/1998/Math/MathML"> = 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In three classical coppices productivity ranged between 13.9 to https://www.w3.org/1998/Math/MathML"> 16.3   m 3 h a - 1 y r = 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> An accurate comparison will be made after soil analyses have been completed. 1.1. Quercus ilex coppices and fire-break maintenance in southern 3.2.1. Problem. The project comprises two aspects. (a) Approximately 400 o00 ha of French Mediterranean forests are covered with agjng and abandonned green oak (Q. ilex) coppices. Harvesting these stands would have a double purpose : an important biomass resource and rejuvenation. (b) Fire-breaks are created and maintained either with hand tools or with sophisticated machines like the scorpion brush harvester-chipper. The material harvested in the maintenance of these fire-breaks could be an Important source of biomass. https://www.w3.org/1998/Math/MathML"> N * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> This letter refers to the full address of the scientists which can be found in paragraph 6 . 3.2.2. Investigators. Yves BIROT, Laboratory of Mediterranean the (A). 3.2.3. Approach. (a) Regrowth of green oak coppices will be stuied under different site conditions, stand ages and harvesting techniques. A series of trials will be established in the Nimes region in 1985. (b) Fire-break maintenance will be studied in order to determine the quantity of dry matter harvested and the subsequent evolution of flora composition, of stand structure and the biomass regrowth. One trial will be established in 1985 in a maquis stand in the Var department. 1.2. Silvicultural improvement of coppice production (3) 3.3.1. Problem. The low productivity of existing coppices may result from at least 3 factors : (a) low site fertility, (b) low stand density and long rotations, (c) improper species. 3.3.2. Investigators. Alain CABANETTES, Laboratory of Silviculture, Luc BOUVARE Technical Biomass Service. https://www.w3.org/1998/Math/MathML"> ( 0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3.3.3. Approach. The different techniques studied are ploughing fertilization, interplanting and variation of rotation period. They have been or will be applied partly or totaly to birch, chestnut and hornbeam stands. 3.3.4. Provisionnal results. Results concern only the oldest trial which was laid out in 1982 in a birch coppice in the sologne (central France, south of oriéans). Surface ploughing with a blade roller and long term fertilization were compared with and untreated control. Site effects were very large and resulted in productivities ranging from 1.1 to https://www.w3.org/1998/Math/MathML"> 4.4   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha-l at age 3. Treatments have shown no significant effect, as expected, since they were intended to have a long-term effect. 2. SHORT ROTATION CULTURES 4.1. Forest tree improvement for short-term biomass production 4.1.1. Problem. A tree improvement programme which is versatile has to be developed for species with multiple uses. Extensive field trials are needed in order to evaluate tree performance on a variety of forest and agricultural sites. Of particular interest is the comparison of growth on rich soils and poor, acid and hydromorphic soils. 4.1.2. Investigators. Eric TEISSIER-DU-CROS, Laboratory of Forest Tree Improvement, Luc BOUVAREL, Technical. Biomass Service (o). Christian DUMAS, Mireille GAGET, Marc VILLAR, Laboratory of Cell Recognition and Plant Breeding (L). 4.1.3. Approach. Three routes are being followed simultaneously: (a) Choice of the most vigorous genotypes derived from species Improved for sawlog production (poplars, larch, Sitka spruce); (b) Addition of selection criteria for biomass production to recently started Improvement programmes (American red oak, yellow poplar, sugi); (c) Initiation of specific improvement programmes (alder, black locust). Route (a) involves improvement of fast growing poplars for wet sites. The ideotypes are clones with a high rooting ability of stem cuttings, adaptation to acid soils, fast juvenile growth and high rigor. One approach is interspecific hybridization which requires overcoming crossing barriers. 4.1.4. Preliminary results. Since 1980, almost 20 ha of field trials have been laid out in different representative sites of several French regions (4). Genotype ranking is now starting to stabilize. Provisional conclusions will be drawn after one more growing season. Studies of interspecific hybridization barriers in poplars have led to a few hybrid seedlings involving 4 species of different sections of Populus which are not normally compatible (5). Several interspecific alder hybrids have been obtained and combinations of Alnus mbra and A. incana look promising. 4.5. Insect pests and fungal diseases in short rotation forestry 4.5.1. Approach. In short rotation forestry, the use of introuced species like red alder, the high foliage density and the coppicing scars may be ideal environments for leaf insects and diseases and twig 4.5.2. Investigators. Jean LEVIEUX, André DELPLANQUE, Laboratory of Forest Entomology (O); Jean PINON, Laboratory of Forest Pathology (N) 4.5.3. Approach and pretiminary results. A survey of insect pests of poplars and alders has been started. The host-insect interaction will be studied in order to determine whether certain chemicals of the host are associated with resistance to insect attack. Pathology studies are concentrated on the poplar rust, Melampsora lariei-populina, and particularly on a new strain of this fungus called Ez which damages clones previously held to be resistant. The forest biomass programme of INRA has many aspects that are shortand-long-term in nature. At present the programme is very young and has only shown preliminary results. This paper was aimed at showing foreign colleagues the nature of our research and at stimulating interest in cooperative research. Readers are encouraged to contact scientists Involved in the various projects. (N): INRA-CRF, Champenoux, 54280 SEICHAMPS (France) (O): INRA, Ardon, 45160 OLIVET (France) (A): INRA, avenue Antoine Vivaldi, 84000 AVIGNON (France) (L) : University of Lyon, 43 boulevard du 11 novembre 1918 , 69622 VILLEURBANNE (France) (1) MOLLE J. F. (1984). La biomasse énergie. Forêt de France. vol 276. 44-49. (2) BOUCHON J., RANGER J. NYS C. (1985). Biomasse forestierre, ressource existante. Evolution de la croissance des tail1is. Compte rendu final des travaux de 1984. Accord cadre INRA-AFME. Convention https://www.w3.org/1998/Math/MathML"> 1984.7 p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (3) CABANETIES A. https://www.w3.org/1998/Math/MathML"> ( 1985 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . BIomasse forestiêre, ressource existante. Amélioration sylvicole de la production des taillis classiques. Compte rendu final des travaux de 1984. Accord cadre INRA-AFME. Convention 1984. https://www.w3.org/1998/Math/MathML"> 8 p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (4) TEISSIER-DU-CROS E. (1983). Improvement of forest Trees for short term biomass production. Energy from Biomass, volume 5, PALZ and PIRRWITZ Ed. 104-111. (5) GAGET M., VILLAR M., DUMAS C. LEMOINE M., TEISSIER-DU-CROS E. (1984). Poplar improvement. New strategies currently in progress in France. Proceedings. IUFRO WP S2.03-07 meeting, Ottawa, Canada, 6 p. (6) AUCLAIR D. (1984). Optimisation de la production des taillis à courtes rotations selon le milieu et la sylviculture. Compte rendu final des travaux de 1984. Accord cadre INRA-AFME. Convention 1984.6. (7) TEISSIER-DU-CROS E., JUNG G. BARITEAU M. (1984). Alder-Frankia interaction and alder-poplar association for biomass production. Plant and Soil 78, 235-243. borens. 3. CONCLUSION 4. ADDRESSES 5. REFERENCES EUPHORBIA PROJECT : RENEWABLE ENERGY PRODUCTION THROUGH THE CULTIVATION AND PROCESSING OF SEMI ARID LAND BIOMASS IN KENYA. M. DECLERCK, PH. SMETS, J. SMETS and J. ROMAN TRACTIONEL ELECTROBEL ENGINEERING 75, Rue de la Loi - 1040 BRUSSELS-BELGIUM 6. Abstract A loo ha plantation of Euphorbia tirucalli and other semi-arid species Was successfully established near Lake Baringo, Kenya. Of the investigated species, Euphorbia tirucalli has so far proven to be the most performing in terms of yleld and resistance, especially under very arid conditions (1984 drought). Several biomass conversion routes were investigated, in bench scale or commercial equipments, and technico-economic evaluations of the most promising processes were performed. At the end of the present phase of the project (March 1985) the elements are now available which make possible the realization on site of a demonstration project on the use of biomass for production of solid and gaseous fuels for the local market (household and small industrial applications). Production of high quality activated coal seems also attractive. Research on other semi-arid species shotild further be Intensitled, thus leading to an optimal use of the human and material resources established between 1981 and 1985. 7. INTRODUCTION The Euphorbia Project is a project undertaken since early 981 and funded by the Belgian and Kenyan Governments in view of detining and evaluating the means for semi-arid land valorization through bionass production in Kenya. Within the scope of the Particular Agreement of March 28,1981, the Goverrments decided to call upon the services ot the Consultant Tractionel Electrobel Engineering, in view of evaluating the project. The main tasks of the Consultant included assistance in project management and coordination, establishment of a program for testing and data collection, and a scientific, techaical and economic evaluation of the selected biomass processing technologies. 8. EXPRRIMENTAL TOOLS FOR THE PROJECT 2.1. In Kenya

Establishment and maintenance of a 100 ha plantation in the Lake Baringo district with Euphorbia tirucalli, and competing semi-arid species, including Prosopis Chilensis, Leucaena L. which covered https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of total planted area.

Set up of a laboratory, enabling the on site thonitoring of the plantations

Optimization of the agronomical conditions and study of seasonal effects, rainfall, ... on biomass yields.

Biomass costs of Euphorbia Tirucalli versus planting density 9. Blomass conversion : main experimental results Estimated production costs 16 BF/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for the methane and bood BF/dry ton or 1400 BF/Gcal for the briquettes. This includes the cost of the fresh biomass (presently estimated at 3700 BF/ton. 4.4. Activated charcoal production F1rst results of the tests, carried out in collaboration with a Belglan university are very promising as the end product competes favorably in terms of quality with the best commercial granulated coals https://www.w3.org/1998/Math/MathML"> ( cfr https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fig.2). A thorough technico-econome evaluatıon of this processing W1ll be carried out upon completion of the bench scale experiments.

REFERENCES

Tractionel Electrobel Engineering, Euphorbia Project, Evaluation Report, January 1984. Idem, Euphorbia Project, Status Report on Testing and Data Collection, July 1984. Idem, Euphorbia Project, Final Report, January 1985. SCHOETERS J., MANIATIS K., BUEKENS A., Research Project Kenya, Euphorbia, Gasification Experiments, Final Report for B.A.D.C., June 1984. VERSTRAETE W., DE WILDE B., Project Euphorbia, Biogasification of Euphorbia trucalli, Report on Phase 2, October 1984.

DUTRECQ and PARMENTIER, Report ont he Phytosanitary cover within the framework of the "Euphorb1a Project", June 1984 .

V. VOLCKAERT, Study of Some Aspects of Euphorbia tirucalli L. cultivation (in Dutch), edited at the Faculty of Agricultural Sciences R.U.G. May 1984. 10. ACKNOWLEDGMENTS We wish to express kind regards to the responsibles of the Belgian Agency for Development Cooperation and to the Kenyan Ministry of Environment and Natural Resources for their making possible the realization of the Project. Also, issuing this paper would not have been possfble without the efficient and appreciated collaboration of the Kenyan and Belgian researchers, technicians and field workers which carried out the testing and data collection program and helped to establish and malntain the pilot plantations. POTENTIALITES DE PRODUCTION D' UN COUVERT VEGETAL

MATERIEL ET METHODES

11. RESULTATS EXPERIMENTAUX 12. DETERMINATION DES POTENTIALITES DE PRODUCTION D^ UNE ESPECE DONNEE : 13. METHODE D'ETUDE DE LA CROISSANCE D' UN COUVERT VEGETAL 14. REFERENCFS GOSSE. G., VARLET-GRANCHER C., BONHOMME R., CHARTIER M_, ALLIRAND JM. LEMAIRE G. - 1985 - Production maximale de matière sèche et rayonnement intercepté par un couvert végétal in Agronomie en cours de publication. MONTEITH J. - 1972 - Solar radiation and poroductivity in tropical ecosystems. J. Appl. Ecol., 9, 747-766. VARLET-GRANCHER C., BONHOMME R., CHARTIER M., ARTIS P. 1982 - Efficlence de la conversion de l'énergie solaíre par un couvert végétal. Oecol. Plant., 3, 3-26. FIGURE. 2 FIGURE. 3 Effet de la vitesse de mise en place de la surface foliaire Courbe https://www.w3.org/1998/Math/MathML"> 1 E i = 0.9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en 2 jours oérienne en https://www.w3.org/1998/Math/MathML"> 29 j / n o l ; 21 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en https://www.w3.org/1998/Math/MathML"> 54 j ; 31 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en https://www.w3.org/1998/Math/MathML"> 80 j ; 41 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en https://www.w3.org/1998/Math/MathML"> 131 j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ω σ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Hyp _ = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Normale de rayonnement de Versailles Plantes de type C3 2 dates https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> implantation FIGURE. 4 FIGURE. 5 FIGURE, 6 PRODUCTIVITE DU ROSEAU PHRAGITES J.M. ALLIRAND, M. CHARTIER, G. GOSSE Institut National de la Recherche Agronomique Station de Bioclimatologie 78850 THIVERVAL-GRIGNON (France) Résumé Une méthodologle https://www.w3.org/1998/Math/MathML"> d † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> approche de la production utile https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> une culture fournissant du matériel lignocellulosique est établie et développée en https://www.w3.org/1998/Math/MathML"> s ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> appuyant sur l' exemple du roseau Phragmites. \begin{abstract}1. INTRODUCTIONLes filleres de production dténergle a partir de la biomasse actuellement envisagées semblent privilégier la production de materiel lignocellulosique. Dans ce contexte, il nous a paru utile de développer une méthodologie d" évaluation de la production d" une culture perrenne a partir de li exemple du roseau Phragmites (common reed), graminée des zones humides tempérées.\end{abstract} 15. EVALUATION DE LA PRODUCTIVITE 16. Estimation de la production potentielle apres slwpliflcation des termes du bllan radiatif dun couvert vegetal, on peut definir une efficience de de la facon suivante: I indice foliaire (LAI) https://www.w3.org/1998/Math/MathML"> ε 1 ϕ = 0,95 ( 1 - 0,875   exp   - 0,506   LAI   )   - on definit le rayonnement abosrb ę  PARa :     PAR_{a }   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Il est possible de relier la production de matiere seche d' un couvert végétal en phase végetative au rayonnement PAR absorbé (of poster CHARTIER, ALLIRAND, GOSSE)

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17. COMPARATIVE BIOMASS YIELDS OF ENERGY CROPS W.H. Smith W.H.Smith Center for Biomass Energy systems University of Florida--IFAS J.R. Frank Gas Research Institute 18. Summary Biomass yield is a major cost consideration in the production of crops for energy. Biomass yields of crops grown for energy rather than food, feed, or fiber often can be doubled through variety selection foud, feed, or fiber often can be doubled through variety selection and appropriate crop management. This paper catalogues the biomass yields of plant species in five plant resource groups (woody, grasses, root and herbaceous, aquatic and hydrocarbon-producing). Much of the data were produced in a joint program of the Institute of Food and Agricultural Sciences and the Gas Research Program which is focused on the production of methane from biomass. Over 150 species comprising more than 350 varieties and cultivars have been field tested to characterize their yield potentials as biomass energy crops. Napiergrass (Pennisetum), water hyacinth (Eichhornia), sugarcane (Saccharum), (Sorghum), and sweetpotato (Ipomoea) are among the most productive of about 20 promising species. These plants are now serving as a focus for more detailed analyses and research efforts to produce methane from biomass. 19. INTRODUCTION Domestic crops now grown were developed over many decades to meet food/feed/fiber needs. Biomass energy crops must possess different plant food/feed/fiber needs. Biomass energy crops must possess different plant characteristics and meet different production criteria (1). Energy crop development will require the scientific methods employed with food/feed/fiber crop improvements but the process should be accelerated by the new biotechnologies available today. Many parameters impact overall costs of energy from biomass, but biomass yield and convertibility appear to be most significant. Both yield and convertibility can be improved. Thus, an important first step is to select high yielding biomass crops for improvement and adantion to energy cropping. This paper catalogues the biomass yields of plant species grown as energy crops in five plant resource groups (woody, grasses, root and herbaceous, aquatic, and hydrocarbon). Much of this data was compiled from the joint program of the University of Florida's Institute of Food and Agricultural Sciences (IFAS) and the Gas Research Institute (GRI). Higher biomass yields have been recorded for several crops in the program but reporting here was restricted to the yields now in the published literature for comparison with other published data. In total, the IFAS/GRI program has evaluated in field tests nearly 350 cultivars and varieties among 150 species. Goals for conversion by anaerobic digestion and systems integration of production/conversion systems for assessing cost sensitivities and research progress are reported in companion papers in this conference (Frank et a). and Mishoe). 2. ENERGY CROP DEVELOPMENT Biomass yleids for several energy crops among the five plant resource groups are listed in Tables I, II, III, IV, and V. Within all groups there are individual species that show superior yields. The energy crops that appear most promising in terms of yields are among the grasses (e.g., Napiergrass Pennisetum), sugarcane (Saccharum) and (Sorghum), aquatics (e.g., Eichhornia), and root and herbaceous (e.g., sweetpotato (Ipomoea). Biomass yields of grasses (Pennisetum and Saccharum) have approached 50-70 https://www.w3.org/1998/Math/MathML"> M g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the south temperate to sub-tropical zones and https://www.w3.org/1998/Math/MathML"> 20 - 30 M g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the north temperate zones (e.g., Sorghum). Tropical water hyacinth yields in field tests have exceeded https://www.w3.org/1998/Math/MathML"> 50 M g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In controlled laboratory tests, hyacinth yields have reached https://www.w3.org/1998/Math/MathML"> 100 M g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , indicating a high potential for the tropical species. In areas where seasonality is important, energy crops with high growth rates over short growing seasons are desirable. For example, industrial sweetpotato has produced yields up to https://www.w3.org/1998/Math/MathML"> 22 M g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This and other succulent herbaceous crops often reach maturity in 60-150 days. The biomass of these crops is in the form of starch and other easily digestable forms for methane production. Some unconventional herbaceous weed species are showing promise as biomass crops. Woody plant yields are generally low but so are the production and storage costs. Storability is an important factor in biomass energy crop selection. While wood has not been a desirable substrate for methane, some recent evidence shows that some hardwoods, especially those grown in high density, very short rotations are reasonably convertible to methane https://www.w3.org/1998/Math/MathML"> ( 34 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Crop environment and management practices are proving to have significant effects on biomass convertibility (35). About 20 species show promise and are being further evaluated and additional species with potential are being sought. The GRI/IFAS program is initially focusing research and development of Napiergrass, water hyacinth and sorghum and the production/conversion systems best suited for generating cost competitive methane. TABLE I. BIOMASS YIELDS OF HYDROCARBON PLANTS IN VARIOUS LOCATIONS TABLE II. BIOMASS YIELDS OF GRASS PLANTS IN VARIOUS LOCATIONS TABLE III. BIOMASS YIELDS OF AQUATIC PLANTS IN VARIOUS LOCATIONS TABLE IV. BIOMASS YIELDS OF ROOT AND HERBACEOUS PLANTS IN VARIOUS LOCATIONS TABLE V. BIOMASS YIELDS OF WOODY PLANTS IN VARIOUS LOCATIONS ACKNOWLEDGEMENT: Mr. K. Reddy assisted in data compilation.

REFERENCES

(1) SMITH, W.H., (1983). Energy from biomass: a new commodity, In: Agriculture in the 21 st Century. S.W. Rosenblum (ed). John Wiley & Sons, N.Y. 61-69. (2) MATSUGA, S. and KUBOTA, H. (1984). The feasability of national fuel-alcohol programs in Southeast Asia. Biomass 4:161-182. (3) ELAWAD, S.H., GASCHO, G.J. and SHIH, S.F. (1982). The energy potential of sugarcane and sweet sorghum. Energy from Biomass and Wastes IV. 65-106. (4) GASCHO, G.J. and SHIH, S.F. (1981). Cultural methods to increase sucrose and energy yields of sugarcane. Agron. J. https://www.w3.org/1998/Math/MathML"> 73 : 999 - 1003 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (5) GIOMDVA, M.J., CLARKE, S.J. and STEIN, J.M. (1984). Sugarcane hybrids for biomass, Biomass, Vo1, 6:61-68. (6) ALEXANDER, A.G. (1982). Management of tropical grasses as a year round alternative energy source. Energy from Biomass and Wastes IV. 87-104. (7) MILLER, F.R. and MONK, R.L. (1984). Breeding and development. In: Hiler, E.A. Sorghums for Methane Production. International Gas Research Conference Proceedings. In press. (8) STANLEY, R.L. and DUNAVIN, L.S. (1985). Potential sorghum biomass production in North Florida. Proc. Third S. Biomass Energy Res. Conf. Gainesville, Fla. In press. (9) KLASS, D.L. (1984). Energy from biomass and wastes: update. Energy from Biomass and Wastes IV. 1-42. (10) PRINE, G.M. and MISLEVY, P. (1983). Grass and herbaceous plants for biomass. Proc. Soil and Crop Sci. Soc. of Florida. Vol. 42:8-12. (11) KOSARIC, N. COSENTINO, G.P. and WEICZOREK. (1984). The jerusalem artichoke as an agricultural crop. Biomass 5:1-36. (12) O'HAIR, S.K., DANGLER, J.M., EVERETT, P. , FORBES, R. B., LOCASIO, S.J., OLSON, S.M. SHUMAKER, J.R. and WHITE, J.M. (1985). Cruciferous and root crops for year-round biofuel production. Proc. Third S. Biomass Energy Res. Conf. Gainesville, Fla. In press. (13) O'HAIR, S.K., LOCASCIO, S.J., FORBES, R.R., WHITE, J.M., HENSEL, D.R., SCHUMAKER, J.R. and DANGLER, J.M. (1983). Root crops and their biomass potential in Florida. Proc. Soil and crop Sci. Soc. of Florida, 42:13-17. (14) GILREATH, J.P. (1985). Effect of plant population on biomass production by six weed species. Proc. Third S. Biomass Energy Res. Conf. Gainesville, Fla. In press. (15) STEWART, G.A., HAWKER, J.S., NIX, H.A., ROWLINS, W.H.M. and WILLIAMS, L.R. (1983). The potential for production of "hydrocarbon" fuels from crops in Australia. CSIRO, 86 . (16) PEOPLES, T.R. (1984). Dry matter and hydrocarbon yields of calotropis procera. Biomass 2:153-158. (17) AYERBE, L., FUNES, E. , TENORIO, J.L., VENTAS, P. and MELLADO, L. (1984). Euphorbia lathyris as an energy crop-part II. Hydrocarbon and sugar production. Biomass 5:37-42. (18) NEWTON, R.J., GOODWIN, J.R., MARGAR, D.L. and PURYEAR, J.D. (1982). Biomass from unconventional sources in semi-arid West Texas. Energy from Biomass and Wastes VI. 167-220. (19) FOSTER, K.E. AND KARPISCAK, M.M. (1984). Arid lands plants for fuel. Biomass 3:269-285. (20) ADAMS, R.P., BALANDRIN, M.F.and MARTINEAU, J.R. (1984). The showy millkweed, asclepias speciosa: a potential new semi-arid land crop for energy and chemicals. Biomass 4:81-104. (21) DEHGAN, B. and WANG, SC.C. (1983). Evaluation of hydrocarbon plants suitable for cultivation in Florida. Proc. Soil and Crop Science Soc. of Florida. Vol. 42:17-19. (22) SACHS, R.M., GILPIN, D.W. and MOCK, T. (1982). Yields of short rotation eucalyptus grandis in high density plantations. Energy from Biomass and Wastes IV. 107-114. (23) ROCKWOOD, D.L., COMER, C.W., DIPPON, D.R., HUFFMAN, J.B., RIEKERK, H. and WANG, S.C. (1983). Current status of woody biomass production research in Florida. Proc. Soil and Crop Science Soc. of Florida. Vo], 42:19-27. (24) ROCKWOOD, D.L., COMER, C.W., CONDE, L.F. AND FISHER, R.F. (1981). Maximizing woody biomass production in Florida. Proc. International Gas Research Conf, Los Angeles, Calf. (25) FREDERICK, D.J., MADGWICK, H.A. and OLIVER, G. (1982). Biomass and energy production of eucalyptus in New Zealand. Proc. 2nd E. C. Conf. on Energy from Biomass. 150-153. (26) POPE, P.E. and GIBSON, H.G. (1984). Biomass and nutrient distribution of robinia pseudoacacia grown under intensive culture. Proc. S. Forest Biomass Workshop, USDA Forest Service, Ashville, N.C. 83-90. (27) RANNEY, J.W., WRIGHT, L.L. AND PERLACK, R.D. (1985). Short-rotation woody crops production research in the south. Proc. Third S. Biomass Energy Res. Conf. Gainesville, Fla in press. (28) OTHMAN, H.B. and PRINE, G.M. (1985). Biomass production and nutrient removal by leucaena in colder subtropics. Proc. Third S. Biomass Energy Conf. Gainesville, Fla. In press. (29) NEENAN, M. (1982). Short rotation forestry as a source of energy and chemical feedstock. Proc. 2nd E. C. Conf. on Energy from Biomass. 142-146. (30) REDDY, K.R., SUTTON, D.L. and BOWES, W. (1983). Freshwater aquatic plant biomass production in Florida. Proc. Soil and Crop Science Soc. of Florida. Vol. 42:28-40. (31) REDDY, K.R. (1984). Water hyacinth biomass production in Florida. Biomass 6:167-180. (32) PRATT, D.C. and ANDREWS, N.J. (1982). Cattails (typha spp.) as an energy source. Energy from Biomass and Wastes IV. 43-64. (33) SNYDER, G.H. and O'HAIR, S.K. (1985). Biomass production from taro (colocassia esculenta) in subtropical wetlands. Proc. Third S. Biomass Energy Res. Conf. Gainesville, Fla. In press. (34) CHYNOWEYTH, D.P. and JERGER, D.E. (1985). Anaerobic digestion of woody biomass. Developments in Industrial Microbiology. In press. (35) SHIRALIPOUR, A. and SMITH, P.H. (1984). Conversion of biomass into methane gas. Biomass 6:85-92. ONOPORDUM NERVOSUM BOISS, AS A POTENTIAL ENERGY CROP J. FERNANDEZ, P. MANZANARES and J. MANERO Division de Biomasa. Programa de Energias Renovables Junta de Energia Nuclear. MADRID (SPAIN) 20. Summary This paper presents the species onopordum nervosura Boiss as a potential crop for lignocellulosic biomass production Its high productivity and adaptation to grow in poor lands makes it a feasible source of biomass for energy or - chemicals. O. nervostum is a plant that grows spontaneously in uncultivated lands of the Iberian peninsula, mainly in Limy sojls, often reaching heights up to 3.5 m. From - experimental measurements in wild populations, it has been estimated an average productivity of 24 tons of dry matter per ha. The fractionation of the dry biomass in the plant was: https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stalks, https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> leaves and https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> capitules. The chemical analysis of the 1Ignocellulose fraction showed a 15-19. of lignin, https://www.w3.org/1998/Math/MathML"> 65 - 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of holocellulose and https://www.w3.org/1998/Math/MathML"> 35 - 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of cellulose referrea to the total dry matter. Some aspects related to the domestication of the species Eor large scale productia have been studied in fiela conditions: jmproverent of the germination rate of wild seeds in order to prevent the natural inhibitors action, determination of the optimum number of plants per ha for maximum biomass production and evaluation of the plant development during its vegetative cycle. 21. INTRODUCTION Until now, Onopordum nervosum has been always considered as a weed and consequently, it has never been cultivated, but erradicatea. However, O. nervosum could be considered as a potential energy crop due to sereral advantages that may be summarized as follows:

Abundant vegetation that prevents others weeds qrowing

that would compete with it.

Plant structure that provides an efficient capture of

solar energy by the leaves distribution along the stem, result inc in high biomass yieldes.

Strong root system that minimize the use of artificial

fertilizers and allow to get vater from the subsoil

Vegetative cycle adapted to continental climate with cold

and dry periods.

Possibility to grow in poor lands which can not support

traditional crops. In several countries of the mediterranean area there are a lot of marginal lands where traditional crops give Iow produc tivity due to hard climatic conditions. In many of these landis O. nervosum could be cultivated for biomass production (1).

EVALUATION OF NATURAL PRODUCTIVITY IN A WILD POPULATION

The estimated productivity would be https://www.w3.org/1998/Math/MathML"> 24.059   k g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (dry weight). TABLE II. Percentage of biomass distribution (based on dry weigth) in three morfological types of O. nervosum. TABLE IV. Mineral composition of stalk and leaves of O. nervosum (percentage based on dry weight) Mineral elements Macronutrients Stalk Leaves Nitrogen 1.56 2.95 Phosphorous 0.17 0.17 Potassium 2.41 3.48 Calcium 1.50 3.22 Magnesium 0.17 0.33 Sulphur 0.07 0.18 Fig. I stalk elongation curve of o. nervosum. STRAW AS A BIOMASS RESOURCE AND ITS ACQUISITION IN THE UNITED KINGDOM J.M. CLEGG*, S.B.C. LARKIN, D.H. NOBLE and R.W. RADLEY Silsoe Lollege, Silsoe, Bedford, England. *Hertfordshire College of Agriculture and Horticulture, St. Albans, England 22. Summary To assist in the development of straw as a fuel, straw production, distribution, disposal and utilisation have been examined to determine how much of the resource could be available. 1984 U.K. straw production is egtimated at 17.6 millian tonnes with 6.3 million tonnes burnt in the field. Costs of not burning straw are given, as are costs of baling, handling, storage and transport. Straw can compete with coal and oil as a fuel in the agricultural, industrial, commercial, institutional and domestic sectors, with up to 1.7 million tonnes potentially being used by the year 2000. 23. INTRODUCTION Cereal straw is the most important agricultural residue in the United Kingdom, having the greatest potential for use as a fuel. A study was therefore undertaken for the Department of Energy covering all aspects of Its production, disposal, acquisition and utilisation as a fuel (1). Some of the results of the study are summarised in this papex.

STRAW PRDDUCTIDN, DISPDSAL AND UTILISATION

Accurate yield and production figures for straw axe not available but applying estimates of straw to grain ratio from a survey (2) to grain yields, straw production in 1984 in the United Kingdom can be estimated at 17.8 million tonnes. For the last two years a survey has been carried uut (3) of straw dispossl in England and Wales. Assuming that in Scotland and Noxthern Ireland https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the straw is baled and https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is burnt in the fields, the disposal of total U.K. straw production can be estimated as 10.2 million tonnes baled, 6.3 million tonnes burnt and 1.2 millian tonnes incorporated into the soji. If the straw baled it has been estimated that 482 thousand tonnes are used off farm in England and Wales with stables, mushroom oroduction and sodium hydroxide industrially treated straw being the main users (5). On the farm a similar quantity is estimated as being used for fuel treated livestock feed, orop storage and for horticultural purposes with the remainder, estimated at 7.4 million tonnes in the U.K. In 1984 being used for livestock bedding, untreated for livestock feed on wasted An estimated 166 thousand tonnes of straw are currentiy used on farms for fuel (1), mainly far domestic heating. other current uses of baled straw are unlikely to increase much, so the estimated 6.3 million tonnes burnt is potentially available for use as a fuel or for new uses such as production of paper or chemicals.

THE COSTS OF STRAW ACQUISITION

The cost of straw acquisition includes recompensing the farmer for foregoing the benefits of bumning and the costs of straw baling, handling, storage and transport. Each of these has been examined (1), with the use Table 1 The use of straw as a fuel, or for any other purpose, will invalve a period of straw storage. The cost of storing straw depends on the methad adopted and the type of bale being stored. If the method of straw storage is improved this will incur extra costs, but will reduce wastage of straw. Straw losses are very variable, but for costing purposes can be taken as https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in a building, https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in a covered stack and https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in an uncovered stack. Costs including losses are shown for the different tymes of bales and a selection of storage systems in Table 2 . Table 2 The cost of straw transport depends on the bale system, the type of vehicle, its level of usage and the length of the jounney. Transporting straw bales is relatively expensive because the low bale density means that vehicles can carry only a fraction of their maximum load. An articulated vehicie with a https://www.w3.org/1998/Math/MathML"> 12.2   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lang low loader trailex is of suitable dimensions to maximise the use of the vehicle carrying capacity compared with other vehicles, for all types of bale except raund bales, which would be unlikely to be chosen for transport. This vehicle has therefore been chosen to give the examples of straw transport costs shown in Table 3. All costs are based on the current U.K. qrass vehicle weight limits and a weekly vehicle usage of https://www.w3.org/1998/Math/MathML"> 800   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Table 3 The cost of straw transport in an articulated vehicle with a low loader trailer (&/tonne) The total costs of straw acquisition are summarised in Table 4. Because costs are so variable ranges and typical costs are given for each of the components. The typical values are in accord with contract prices that have been made for the supply of straw to industries. https://www.w3.org/1998/Math/MathML">   Table   4   Eueral I   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Costs of not buaning Baling and handling Transport https://www.w3.org/1998/Math/MathML"> ( 40   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> round trip) Total Range Typical &/tonne &. tonne 0-12 5 7-14 9 3-6 4 4-6 5 14-38 23 14-38

THE PUTENTIAL MARKETS FUR STRAW AS A FUEL

Straw can potentially be used as a fuel as whole bales, or in the form of chopped straw ox as briquettes. It could be used as a fuel on the farm, in industry, for commercial ar institutional use ur as a domestic fuel. Baled straw is most suitable for use on the farm. Chopped straw is suitahle for indugtry and lamge goale agriaultural purpeses of these systems may be appropriate in the cammercial and institutional sector depending on scale. Briquettes are the only form of straw fuel suitable for the domestic market. Each of these potential methods of using straw for fuel has been assessed, technically and economically (1). The distribution of fuel demand has been compared with the distribution of sumplus straw (mainly in Eastern England). Using this infoxmation the maximum possible use of straw as a fuel has been estimated, together with likely use of straw by the year 2000 https://www.w3.org/1998/Math/MathML"> ( 1,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the short term the most significant user of straw as a fuel will be agriculture far purposes such as farmhouse domestic heating, glasshouse heating, grain drying and pig house heating. There are examples of all of these in use at present in the U.K. The maximum potential could be 1.9 million tonnes, with 0.9 million tomnes used by 2000. Straw could be used as an industrial fuel, mainly to replace coal ur ail in boilers, but also mixed with coal in furnaces in industries such as cement or brick. From estimates of fuel consumption in industries where straw could economically replace oil, located in Eastern Enqland where surplus straw is available, the maximum possible use of straw would be 5.1 milifon tonnes. Because penetration of the markst is not likely to be rapid the maximum use of straw by 2000 is 386 thousand tonnes in industry. Straw could be used as a fuel for schools, colleges lespecially agricultural colleges), hospitals and offices located in rural areas where straw is available. To replace present fuels in the commercial and institutional sector in Eastern England a maximum af 4.3 million tonnes af straw would be required with 230 thousand tonnes achieveable by 2000. Straw briquetees are available from nine briquetting presses curcently installed in England. While it is too early to judge the success of these enterprises at present it seems unlikely that with present equipment they can be run economically and produce a fuel. sufficiently attractively priced to maintain a large share of the domestic market. https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the domestic coal market in Eastern England is estimated to be equivalent to 115 thousand tannes of straw briquettes, which could be the market size by 2000. It is concluded that up to https://www.w3.org/1998/Math/MathML"> 1.7 m i l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> inn tonnes af straw could be used as a fuel in total in the U.K. by 2000. STUDIES ABOUT THE POTENTIAL OF SWEET SORGHUM AND JERUSALEM ARTICHOKE FOR ETHANOL PRODUCTION BASED ON FERMENTABLE SUGAR G. KAHNT and L. LEIBLE Dept of Agriculture, University of Hohenheim Box 700562,7000 Stuttgart 70 , Germany 24. SUMMARY A two-year experiment with sweet sorghum and Jerusalem artichoke was conducted at three locations in the south of Germany, evaluating the potential for ethanol fuel production. Jerusalem artichoke (tubers is more stable in yield of fermentable sugar respectively ethanol than sweet sorghum; with increasing temperature it is significantly surpassed by sweet sorghum. 25. INTRODUCTION Passing the first oil crisis in the beginning of the seventies, the interest in renewable fuel resources increased rapidly. Nearly forgotten crops like sweet sorghum [Sorghum bicolor (L.) Moench] and Jerusa.lem artichoke [Helianthus tuberosus ( https://www.w3.org/1998/Math/MathML"> L * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> )] got a renaissance (6, 8,5,9 ). In Germany in the past sweet sorghum was primarily evaluated under the viewpoint of forage production, as a direct competitor to corn for silage https://www.w3.org/1998/Math/MathML"> ( 2,3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Today sweet sorghum seems to gain new interest for its potential in ethanol fuel production (4). The cultivation of Jerusalem artichoke has an old tradition in Germany (7); but in spite of the extensive experience with this high yielding crop, Jerusalem artichoke today has only local importance for some schnaps producing farmers in the south-west of Germany. The objective of the studies reported here was the evaluation of the potential of sweet sorghum and Jerusalem artichoke for ethanol production under different agricultural conditions.

MATERIALS AND METHODS

The field trials in 1982 and 1983 were conducted at three locations. Description of Localities Loc. 1 LoC.2 LoC.3 IItitude https://www.w3.org/1998/Math/MathML"> [ m ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> : 1982 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9.2 9.3 9.4 Temperature https://www.w3.org/1998/Math/MathML"> [ aC ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> : 1983 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9.1 9.7 9.6 877 825 798 Precipitation https://www.w3.org/1998/Math/MathML"> [ mm ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> : 1982 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 61983 64 940 724 Sweet sorqhum varieties Dale and Rio (1982 only Dale) were planted In May 5th-13th 1982 respectively in June https://www.w3.org/1998/Math/MathML"> 14 th - 16 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> l983. Averaged plant population was 20 plants per sqm in rows 50 cm wide. Two local varieties https://www.w3.org/1998/Math/MathML"> ( S 2 , S 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Jerusalem artichoke and two registered varieties (Topianka and Rozo) were planted https://www.w3.org/1998/Math/MathML"> 18 th - 21 st https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of April 1983. In 1982 only the variety s2 was examined, planted at https://www.w3.org/1998/Math/MathML"> 2 nd - 6 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of April. Plant density was 6 plants per sqm https://www.w3.org/1998/Math/MathML"> ( 50 × 35 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The N fertilization was applied 4 weeks after planting, at rates of https://www.w3.org/1998/Math/MathML"> 0,200,300,400   k g   N / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in 1982 and at rates of https://www.w3.org/1998/Math/MathML"> 0,80,160,240   k g   N / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Sweet sorghum (stem and leaves) was harvested in the middle of October and Jerusalem artichoke (tops and tubers) in the middle of November. The samples were ovendried at https://www.w3.org/1998/Math/MathML"> 70   ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The fermentable sugar (FS) Was extracted with water and additionally the extracts of the Jerusalem artichoke tubers were hydrolysed with hydrochloric acid https://www.w3.org/1998/Math/MathML"> ( 0.5 % ( w / w ) ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> 30   m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in a water bath (95 https://www.w3.org/1998/Math/MathML">   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The fermentable sugar was determined enzymatically and expressed in % (w/w) sucrose (1). Based on FS the potential ethanol yield was calculated, assuming that https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the theoretical ethanol output can be realized under practical conditions. Multiple comparisons were tested with Tukey's HSD test. 26. RESULTS AND DISCUSSION 27. Biomass yield (Fig.1) In 1982 biomass yield of sweet sorghum (Dale) was 31.1 tha at the https://www.w3.org/1998/Math/MathML"> 200   k g   N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> rate. In 1983 the averaged yield level of Dale was 12.8 tha Iower than in 1982, because the planting date was nearly 5 weeks later due to the weather conditions in May- In 1983 the variety Rio yielded 2.5 4.o t/ha higher than Dale. P1e. 1 Biomass yield of sweet sorghum and Jerusalem artichoke as affected by year, location, variety and x fertilization Jerusalem artichoke yielded in 1982 at the https://www.w3.org/1998/Math/MathML"> 200   k g   N / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> rate 11.1 metric tha tops and 10.5 metric tha tubers. Increasing N rate resulted in a depression in biomass yield. The averaged yield level in tops and tubers in 1982 was o.9 tha respectively https://www.w3.org/1998/Math/MathML"> 2.2 t h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> higher than in 1983, due to the better weather conditions in 1982 . The registered varieties were not superior compared to the local varieties. Yield of fermentable sugar (FS) respectively ethanol (Fig.2) In 1982 sweet sorghum yield was 11.4 t FS/ha at location 1 (not separately figured out). The averaged yield of Dale was 7. t FS/ha respectively 3990 l ethanol per ha. In 1983 yield of variety Dale was 4.8 t FS/ha at location 1, significantiy surpassed by Rio (6. 1 tha), due to the greater biomass yield and the higher FS content of Rio. P1g. 2 Y1eld of fermentable sugar and ethanol of sweet sorghum and Jerusalem artiohoke as affected by year, location, variety and N fertilization In 1982 Jerusalem artichoke (tubers) achieved 6.7 t FS (3840 I ethanol) per ha (average of 3 locations) at the https://www.w3.org/1998/Math/MathML"> 200   k g   N / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Iate. The best location https://www.w3.org/1998/Math/MathML"> ( Loc . 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> resulted 10.3 t https://www.w3.org/1998/Math/MathML"> F S / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (not separately fiqured out) respectively 5850 I ethanol. In 1983 variety https://www.w3.org/1998/Math/MathML"> S 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yielded 1.5 tha less than in 1982 (average of 3 locations). Variety https://www.w3.org/1998/Math/MathML"> S 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> realized the greatest Fs and ethanol yield, i.e. 5.9 t FS respectively 33801 ethanol per ha (average of 3 locations and https://www.w3.org/1998/Math/MathML"> 4   N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> rates). In 1982 sweet sorghum yielded significantiy more ethanol per ha than Jerusalem artichoke, but in 1983 Jerusalem artichoke produced higher ethanol yields (2950 1/ ha ) than sweet sorghum https://www.w3.org/1998/Math/MathML"> ( 21901 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha), regarding total averages. Jerusalem artichoke seems to be more stable in yield of FS and ethanol than sweet sorghum; but sweet sorghum can surely be better adapted to the described climatic conditions by plant breeding. Because of THE POTENTIAL FOR STRAW AS A FUEL IN THE UK* L P MARTINDALE AERE Harwell, UK Energy Technology Support Unit Summary Of the straw produced each year in the UK, some https://www.w3.org/1998/Math/MathML"> 7.5 m i l l i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes, equavalent to https://www.w3.org/1998/Math/MathML"> 2.4 m t l 1 i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes of of1 (Mtoe) find no saleable outlet; this surplus is largely burnt in the fleld. However, straw could be put to cost effective use as fuel both on the farm and th could be put to cost effective use as fuel hoth ort the farm and in https://www.w3.org/1998/Math/MathML"> ( 0.06 M t o e / y ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are used on farms, and this could rise to around https://www.w3.org/1998/Math/MathML"> 0.9 m i l 110 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes/year https://www.w3.org/1998/Math/MathML"> ( 0.29 M t o p / y ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by the year 2000 straw fo 0.9 million tonnes/year (0.29Mtoefy) by the year 2000. Straw Ls that use in rural-industry and institutions could reach 616,000 tonnes/year https://www.w3.org/1998/Math/MathML"> ( 0.20 M t o e / y ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by the year 2000 Research, Development and Demonstration Programmes supported by the Department of Energy are deslgned to help bring forward and extend this potential; total value of these Programmes https://www.w3.org/1998/Math/MathML"> 1   s E O . 55 M . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 28. INTRODUCTION The nature of straw production in the Uk has changed rapidly since the https://www.w3.org/1998/Math/MathML"> 1960 ∘ s ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the area under cereals has grown by https://www.w3.org/1998/Math/MathML"> 30 % : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the ylelds of grain have increased dramatlcally, although with a reduction in cereal straw heights: winter cereals have become commonplace: wheat is now more widely planted than barley, oats have all but disappeared, and of1 seed rape has now become the third blggest crop: combine harvesters have taken over collection operations: antmal numbers in cereal producing taken over collection operatlons: antmal numbers 1n cereal producling straw production has almost doubled, and tutlisation has fallen. The "surplus" created is now largely burnt in the field, with concern over the resultant environmental (and publlc) lmpact recently leading to calls for a ban on burning. It is perhaps not surprising that the use of straw as a fuel in the UK https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> very much in 1ts infancy. Rising fosstl. fuel prices in the https://www.w3.org/1998/Math/MathML"> 1970 ' s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> only then made straw an economic fuel for on-farm use, and the increaslng avallability of straw and pressure to find alternative uses for the surplus have since led to a rapid growth in titifsation as fuel. Suddenly, straw can now be an economically viable fuel for industrial users situated in arable areas, and with further tncreases ln fossil fuel prices utilisation of straw is certain to grow. Hence the Department of Energy through lts Blofuels R&D Programme and the Energy Efficiency Demonstration Scheme is actively supportings work to develop and demonstrate effectlve ways of using straw as fuel.

The views expressed in this paper do not necessarlly represent the official views of efther the Department of Energy or UKAEA.

29. THE STRAW RESOURCE 30. THE POTENTIAL FOR STRAW AS FUEL There is technology available that permits the processing and efficient combustion of straw over a wide range of outputs. The smallest botlers are already being uped on-farm while larger ingtallationg have been demonstrated in Denmark and will be demonstrated in the UK over the next few vears. The best opportuntties wi11 be where high rates of uttlisation can be achleved, where fuel costs are a significant proportion of total costs, and where straw https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> considered "credtble" because similar materials are already being handled. In the short term, the most slgnificant outlet for straw as fuel is for on-farm applications, Already there are around 7700 botlers in the UK that are at least in part fired by straw, and these consume around 166,000 tonnes of straw (0.06Mtoe) each year. S1lsoe College have analysed the potential for use of straw on the farm; they report that the maximum utilisation of straw could be 1.9 million tonnes/year, and that use is likely to reach 0.9 million tonnes/year (0.29Mtoe/y) by the year 2000 (Ref. 3) Currently, straw is only marglnally more attractive than coal as a fuel for rural-industry and institutions, although the economics versus ofl are generaly much better. The lead rural industrial markets have been identified as food and drink, fruit and vegetable processing, sugar, milk and milk products, cement and brick, and light engineering. The scale of these markets is large, and Silsoe College s analyses suggest that up to 5. https://www.w3.org/1998/Math/MathML"> 1   m 111 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes of straw could in theory be used as fuel. However, a more reallstic assessment is that the of some 386,000 tonnes of this (0.12Mtoe) annually could be realised by the year 2000 (Ref. 3). Silsoe College's analyses also suggest that a further 230,000 tonnes/year cotrld be being used by the year 2000 in the institutional/commercial sectors (Ref, 3). Althotigh there has been a lot of interest in the briquetting of straw to produce a domestic fuel - and up to 1984 around 13 presses had been Installed in the the UK - the high costs of compaction lears to a poor economic retirn to the producer, and little financial incentive for the user to switch from coal or wood. Thus, there is some uncertalnty over the future of this market, reflected in an assumed market potentlal of no more than 115,000 tonnes of straw (0.04Mtoe) by the year 2000 (Ref. 2). 31. THE DEPARTMENT OF ENERGY'S RD&D PROGRAMMES Much of this assessment of the potential for straw as a fuel is based on an earlier study by słlsoe College, commissioned by ETSU on behalf of the Department of Energy (Ref. 3). Although a significant part of this potential is likely to be realised on the farm, the Department of Energy https://www.w3.org/1998/Math/MathML">   ⊤ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> s current RD&D programmes are designed to develop the off-farnt markets, stnce:

more straw 13 produced than can be used on farms

H. STURMER, H. THOMA, E. ORTMAIER Technische Universität Muinchen Lehrstuhl fur Angewandte landwirtschaftliche Betriebslehre, https://www.w3.org/1998/Math/MathML"> D - 8050 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Freising-Weihenstephan 32. Summary It is possible to produce liquid fuel from many crops containing sugar, starch or oil, but right now only few agricultural plants can be converted to fuel with a satisfactory result. One reason is that for big scale production crops must be well known, widely spread and allow a relatively easy processing. Crops fulfilling these demands are e.g. cereals, maize, sugar beet, rape seed and sunflower, beet and rape being the most interesting from the economic point of view for large parts of Europe. This paper examines the costs of agricultural production with different methods and levels of yield and gross margins at EEC prices The sensitivity to changing prices of fossil inputs is analysed. One result is that neither ethanol nor plant oil are competitive with gasoline or diesel at the present stage, but ethanol more than oil may become economic if prices of fossil fuel increase. 33. LIOUID FUEL CROPS Although crude oil prices were stable in the last years, it could become necessary to produce Iiquid fuels from biomass in the future due to various reasons. Two different levels of demand ought to be considered: A: Ad hoc production within one or two years for example after a sudden delivery failure. B: Long term partial substitution of crude oil within about the next fifteen years, to reduce dependence and to create new EEC agricultural markets. Whereas in the long run many plants have to be examined on their energy use, right now few crops can be converted to fuel with a satisfactory result. This paper focuses on biofuel which could go into production right away. For that purpose some conditions have to be fulfilled:

The raw material should be a widely spread and will known crop with Iow production risk (Farmers will not make risky experiments).

The conversion process should be well known.

The end product should be suitable to normal engines.

In the EEC ethanol from sugar beets as a petrol additive and rape oil as a diesel substitute seem to be promising. Different production methods and levels of yield (sugar beets 40 tha, 47.5 tha, 65 tha, rapeseed https://www.w3.org/1998/Math/MathML"> 2.5 t / h a , 3.0 t h a , 3.5 t / h a ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> have been compared and the variable costs of production calculated. They vary from https://www.w3.org/1998/Math/MathML"> 1480 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha to https://www.w3.org/1998/Math/MathML"> 2200 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha https://www.w3.org/1998/Math/MathML"> ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sugar beets) and from https://www.w3.org/1998/Math/MathML"> 1150 D M / h e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 1430 D M / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (rapeseed), calculated on the base of 1980 energy prices, which are very similar to 1984/85 prices. Other price assumptions of course change production costs. These costs include an amount of 250 to 400 DM/ha for direct (diesel, fuel oil, electricity) and indirect (seed, fertilizer, plant protecting agents) energy input, representing an equivalent of 17 % to https://www.w3.org/1998/Math/MathML"> 23 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of total variable costs. Ceteris paribus doubled energy prices increase production costs by about one fifth and cause a lack of gross margin which could be compensated by increasing the product prices between https://www.w3.org/1998/Math/MathML"> 6 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 10 %. Former studies (1), (2), (3), (4) compare different prices for fossil fuel with biofuel, give more detailed information about production systems and levels of yield and discuss several crops and different models. 34. CONCLUSIONS Sugar beets and rape seed can be easily planted and processed, but at actual prices they are not competitive with fossil fuel, if no subsidy or tax exemption is granted. The actual monetary ratio between agricultural ethanol and gasoline is 2:1 and between rape oil derivates and diesel is 3:1 (taxes not considered). The prices of both crops are very insensible to changing oil prices, therefore rising oil prices improve their competitive ability considerably. It is expected that technical progress in agriculture and in conversion technology will cut down the costs per liter biofuel in future, but after all a political decision is necessary to start up biofuel production. 35. REFERENCES (1) S'URMER, H., ORTMAIER, E. and THOMA, H.: Production Costs and Economics of Energy Plants at Rising Energy Prices. Bio Energy 84 World Conference, Göteborg 1984 (2) STttrMeR, H und THOMA, H. Fnergieverteuerung und Wirtschaftlichkeit nachwachsender Rohstoffe - Auswirkungen einer weiteren Energieverteuerung auf die Rentabilität der Nutzung nachwachsender Rohstoffe zu Energiezwecken . Eine ơkonomísch-statistische Auswertung fir vier ausgewăhlte Lander. Schriftenreihe des Bundesministers für Ernährung, Landwirtschaft und Forsten, Reihe A: Angewandte Wissenschaft Heft 290 , MünsterHiltrup 1983 (3) THOMA, H., ORTMAIER, E. und STURMER, H.: Auswirkungen steigender Energiepreise auf die Kosten variabler Input-Komponenten in der I andwirtschaftiichen Produktion der BRD. 1 a Conferenza Internazionale Energia e Agricoltura, Vo1. 3, P. 40/1- 40/28, Milano 1983 (4) THOMA, H., ORTMAIER, E. and STURMER, H.: Effects of the Rising Price of Bnergy on the Variable Input-Factors in Agricultural Production. Bio Energy 84 World Conference, Göteborg 1984 ENERGETIC OUTLETS OF AGRICULTURE IN THE EEC https://www.w3.org/1998/Math/MathML">   J.J. BECKER     CEMAGREF, division ENERGIE,     ANTONY (France)   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 36. Sunmary Since 1962 , the progressive develomment of the Common Agricultural Policy (CAP) has led to reach or exceed self-sufficiency as far as the main agricultural produces are concerned. In a more general context, when defining the use of land no longer needed for food purposes the energy production from biomass was analysed and estimated from an economic viewpoint. A first comparison with alternative solutions was outlined. One of the main concerns in estabilshing Green Europe was to guarantee a sufficient supply of foodstuffs in the EEC. The increases in productivity enabled the objectives for stricto sensu self-sufficiency to be exceeded (vexed question of surpluses...). It would be necessary to question the exclusive use of agriculture for food production purposes which seems to be brought to a standstill as far as outlets are concerned. This research will firstly be based on a prospective evaluation of main foodstuff supply balances for 1990/1995. It would then be possible to assess the cultivated area not necessary for EEC food self-sufficiency. The results obtained are presented in the following table, land areas being classified according to their original use. Table 1 SURPLUS LAND TN THE EEC https://www.w3.org/1998/Math/MathML"> 10 6   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1990 ZLLL 1995 As a result, 12 to https://www.w3.org/1998/Math/MathML"> 14 m i 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ion hectares (i.e 12 to https://www.w3.org/1998/Math/MathML"> 14 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the EEC agricultural area) will produce surpluses for the 1990/1995 years unless new outlets are not defined by the time. The analysis of energy outlets for agriculture takes an exhaustive survey of energy processes from biomass as a basis and leads to energy vectors suitable for meeting all requirements. The procedures in use in agribusiness (particularly in sugar industry) would be applied to this production namely:

decentralized agricultural production, the charge of which would generally be taken on by numerous independent farmers.

collection and processing taken on by an industry (possibly a cooperative)

An economic assessment of the various processes was made in two stages:

determining the cost of agricultural raw materials in variots farming systems (cereals, cattle-milk, cattle-beef). The cost was defined as the lowest price that keeps steady agricultural income at the same level.

calculating agricultural raw material conversion costs in various units. Their size was optimized in terms of collection costs as well as economies of scale that could be made at the conversion level.

As shown in the diagram 2, the most interesting energy production routes are reviewed and the production cost ranges of the various energy vectors obtained are mentioned. Some conclusions can be drawn up from now on:

the competitiveness of energies produced from biomass compared with fossil energies i.s not get reached taking both heat and fuel production into account.

energy vectors drawn from a lignocelitlosic biomass crop are the nearest to economic profitability.

ABE mixture is not competitive with ethanol. But its main advantage consists in its use as a co-solvent for methanol.

The above analysis of economic factors enable to make a first comparison among other potential uses for "surplus lands". Three different options are taken into account:

following current trends, which means either selling foodstuff production on the world markets, or on the EEC markets at preferential prices. It implies regulation costs that can be estimated from the average cost entailed by the elimination of agricultural surpluses in the EEC countries during the last decade.

developing protein production Eor animal freeding. EEC is particularly poor in feedstocks and imports great amounts of soya cakes. This option can be evaluated on the basis of rape internal production. To compete with imported products, protein production must be supported by direct subsidies, the amount of which can be assessed by means of studies concerning that production in the last decade.

freezing surplus lands. Its cost can be evaluated on the basis of the unempioyment benefits that must be paid in case of original farming activity cessation, that is to say 58 ooo FF per worker.

Conclusions from the comparative analysis are given in the following figure in terms of right amount of subsidies per hectare to be paid to implement D.TAGRAM 2 ENERGY PRODUCTION ROUTES FROM BIOMASS ENERGY CROP ENERGY CARRIER https://www.w3.org/1998/Math/MathML"> ( 7250 - 8950   F / T O E ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4000-6500 F/t (6250-10 100 F/TOE)7350-9200 F/t https://www.w3.org/1998/Math/MathML"> ( 9670 - 12000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> F/TOE) https://www.w3.org/1998/Math/MathML"> 3800 - 5400   F / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (5900-8500 F/TOE) https://www.w3.org/1998/Math/MathML"> 6400 - 9000   F / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 8000 - 11800   F / T O E ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 5300 - 8900   F / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 6000 - 11000   F / T O E ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sunflower NB ABE= Acetone Butanol Ethanol mixture th https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> french thermal unit each project in the best possible way. In order to assess the subsidies to be granted for energy activities breakeven prices for energy from biomass are defined using the most competitive fossil energies as point of reference : coal for heat production, high-grade gasoline and Diesel fuel. for mechanical energy production As for alcohols, two methods of calculation were followed : in case of high level blends with gasoline substitution made on a thermal unit basis (supposing an little improvement in engine efficiency. ) and in case of low level blends substitution made on a volume basis (in the second case methanol from biomass is compared with methanol from natural gas) Figure 3 AMOUNT OF SUBSIDTES REQUIRED land Z̸ Et@H/gasoline substitution on a volume basis https://www.w3.org/1998/Math/MathML"> M e O H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from biomass competing with MeOH from fassel material Abstract From the economic profitability point of view, the confrontation of the various data collected shows that energy production will bring a more positive contribution than competing options. Sti11 we have to choose the Indeed, those factors are insufficient to bring the study to a close : the effects on the balance of payments should be examined and the assessment of conventional options (export or protein production) should be, of MANAGING STANDS FOR CONTINUED PRODUCTIVITY D.R. DUBBE, B.G. GARVER, and D.C. PRATT Bio-Energy Coordinating office University of Minnesota 37. Sunreary Through a combination of basic and applied research covering bionass production, harvesting, land use planning, and economics, the BioEnergy Coordinating Office st the University of Minnesota is in the process of generating multiseesonal information critical to an evaluation of the commercial potential of using emergent aquatic plants grown on marginal lands as sources of bio-energy. 38. INTRODUCTION Emergent aquatic plants such as Typha (cattail), Phragmites (reed), and Scirpus (rushes) are of interest for bio-energy production in Minnesota because of their high productivity, and the fact that they grow naturally on subetantial portion of the state's 3.5 million hectares of wet marginal lands (1). Evaluation of the commercial potential of emergent aquatic plants as an energy source depends on an understanding of the tradeoffr between productivity and production costs. Pesearch at the University of Minnesota has sought, through a multidisciplinary program, to generate the information base needed to make this evaluation. Projects involving production, equipment development, land use planning, and economics have been supported and coordinated through the University's Bio-Bnergy Coordinating Office. Typha species have received the greatest attention because of their superior productivity, pest resistance, and adaptability to wide ranging wetiand conditions. This paper highlights several current projecta examining aspects of stand establishment, management, and harvesting.

STAND RSTABLISEMENT METHODS AND PRODUCTIVITY

As shown in Table I, field experiments have demonstrated that Typha stands can be successfully established by transplanting seedlings or rhizome pieces and, in one case, planting seed. The values shown in Table I gre aggregates from several field experiments examining various aspects of Typha stand management. Because of this, the values do not represent the maximum productivities that have been achieved within individual experiments. Table I does, however, provide insights into factors affecting multiseason Typhe productivity. The most important stand establishment factors affecting productivity appear to be the species of Typhe selected and the initial planting density. Contrary to expectations based on natural stand studies (2), Typha latifolia appears to have lower biomass yields than either Typha angustifolia or the hybrid Typha x glauca. The lower yields may be attributable to increased flowering, lower shoot densities, and increased Table I. Multiseason Productivity of Typha spp.

Establishment Method: https://www.w3.org/1998/Math/MathML">   S = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Seeded; T= Transplanted

STAND MANAGEMENT

Following the initial establishment phase of the production process, management of The ine stands becomes critical for maintaining high sustained productivity. Pest control, nutrient input requirements, and water level control are of primary concern. Pests, in the form of weeds, insects, and herbivores, have been studied, but currently do not appear to seriously reduce productivity in either natural or managed stands of Typha (3). Because of this, current research is focused on gaining a better understanding of nutrient uptake patterns, nutrient requirements, and water use of Typha spp. Fertilizer represents a potentially large input into the Typha production system. Nitrogen is of primary interest because of its cost and potential for loss through denitrification. Basic research examining the magnitude of denitrification losses, factors affecting low level associative nitrogen fixation (4), and the role of mycorrhizae in nutrient uptake is currently being conducted. Complementing these basic studies have been field studies examining seasonal nutrient uptake and alternative methods of fertilizer application. A two year field study examining seasonal biomass accumulation, nutrient uptake, and biomass/nutrient partitioning between the above- and belowground portions of Typha sought to provide information that could be used to: 1) develop a fertilization schedule that would minimize nutrient losses by timing application to coincide with the period of greatest nutrient uptake, and 2) develop a harvesting schedule that would minimize nutrient reitoval (3). Figure I presents results of this study for nitrogen; phosphorus and potassium accumulation follow similar patterns. Figure I. Seasonal nitrogen accumulation for Typha spp. during the establishment and second growing season. During the establishment season (planting date = June 9), growth was in q laó phase until early Augrist, and maximum biomass accrusl occurred in a lag phase until early August, and maximun bibmass accrual occuried between the sampling dates of august 4 and september 2. Forty.six percent of the season's total biomass was produced during this period. The greatest amount of each nutrient (o/ma basis) was also taken up in this greatest anount of each nutrient https://www.w3.org/1998/Math/MathML"> g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> basis https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was also taken up in this period with https://www.w3.org/1998/Math/MathML"> 48 % , 46 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and https://www.w3.org/1998/Math/MathML"> 48 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the season https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> s total N, , and K accrued, respectively. During the last two months of sampling, changes in partitioning of biomass and nutrients ocmurred, with total plant biomass partitioning of biomass and nutrients occurred, with total plant biomass and nutrients continuing to increase but with shoot biomass and nutrients decreasing and rhizome biomass and nutrients increasing rapidly. The period of maximum biomass production in the second year occurred at the same time as in the first year in terms of shoot age (between 66 and 84 days after plant growth began), but this period was reached one month earlier during the second season. Additionally, in most cases greatest nutrient uptake preceeded the period of greatest biomass production in the second season. Biomass and nutrient partitioning was similar to that occurring in the establishment season. The patterns of nutrient and biomass accrual observed in thi experiment can serve as a starting point for testing Typha stand management options such as time of fertilization and harvesting. If fertilizer, particularly nitrogen, had been applied to these plots at the beginning of the growino sesson, much of it may have become unavailable through physical and biological processess before it could be used by Typha. Methods of midseason application are being examined. This study also sugrests that harvest of aboveground material could take place as also subgests that harvest of aboveground material could take place as late as the end of september without much sacrifice in aboveground biomass, and that fewer nutrients will be removed from the system at this time. Another potentially positive factor of a late harvest is that the biomass may be drier by the end of september. For these experiments, moisture percent had dropped from a mean of https://www.w3.org/1998/Math/MathML"> 76 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in early September to https://www.w3.org/1998/Math/MathML"> 72 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in late September. These values may be more or less, depending on weather conditions. Although total plant biomass increased throughout october, aboveground biomass decreased, and plants lodged, making harvest difficult. Plant water requirements and water level control are another area of stand management currently under investigation. Although Typha will be grown on wetlands, irrigation and water control may be necessary to ensure optimum conditions for growth and accessibility by harvesting equipment. Based on preliminary experiments, Typhst evapotranspiration in Minnesota appears to be about twice that of two common agricultural crops, Zea mays and Medicago sativa. A study supported by the Herbaceous Biomass Program of the U.S. Department of Energy (DOE) will be conducted this summer to determine water loss of three species of Typha under various water management scenarios. 1. HARVESTING When Typha was first being considered as a biomass candidate, one of the attractive features of the plant was the belowground rhizome system consisting of about https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total plant biomass and composed of https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> starch and sugars. As a result, agricultural engineers began an equipment development project to develop a rhizome harvester based on existing agricultural equipment. An experimental potato harvester was modified and successfully tested in field experiments (5). The harvester is capable of cutting and lifting strips of soil and rhizomes. Further studies on methods of separating rhizomes from soil are currently underway. Because of the difficulty and potential expense of harvesting rhizomes, the uncertainly as to how a rhizome harvest would affect subsequent year's productivity, and largely unspecified compositional requirements for biomass, a simpler harvesting system involving shoot biomass only is being considered. With support from DOE, a new study was begun at the end of 1984 to evaluate sustained productivity under three harvesting scenarios in both natural and managed stands of Typha. The three harvesting scenarios include; 1) shoot biomass only, harvested annually, 2) shoot biomass only, harvested semiannually, and 3) shoot biomass harvested annually, rhizome biomass harvested biennially.

CONCLUS IONS

Information generated from multiseason studies of Typha spp. is being used to suggest and evaluete biomass production options that will result in high sustained productivity, while at the same time minimizing production costs. At this point in time, Typha spp. remains a promising biomass candidate for production on wet merginal lands. Further information on sustained productivity under different harvesting scenarios is being gathered which should allow a fingl evaluation of Typha's potential within the next several years. 2. REFERENCES CENTER FOR URBAN AND REGIONAL AFFAIRS. (1981). Available wetlands for bio-energy purposes: Lane use and drainage constraints. Map produced under contract with the Minnesota Hnergy Agency. PRATT , C ANTREWS N J GLASS , I and IOVRTFN R R. Production of Wetland Energy Crops in Minnesota an update. Proceedings of Biomass Workshop sponsored by Midwest Universities Energy Consortium, pp. 158-175. Bnergy Consortium, pp. 158-175. PRATT, D.C., DUBBE, D.R., GARVER, B.G. and LINTON, P.J. (1983). Wetland Biomass Productiont Buergent Aquatic Manageulent Options aud Bvalue 74 pp. BIESBOER, D.D. (1984). Nitrogen fixation associated with natural and cultivated stands of Typha latifolia L. (Typhaceae). American Journal of Botany 71:4, pp. 505-511. SCHERTZ, C., DUBBE, D.R. and PRATT, D.C. (1983). Harvesting Catcail (Typha spp.) Rhizomes as an Alternative feedstock for Alcohol Production: Modifications of Potato Harvester. Findi. report to Dept. of Energy - Alcohol Fuels Division under subcontract DOE/DE-FG07-811D12343. https://www.w3.org/1998/Math/MathML"> 19 p p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . ENERGY FROM AGRICULTURE - SOME RESULTS OF SWEDISH ENERGY CROPPING EXPERIMENTS U. Wunsche Department of Plant Husbandry Swedish University of Agricultural Sciences Abstract Summary Within the project Agro-Bioenergy surveys are made of the yields of various energy crops in Sweden. Some results of these energy cropping experiments are given. Tops of Jerusalem artichoke (HeIianthus tuberosus) can be used for biogas production. The highest yields obtained was 20 tons of dry matter per ha. Winter wheat varieties wth a high yield of gtarch for ethanol production have been tested since 1981 in 10 field trials in different parts of Sweden. In a number of cases some of the tested varieties yielded more than 10 tons of grain per ha. Also root crops for ethanol production have been tested. In six field experiments in different parts of Sweden the yields of four grass species are compared at six different harvesting times and at four nitrogen levels. The results obtained hitherto show that several agricultural crops may be of interest for energy purposes owing to their ability to give high dry matter yields. 1. INTRODUCTION Energy cropping research at the Swedish University of Agricultural Sciences started in 1979 At present it is being conducted within the framework of the Agro-Bioenergy project and is financed by the National Energy Administration. It is an interdisciplinary project ranging over several subject areas such as plant husbandry, inicrobiology, chemistry, technology and economics. The aim of the project is to identify possible fuel crops in agriculture and which kinds of energy carriers can be processed from these raw products. Surveys are made of the ylelds of various energy crops under different production conditions. Some results of these energy cropping experiments are given below. 3. JERUSALEM ARTICHOKE FOR BIOGAS PRODUCTION The idea to use Jerusalem artichoke (Helianthus tuberosus L.) as an energy crop is not new. It has been tested for production of ethanol and also for production of an alternative sweetener (fructose) (1), (2), (4), (5). In our experiments we have studied the possibility of producing biogas (methane) from the above-ground parts of the plant. Three varie- ties were tested, one of which (No. 1168) is a hybrid of Jerusalem aftichoke and sunflower. The tubers were planted in early May in rows spaced at https://www.w3.org/1998/Math/MathML"> 70   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with https://www.w3.org/1998/Math/MathML"> 33   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> between the tubers at a depth of about 7 cm. The total amount of nitrogen fertilization corresponds to 100 kg N /ha. Beginning in the firgt week of September the above-ground part Beginning in the first week of september the above-ground parts of the plants were harvested. Fotr harvesting times at intervals of two weeks were compared. The tested varieties are adapted for high tuber production in Central Europe but are rather late in tuber production under long day conditions. Normally they did not flower in our field. At this latitude tuber production does not start until late september, but instead the plants produce a strong vegetative growth of stems and foliage. The highest yield obtained was 20 metric tons of dry matter per hectare. An advantage of Jerusalem artichoke as an energy crop is that it can be kept as an permanent crop. The tubers can be left in the soil over the winter period to produce a new crop in the following year. Anaerobic digestion experiments have shown the possibility of producing biogas from both fresh and ensiled above-ground parts of Jerusalem artichoke (6). Harvesting year after planting 2 3 Fige 1 Dry matter yields of tops of two varieties of Jerusalem artichoke at four harvesting times. First, second and third year after planting. 4. WINTER WHEAT AND ROOT CROPS FOR ETHANOL PRODUCTION If wheat is to be used as raw material for ethanol production one could reduce some of the demands concerning baking quality Therefore, it is of interest to test varieties with poorer baking quality and low protein content but with a high yield of starch. Such wheat varieties have been tested since 1981 in 10 field experiments in different parts of Sweden. In a number of cases some of the tested varieties yielded more than 10 tons of grain per hectare. The results of the field experiments with wheat are summarized in Fig. 2. In the near future a maximum starch production per unit area will be the most important goal. In the long run, however, also the content Fig. 2. Grain yields (15% moisture content) of seven winter wheat varieties. To the left: mean values for 10 experiment sites,1981-84 ( 35 trials). Holme https://www.w3.org/1998/Math/MathML"> 6970   k g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . To the right: meanvalues for 16 trials in scania (south Sweden). Holme=7480 https://www.w3.org/1998/Math/MathML"> k g / h a . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Different types and varieties of root crops (sugar beet and fodder sugar-beet) have been tested in field experiments. Root crops could be used for production of ethanol as well as biogas. Regults of trials in different parts of Sweden during 1981 - 1984 are summarized in Fig. 3. Fig. 3. Dry matter yields of sugar beet and fodder sugar-beet varieties. Mean values for six experiment sites, 1981-84 ( 25 trials). The hatched parts of the bars indicate the amount of sucrose. The variety Kyros, a fodder-sugar beet, had an average yield of 57 tons of roots per ha against 40 tons for the sugar beet varieties. As the sugar beet varieties had a considerably higher dry matter content than the fodder sugar beet, the dry matter yield was almost the same for all varieties, on average arond 10 tons per ha of which 7-7.5 tons consists of sucrose. 5. ENERGY GRASS Grass can be used as a solid fuel or for the production of biogas. In six field experiments in different parts of Sweden the yields of four grass species are being compared. The following species were tested: Timothy (Phleum pratense), Smooth bromegrass (Bromus inermis), anary grase (Phalarig arundinaceg) and Tall fescue (Featuca arundinacea). The experiments include six different times of the first harvest (15 June, 1 July, 15 July, 1 August, 15 August and 1 September) and a second harvast on 1 october. In another series of field trials the yields at four different levels of nitrogen application are compared. The nitrogen levels are 0,100,150 and https://www.w3.org/1998/Math/MathML"> 300   k g   N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per ha. Depending on species, harvesting time, nitogen level and site of experiment, the yields varied between 3 and 17 tons of dry matter per ha (total of two harvests). Tall fescue often ylelded more than other qpecies, especially in areas with high precipitation. The optimal harvesting time varied with location of the field trials. On average,the highest total yields were obtained with the first harvest in the middle of June and the second harvest on 1 October. 6. DISCUSSION In this paper, illustrated with a poster during the conference, only part of the energy cropping experiments within the Agro-Bioenergy project have been dealt with. In addition for example we are comparing short rotation forestry (different species of Salix) with agricultural crops on farm land. However, no conclusions can yet be drawn from the results as the experiments have been carried otit for only four years. The project has been restricted to the cultivation of energy crops on arable land with the aim of studying the entire system from cultivation to the use of the produced energy carrier. The results obtained hitherto show that several agricultural crops may be of interest for energy purposes owing to their ability to give high dry matter yields per hectare. Thus, for example the cultivation experiments and assessments of plant breeding possibilities show that in the year 2000 it would be possible in practical production to obtain yields of 7 - 15 tons of dry matter per ha for energy grass, winter wheat and sugar beet. Even highex yields may be obtained if high-yielding crops suitable for production of biogas are chosen. Chemical analyses show that in addition to the energy raw products, also considerable amounts of by-products with different ranges of use are obtained in many cases, e.g. as feeds for domestic animals. Valuable chemical components can be used in technology as chemical raw products (7). The introduction of fuel crops on agriculural land naturally depends on the economic conditions. In a systems analytic approach the following issues have been penetrated: Can energy from agriculure compete with other alternatives? Is energy cropping competitive with food cropping ? How do energy crops from agriculture affect the national economy of Sweden? (8), (9). 7. REFERENCES (1) SHOEMAKER, D.N. (1927). The Jerusalem Artichoke as a Crop Plant. U.S.Dep.of Agr. Technical Bulletin No.33, https://www.w3.org/1998/Math/MathML"> - 32 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (2) STAUFFER, M.D. (1979). Jerusalem Artichoke - What is its Potential Inter-Energy 79. Proceedings. Agriculture. R3M 357 Manitoba, Canada Oct. 1979. XXITI: 1=5. (3) KOSARIC, N., COSENTINO, G.P., WIECZOREK, A. & DUVNJAK, Z. (1984). The Jerusalem Artnichoke as an Agriculural Crop. Biomass, https://www.w3.org/1998/Math/MathML"> 5 _ , 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 36 . (4) CHABBERT, N., BRAUN, Ph., GUIRAUD, J.P., ARNOUX, M. & GALZY, P. (1983). Productivity and Fermentability of Jerusalem Artichoke According to Harvesting Date, Biomass, 3,209-224. (5) CHUBEY, B.B. & DORELL, D.G. (1974). Jerusalem Artichoke, a Potential Fructose Crop for the Praries. Can. Inst. Food Sci.Tech.J., 7: 98-100. (6) GUNNARSON, S., MALMBERG, A., MATHISEN, B., THEANDER, 0., THYSELIUS, L. & WuNSCHE, U, (1985) Jerusalem Artichoke (Helianthus tuberosus) for Biogas Production. Biomass, 규: in print. (7) THEANDER, 0. (1985). Cemical Investigations in the Swedish Agrobioenergy Project. Third EC Conference Energy from Biomass, March 25-29,1985, Venice, Italy. PIII/208. (8) BERGMAN, K.-G. (1982). Energy from Agriculture - Economic Aspects. Swedish Univ. Agric. Sciences, Dep. of Economics and Statistics, Report no. 205. (9) GUNNARSON, S., HANSSON, K. & JOHNSSON, B. (1984). Economic Studies of Fuel Crops in Swedish Agriculture. Unpublished stencil. Dep.of Economics and Statistics, Swedish Univ. Agr. Sciences, o Box 7013 , S-750 7 Uppsala, Sweden. EPURATION DES EAUX ET PRODUITS DE HAUTE VALEUR TIRES DE LA JACINTHE D'EAU F.SAUZE Station d'Amélioration des Plantes - INRA, 9 place Viala 34000 - MONTPELLIER FRANCE 8. Summary The culture of waterjacinth, especially studied and practised in hot countries, is also possible under temperate climates, with yields of 30 to 50 tons/ha of dry matter, data which proceed from recent experiences in FRANCE. Wastewaters constitute a particularly convenient medium of culture, from a double economic and environmental point of view, and are efficiently depolluted by plants of this species. Study of feasibility shows that processes including proauction, methanization, and valorization of biomass with products contained in sludges of digestion, would be able to give an income competitive with these of conventional sources. 9. INTRODUCTION La culture de la jacinthe d'eau a été surtout étudiée dans les pays chauds, assez peu dans les climats tempérés ou froids. Or cette plante peut Y présenter un intéret tout aussi grand, car meme sous de tels climats ses potentialités se montrent souvent supérieures à celles d'autres espèces, notamment terrestres, tant pour la productivité que pour la composition chimique. En outre il semble possible, dans les régions tempérées, d'accroitre sa durée annuelle de végétation soit en recouvrant la culture d'un abri durant la mauvaise saison, soit en utilisant un réchauffage de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> eau à 1'aide de calories de récuperration. Cependant diverses expériences réaljaées en FRANCE au cours de ces dernieres années, à l'échelle de petits bassins pilotes, ont montré qu'en atmosphere naturelle et sous climat assez ensoleillé, on peut escompter une période productive de plus de six mois, permettant une production totale en biomasse seche superieure a celle de toute autre culture. En climat plus méridional ceux des pays méditerranéens par exemple, des rendements plus élevés encore pourraient etre obtenus. Compte tenu de ces résultats expérimentaux, des opérations pilote à échelle réelle sont actuellement entreprises, et une approche est tentée pour prévoir la faisabilité d'un système de culture et de valorisation. II. ESTIMATION DU POTENTIEL EN BIOMASSE ET DU POUVOIR EPURATEUR Sur le tableau I sont portéesles durées des périodes culturales et les productivités moyennes obtenues dans les principales expériences réalisees en FRANCE, à diverses latitudes allant de celle du littoral méditerranéen à celle de PARIS, les périodes de croissance s'étalant sur 6 à 7 mois, et la température de l'eau variant de 5 à https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Toutefois deux expériences, celles de l'E.D.F. (Electricité de FRANCE), et celle du C.E.N. (Centre d'Etudes Nucléaires) ont été effectuées en eau réchauffée par rejets thermiques. En conditions naturelles, on peut retenir une productivité probable de 15 à https://www.w3.org/1998/Math/MathML"> 20   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . de matière sèche (MS) par m2 et par jour dans les regions Nord, (Centre, Bassin Parisien, Loire) et 25 a https://www.w3.org/1998/Math/MathML"> 30   g / m 2 / J . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dans la zone méridionale. Ces valeurs correspondent à des rendements ì https://www.w3.org/1998/Math/MathML"> 1 ' hectare https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de 30 et https://www.w3.org/1998/Math/MathML"> 50 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . de MS environ, Des rendements plus élevés peuvent être espérés pour l'avenir, grâce à des améliorations génétiques de l'espèce, et à l'optimisation des méthodes culturales. Tableau Expériences de culture des jacinthes d'eau sur divers milieux en atmosphere naturelle. Winfluence du type de milien nutritif sur les rendements ne semble pas prépondérante, mais elle modifie comme on le verra la composition chimictie the végétal. Lit absorption par la plante des éléments constituant la pollution des eaux résiduaires urbaines a fait l'objet de nombreux essais, en particulier départ a ensemencer des bassins d'environ 20 m2, situés en bordure d'une station de lagunage, et ces premiers essajs se prolongent actuellement par une expérience de culture dans des lagunes réelles, avec https://www.w3.org/1998/Math/MathML"> 350   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de culture. Bien que les biomasses produites sous cette latitude soient un peu inférieures à celles de DISNEYWORLD en FLORIDE, les taux d'élimination des principaux polluants ont été au moins équivalents. III - POTENTIEL EN PRODUTTS CHIMIQUES ET EN ENERGIE. La composition chimique d'Eichhornia en fait une plante spécialement intéressante parmi les especes aquatiques. ta teneur en protéines de la biomasse produite en milieu eutrophe peut atteindre https://www.w3.org/1998/Math/MathML"> 35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> du poids sec, ces protéines renfermant plus de https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d'acides aminess essentiels pour https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> alimentation. Cependant certaines filières de valorisation plus complexes incluent 1' extraction d'autres produits, doués de pouvoir energétique par exemple, et fournissant un résidu ou un tourteau qui renferme sensiblement autant de protéines que la plante d'origine. La filière méthanique a été la mieux étudiee, aux ETATS-UNIS et en FRANCE notamment, avec des rendements en biogaz qui sont les plus élevés parmi ceux obtenus avec un substrat exclusivement végétal. La production potentielle d'un ha d'Eichhornia peut dépasser I5. ooo m3 de méthane à 1 'ha reorésentant une éneraie bien supérieure à celle d'l ha de culture alcooligène ( 4.000 l/ha). Le bilan énergétique reste supérieur à celui de la plupart des filieres de la biomasse. L'énergie pourrait être également extraite par d' autres filières de conversion, notamment celle des corps gras, qui constituent de 1,5 à 3 % de la matiere seche. Le tableau II indique les potentialités en huiles de la jacinthe d'eau ainsi qu'en protéines exploitables dans les tourteaux, en comparaison avec celles https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> autres especes aquatiques et de cultures actuelles sur sol. Le rendement a'Eichhornia serait superieur en huile a ceux des oléagi neux terrestres courants en climat tempéré https://www.w3.org/1998/Math/MathML"> ( 0,4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> à 1,5 t d'huile/ha https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et très largement superieur en protéines a ceux des meilleurs protéagineux telles que les léqumineuses : https://www.w3.org/1998/Math/MathML"> 15 t / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( contre 0,5 à 3 ). 10. Tableau II Rendements en matières grasses et en protéines de diverses plantes aquatiques ( climats tempérés). Les matières grasses d'Eichhornia sont surtout à base d'acides gras saturés et conviendraient à la fabrication de carburants, lubrifiants, savons, et produits divers d'industrie chimique. De très hautes teneurs en phosphore - jusqu'à 2,7% - ont été observées chez les plantes issues de nos cultures en eau résiduaires partiellement sous forme de produits de haute valeur telle que phospho-lipides. Pour l'obtention de carburants légers, les huiles brutes peuvent être estherifiées ou crackées, mais il serait également possible de les utiliser telles quelles dans certains moteurs diesel ou du type Stirling. Cependant le coût des huiles végétales, comparé à celui des hydrocarbures fossiles, pourrait être un obstacle à cette utilisation. Cesdivers produits riches se retrouvent encore, au moins partiellement, dans les digestats issus de la méthanisation. La concentration en matière sèche y est souvent supérieure à celle de la biomasse d'origine, ce qui. constituerait un avantage économique pour le traitement dans les huileries ou les usines d'aliments, et le bilan énergétique de la filière complète serait amélioré par: la production de biogaz. Une autre option consiste à utiliser le digestat comme compost agricole, dont la valeur fertilisante réside non seulement dans ses éléments nutritifs, mais en outre dans des stimulateurs biologique éqalement présent dans les jus de jacinthes d'eau. 11. III - FAISABILITE ECONOMIQUE Pour tenter de préciser la faisabilité et le coût du système, une étude chiffrée à été réalisée sur le modele suivant :

Unité de 10 ha de bassins d'épuration et de culture, application de la Eiliere : eau résiduaire urbaine https://www.w3.org/1998/Math/MathML"> → https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> méthane https://www.w3.org/1998/Math/MathML"> → https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> valorisation du digestat, avec 2 variantes . valorisation comme fertilisant ( compostage ). - valorisation comme aliment de bétail.

Population desservie par les bassins de culture - épuration : 20. ooo habitants.

La production de biomasse est de 500 tonnes MS/an, celle de biogaz de https://www.w3.org/1998/Math/MathML"> 150.000   m 3 / a n . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> On admet que les frais de personnel sont répartis par moitié, entre le fonctionnement habituel de la station communale pour lepuration et celui de la filière introduite. En échange, la commune bénéficie de la surprime encaissée ch fait de la qualité accrue de l'effluent Sortant. https://www.w3.org/1998/Math/MathML"> ( 0,25   F / m 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Une fraction du biogaz https://www.w3.org/1998/Math/MathML"> ( 20 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est auto-consommée. Les valeurs acmises pour les produits sont: biogaz https://www.w3.org/1998/Math/MathML"> 2   F / M 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Compost https://www.w3.org/1998/Math/MathML"> 300   F / t ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> aliment https://www.w3.org/1998/Math/MathML"> 4.000 E / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de protéine. On aboutit ainsi à un coût de la biomasse de https://www.w3.org/1998/Math/MathML"> 1.100   F https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> à la tonne de ms. Les bénéfices correspondants sont respectivement dans le cas de l'aliment et dans celui du compost de 824 et https://www.w3.org/1998/Math/MathML"> 17.4   F . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , assurant un temps de retour de sept ans environ dans le premier cas. Dimension nécessaire de I'unité de production en fonction du bénéfice escompté. Il est évident que ce bilan est fortement influencé par la dimension de l'unité pilote, correspondant à la population désservie. Le graphique ci-dessus montre les seuils dimensionnels permettant d'escomoter un niveau de rentabilité donné pour les deux options. Celle du compostage devient bénéficiaire pour une poputation d'au moins 10.000 à 15.000 eq. habitants, tandis que celle de l'aliment rapporte déjà près de https://www.w3.org/1998/Math/MathML"> 0 ,   F 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> par kg de MS. pour moins de https://www.w3.org/1998/Math/MathML"> 1000 e - h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . On constate que dans la mesure des disponibilités en capitaux et en terrain, il y a intérêt à accroitre la superficie cultivée, même au-delà du minimum qu'impose la seule finalité de l'épuration des eaux. Abstract On peut également penser, en vue d'accroitre la rentabilité, à traiter en mélange avec les jacinthes d'eau divers déchets urbains ou agroalimentaires, souvent disponibles en plus des eaux usees domestiques : boues d'épuration, ordures ménageres, déchets industriels liauides ou solides, grâce auxquels les équipements de conditionnement, transport, et méthanisation fonctionneront plus longtemps dans https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> année. Par ailleurs il n'est pas exclu d'envisager pour l'avenir une valorisation supplémentaire par le phytoplancton, qui offre souvent des potentia Iités non moins prometteuses que les plantes supérieures. Des progres notables restent toutefois à accomplir pour améliorer la faisabilité de sa Dans l'immédiat le système à macrophytes, même limité à son fonctionnement estival, apparait comme techniquement et économiquement réalisable. La culture sur les milieux nutritifs constitués par les eaux résiduaires et autres déchets paraît être la plus intéressante, grâce à la simplicité et au faible coût de revient par rapport à ceux des cultures en conditions artificielles telles qu'atmosphère contrôlée, effluents thermiques, nutrition par engrais du commerce. Le système peut facilement https://www.w3.org/1998/Math/MathML"> s ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> insérer dans les unités existantes de traitement des eaux de type classique ou du type lagunage, et il y aurait grand intérêt a l'adopter dans les futures stations BIBLTOGRAPHIE DINGES R. (1978) Upgrading stabilization pond effluent by waterhyacinth culture. Journ. Wat. Poll. Control. Fed, mai, 833-845 SAUZE F. (1983) Culture de jacinthes d'eau sur eau résiduaire. In " Valorisation de la jacinthe d'eau : EDF-DER, série A 3/4,27-33 CHATOU SAUZE F. (1983-1984) Croissance de la jacinthe d'eau en eau résiduaire urbaine, et effet épuratoire de la culture. Ecologia Mediterranea; T.IX, 3/4 55-77 et TX 3/4, 51-73 REDDY K.R. et SUTTON D.L. (1984) Waterhyacinth for quality improvement and biomass production. J. Environ. Qual. 13, 1, 1-6 WOLVERTON B.C. et Mac DONALD R.C. (1979). Upgrading facultative wastewater lagoons with vascular aquatic plants. Journ. Wat. Poll. Control, https://www.w3.org/1998/Math/MathML"> 51 n ∘ 2,305 - 213 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> AN INTEGRATED SYSTEM : MASS ALGAE CULTURE IN POLLUTED LUKE-WARM WATER FOR PRODUCTION OF METHANE, HIGH-VALUE PRODUCTS AND ANIMAL FEED. A. Legros_**, E. Dujardin https://www.w3.org/1998/Math/MathML">   ⋆ , F . C o l ⁡ 1 a r d * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , H. Naveau https://www.w3.org/1998/Math/MathML">   ⋆ ⋆ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , E.J. Nyns and C. Sironval https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . "Laboratoire de Photobiologie. Université de Liège. B.22, Sart Tilman. Belgique.

Unité de Génie Biologique. Université Catholique de Louvain. Place Croix du Sud, 1, Bte 9; B-1348, Louvain-la-Neuve. Belgique.

12. Summary An integrated cyclic system for mass algae culture has been set up. Its various processes, shown in figure 3 , include: (I) production of fuel, chemicals, animal feed; (II) recycling of wastes; (III) thermal and biochemical depollution; (IV) production of oxygen in the atmosphere and consumption of CO_ Biomethanation of Hydrodictyon algae with a second generation system, 2 phases, js -1 characterized by 1) high volumetric loading rates https://www.w3.org/1998/Math/MathML"> 12,5 c o d - 1 ⁡   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0,1951 C H 4 ⋅ g - 1 - 1 C O D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> introduced) higher than with classical system https://www.w3.org/1998/Math/MathML"> 0,175 c H 4 4   g - 1 C O D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4) reliable and stable digestion. The integrated, cyclic system will be further developed in a pilot of industrial size, aimed at optimizing the various variables involved and at demonstrating the integrated functioning of the whole.

PURPOSE OF THE WORK

The goal of our research was the setting-up of a cyclic integrated system which produces : 1.- fue1; 2.- high-value chemicals; 3.- feed for domestic animals and 4.- fertilizers, from macroalgae grown in luke-warm water of industrial origin.

RESULTS

A. Part I - Algae cultures Since 1978 the alga Hydrodictyon reticutatum has been grown in shallow lagunes irrigated by the polluted luke-warm water https://www.w3.org/1998/Math/MathML"> 20 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> coming out the cooling circuit of the nuclear power-plant at Tihange (Belgium) The culture has been extended progressively from https://www.w3.org/1998/Math/MathML"> 400   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> up to https://www.w3.org/1998/Math/MathML"> 2200   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; it will reach https://www.w3.org/1998/Math/MathML"> 1 h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in 1985 . The biological composition of the biomass has been continuously controlled. The algal biomass has been bioconverted into biogaz (fuel) in a two phase biomethanation process. Highvalue chemicals have also been extracted from the biomass. The by-products have been used as feed for animal breeding. The residues from animals and from biomethanation have been recycled into a pilot plant for intensive algae culture (18.000 liters). The heat contained in the luke-warm water was found to be able to increase the yield of the collected dry Hydrodictyon reticulatum biomass from 6-7 tons/ha year (non heated lagunes) up to 10 to 12 tons / ha year. The algae were fed with the mineral and organic components (including pollutants) of the River Meuse. The biological composition of the harvests has been well reproducible from 1979 to 1984 (fig.1); it was shown that Hydrodictyon was the dominant species, while Lemna and gastropods fluctuated between 2 to https://www.w3.org/1998/Math/MathML"> 36 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is 1983. The chemical composition of the biomass has shown a high content in minerals. These include mainly ca carbonate (due to the calcareous zone through which River Meuse is flowing upstream), and salts of k, Mg , S, I, https://www.w3.org/1998/Math/MathML"> N a , C u , Z n , H g , P b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Cd not detectable). The protein fluctuates between 16 to 25%; its lysine content https://www.w3.org/1998/Math/MathML"> ( cab % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is suitable for the feeding of 16 Lo https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; its lysdomestic animals. extracted from the biomass (yield around from the extraction were used to feed fishes and laying hens. The residues from animal breeding (manure) and from biomethanation of the algal biomass have been used as nutrients instead of mineral fertilizer in an intensive culture of microscopic algae (scenedesmus) and in a https://www.w3.org/1998/Math/MathML"> 132   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pilot plant. Fig. 2 shows the growth of Scenedesmus on mineral fertiliser (curve 1) and on the hen's dung (curve 2). The growth is very similar on both nutrient media. On the other hand, the meat of the fishes (Tilapias, chinese carps...) and of the hens is considered as excellent by customers, The eggs are of the best quality (the brown color of the shell is very attractive, the shell is very smooth and thick, the yolk is intense yellow, the white is very viscous). Fig. 3. the integrated system may be represented as follows : Part II - Biomethanation of Hydrodictyon algae in a second generation digestion system. A second generation digestion system has been set up at laboratory scale as a two-phase system on the basis of previous results. An active biomass accumulation has been developped in the second phase of the diges tion system by using an upflow anaerobic digester. The second main goal was to optimise the liquefaction and acidogenesis phase. For this, it was necessary to design a fermenter allowing good individual control of parameters. A.1. Design of the second generation digestion system. This system is composed of a percolation phase in which dissociation of hydraulic and solid mean retention times is possible. A continuous dilution of the liquid phase can be operated due to the sedimentation and flottation of the solid fraction and the possible preferential extraction of the liquid fraction. This liquid fraction contains the excess of the fermentation products of the liquefaction and acidogenesis phase and is brought to the methane producing active biomass of the second fermenter (the up-flow digester) by over-flow. The over-flow of the latter up-flow digester can be recycled as liquid of dilution for the first fermenter. This over-flow contains the excess active biomass which can be collected in a small decanter before the recycling of the liquid. The percolator is loaded with solid substrate on a semi-continuous basis. The liquid effluent of the system is withdrawn from the effluent of the un-flow digester. Two identical second generation digestion system were built and run in paralle at https://www.w3.org/1998/Math/MathML"> 20 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The evaluation of the biomethanation potentiality of the solid effluent of the percolator was done in a batch digester by filtration of the mixed liquor effluent of the percolator on a Wattman filter (rapid). Filtration cake is resuspended in water and introduced in a batch digester. A classical two phase biomethaqation system was run with a low volumetric loading rate https://www.w3.org/1998/Math/MathML"> B V : ± 1   gCOD . 7 - 1 . d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and long mean retention time https://www.w3.org/1998/Math/MathML"> ( θ = 56 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d) in order to give a reference for the yield of biomethanation. Table I: Global results obtained with the second generation digestion system Table II : Abbreviations, symbols and units https://www.w3.org/1998/Math/MathML"> - θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : mean retention time https://www.w3.org/1998/Math/MathML"> ( d ) , θ s : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mean solid retention time https://www.w3.org/1998/Math/MathML"> ( d ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A.2. Liquefaction and acidogenesis of Hydrodictuon a gae The yield of Tiquefaction increases respectively with the temperature while absolute yield of acidogenesis is decreasing. The initial rates of Iiquefaction and acidogenesis increase with the pH. Maximum rate of liquefaction appears at pH https://www.w3.org/1998/Math/MathML"> = 7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (10.78g coD. https://www.w3.org/1998/Math/MathML"> 7 - 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and maximum rate of acidogenesis at pH https://www.w3.org/1998/Math/MathML"> = 6.5 10.77 C O D . - 1 . d - 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The maximum yields of liquefaction and acidogenesis are observed at pH https://www.w3.org/1998/Math/MathML"> = 7.0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and are after 12 days of batch fermentation, https://www.w3.org/1998/Math/MathML"> 69 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1iquefaction) and https://www.w3.org/1998/Math/MathML"> 57 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (acidogenesis). Relative yield of acidogenesis is also maximum at pH = 7 https://www.w3.org/1998/Math/MathML"> ( 83 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . At a https://www.w3.org/1998/Math/MathML"> 11 p H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> values, acetate is the major product of fermentation and represents https://www.w3.org/1998/Math/MathML"> 58 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 56 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total products respectively at https://www.w3.org/1998/Math/MathML"> p H = 4.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 7.0. It only represents 338 of the former products at pH https://www.w3.org/1998/Math/MathML"> = 5.5 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In semi-continuous experiments at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a volumetric loading rate of https://www.w3.org/1998/Math/MathML"> 16   g C O D . 7 - 1 ,   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a solid retention time of https://www.w3.org/1998/Math/MathML"> 5   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be maintained in a percolator with a mean hydraulic retention time of https://www.w3.org/1998/Math/MathML"> 1.04   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a pH of the mixed liquor of 7.2. The yield of liquefaction ( https://www.w3.org/1998/Math/MathML"> g C O D S O ⋅ g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COD ) increases also with the volumetric loading rate. A. 3. Biomethanation of Hydrodictyon algae in a second generation digestion system. From Table I, it is shown that higher methane yields (Ycha/CoDo) can be obtained in the up-flow digester with higher yield of acidogenesis in the percolating step. This yield of acidogenes is is thus the limiting step in the up-flow digester. The evaluation of the biomethanation potentiality of the solid effluent of the percolator shows that the methane yield (ych4/CODo) decreases with the increase of efficiency of the second generation digestion system. The global results of the second generation digestion system compared with the reference are presented in Table I. These results show that this second generation digestion system can be run in a reliable way with a volumetric load of https://www.w3.org/1998/Math/MathML"> 12.50   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CODo. 1 . d 1 and a mean solids retention time of https://www.w3.org/1998/Math/MathML"> 5   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In those conditions, the methane yield obtained https://www.w3.org/1998/Math/MathML"> Y C H 4 / C O D 0 = 0.195 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1 C H 4 . g - 1 C O D 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) is greater than the yield obtained with the reference biomethanation system https://www.w3.org/1998/Math/MathML"> Y C H 4 / C O 0 = 0.174 C H 4 . g - 1 C O 0 O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The biomethanation is also more stable. 13. REFERENCES (1) LEGROS, A. , ASINARI DI SAN MARZANO, C.M., NAVEAU, H. and NYNS, E.J (1982). Fermentation profiles in bioconversions. Biotechnology Letters, 5(1), 7-12. (2) DUJARDIN, E., COLLARD, F., LEGROS, A. , ASINARI DI SAN MARZANO, C.M., NYNS, E.J. . NAVEAU, H. and SIRONVAL, C. (1983). Methane production by anaerobic digestion of algae. II. Production of algae. In "Energy from Biomass". Series E. vol. 5. Palz, W. and Pirrwitz, D. eds, Reide D Publishing Company. Dordrecht; Holland, 218-225. 14. Summary The properties of starch production and its fermentative degradation were investigated during growth of the unicellular green algae Chlorogonium elongatum and Chlamydomones reinhardii. Biomass and cellular starch were effectively produced during photoheterotrophical and heterotrophical growth at https://www.w3.org/1998/Math/MathML"> 28 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with 2 mM phosphate and 5 mM ammonium. The rate of starch fermentation depended on the plastidic starch content. The results gave evidence for the determination of the algal fermentation rate by parameters affecting plastidic starch activation e.g. the phosphate concentration within the chloroplast.

INTRODUCTION

The microalgae Chlorogonium elongatum and Chlamydomonas reinhardil effectively produce high value biomass during autotrophical, photoheterotrophical and heterotrophical growth. This biomass can be degraded by subsequent fermentation to energy-rich products e.g. acetete, ethanol, formate, glycerol, lactate, 2,3-butenediol and hydrogen (1). Recent investigations confined cellular starch as sole substrate for algal fermentation (2). However, this starch is known to be completely localized within the chloroplast of both algae. The all-over efficiency for the conversion of the biomass produced to energy-rich products is firstly dependent on the amount of starch synthesized and secondly on the parameters determining the rate of starch degradation within the whole cell or the algal chloroplast. The aim of this study is to elucidate the influence of aifferent growth perameters on the production of starch during continuous cultivam tion of Chlorogonium elongatum. Further analysis of starch degradation in whole cells and isolated chloroplasts from Chlamydomonas reinhardii will give evidence for the parameters determining the rate of starch degradation and thus the rate of algal fermentation. 15. EXPERTMENTAL Algal strain and cultivation. Chlorogoníum elongatum, L https://www.w3.org/1998/Math/MathML"> 12 - E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and Chlamydomonas reinhardii, https://www.w3.org/1998/Math/MathML"> 11 - 32 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , were obtained from the Sammlung fin Algenkulturen, Göttingen, FRG. Chlorogonium elongatum was continuously (4) and Chlamydomonas reinhardii synchronuously (2) cultivated under axenic conditions. Cellular prameters. The determination of biomass (D.W.) and of the cellular content of starch, protein, lipids and of chlorophyll followed the methods given in reference (5). Fermentation. The incubation procedure for the fermentative degradation of cellular stareh resembled that described elsewhere https://www.w3.org/1998/Math/MathML"> ( 2,3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Potassium phosphate https://www.w3.org/1998/Math/MathML"> ( 50 m M , p H 6.8 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was replaced by https://www.w3.org/1998/Math/MathML"> 50 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Hepes ( https://www.w3.org/1998/Math/MathML"> p H 6.8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) in cases, where the influence of phosphate on the fermentation was investigated. Chloroplast preparation. Intact chloroplasts were isolated from protoplasts of Chlamydomonas reinhardii as described earlier (3). Cross contamination with mitochondria or cytoplasm was judged from the activities of phosphoenolpyruvate carboxylase (cytoplasm) and cytochrom c oxidase (mitochondria), respectively. The intactness of chloroplasts wes proofed by the ferricyanid dependent Hill reaction and inspection by electron microscopy The isolated chloroplasts photosynthetically fixed co with a rate of 46.8±7.0 umol https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mg https://www.w3.org/1998/Math/MathML"> C h l - 1   h ± https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The content of dihydroxyacetone phosphate and 3-phosphoglyceric acid was estimated as given in (6). 16. PARAMETERS INFLUENCING STARGH PRODUCTION Growth rate. Biomass production increased during light limited photor heterotrophical growth from 0.227 i https://www.w3.org/1998/Math/MathML">   - 1   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at an irradiance of 0. 371 w m up to itg maximum of https://www.w3.org/1998/Math/MathML"> 3.179   g 1 - 1   d - 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 5.76 w m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. The composition of cellular dry matter did not change with increasing irradiance and remained constant with 57.3 protein, https://www.w3.org/1998/Math/MathML"> 14.9 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> starch and 5.0 % lipids. During oxygen 1.1mited heterotrophical growth the deily biomess gutgut increased from https://www.w3.org/1998/Math/MathML"> 0.78   g - 1   d 2 a t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a flow rate of https://www.w3.org/1998/Math/MathML"> 0.1   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 1.89   g l - 1   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at a flow rate of https://www.w3.org/1998/Math/MathML"> 18.01   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In contrast to light Iimited growth the content of cellular protein decreased from 60 % to https://www.w3.org/1998/Math/MathML"> 52 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and that of starch increased from https://www.w3.org/1998/Math/MathML"> 10.4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively, whereas lipids remained constant at https://www.w3.org/1998/Math/MathML"> 3.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dry metter. The date for meximum production rate are compiled in Table I, which shows the production of important amounts of starch even under heterotrophical dark conditions. 17. Table I MAXIMUM PRACTICAL BIOMASS PRODUCTION BY CHLOROGONIUM ELONGATUM DURING CONTINUOUS HETEROTROPHIC (DARK) AND PHOTOHETEROTROPHIC (LIGHT) CULTIVATION. During heterotrophic conditions muximum biomass production yielded with an aeration rate of https://www.w3.org/1998/Math/MathML"> 18.0   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at a specific growth rate of O.22 h During photoheterotrophical cultivation maximum biomass production was ob tained with an irradlance of https://www.w3.org/1998/Math/MathML"> 5.76 w w - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at spectfic growth rate of https://www.w3.org/1998/Math/MathML"> 0.22   h - 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fraction Maximum Production Rate https://www.w3.org/1998/Math/MathML">   heterotrophic   m g 1 - 1   d - 1   photoheterotrophic   m g 1 - 1   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Biomass (D.W.) 1870.0±28.4 3179.0±47.6 Protein 1037.6±24.9 1818.4±27.3 Starch 387.5±7.4 473.6±9.1 Lipids 66.2±3.5 159.0±0.9 Temperature. The temperature of algal cultivation influenced the cellular starch content during photoheterotrophical growth of Chlorogoniun https://www.w3.org/1998/Math/MathML">   elongatum   _ ( F i g ⋅ A ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Therefore optimum biomass production, which was found at https://www.w3.org/1998/Math/MathML"> 40 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , did not coincidenced with the maximum of starch production at https://www.w3.org/1998/Math/MathML"> 28 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . With temperatures higher than https://www.w3.org/1998/Math/MathML"> 41 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> algal cells lost the https://www.w3.org/1998/Math/MathML"> 1 r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> chlorophyll and no growth further persisted. Phosphate and ammonium. Optimum biomass and starch production rates resulted with phosphate concentrations as low as https://www.w3.org/1998/Math/MathML"> 2 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Further increase in phosphate up to https://www.w3.org/1998/Math/MathML"> 30 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> only caused minor changes in yield and in the cellular composition of dry matter. Fig. 1. The influence of temperature https://www.w3.org/1998/Math/MathML"> ( A ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and ammonium https://www.w3.org/1998/Math/MathML"> ( B ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the production rate of biomass ( ) and of cellular protein https://www.w3.org/1998/Math/MathML"> ( 0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , starch ( https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and lipids ( Δ ) during photoheterotrophical growth of https://www.w3.org/1998/Math/MathML">   Chlorogonium elongatum.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In contrast, with varying ammonium concentrations from https://www.w3.org/1998/Math/MathML"> 0.2 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 50 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a more pronounced effect in biomass, protein and lipids were observed (Fig. 1B). Nevertheless, starch output was hardly stimulated by increasing ammonium concentrations https://www.w3.org/1998/Math/MathML"> ( 0.2 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 8 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and significantly droped with ammonium higher than https://www.w3.org/1998/Math/MathML"> 10 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 18. STARGH DEGRADATION Cellular starch content. The fermentative starch degradation depended on the cellular starch content in cells of Chlamydomonas reinhardil (Fig. 2A) yielding in a typical saturation kinetics. From the double reciprocql plots (Fig.2A, insert) an apparent K of https://www.w3.org/1998/Math/MathML"> O . 38 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hmol glucose unit mg Chl https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> resulted. The maximum theoretical rate of starch degradation was determined to 1.8 \mumol glucose units mg Chl https://www.w3.org/1998/Math/MathML">   - 1   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In whole cells. Starch content of the chloroplast. The isolation of chloroplasts with a high starch content appeared extremely difficult due to the fragility of this large organell. Therefore the starch content per mg chlorophyll was lower in the intact, isoleted chloroplasts than in whole cells (Fig. 2B). Nevertheless, even under these conditions the rate of starch degradation depended on the actual plastidic starch content and showed saturation kinetics. The corresponding kinetic data for plastidic starch degradation were https://www.w3.org/1998/Math/MathML"> K m = 3.8 μ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mol glucose units https://www.w3.org/1998/Math/MathML"> m g C h l - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> V m a x = 1.4 μ m o l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> glucose units mg Chl https://www.w3.org/1998/Math/MathML"> - 1.8 μ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mol glucose units mg Chl the and https://www.w3.org/1998/Math/MathML"> m a x = 1.4 μ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mol Phosphate. The fermentative starch degradation was not affected by varying extracellular phosphate concentrations from https://www.w3.org/1998/Math/MathML"> 0.2 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 20 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in whole cells of Chlamydomonas reinhardii (Fig.3, A). In contrast, starch catabolism of isolated chloroplasts clearly depended on the addition of of phosphate. Saturation pattern resulted with increasing phosphate from Fig.2. The dependency of starch de- gradation on the stareh onntent in (A) whole cells and (B) isolated chlo- roplasts from Chlamydomones reinhardit. https://www.w3.org/1998/Math/MathML"> 0.2 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 5 m M ( F i g . 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , ). Nevertheless, the observed K of https://www.w3.org/1998/Math/MathML"> 0.42 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pointed to the necessity of only low phosphate concentrations to yieldoptimum rates in stsrch degradation optimum rates in starch degradation. Products of anaerobic starch degradation. In whole cells aneerobically degraded starch carbon could be balanced by 96 % in the analyzed products formate, acetate, ethanol and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Teble II). Main products of the anaerobic starch degradation in isolated chloroplasts were dihydroxyacetonephosphate and 3-phosphoglyceric acid, which both accounted for 7/ 㸓 of the catabolized starch carbon (Table II). In contrast to the results with whole cells no fermentation produets could be detected during anaero bical starch mobilization in the chloroplast. 19. CONCLUSIONS Optimum conditions for the production of cellular starch differs from that for maximum biomass production in unicellular green algae. Nevertheless, the high yields in starch synthesis during heterotrophic and photoheterotrophical cultivation offers the advantage for a low cost production of fermentable biomess on waste water in the dark and in the ilght. The rate of algal fermentation is determined by the rate of cellular starch degradation. The failure of a fermentative starch metabolism in isolated chloroplasts rules out an regulatory function of the fermen- Table II ANAEROBIC STARCH DEGRADATION IN WHOLE GELLS AND ISOLATED CHLOROPLASTS FROM CHLAMYDOMONAS REINHARDII. Cells were incubated in https://www.w3.org/1998/Math/MathML"> 50 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> potassium phosphate (pH 6.8) and chloroplasts in https://www.w3.org/1998/Math/MathML"> 50 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Hepes (pH 6.8), containing https://www.w3.org/1998/Math/MathML"> 120 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mannitol, https://www.w3.org/1998/Math/MathML"> 5 m M P , 1 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> M n C l 2 , 1 m M M g C l 2 , 2 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> EDTA. Aliquots https://www.w3.org/1998/Math/MathML"> ( 200 μ g C h l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were gased with argon for 90 min and incubated for https://www.w3.org/1998/Math/MathML"> 1   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 25 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Starch is given in glucose units. Products Cells Chloroplasts https://www.w3.org/1998/Math/MathML"> μ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mol https://www.w3.org/1998/Math/MathML"> m g C h l - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> μ m o l m g C h l - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Starch 1.30 7.80 0.68 4.08 Formate 2.34 2.34 0.00 0.00 Acetate 1.31 2.62 0.00 0.00 Ethanol 1.20 2.40 0.00 0.00 https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.09 0.09 0.05 0.05 https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.10 0.10 Dihydroxyacetone phosphate https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.48 1.44 3-Phosphoglyceric acid https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.53 1.59 sum 7.45 3.08 C analyzed 0.96 0.76 tation pathway itself and points to a rate limiting step involved during plastidic starch activation.

RFFFRENCES

(1) KLEIN, U., KREUZBERG, K. and BETZ, A. (1981). Chemicals produced by unicellular green algae in anaerobiosis. Adv. Biotechnol., Vol II , pp. 97-100. (2) KREUZBERG, K. (1984) Starch fermentation via formate producing pathway in Chlamydomonas reinhardii, Chlorogonium elongatum and Chlorella fusca. Physiol. Plant. 61,87-94. (3) KREUZBERG, K. https://www.w3.org/1998/Math/MathML"> ( 1984 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Evidences for the role of chloroplast in algal fermentation. Adv. Photosyn. Res. Vol III, pp. 437-440 (4) KRFUZBERG, K, and HFMPFLING, W.P. (1981). Properties of the green alga Chlorogonium elongatum during light limited continuous culture in the Phauxostat. Adv. Biotechnol., Vol I, pp. 287-293. (5) REZNICZEK, G. and KREUZBERG, K. (1984). Carbon and energy balance during continuous algal growth. Adv. Photosyn. Res., Vol III, pp. 395-398. (6) WIRTZ, W., STITT; M. and HELDT, H.W. (1980). Encymic determination of metabolites in the subcellular compartments of spinacea protoplasts. Plant Physiol. 66, 187-193. POTENTIALITES DE PRODUCTION DE BIOMASSE AQUATIQUE DANS LES IAGUNES D'EPURATION M. VULILOF, J. BARBE et Coll. CFMAGREF Division Qualité des Eaux, Pêche et Pisciculture 3,Quai Chauveau - 69009 - LYON 20. Résumé Les lagunes d'épuration sont le siège d'une importante production vivante, sous-produit de la transformation de la charge polluante traitée. Un programme d'étude sur sites réels, visant à préciser les conditions de production de cette biomasse a été engagé. Ont été suivies simultanément les performances d'épuration des installations, l'évolution qualitative et quantitative du phytoplancton et les cinétiques de croissance des macrophytes flottants. Ont été mises en évidence la valeur en moyenne élevée et les variations importantes dans le temps de la biomasse algale présente. La production de lemnacées et 1 ' exportation possible de nutrients par récolte des végétaux ont été quantifiées. Des régles de gestion compatibles avec le maintien des performances d'épuration ont été proposées. Sont présentés ici les résultats relatifs à un des lagunages qui ont été étudiés. 21. 1.- PRESENTATION Le layunage naturel est un procéde de traitement des eaux résiduaires. Les installations sont constituées d'une série de bassins peu profonds (lagunes) dans lesquels s'opére une dégradation bactérienne, essentiellement aérobie, des matières organiques. L'oxycëne nécessaire à cette dégradation provient de l'activité photosynthétique des organismes chlorophylliens qui se développent dans les bassins. Ceux-ci assimilent également une part des éléments minéraux dissous. Un dẹpot organique se forme progressivement dans le fond des bassins, par sédimentation des matières en suspension contenues dans les eaux usées et des biomasses mortes. Il concentre la plus grande partie du flux de matière entrant dans https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> installation. Ie reste se retrouve, largement transformé, dans la pleine-eau et dans l'effluent, sous forme dissoute ou particuIaire (déchets, bactéries, alques, zooplancton) Ces prodults de transformation des charges polluantes, plus diversifiés que dans les stations d'épuration classiques, représentent un potentiel dont les conditions de valorisation méritajent d'être étudiées, en liaison avec l'augmentation rapide, en France, du nombre des installations de lagunage naturel en service. Un programe particulier d'étude des conditions de production des biomasses planctoniques et macrophytes a ainsi été entrepris par le CEMAGREE avec le concours incitatif de l'Agence Française pour la Maitrise de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Energie. Est présentée ici une synthèse des résultats obtenus sur une des installations qui ont étê étudiées dans le cadre ce de progranme. Ie suivi, conduit sur une période de 3 ans, de 1980 à 1983, s'est attaché à caractériser le fonctionnement du laqunage, les bionasses et la production algales, les populations zooplanctoniques et les conditions de production et de récolte de végétaux flottants (Lemnaceae) colonisant les bassins. 2. - CARACTERISTIQUES ET CONDITIONS DE FONCTIONNEMENT DU LAGUNAGE DE CHAUCERNE (IIG. 1 ) https://www.w3.org/1998/Math/MathML">   t r a i t e r   l e s   e a l u s   u s e s e s   d e n e s t i c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> traiter les eaux uses domestiques diun village de 500 habitants. Elle a été mise en service en avril 1980. Ses principales caractéristiques de conception et de dimensionnement sont présentées à la figure 1 ci-après. Les eaux acheminées par le réseau d'assainissement sont pompées dans un poste de relevement, et admises sans traitement préalable en tête de la premierre lagune. Peu après la mise en service, les bassins se sont trouvés colonisés par plusieurs espëces de lentilles d'eau. Les conditions de fonctionnement ont été appréciées principalement sur la base de cing camparnes de mesure, d'une durée de 24 à 48 heures, entre mai 80 et juillet 83 , permettant la collecte et l'analyse d'échantilions moyens et l'enregistrement de paramètres caractéristiques (débits, oxygène dissous et température dans les bassins).L' installation reçoit une charge polluante à peu prês constante et égale en moyenne à https://www.w3.org/1998/Math/MathML"> 13   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DCO/jour (5kg DBO/jour), soit environ 208 de sa charge nominale. Toutefois, les débits à https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> entrée présentent de grandes fluctuations, en raison du caractère pseudoséparatif et drainant du réseau d'assainissement : pour une charge hydraulique nominale de https://www.w3.org/1998/Math/MathML"> 75   m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> jour, les valeurs mesurées varient de https://www.w3.org/1998/Math/MathML"> 45   m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> jour en période séche (juin 1981) à plus de https://www.w3.org/1998/Math/MathML"> 370   m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> jour (janvier 1982). En période trẽs pluvieuse, les pompes de relèvement ne peuvent suffir à évacuer l'ensemble des débits, et les lagunes peuvent être by-passées. A partir des enregistrements pluie/débit réalisés, la charge hydraulique moyenne sur une année peut être estimée a environ https://www.w3.org/1998/Math/MathML"> 120 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de la charge nominale. Les performances d'êpuration et la qualité de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> effluent rejeté dans le milieu naturel sont fortement influencée par le développement des lentilles d'eau : les lagunes présentent un fonctionnement satisfaisant lorsque ces vëgétaux sont absents (mai 80 , aout 80 , janvier 82 ), ou lorsqu'ils sont récoltés avant 1'apparition d'un pallier de production. Dans ces conditions, les abattements moyens sont sur les flux entrants, de https://www.w3.org/1998/Math/MathML"> 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pour la DCO et les MES, https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur 1'azote kheldahl et https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur le phosphore total. En revanche, lorsque les lentilles a'eau ne sont pas récoltées à temps, la présence d'un couvert végétal dense finit par obérer le fonctionnement des laqunes : les analyses traduisent une oxydation tràs faible des compose laniques et un pH inférieur a la normale. Le traitement est également perturbé par les relargages d'éléments réduits consécutifs aux variations du poten. tiel d'oxydo-réduction au niveau du sédiment. Le résultat global est un rejet dont les caracteristiques chimiques sont proches de celles de l'effluent à l'entrée. 22. 3.- BIOMASSE EF PRODUCTION ALGALES DANS IES IAGUNES (fIG.2 Ies populations algales ont été observées à un rythme hebdomadaire : identification et cotation en abondance relative des espëces présentes, dosage des pigments chlorophylliens (méthode SCOR UNESCO), et évaluation de la production primaire (méthode STEEMAN NIEISEN). 22 taxons se développent avec abondance dans Ll ( 26 dans Li3). Ils appartiennent essentiellement aux chlorophycées (L1 : 548; L3 : 38%) et aux Euglénophycées (L1 : https://www.w3.org/1998/Math/MathML"> 41 ∘ ; L 3 : 308   Les diatamophyc é es sont pr é sentes dans   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> L 3 (198). Les cyanophycées sont peu représentées. Ces taxons se regroupent en 4 peuplements principaux sur LI (5 sur Li3) qui se succèdent dans le temps. L'optimum de développement d'un peuplement correspond à un maximum de bicmasse présente dans les bassins (jusqu'a https://www.w3.org/1998/Math/MathML"> 2285 m g c h l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a.m https://www.w3.org/1998/Math/MathML">   - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur Ll et https://www.w3.org/1998/Math/MathML"> 3200 m g ⋅ m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur L3; Il s'agit dans les deux cas d'un peuplement dominé par Chlamydomonas sp.) Le passage d'un peuplement à un autre se traduit par une baisse importante des concentrations. La succession des peuplements est liée principalement aux variations des paramëtres abiotiques (dilution plus ou moins importante de la charge entrante) et dans un second temps aux conditions météorologiques. Ces facteurs, lorsqu'ils varient rapidement, modifient également la dymamique de chaque peuplement. Les lentilles d'eau, lorsqu'elles recourrent complétement les bassins, favorisent le développement de bactéries hétérotrophes au détriment des algues : par exemple, celles ci disparaissent complétement dans Ll du 5 au 12 aoat 82 (densité des lemacées : https://www.w3.org/1998/Math/MathML"> 6   k g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) pour recoloniser rapidement le milieu dès la récolte. La prédation par le zooplancton provoque également d'importantes fluctuations de la biamasse présente : par exemple, en mars 82 , un développement de Daphnies dans li se traduit par une baisse de plus de 90 & de la bicmasse algale en une semaine (de 300 a https://www.w3.org/1998/Math/MathML"> 20 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> chl.a. https://www.w3.org/1998/Math/MathML"> m - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). En moyenne annuelle, la biamasse algale présente des valeurs élevées décroissantes du ler au 3ème bassin (de 250 a https://www.w3.org/1998/Math/MathML"> 150 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> chl.a. https://www.w3.org/1998/Math/MathML"> m - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), mais elle se caractérise surtout par une forte instabilité. La production primaire maximale peut être très importante lorsque la biamasse est élevée (jusqu'a https://www.w3.org/1998/Math/MathML"> 3700 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C.m https://www.w3.org/1998/Math/MathML"> 3 . h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Les profils verticaux sont typiques des milieux chargés, avec un maximum en surface, et une diminution rapide en profondeur; en été l'épaisseur de la zone trophogene est inférieure a 30cm. 23. 4. - CROISSANCE ET PRODUCTION DES IENTILLES D'EAU (Fig. 3 et 4) Les lemmacées ont colonisé spontanément les lagunes, dês 1980 sur L 3 (Lemna minor) et à partir de 81 sur Ll (peuplement daniné par https://www.w3.org/1998/Math/MathML"> L . g i b b a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) L'évolution des macrophytes a été étudiée en 81,82 et 83 par êchantillion nage hebdamadaire, et pesée de la totalité des végétaux lors des récoltes. En 81 , les lentilles d'eau sont récoltées chaque fois qu'elles recouvrent la totalité de la surface des lagunes ( 3 récoltes sur Ll; 4 sur L3); en 82 la récolte est réalisée lorsqu'est atteint un pallier de production, avant la sédimentation des plantes (1 récolte sur chaque lagune); en 83, 1'évolution est suivie sans interventions. La période de végétation s'étend de mai à octobre. En début de saison, la croissance est exponentielle. En absence de récolte, elle atteint un pallier après environ 60 jours. Les végétaux carmencent alors à se nécroser, puis a sédimenter et les courbes de croissance présentent un aspect irrégulier. En 82, la biamasse maximale mesurée a ce stade est de https://www.w3.org/1998/Math/MathML"> 6   k g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur Ll et https://www.w3.org/1998/Math/MathML"> 3,5   k g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur https://www.w3.org/1998/Math/MathML"> L 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( en poids frais). Elle dépasse https://www.w3.org/1998/Math/MathML"> 7   k g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sur L3 en 83 , en liaison avec des conditions climatiques estivales exceptionnelles (au mois de juillet : température moyenne de l'air : https://www.w3.org/1998/Math/MathML"> 24 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; précipitations : 26m, les valeurs moyennes sur 35 ans étant https://www.w3.org/1998/Math/MathML"> 18 , 7 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et https://www.w3.org/1998/Math/MathML"> 79 mm https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . En 1981, la réalisation régulière d'opérations de récolte permet de maintenir une croissance exponentielle durant tout l'été. A l'autanne, les conditions climatiques (vent et precipitations) deviennent limitantes et perturbent fortement le développement des végétaux. Le tableau de la page ci-aprës résume les dornées relatives à la production récoltable. L'évolution des teneurs des végétaux en composés azotés et phosphorés a été suivie en 1983 . L'azote se trouve sous forme organique (85%) ou ammoniacale https://www.w3.org/1998/Math/MathML"> ( 15 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Les concentrations maximales ont été mesurées sur lespeuplements jeunes (age compris entre 10 et 40 jours). L'azote "kjeldahl" représente alors 78 du poids sec. Cette teneur décroit ensuite avec l'age des peuplements et https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> état physiologique des végétaux, jusqu'à des valeurs de l'ordre de 48 du poids sec. Le phosphore est également présent sous forme organique (36%) et minérale (64%). Les teneurs apparaissent relativement stables : le phosphore total represente l, https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cu poids sec et les ions orthophosphate 0,98 . Selon les teneurs en N et P et les courbes de croissance peut être déterminée la date de la récolte qui permet l'exportation maximale de nutrients. Sur la lagune t.3, en 1983 , celle-ci se situe aprës 60 jours de croissance. Ia biamasse en place représente alors https://www.w3.org/1998/Math/MathML"> 2,3 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . de matière séche/ha, et sa réColte permet l'exportation de https://www.w3.org/1998/Math/MathML"> 125   k g N k / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et https://www.w3.org/1998/Math/MathML"> 30   k gP https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> total/ha (voir fig.4). 5.- CONCLUSION. Compte tenu des fluctuations importantes et des difficultés de récolte de la biamasse algale, les macrophytes apparaissent came la principale biomasse exploitable. Dans le cas des lentilies d'eau colonisant spontanement les lagunes, la récolte périodique des végétaux est à la fois compatible avec l'épuration, et nécessaire au maintien des performances de l'installation. Elle permet de plus une exportation significative de nutrients et évite un vieillissement accéléré des lagunes par sédimentation des plantes a https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> autome. Ainsi les opérations de récolte peuvent pour une part s'intégrer aux taches normales de maintenance. Une valorisation des produits permettrait d'en réduire le cout global. Ie caractére dispersé de ce type de production et la faible taille moyenne 'des lagunes d'epuration ne semble toutefois permettre actuellement que des valorisations locales, selon des circuits courts a faible valeur ajoutée. 24. PRTNCIPALES REFERENCES BIBLIOGRAPHIQUES BARBE J. (1981) - Les peuplements planctoniques des installations de lagunage en France.C.R.Congr. Int. Phytoépuration. Parme (Italie), 15-16 mai 1981. p. 321-329 BOUTIN C. (1983) - Les Macrophytes : leur rôle dans I' épuration des eaux usées; étude sur site réel de l'exportation d'éléments nutritifs par les lentilles d'eau. Mémoire ENSP-CEMAGREF, Sept.83, 105p. CEMAGREF (1984) - Biomasse dans les lagunes d'épuration. Rapport AFME, mai https://www.w3.org/1998/Math/MathML"> 84,45 p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . STEINER B (1984) - Sur I'utilisation du phytoplancton pour la caractérisa tion des installations de lagunage naturel. Thèse doc. 3ème cycle. Bio. Végt. juillet https://www.w3.org/1998/Math/MathML"> 84.225 p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . VUILLOT M (1982) - Biamasse végétale récoltable dans les lagunes d'épuration de Chaucenne(Doubs). Actes du séminaire des contractants AFME, Sophia Antipolis - 27 mai 1982 . Fig.1 : Lagunes de CHAUCENNE. Vue en plan et coupes Fig.2 : Evolution des teneurs en chl.a et des peuplements dans Li Fig. 3 : Courbes de croissance des lentilles d'eau. PRODUCTION OF ALGAL BIOMASS IN VENICE LAGOON, GUTDO MISSONI MARIO MAZZAGARDI AGIP S.p.A. - ROME (ITALY) C.S.A.R.E. - VENICE (ITALY) Abstract INTRODUCTION AGIP and C.S.A.R.E. have carried aut a study, which has followed an erpirical approach in the attempt of defining canditions and parameters useful to the assessment of: a) partial harvesting of macroalgae in ander to control the amount of biomass present in the lagoon; b) transforming, via anaerobic digestion, algal biantass into valuable products (biogas and materials for agriculture) and at the same time renoving nitrogen and phosphorus from the lagoon. A - MACROALGAE PRODUCTION UNER PERIODICAL YEARLY HARVEST The algal growth follows a typical seasonal cycle. Only occasionally the concentration of algae reaches https://www.w3.org/1998/Math/MathML"> 40 ÷ 50   k g / m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Macroalgae species are Ulva Rigida, Gracilaria Confervoides, Craetomorfa Aerea and Valonia Aegrophila. As climatic conditions improve, vegetation expands, different soecies succeed to cne another, Ulva Rigida is the cne that finally obtains the langest diffusion and density https://www.w3.org/1998/Math/MathML"> 15 K g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The regrowthing time of macroalgae after harvest has been investigated in a small fenced aerea: the biomass doubling time is 3÷5 days when optimal enviromental parameters f have been adopted. Sempling of macroalgae density through the lagoon has indicated the areas where anounts of incustrial relevance could be harvested and where such a harvesting could be beneficial to the envirorment. The areas are listed in the following table: MACROALGAE IN LAGOON 25. B - MACROALGAE HARVESTING Harvesting must not be harmful to the ecosystem; specifically, it must not inpair the possibility of repeated harvest, year after year. The harvesting must be carried out so that the cost of algal bionass be minimal: it must be canpatible with algae regrowing. In the program two problens have been considered: design of a harvesting boats and harvesting procedure. A special type of boat has been designed. With such a fleet of boats and berges it could be possible to harvest in 50 days the area in the central basin where available algal density is at least https://www.w3.org/1998/Math/MathML"> 5   k g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This area has an extension of about https://www.w3.org/1998/Math/MathML"> 35 K m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 26. C - PRETREATMENT OF ALGAL BIOMASS It is useful to pretreat the algal biomass before feeding it to a digester. In fact while the cell liquids are easily digested, the cll walls rich in cllulose and lignine resist digestion and present a good yield of the process if not properly fragnented. Different treatments have been tested: a) grinding, pressing and fractional wet pressing, in order to separate a liquid fraction containing most of the digestable matter fram a residue consisting of cellulose material (cell walls); b) hamogenization of the algal biomass in order to produce a fluid in which the cells are broken and cell walls reduced to small fragnents. only the last ane gave satisfactory results. After homogenization of algal biamass it is convenient to check the possibility of separating it in to a "liquid fraction" to be digested with fix bed digestors and a "solid fraction" to be fed to continuous stirred reactors or to be gasified. To achieve this separation the homogenized algal biomass is centrifuged. Analysis of harvested and dripped algae, of hamogenized fluids and of liquid and solid fractions gives the following informations: - a) To homogenize the algae in equal amount of water must be added. -b) The solid fraction, by weight, accounts for abount https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the hono genized biomass. https://www.w3.org/1998/Math/MathML"> - c ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The original content of total and volatile solids of the algal biomass is shared at about https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> between the two fractions. https://www.w3.org/1998/Math/MathML"> - d ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The ratio https://www.w3.org/1998/Math/MathML"> BO D 5 / COD https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , taken as an indicator of biodegradable onganic matter, increases in the liquid fraction and decreases in the solid cne. https://www.w3.org/1998/Math/MathML"> - c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) Dry matter in the solid fraction is made of: https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ashes and https://www.w3.org/1998/Math/MathML"> 62 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volatiles. The volatile composition is: fats https://www.w3.org/1998/Math/MathML"> 21 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , lignine https://www.w3.org/1998/Math/MathML"> 27 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , cellulose fiber https://www.w3.org/1998/Math/MathML"> 5 % % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Dry matter in the algal bionass, cnly washed after harvest, contains: ashes https://www.w3.org/1998/Math/MathML"> 24 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 76 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volatile solids, whose carlposition is carbohydrates + fats = 35%, lignine https://www.w3.org/1998/Math/MathML"> = 11.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , cellulose fibers https://www.w3.org/1998/Math/MathML"> 61 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These figures indicate that to a great extent hamogenization breaks the algal cells leaving fibrous structures and cell inner fluids separated ard that the ensuing centrifugation actually enriches the solid fraction with cellulose and lignine fragnents, leaving a liquid fraction which contains anly about 50% of original volatile matter but probably the most digestible one. 27. D - ANAEROBIC DIGESTION OF PRETREATED MACROALGAL BIOMASS It has been found necessary to carry out direct measurenents of the relevant parameters of macroalgae anaerobic digestion in order to check: https://www.w3.org/1998/Math/MathML"> - a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) Actual possibility of digesting pretreated macroalgae or fraction thereof with fix bed as well as stirred reactors. -b) Definition of process parameters at pilot plant scale. After several runs at laboratory scale, a https://www.w3.org/1998/Math/MathML"> 5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stirred reactor and a 301 fix bed reactor have been used with the following results: a) homogenization plus centrifugation actually transfer https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the easily digestable organic matter from algal biomass to the liquid fraction. -b) The liquid fraction is more easily digestable. https://www.w3.org/1998/Math/MathML"> - c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) The stirred reaction pilot plant has been rm with a load of https://www.w3.org/1998/Math/MathML"> 5.25 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> total solid/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reactor/d, HRT https://www.w3.org/1998/Math/MathML"> = 12 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> days, terp. https://www.w3.org/1998/Math/MathML"> = 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , yield https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> = 0.27 N m / K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TS or https://www.w3.org/1998/Math/MathML"> 0.36 N m 3 / K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volatile solids. https://www.w3.org/1998/Math/MathML"> - d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) The fix bed reactor has performed quite well digesting the liquid fraction. https://www.w3.org/1998/Math/MathML"> H R T = 0.88 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , load up to https://www.w3.org/1998/Math/MathML"> 36.7   k g I S / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> 15.2   k g V S / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with https://www.w3.org/1998/Math/MathML"> 30,000 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> ∞ 00 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> have been tested. -e) Deprimental effects od inhibitars (C1, https://www.w3.org/1998/Math/MathML"> S O 2 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 2 S) have been kept to such a minimum as not to inpair good yields. All these results show that anaenobic digestion of pretreated macroalgae is feasible although further data are needed for the industrial plant. A great problem of such a plant is the disposal of wastes. 28. E - OUTLINE OF THE INDUSTRIAL PROCESS Two possible solutions have been devised. First solution: after harvest and homogenization the algal biomass is fed to stimed reactors, the effluents of which are centrifuged. The solid fraction is dried and used as amendant. The liquid fraction is sent to the Mestre (Venice) plant for treatment of urben and industrial wastes. Second solution: the hamogenized biamess is first centrifuged and the liquid fraction fed to a fix bed reactor while the solid fraction is ance again dried and used as amendant. The liquid effluent from the digester is sent to the Mestre treatment plant. A very preliminary economic assessment indicates that, although biogas and amendants are valuable resources, they cannot cover the cost of the whole operation, which must there fore be considered also as an enviromental control and thus financially supported accordingly. HYDROGEN PRODUCTION, AMMONIA PRODUCTION AND NITROGEN FIXATION BY FREE AND IMMOBILISED CYANOBACTERIA M. BROUERS and D.O. HALL Department of Plant Sciences, King's College, London SE24 9JF, U.K. 29. Summary A comparative study was made of hydrogen and ammonia production by free and immobilised Anabaena azollae. Polyvinyl foams and alginate matrices were tested. Immobilisation of cyanobacteria led to an increase and/or to a stabilization of the rate of H photoproduction under argon as compared with free living cells; this increase occurred mainly via hydrogenase-mediated production. Immobilisation also stabilized the acetylene reduction activity (nitrogenase activity, equivalent to nitrogen fixation) under continuous working conditions; an increase in the initial rate of acetylene reduction was observed which was best seen when immobilising the Mastigocladus laminosus in polyviny foam. High yields of ammonia production were obtained from polyvinyl-immobilised A. azollae (up to ca. https://www.w3.org/1998/Math/MathML"> 400 μ m o l e s N H 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per mg chl a during a https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . incubation period) in the presence of an inhibitor of gTutamine synthetase activity : L-methionine-DL-suTphoximine (MSO); free-living and alginate-immobilised cells produced less than https://www.w3.org/1998/Math/MathML"> 10 μ m o l e s m g c h l - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the same conditions. Pretreatment of aiginate beads with acetone led to a net increase of ammonia production; this was observed even in the absence of MSO, suggesting an inhibition of glutamine synthetase by the acetone treatment. 30. INTRODUCTION Cyanobacteria (blue-green algae) are https://www.w3.org/1998/Math/MathML"> 0 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -evolving photosynthetic prokaryotes most of which show ATP-dependent nitrogenase activity and are able to fix atmospheric https://www.w3.org/1998/Math/MathML"> N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1). Concomitant to the fixation of https://www.w3.org/1998/Math/MathML"> N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a nitrogenase-mediated https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production is observed (2). Besides nitrogenase at least two other enzyme activities are involved in the metabolism of https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a so-called uptake hydrogenase (membrane bound) that catalyses https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> consumption and a soluble hydrogenase that catalyses ATP-independent https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> formation https://www.w3.org/1998/Math/MathML"> ( 3,4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Hydrogen evolution from nitrogenase is inhibited by https://www.w3.org/1998/Math/MathML"> N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C 2 H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> but not by https://www.w3.org/1998/Math/MathML"> C O ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in contrast hydrogenases are sensitive to CO and are unaffected by https://www.w3.org/1998/Math/MathML"> N 2 ( 5,7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Although nitrogenase activity is inhibited by 0 , heterocystous cyanobacteria fix N in aerobic conditions because the heterocyst provides https://www.w3.org/1998/Math/MathML"> O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> protection for the enzyme (it lacks photosynthetic https://www.w3.org/1998/Math/MathML"> O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> evolution and has an envelope which serves as an o barrier). Nitrogenase and untake hydrogenase are located in the heterocyst while hydrogenase is found both in heterocyst and vegetative cells. It has been shown that immobilisation and subsequent use in bioreactors greatly facilitates the use of many biocatalysts. The main advantages are the prolonged operational stability, the cheaper isolation of the excreted product, the increase in biomass ratio, and the possibility of avoiding washout at high dilution rates. This paper reports on https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and ammonia production by free-living and immobilised cells of heterocystous cyanobacteria A. azollae and of acetylene reduction (nitrogenase activity, equivalent to https://www.w3.org/1998/Math/MathML"> N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fixation) by free-living and immobilised A. azollae and Mastigoctadus laminosus. Immobilisation was performed either in Ca-a Tginate beads or in polyviny foam matrices. A. azollae occurs naturally as a symbiotic partner of the water fern Azolla and is known to have a heterocyst frequency of https://www.w3.org/1998/Math/MathML"> 30 - 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total cells present, and to excrete ammonia for host metabolism when living in the symbiotic association (8). In normal physiological conditions the nitrogen fixed by the cyanobacteria is not released as ammonia but enters the nitrogen metabolic pathway. In order to induce extracellular release of ammonia the primary enzyme in ammonia assimilation, namely glutamine synthetase, is inhibited by L-methionine-DL-sulphoximine (MSO) (9). To test the role of membrane permeability on the yield of ammonia production an acetone pretreatment of alginate beads containing immobilised cyanobacteria was performed. 31. MATERIAL AND METHODS Anabaena azollae and Mastigocladus Taminosus were grown on BG11 medium (10) without nitrate plus micronutrient solution of Allen and Arnon (11) or on A11en and Arnon medium (11), respectively. Immobilisation in polyviny 1 foam (code Jan. 84 and PR22/60, Caligen Foam Ltd, Accrington, UK) was performed according to procedure described by Muallem et al (12) by inoculating cyanobacteria into growth medium containing pieces of foam. The method for immobilisation in Ca alginate beads was described elsewhere https://www.w3.org/1998/Math/MathML"> ( 13 ) ; 211 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> manipulations were performed under sterile conditions. After immobilisation beads were stored in the growth medium (without phosphate) renewed each https://www.w3.org/1998/Math/MathML"> 48   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Na-alginate Protona 110/60 was provided by Protan A.S, Drammen, Norway. Nitrogenase activity was assayed by acetylene reduction under a gas phase argon/10% https://www.w3.org/1998/Math/MathML"> C 2 H 2 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethylene formation was measured by gas chromatography. H photoproduction was followed under argon or argon/4% https://www.w3.org/1998/Math/MathML"> C O . H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was measured by gas chromatography. For determining ammonia production, polyvinyl or alginateimmobilised and free-living A azollae were incubated in the light in the growth medium during three successive https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . periods in the presence or absence of https://www.w3.org/1998/Math/MathML"> 50 μM https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MSO. The media were sampled at the end of each https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . period for determination of ammonia concentration by the colorimetric method of solorzano https://www.w3.org/1998/Math/MathML"> ( 14 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The algae were then resuspended in the growth media for the next https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . period. For acetone pretreatment, alginate beads were suspended in acetone for https://www.w3.org/1998/Math/MathML"> 1   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . before the first https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . incubation period. 32. RESULTS 3.1 Hydrogen production Hydrogen photoevolution by A. azollae, free-living or immobilised in a lginate beads and in polyviny https://www.w3.org/1998/Math/MathML"> foam - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , is shown in Fig. Under argon, free-living cells showed a net https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> photoproduction up to https://www.w3.org/1998/Math/MathML"> 9   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . after onset of illumination up to a total of ca. 8 umoles https://www.w3.org/1998/Math/MathML"> H 2 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> chl 1 . A decrease in the https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> content was then observed. When CO (an inhibitor of hydrogenase activity was present) the total amount accumulated was 7 , μ moles https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mg chl-1, after https://www.w3.org/1998/Math/MathML"> 9   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . and remained constant up to https://www.w3.org/1998/Math/MathML"> 20   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This shows that most of the https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was produced from nitrogenase activity and that the decrease under argon was due to the development of an uptake hydrogenase activity. When A. azollae was immobilised in foam the rate of https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> evolution under argon was increased by a factor 2 as compared with Fig. I. Hydrogen photoproduction by 8 d old free living ( 0, ) and immobilised https://www.w3.org/1998/Math/MathML"> A _ . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> azollae in alginate beads https://www.w3.org/1998/Math/MathML"> ( 0,0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> two d. after immobilisation, and in polyvinyl foam matrix Jan. https://www.w3.org/1998/Math/MathML"> 84 ( 0,0 ) 8   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after foam inoculation. The samples were incubated beneath an initial gas atmosphere of Argon/4% CO (closed symbols) or Argon(open symbols). Light intensity: 250 mmoles photons https://www.w3.org/1998/Math/MathML"> m - 2 s e c - 1 ,   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Temp. https://www.w3.org/1998/Math/MathML">   25 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> free-living cells. Comparison with https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production under argon / 4% CO showed that ca. https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> evolution was hydrogenase mediated (instead of ca. https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the free-living sample) indicating that the increased https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yield was mainly due to increased hydrogenase activity. Alginate-jmmoblised cells https://www.w3.org/1998/Math/MathML"> 2   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after immobilisation produced 12 umoles https://www.w3.org/1998/Math/MathML"> H 2 m g c h 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under argon after https://www.w3.org/1998/Math/MathML"> 19   h . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> illumination; in this case, https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production was hydrogenase mediated. When assayed https://www.w3.org/1998/Math/MathML"> 40   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . after immobilisation, alginate-immobilised cells were no longer able to photo produce https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 33. 3.2 Nitrogenase activity The initial rates of acetylene reduction (nitrogenase activity equivalent to nitrogen fixation) and rates after https://www.w3.org/1998/Math/MathML"> 10   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . continuous 1 ight under argon/10% https://www.w3.org/1998/Math/MathML"> C 2 H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are shown in Table I. Free-living A. azollae cultures showed a decrease in nitrogenase activity from 8 to https://www.w3.org/1998/Math/MathML"> 40   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . No activity was measurable in https://www.w3.org/1998/Math/MathML"> 40   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . old cultures. Immobilisation in alginate beads led to an increase in the initial rate of https://www.w3.org/1998/Math/MathML"> C 2 H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reduction. The activity was maintained at an appreciable Tevel even after https://www.w3.org/1998/Math/MathML"> 40   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . immobilisation in polyviny foam. Immobilisation was also shown to stabilize the nitrogenase activity; the remaining activity after https://www.w3.org/1998/Math/MathML"> 10   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . continuous light incubation was greater in immobilised than in free-living cells (Table I). In recent experiments the increase of https://www.w3.org/1998/Math/MathML"> C 2 H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reduction activity on immobilisation was more evident when comparing free-living and polyvinyl-immobilised M. Taminosus: initial rates increassed by a factor 10 in the immobilised sample (3.6 \mumoles https://www.w3.org/1998/Math/MathML"> C 2 H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reduced https://www.w3.org/1998/Math/MathML"> m g c h 1 - 1   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as compared with the free-living sample https://www.w3.org/1998/Math/MathML"> ( 0.3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> umoles mg.ch https://www.w3.org/1998/Math/MathML"> 1 - 1   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 33.1. Ammonia production Ammonia production by free-living and immobilised A. azollae was measured after three successive https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . incubation periods in the Tight https://www.w3.org/1998/Math/MathML"> ± https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MSO (Table II). Low amounts of ammonia were produced by free-living and a Isinate-immobilised cyanobacteria without acetone pretreatment High yields were however obtained from alginate-immobilised cells when beads were pretreated with acetone (tinso) and from polyvinyl-immobilised cells in the presence of MSO. It must be emphasized that acetone pretreatment of alginate beads resulted in a subsequent excretion of phycobilins into the incubation medium. At the end of the three https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . periods, the beads were light green indicating a degradation of chlorophy 11 pigments. Production of ammonia in Table Il is expressed relative to the initial chlorophy 11 content. 34. DISCUSSION Free-living and polyviny https://www.w3.org/1998/Math/MathML"> ⌉ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -immobilised A. azollae produced https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under argon for 7 to https://www.w3.org/1998/Math/MathML"> 8   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . After that time https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was consumed due to the development of uptake hydrogenase activity as shown when CO (inhibitor of hydrogenase activity) was added in the gas phase (see Fig. 1). The amount of https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> produced under argon by polyvinyl-immobilised cells was twice that produced by free-living cells; however, under argon and https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lo it was similar for both samples. Fhis indicates that the increase seen on immobilisation is mainly due to an increase in hydrogenase-mediated https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production. Imobili. sation in alginate did not significantly increase the rate of https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production as compared with free-1iving cells but it maintained a net production for at least https://www.w3.org/1998/Math/MathML"> 20   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This can be due either to a stabilization of the enzymes on immobilisation or to d lower level of uptake hydrogenase activity in the immobilised cells. If we assume that hydrogenase and uptake-hydrogenase activity were completely inhibited in argon/4% CO and that no appreciable uptake-hydrogenase activity was developed under argon after 7 h illumination, the comparison of https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production under argon (hydrogenase + nitrogenase-mediated https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production) and under argon/4% CO (nitrogenase-mediated H https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production) allows an estimation of the percentage of hydrogenasemediated H production. The calculated percentages were 26,52 and https://www.w3.org/1998/Math/MathML"> 86 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for free-living, polyviny 1 -immobilised and alginate-immobitised cyanobacteria, respectively. The percentage of https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production from hydrogenase was significantly increased on immobilisation, although nitrogenase activity (measured as https://www.w3.org/1998/Math/MathML"> C 2 H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reduction) was maintained (see Table I). High yields of ammonia production were obtained from immobilised A. azollae in alginate with acetone pretreatment, and in polyvinyl foam PR22/60 in the presence of MSO. To our knowledge, such high yields have not been reported using cyanobacteria. Acetone pretreatment is known to increase the permeability of cell walls and membranes leading to facilitated transport of reactants and products. In the present case, excretion of phycobilins and degradation of chlorophylls during incubation following the acetone treatment indicates that it induces lysis of the cells and also affects the interna membranes, thus leading to the production of immobilised, non-viable cells; nevertheless, nitrogenase activity is preserved at least for https://www.w3.org/1998/Math/MathML"> 72   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Production of ammonia by acetone-pretreated, alginate-immobilised cells even in the absence of MSO suggests that glutamine synthetase activity was partly inhibited by the acetone treatment. The highest ammonia production yield was obtained from https://www.w3.org/1998/Math/MathML"> A _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . azollae immobilised in polyvinyl foam. As this is not correlated with an increase of nitrogenase activity ( https://www.w3.org/1998/Math/MathML"> C 2 H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reduction) as compared with alginate-immobilised or free-living cells, it can be inferred that this high yield is related to an increase in cell wall permeability induced by the immobilisation process itself; this allows a greater accessibility of substrates and the inhibitor MSO and facilitates excretion of ammonia. Similar effects of immobilisation has been reported previously for bacteria immobilised in polyacrylamide matrices (15). 35. ACKNOWLEDGEMENTS M. Brouers is in receipt of a training contract from the Commission of the European Communities (Biomolecular Engineering programme). 36. REFERENCES (1) CARR, N.G. and WHITTAN, B.A. (1982). The biology of cyanobacteria. Blackwell, oxford. (2) LAMBERT, G.R. and SMITH, G.D. (1981). The hydrogen metabolism of cyanobacteria. Biological Reviews. 56,589-660 (3) TEL-OR, E., LUIJK, L.W. and PACKER, L (1977). FEBS Lett. 78, 49-52. (4) TEL-OR, E., LUIJK, L.W. and PACKER, L. (1978) , Arch. Biochem. Biophys. 185-194. (5) HOBERMAN, H.D. and RITTENBERG, D. (1943). J. Biol. Chem 147, 211-227. (6) PETERSON, R.B. and BURRIS, R.H. (1978) Arch. Microbiol. 116, 125-132. DADAY, A. LAMBERT, G.R. and SMITH. G.D. (1979). Biochem. J. 177, (8) PETERS, G.A., RAY, T.B. MAYNE, B.C. and TOIA, R.E. (1980). In Nitrogen fixation (Newton, W.E., Orme-Johnson, W.H. eds.). Vol, II, pp.293-309. University Park Press, Baltimore. (9) STEWART, W.D.P. and ROWELL, P. (1975) . Biochem. Biophys. Res. Comm. 65,846-856 (10) STAINER, R.Y. , KUNISAWA, R., MANDEL, M and COHEN-BAZIRE, G. (1981) Bacteriol. Rev. 35, 171-205. (11) ALLEN, M.B. and ARNON, D.I. (1955). Plant Physiology 30, 366-372. (12) MUALLEM, A., BRUCE, D. and HALL, D.O. (1983). Biotech. Lett. 5, 365-368 (13) BROUERS et. a1. In "Photochemica 1, Photoelectrochemica 1 and Photobiological processes" (1982-1983) (D.0. Ha11 and W. Palz eds.) Vo1. I. pp.134-139. Vol II pp. 170-178. D. Reidel Pub. Co. Dordrecht. (14) SOLORZANO, L (1969). Limnol, Oceanogr. 14. 799-801. (15) YAMAMOTO , K., SATO, T., TOSA, and CHIBATA, I. (1974). Biotechnol. Bioeng. XVI, 1589-1599 and 1601-1610. EFFECT OF DIFFERENT FACTORS ON THE PRODUCTIVITY OF THE NITROGEN FIXING BLUE-GREEN ALGA Anabaena variabilis UNDER OUTDOOR CONDITIONS A.G. FONTES, J. MORENO, M.A. VARGAS, M.G. GUERRERO and M. LOSADA Departamento de Bioquímica, Facultad de Biología y C.S.I.C. Apartado 1095, E-4 1080 Sevilla, Spain 37. Summary The effect of several relevant factors influencing the productivity of the blue-green alga Anabaena variabilis has been investigated in outdoor semicontinuous cultures. Air. sparged through the cultures to promote turbulence, was enough by itoelf to protide all the carbon and nitrogen needed for maximal productivity when supplied at a flow rate of 601 per 1 of cell suspension per h. As a matter of fact, the addition of either or both, https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and combined nitrogen (as https://www.w3.org/1998/Math/MathML"> K N O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> N H 4 C l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), did not result in any productivity increase. For a suspension depth of 25 cm, the optimal cell loading was 0.2 https://www.w3.org/1998/Math/MathML"> - 0.3   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (dry weight) https://www.w3.org/1998/Math/MathML"> 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Reciprocally, for a cell loading of https://www.w3.org/1998/Math/MathML"> 0.2   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (dry weight) 1^1, optimal suspension depth was determined to be 20 https://www.w3.org/1998/Math/MathML"> - 25   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Under these conditions, the protein content of the cells was about 65 & of the dry weight, and obtained productivity values were https://www.w3.org/1998/Math/MathML"> 13 ± 1 g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (dry weight) https://www.w3.org/1998/Math/MathML"> m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The nitrogen-fixing blue-green alga A. variabilis seems thus a suitable organism for the production of protein-rich biomass at the expense of solar energy and atmospheric nitrogen, the latter being fixed at a rate of about https://www.w3.org/1998/Math/MathML"> 1.4   g   N   m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A dual extrapolation, both in time and area, of the results obtained gives a productivity value per ha and year of 47 ton dry biomass with a content of 30 ton protein, which corresponds to the fixation of 5 ton nitrogen. 38. INTRODUCTION The use of microorganisms for the generation of biomass with a high protein content, suitable for different aims, is a scope increasing Interest. Among the microalgae, the nitrogen-fixing blue-greens (cyanobacteria) appear particularly attractive for the production of protein-rich biomass, since they are able to synthesize all their cell components, at the expense of solar energy, from water, air and a few mineral salts. Nitrogen fertilizer, expensive in terms of both money and energy, is no required as a component of the growth medium for these organisms, since they can use atmospheric nitrogen as the sole nitrogen source (1). A basic issue in microalgae biomass production is the achievement of conditions under which an optimal use of incident sunlight energy by the cells in the culture takes place. In this context, and provided that nutrients are not limiting, factors as the cell density and the depth and turbulence of the suspension have a relevant effect on productivity Figure 2. Effect of the culture depth on biomass productivity in semicontinuous outdoor cultures of A. variabilis. The density of the cell suspensions was maintained at a value of https://www.w3.org/1998/Math/MathML"> 2 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (chl) 1-1. The values show, with their corresponding standard deviations, are averages of four independent determinations throughout four consecutive days. Figure 3. Effect of the culture depth on the chlorophyll and nitrogen content of A. variabilis cells in semicontinuous outdoor cultures. The density of the cell suspensions was maintained at a value of 3.5 ng https://www.w3.org/1998/Math/MathML"> ( c h 1 ) 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The values shown, with their corresponding standard deviations, are averages of three independent determinations throughout three consecutive days. AN ENERGY BUDGET FOR ALGAL CULTURE ON ANIMAL SLURRY IN TEMPERATE CLIMATIC CONDITIONS H.J. Fallowfield https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and M.K. Garrett, Department of Agricultural and Food Chemistry, Queen's University of Belfast, Newforge Lane, Belfast, Northern Ireland 39. Summary A pilot plant https://www.w3.org/1998/Math/MathML"> 11.1   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for the outdoor photosynthetic treatment of the diluted (1:9) 1iquid phase of pig siurry using the green alga Chlorella vulgaris was operated in autumn 1981 and summer 1982. Pilot plant performance, algal biomass proauction and effluent treatment efficiency was monitored. Electrical energy inputs and potential biomass energy Y lelds were determined and an energy budget for mass algal culture was constructed. Algal culture mixing was the most energy intensive pilot plant operation. The algal biomass, tocrether with a relatively minor contribution from the separated slurry solids, was the major potential sotrre of energy. The results of the pilot plant study were used to produce a theoretical energy budget for a large integratea energy yielding system by which electrical energy may be generated from algal biomass via anaerobic digestion. 40. INTRODUCTION The concept of the high-rate algal pond for mass algal culture in wastewater has been researched and developed by Oswald (1 & 2) and Shelef (3). The integration of intensive animal rearing units and algal treatment systems may, however, more effectively utilise the potential value, both nutritional and calorific, of the algal biomass produced (4). Following almost a decade of laboratory studies by Garrett and co-workers (5) an outdoor pilot plant for the culture of algae in the diluted liquid phase of pig slurry was constructed and operated (1981-1982) at the Agricultural Research Institute, Hillsborough, Co, Down. The aims of the project were, firstly to determine algal dry matter (DM) productivities and effluent treatment capability and secondly to construct an energy budget for the process. The detailed results of pilot plant operation, effluent treatment efficiency and biomass production have been presented elsewhere (6) The potential for algal bioconversion of solar energy has been reviewed by several workers https://www.w3.org/1998/Math/MathML"> ( 7,8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> & 9 https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and data are available for troplcal and sub-tropical locations https://www.w3.org/1998/Math/MathML"> ( 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> & ll). In this paper an energy budget is presented for algal culture in pig slurry in the temperate climatic conditions of Northern Ireland.

PILOT PLANT DESIGN AND OPERATION

Pilot plant design considerations were previously discussed (1.2). The two raceways for algal culture each provided a surface area of ll. Im which, at a depth of https://www.w3.org/1998/Math/MathML"> 0.2   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , gave a volume of https://www.w3.org/1998/Math/MathML"> 2.2   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The cultures were Fig. 1 The power consumption and energy input for pumping slurry to algal cultures. mixed by a 12 bladed padalewheel powered by a 3 phase electric motor. The cultures were operated continuously with the rate of addition of separated, flocculated diluted pig slurry (via a diaphragm metering pump) controlling retention times. The power inputs in the slurry pretreatment area were; the slurry mixer https://www.w3.org/1998/Math/MathML"> 135   k J   s - l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a submersible pump (269) delivering slurry to the rotary press screen separator which was powered by a 3 phase electric motor https://www.w3.org/1998/Math/MathML"> ( 570 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 41. ENERGY INPUTS The energy expenditure for slurry separation was dependent upon retention times https://www.w3.org/1998/Math/MathML"> ( 12.8 - 4.5 d ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and varied from https://www.w3.org/1998/Math/MathML"> 2.93 - 5.71   k J   m - 2   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> This energy input was offset against that potentially available from the separated solids (18.5 kJ https://www.w3.org/1998/Math/MathML"> g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Assuming a 28 solids removal there was a net energy deficit for separation of https://www.w3.org/1998/Math/MathML"> 2.1 - 4.05   k J   m - 2   d - 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Delivering slurry to the cultures at a rate of https://www.w3.org/1998/Math/MathML"> 24   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (retention time 4.5 d) , continuously over https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , expended https://www.w3.org/1998/Math/MathML"> 9.12 M J d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> equivalent to https://www.w3.org/1998/Math/MathML"> 821   k J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ta https://www.w3.org/1998/Math/MathML">   - 2   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The energy requirement was estimated (FLg 1) for pumping to systems with larger surface areas (retention time https://www.w3.org/1998/Math/MathML"> 4.5 d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) ; depth https://www.w3.org/1998/Math/MathML"> 0.2   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . It was evident from the data that at surface areas https://www.w3.org/1998/Math/MathML"> < 50   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> there was an inverse relationship between energy input and surface area. The energy requirement for pumping was excluded from the energy budget; firstly because the size of the plant was artificially inflating the energy input and secondly, gravity flow was considered a more appropriate delivery method for larger treatment systems. The algal culture was mixed https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) at constant mean surface velocity of https://www.w3.org/1998/Math/MathML"> 0.2   l m   s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which required an input of https://www.w3.org/1998/Math/MathML"> 688.8   k J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> m - 2   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

POTENTIAL SOURCE OF ENERGY

The mean https://www.w3.org/1998/Math/MathML"> ( x ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> energy content of the algal/bacterial biomass was 21.17 kJ https://www.w3.org/1998/Math/MathML"> g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This value together with the total DM productivity was used to calculate the potential qross biomass energy proauction (Table I). These results suggested a https://www.w3.org/1998/Math/MathML"> 153 d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Northern Ireland growing season with a productivity of https://www.w3.org/1998/Math/MathML"> 0.16 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha https://www.w3.org/1998/Math/MathML">   - I   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> equivalent to a gross energy yield, at 2.38 solar conversion efficiency (visible spectrum), of 3.38 GJ ha -1d-1. Table I Mean https://www.w3.org/1998/Math/MathML"> ( x ‾ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biomass production values https://www.w3.org/1998/Math/MathML">   Productivity     Sept-Nov, 1981   x ‾   g   m - 2   d - 1 7.18   Total DM   x ‾   k J   m - 2   d - 1 152 15.33 325   May-Aug,   1982 x ‾   g   m - 2   d - 1 18.29 28.52 x ‾   k J   m - 2   d - 1 387 604 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 42. AN ENERGY BUDGET FOR ALGAL CULTURE Overall there was a net energy deficit for algal cultures operated on a https://www.w3.org/1998/Math/MathML"> 24 h d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mixing regime. Isolated net energy surpluses were recorded in June, July https://www.w3.org/1998/Math/MathML"> + 259   k J   m - 2   - 1   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and August. The major energy input was for culture mixing. Preliminary experiments suggest that an 8h a-l mixing regime, whilst significantly reducing the energy input, has only a minor effect upon algal productivity. A theoretical budget for https://www.w3.org/1998/Math/MathML"> 8 h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mixing, assuming no decrease in productivity, is also presented in Table II. Further calculations show that such a culture could withstand a 30-40 % reduction in mean total DM production whilst still maintaining at least a balanced energy budget. Table II An energy budget for algal culture in pig slurry liquid phase 1981 1982 Mixing Regime Sept Oct Nov May June July Aug https://www.w3.org/1998/Math/MathML"> 24   h   d - 1   k J   m - 2   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 230 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 426 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 380 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 300 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 72 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 58 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 61 https://www.w3.org/1998/Math/MathML"> 8   h   d - 1   k J   m - 2   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 228 33.3 19.2 159 387 401 520

A THEORECTICAL ENERGY BUDGET FOR A LARGE INTEGRATED ENERGY YIELDING SYSTEM

It was possible using Manning's equation, describing open channel flow to estimate https://www.w3.org/1998/Math/MathML"> 8   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d 1 mixing energy requirements for 1 ha pond systems. theoretical energy budget for an integrated algal biomass - anaerobic digestion - electrical generation system was calmulated using algal productivities attained in the https://www.w3.org/1998/Math/MathML"> 11.1   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pilot plant system. The daily energy budget for outdoor mass algal culture (May - September) In temperate climatic conditions is presented in Fig 2. The following assumptions were made; an https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> harvest efficiency https://www.w3.org/1998/Math/MathML"> ( 9,10 ) ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a 60 옹 recovery of solar energy via methane (9) and electrical energy generated from methane at 25 ó efficiency (9). Further calculations suggest that, from algal biomass produced at a photoefficiency of https://www.w3.org/1998/Math/MathML"> 2.3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , methane and electricity may be generated at 1.1 and 0.38 solar conversion efficiencies respectively.

DISCUSSION

The algal productivities presented here are approaching the predicted 43. REFERENCES 1 Present address: Microbiology Department, The west of scotland Agricultural College, Auchincruive, Ayr, U.K. 44. PHOTOSYNTHETIC BASIS OF BIOMASS PRODUCTION BY WATER HYACINTH A. LARIGAUDERIE, J. ROY and A. BERGER, Laboratoire d'Ecophysiologie, C.N.R.S./ Centre Louis Emberger, Route de Mende BP 5051, 34033 MONTPELLIER cedex, FRANCE. 45. ABSTRACT Long term co2 enrichment do not decrease either the high photosynthetic capacities of water hyacinth or its ability to utilize high irradiances. The response of water hyacinth to col enrichment differs from what has been shown on other species. The relationships between these results and the high bionass production capacity of water hyacinth are discussed. 46. INTRODUCTION Short term exposure to high https://www.w3.org/1998/Math/MathML"> C 02 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> atmospheric concentrations enhances photosynthetic rates (e.g.: BRUN and COOPER 1967, MAUNEY and al. 1979 , MORISON ana GIFFORD 1983… and in most cases culture of plants at high cu2 levels in optimized systems results in enhanced dry inatter accumulation le.g.: COOPER and BRUN 1967 , WONG 1979 , SIONIT and al. 1980 , CARLSON and BAZZAZ 1982…. However, long term CO2 enrichment affects not only photosynthesis but also its regulation by other physiological processes not clearly defined. Very few studies have examined the effect of long term co2 enrichment on the photosynthetic capacities of the piants and their results suggest that elevated rates of photosynthesis observed during short term exposure cannot be maintained during long tern exposure and that growth at high co2 concentration results in a reduction of photosynthetic capacity (RAPER and PEEOIN 1978 , CLOUGH and a1. 1981). More studies are needed on the response of the physiological mechanisms to co2 enrichment and on the variation of this response between species. The plant examined in this study is water hyacinth (Eichhornia crassipes). It is a perennial, fresh water plant which constitutes the more important weed in most tropical or subtropical countries because of its high capacity of biomass production -by vegetative hultiplication essentially- This biomass can be utilized for different purposes and is in our case exploited for protein production. Photosynthetic response to light and to https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration of water hyacinths grown at normal and https://www.w3.org/1998/Math/MathML"> 10000 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C02 are presented. 47. MATERIAL AND METHODS Water hyacinths fron a single clone were grown during the sumner under two conditions: in a greenhouse at https://www.w3.org/1998/Math/MathML"> 10000 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CO2 (Relative humidity https://www.w3.org/1998/Math/MathML"> ≃ 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Day/ Night temperature: https://www.w3.org/1998/Math/MathML"> 30 - 40 ∘ C / 20 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , PAR - Photosynthetic Active Radiation- received per summer month: 800 mol.mi-2) and outside at normal (330-340 ppm) C02 concentration (Day/ Night temperature: 25-65^{\circ} \mathrm { C } / 1 5 - 2 0 ^ { \circ } \mathrm { C } \text { , } PAR received per summer month: https://www.w3.org/1998/Math/MathML"> 1300 m o 1 . m - 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . We used a COIC- LESAINT nutritive solution whose composition was verified and adjusted daily. Photosynthetic measurements were done on the last fully expanded leaves. Non excised leaves were enciosed in assiinilating chambers connected to an open gas exchange system (WINNNER and MOONEY 1980). Light, humidity, ambient co2 concentration and temperature were controlled. All the curves presented were realized in the optimal range of leaf temperatures. 48. RESULTS AND DISCUSSION

I Photosynthetic response to co2 concentration Greenhouse plants present a classical response to increasing ambient

co2 concentration, with a saturation plateau reached at about 1800 pmm (Fjgure 1A, three repetitions on different leaves are presented). For outside plants, maxtmum co2 assimilation rate is reached at 1000 - 1200 ppr but then decreases (Figure 1B, four repetitions ). The decrease of net photosynthesis with increasing Co2 concentration is immediately reversible. An interaction between light intensity and co2 concentration during growth is responsible for this particuliar photosynthetic response to coz of outside plants (LARIGAUDERIE 1985). Mean maximum net photosynthetic rates are 63.1+7.4 and 56.9+4.4 \mumo1C02.m-2.s-1 (mean tstandard error) respectively for outside and greenhouse plants. These values are not statistically different. Thus, in water hyacinth, long term Co2 enrichment do not decrease the photosynthetic capacity. The maximum net photosynthesis (at 1200 ppm) is high and twice that at normal C02 level ( https://www.w3.org/1998/Math/MathML"> 340 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) for both types of plants. Figure 1: Response of net photosynthes is to ambient https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration https://www.w3.org/1998/Math/MathML"> ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yool. https://www.w3.org/1998/Math/MathML"> = 50 / - 1 ) ; E = 2000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> umol,m-2.5-1, https://www.w3.org/1998/Math/MathML"> VPD = 1 K P a ; A https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; plants grown at https://www.w3.org/1998/Math/MathML"> 10000   p P m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> B: plants grown at https://www.w3.org/1998/Math/MathML"> 340 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 48.1. Photosynthetic response to light intensity Regardless of their growth conditions plants are capable of utilizing very high frradiances. Photosynthesis is not light satured at 1500 HIno1.m-2.s-1 when measured either at 340 pom or at 1200 pom (Figure 2). Quantum yleld (jmolco2 fixed per umol quanta absorbed) is determined by the photosynthesis versus light curves at low light intensities. Quantum yield measured at 340 ppm is similar for outside and greenhouse plants https://www.w3.org/1998/Math/MathML"> ( . 0562 ± . 0086 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> . 0562 ± . 0069 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and increases by 30 and https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> when measured at 1200 ppm for these two types of plants respectively. The increase of quantum yield with co2 has already been shown on plants grown at normal co2 concentration (EHLERINGER and BUORKMAN 1977 ) and is attributed to the decrease of the oxygenase activity of the RTbulose I-5, Biphosphate Carboxylase 0xygenase with respect to its carboxylase activity. Our study shows that growth of the plants at high co2 level does not reduce their quanturn yjeld. The higher response of the quantum yield to the ambient coz in greenhouse plants compared to the outside plants needs to be confirmed. Figure 2: Response of net photosynthes is https://www.w3.org/1998/Math/MathML"> ( μ m o l . m - 2.5 - 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to light intensity (unnol, https://www.w3.org/1998/Math/MathML"> m - 2.5 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ); https://www.w3.org/1998/Math/MathML"> Tf = 32 ∘ C , VPD = 1 K P a : A : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> plants grown at https://www.w3.org/1998/Math/MathML"> 340 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , B‡ plants grown at https://www.w3.org/1998/Math/MathML"> 10000 p p m 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 49. CONCLUSION Our water hyacinth clone produced a very high biomass production grown in CO2 enriched atmosphere (BROCHIER and al., this symposium). The physiological measurements presented in this study are in good agreement with bionass measurements: Long term C02 enrichment does not decrease the high photosynthetic capacity of water hyacinth as it does with other species. Photosynthetic rates at https://www.w3.org/1998/Math/MathML"> 340 p p m ( 35 - 40 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> дmolc02.m-2.s-1) are higher than the mean values for other C3 plants (14-23 дmolc02.m-2.s-1) (KORNER et al. 1979). Models of the photosynthetic efficiency of crop species (VARLET-GRANCHET and aT. 1981) indicate that quantuin yield and photosynthetic rate at saturating light are two illuportant parameters as far as canopy productivity is concerned. These results show that physiological in addition to demographic (leaf and rainet birth rates) traits contribute to the high productivity of water hyacinth and make it an adequate species for biomass production in https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> enriched atmosphere. 1. REFERENCES BRUN W A. and COOPER R.L. 1967 - Effects of light intensity and carbon dioxide concentration on photosynthesis rate of soybean. Crop sel. 7,451-454. CARLSON R.W. and BAZZAZ F.A., 1982. - Photosynthetic and growth response to fumigation with 502 at elevated https://www.w3.org/1998/Math/MathML"> CO 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> C 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> plants. Decologia, 54, 50-54. CLOUGH J.M, PEET M W., and KRAMER P, J. 1981. - Effects of high atmospheric CO2 and sink size on rates of photosynthesis of a soybean cultivar. Plant Physiol., 67, 1007-1010. COOPER R.L. and BRUN W.A., 1967. - Response of soybeans to carbon dioxide-enriched atriosphere. Crop Sci. 7,455-457. EHLERINGER J. and BJÖRKMAN 0., 1977. - Quantum yield for co2 uptake in C3 and C4 plants. Plant Physiol., 59, 86-90. KÖRNER Ch., SCHEEL J.A. and BAUER H., 1979 . - Maximum leaf diffusive conductance in vascular plants. Photosynthetica, 13, 45-82. LARIGAUDERIE A., 1985. - Ecophysiologie des ēchanges gazeux chez Eichhornia crassipes Mart. Solms (Jacinthe d'eau): réponse aux fortes teneurs en c02. Third cycle thesis, U.S.T.L. Montpellier, 1090. MAUNEY J.R., GUINN G. FRY K.E. and HESKETH J.D., 1979. - CorreTation of photosynthetic carbon dioxide uptake and carbohydrate accumulation in cotton, soybean, sunflower and sorghum. Photosynthetica, 13,260-266. MORISON I.L. and GIFFORD R.M., 1983. - Stomatal sensitivity to carbon dioxide and humidity, Plant Physiol... 71,789-796. RAPER C.D. and PEEDIN G., 1978 . - Photosynthetic rate during steadystate growth as influenced by carbon-dioxide concentration. Bot. Gaz, 139, 147-149. SIONIT N., HELLMERS H. and STRAIN B.R., 1980 . - Growth and yield of wheat under cu2 enrichment and water stress. Crop Sci., 20, 687-690. VARLET-GRANCHET C., BONHONHE R. CHARTIER M. and ARTIS P., 1981. - Evolution de la reponse photosynthétique des feuiltes et efficience thêorique de la photosynthẽse brute d'une culture de canne à sucre (Saccharum officinarum L.). Agronoinie, 1,473-481 WINNER W.E. and MOONEY H.A., 1980. - Ecology of s02 resistance: I. Effects of fumigations on gas exchange of deciduous and evergreen shrubs. Decologia, 44, 290-295. ACKNOWLEDGIENTS We thank J. Brochier, F. Jardon, J. Fabreguettes and J.L. Salager for their assistance during the experiments. This work was supported by spie Batignolles. EICHHORNIA CRASSIPES : PRODUCTION IN REPEATED HARVEST SYSTEMS ON WASTE WATER IN THE LANGUEDOC REGION (FRANCE) Marie-Luce CHASSANY DE CASABIANCA CNRS - USTL, Place Bataillon, F-34060 Montpellier Cedex France 2. Summary The original method attempted allows the study of E. crassipes produc- tion (in terms of real harvest values) and the purification results (in terms of biomass removed) on a seasonal and annual basis, using five systems operating in parallel on waste water. These systems have different on-site biomass values, maintained by regular harvests ; the harvest is adjusted each time according to system production. Production, conditioned by maximum temperatures greater than https://www.w3.org/1998/Math/MathML"> 15 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , went on for 6 months, 4/5 (production greater than https://www.w3.org/1998/Math/MathML"> 20   g   m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day 1 ) being concentrated in the three summer months. An integrated harvest systems the mean varies between 40.5 to 47 t ha-1 year-1 Dw https://www.w3.org/1998/Math/MathML"> 30.6 - 35.2   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Dw https://www.w3.org/1998/Math/MathML"> m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day-l for the whole of the produc- tion period). This corresponds to the removal of https://www.w3.org/1998/Math/MathML"> 1500 - 1900   g - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Cn https://www.w3.org/1998/Math/MathML"> 180 - 220 g m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of N and https://www.w3.org/1998/Math/MathML"> 35 - 43   g - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> P 2 0 5 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The best system (annual production of 69.5 t ha-l year-l) in this cult.ivation mode had an on- site biomass of https://www.w3.org/1998/Math/MathML"> 13   k gWW   m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at the beginning of the summer and 33 kg WW m-2 at the end. Production and purification of systems limited to a single harvest (at the end of the summer) were inferior by a factor of 3 . 3. INTRODUCTION The study was part of a coordinated and integrated regional effort combining summer biomass, its development and water purification. Ihe use of Eichhornia crassipes systems in a semi-artificial environment ith waste water was analysed. It is a well known fact that this species has a high productivity and purification potential. The acclimatization of E. crassi- pes and its adaptability to waste water were tested in preliminary experi- ments carried out at the medium load sludge purification station at saint- Gély-du-fesc, in the Hérault departement (1). We chose to characterize production and/or purification systems in terms of biomass removed in the different harvest methods and the annual climatic variability in the Languedoc region. When compared to the large number of previous studies on this topic (2-10) this study of E. crassipes presents several new problems:

If pilot projects are to be set up, it is essential to establish

seasonal as well as annual production and purification figures. These data should have the following two unprecedented characteristics : They should represent vorkable figures, with which valid averages may be established, i. e. based on various cultivation modes, and reduces to a specified initial biomass https://www.w3.org/1998/Math/MathML"> m - 2 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

They should represent production and purification values which correspond to a real biomass value removed by harvest.

New elements, which allow the testing of harvest influence on the production system. 2. METHODS

The experiments vere carried out at the medium load activated sludge purification station at Saint-Gély-du-Fesc (Hérault, France) on samples of Congo strain E. crassipes. They were cultivated in five basins with a surface of 8 m and a depth of https://www.w3.org/1998/Math/MathML"> 0.5   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , operating in parallel on waste water, in a discontinuous mode, with total water replenishment by siphoning. 3 day detention time in the basins was adopted for a high nutritive salt surplus feeding (the nutritive salt variations vere 0.1-19 ppm of N for https://www.w3.org/1998/Math/MathML"> N H 4 , 0.05 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ppm of N for https://www.w3.org/1998/Math/MathML"> N O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> N O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 2.4 to 27 pprn of https://www.w3.org/1998/Math/MathML"> P 2 0 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> P 0 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). (1) The stands vere monitored for 5 months from 25 May to 25 Dctober, 1983. Five basins with differents biomass pperated in parallel. Each of the first four was reduced to its original biomass by weekly harvesting. The harvest was adjusted to the production value. The fifth basin was not harvested until the end of the season. The experimentation period as a whole can be divided into three phases. which appear in Fiq. 1 : (i) Spring and summer (from 10 June to 3 August, 1983) with harvests during which the chosen initial biomass values were respectively https://www.w3.org/1998/Math/MathML"> ( k g ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : 1,4,6,8 and 11. (ii) Summer allows the populations to grow, giving greater biomass values. (iii) Fall, during which the chosen initial biomass values were respectively https://www.w3.org/1998/Math/MathML"> ( k gw   W - 2 ) : 24,28,33 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 40 . The formulae for production, growth and purification were as follows. Annual production of E. crassipes in the Languedoc region, in open air systems, uas calculated in 1983 for the 4.5 months experimentation period from the average values for the four basins and uas based on real harvest values, without extrapolation. It corresponds to the formula : https://www.w3.org/1998/Math/MathML"> Pt = ( Bf - Bi ) + ∫ t t n   P s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> P = ( Bf - Bi ) + ∫ t 0 tn   Hs https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where Bi and Bf are, respectively, initial and final biomass and where the total of the seasonal production, Ps can be integrated with the total of the successive harvests Hs. 3. RESULTS A. Production variations according to climatic data https://www.w3.org/1998/Math/MathML">   Fig.   2   : Daily production     means over the whole of     the systems with harvests     lmean values and deuia-     tions trom the mean calcu-     lated oven two consecutive     time intervals, each sepa-     rated by two harvestsl.     Hatching for phoduction     greater than   20   g Dom   - dayt   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The mean production curve snows very clearly that, outside, E. crassipes production over the year is qreater than 10 प DW day https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> over 6 months. Virtualiy all the production took place over three months, with a mean The formula https://www.w3.org/1998/Math/MathML"> y = 1.65 x - 25.13 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> shows in particular:

No production when the mean maximum temperature of the period under oonsideration is less than https://www.w3.org/1998/Math/MathML"> 15.150 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

A mean production located between 10 and https://www.w3.org/1998/Math/MathML"> 20   g D W m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for maximum temperatures between https://www.w3.org/1998/Math/MathML"> 20 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 30 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Mean production greater than https://www.w3.org/1998/Math/MathML"> 30   g D W m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for maximum temperatures greater than https://www.w3.org/1998/Math/MathML"> 33 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

B. Production analysis according to on-site biomass Fig. 4 shows that the curves (curves 1 et 2 ) of production depend on the on-site biomass. The following was observed : there was a production increase, depending on the on-site biomass increase, up to the production peak obtained in spring with a biomass value of https://www.w3.org/1998/Math/MathML"> 13.1 ± 2.2   k g W W m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and in autumn with a biomass value of https://www.w3.org/1998/Math/MathML"> 32.5   k g W W m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , whereas the density peak occurred in the inflection zone: 10 20 30 40 Fig. 4 : Daily production means per system, as a function of the connespon- bing mean initial biomass. Period from 10 June to 3 August, 1983 (curve 11 . Period from 15 September to 11 october, 1983 icurve 2). Excepting the shift of the growth curve on the ordinate, uhich should be attributed to seasonal temperature influence, the shift of the growth on the abscissa can be connected to another physiological phenomenon linked to the season through population structure: hence, the exponential phase of curve (1) corresponds to a great extent to horizontal multiplication through runners, whereas curve (2) corresponds more to vertical growth rather than to horizontal vegetative propagation. C. Seasonal and annual productions and purification resulting from the biomass removed by harvest in the various systems (Table 1) Table 1 : Mean Annual Production and Purification in Harvested Systems https://www.w3.org/1998/Math/MathML"> | I , II , IV | https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Characterized by Increasing Biomass Ranges, and in wH (without harvest) Sustems during the Spring and Fall periods Different Productinna Haments removed by harvest Element Hest Haruest Elements removed by harvest Different Production Harvest (g m-2 year-1) - OT CABIIV ha or daily produc- 30.62 35.22 35.22 35.16 16.4 51.25 https://www.w3.org/1998/Math/MathML"> ( *k ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (g) https://www.w3.org/1998/Math/MathML">   (*) (g DW   m - 2   day   - 1   )   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a Production (t DW ha https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> year https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) expressed in biomass removed by harvest in the different systems (malelslated over 4 months) b Purification : nitrogen and phosphorus removed by harvest (g DW m-2) 4. CONCLUSIONS I) The mean production figures for the harvested systems in uaste water show relatively small differences and vary between 38 and 45.5 t ha year-1; this corresponds to a mean daily production from 30.6 to 35.22 g Dw m-2 day-1, calculated for the experimentation period. These values cor- respond to https://www.w3.org/1998/Math/MathML"> 1500 - 1900   g   m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of carbon, from 180 to https://www.w3.org/1998/Math/MathML"> 220   g   m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of nitrogen and from 35 to https://www.w3.org/1998/Math/MathML"> 43   g   m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of phosphorus removed annually (calculated over 4.5 months).

In a system with no harvest, production obtained is only 20 t ha^-l year-l, i.e. is half as much, on a production or purification level, as in the harvested systems.

The highest cumulative production values are 64.76 t ha https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> year-1 with a daily mean of 51.25 g DW m-2 day-l over 4.5 months. These figures correspond to a range of on-site biomass maintained in the basins of l3 kg https://www.w3.org/1998/Math/MathML"> WW m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> during the first period and https://www.w3.org/1998/Math/MathML"> 30 - 33   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> WW https://www.w3.org/1998/Math/MathML"> m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> during the second and third periods.

The mean daily production values obtained in Saint-Gély-du-Fesc over the entire production period, compared to the existing data (2-10), are in general greater; thus, the daily production values, correlated with the maximum temperatures, can in the most efficient systems in SaintGély-du-Fesc reach mean values of https://www.w3.org/1998/Math/MathML"> 65   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DW https://www.w3.org/1998/Math/MathML"> m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day-1 over the production period. However, the staggering of the production period, beinglimited by minimum temperatures less than https://www.w3.org/1998/Math/MathML"> 10 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , reduces the daily production calculated over 12 months to a value of less than one-third of this.

5. REFERENCES (1) CHASSANY DE CASABIANCA, M.L. (1983). Données préliminaires sur la production d'Eichhornia crassipes sur eaux résiduaires (Station d'Epuration de St Gély du Fesc, Hérault, France). Rapp. Comm. int. Mer Médit. https://www.w3.org/1998/Math/MathML"> 28 ( 6 ) , 365 - 67 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (2) SEAMAN, D.E. & PORTERFIELD, W.A. (1964). Control of aquatic weeds by snail Marisa eornaurietis. Weeds, 12, 87-92. (3) MORRIS, T.L. (1974). Water hyacinth Eichhornia crassipes (Mart.) Solms. : its ability to invade aquatic ecosystems of Paune's Prairie Reserve. MS Thesis. University of Florida, Gainsville, USA. (4) KIRBY, C.J. & GOSSELINK, J.G. (1976). Primary production in a Louisiana gulf coast Spontina alterniflora marsh. Ecology, 57, 1043-51. (5) CENTER, T.D. & SPENCER, N.R. (1981). The phenology and growth of water hyacinth (Eichhornia crassipes (Mart.) Solms.) in a eutrophic northcentral Florida lake. Aquatic Bot., 10, 1-32. (6) DEBUSK, T.A., RYTHER, T.A.. HANISAK, L.D. & WILLIAMS (1981). Effects of seasonality and plant density on the productivity of some freshwater macrophytes. Aquatic Bot., 10, 133-42. (7) TUCKER, C.T.& DEBUSK, T.A. (1981). Seasonal growth of Eichhornia crassipes (Mart.) Solms. : relationship to protein, fiber and available carbohydrate content. Aquatic Bot., 11, 137-41. (8) BOYD, C.E. & SCARSBROOK, E. (1975). Influence of nutrient additions and initial density of plants on production of water hyacinth Eichhornia crassipes. Aquatic Bot., 19, 253-61. (9) WOLVERTON, B.C. & MCDONALD, R.C. (1979). Water hyacinth (Eichhornia crassipes ) productivity and harvesting studies. Economic https://www.w3.org/1998/Math/MathML">   Bot.   - , 33 ( 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1-10. THE EFFECT OF NUTRIENT APPLICATION ON PLANT AND SOIL NUTRIENT CONIENT IN RELATION IO BIOMASS HARVESTING T.V. CALLAGHAN, G.J . LAWSON, A.M. MAINWARING and R. SCOTT Institute of Terrestrial Ecology, Grange-over-Sands, Cumbria, UK 6. Summary In field trials, bracken (Pteridium aquilinum), Japenese knotweed (Reynoutria faponica) and cordgrass (Spertina anglica) showed Ijttle positive yleld response to nitrogen, potassium and phosphorus fertilizer application. Tissues analysed contained elevated levels of nutrients but this was not reflected in greater biomass production, which seems to be limited by other factors. Soll N and K levels were depressed in cropped areas of bracken and Japanese knotweed. Soll. concentration of P was lower on cordgrass and knotweed sites after annual cropping for three years. Surprisingly the bracken soil did not show 8 reduction In P level. The lack of response of plants to nutrients is difflcult to interpret and it appears that application of nutrients mey not give enhancement of yield in some vegetation types. These results highlight the need to Lnvestigate further the crop physiology of candidate species for biomess harvesting. befects of biomass removal on soil fertility will need to be examined In order to construct nutrient budgets. These are often specific to the site and the crop plant. 7. INTRODUCTION Previous papers https://www.w3.org/1998/Math/MathML"> ( 1,2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> have reported the yield, nutrient content and organic composition of a range of naturally occurring species which and OL Gantc composition of a rairge of naturally occurring spectes unhich could be used as energy crops in the United Kingdoi. There would be positive benefits in using certain large areas of vegetation, for example bracken and heather moors, whose amenity and wildlife function would not be adversely affected (3). Blomass cropping from areas of land not previously utilized (here called natural vegetation) and from plantations dedicated to fuel production would remoye inorganic nutrients from the site and decrease the soil fertility. We have constructed budgets for the smount of each element that woula need to be replaced under different cromping regimes to malntatn the desired level of yleld (4) simple replacement budgets are unlikely to provide the complete answer as many other growth factors are involved. In the case of dedicated energy plantations the high investment in the crop would dictate that high levels of yield ahould be maintained. This would be less important ln opportunity crops when fuel production would only be an adjunct to existing management. Other features are Iinked to the nutrient economy of the plant which it is impossible to consider in isolation. Damage to roots during Figure 1. Yield and nutrient content of bracken, cordgrass and Japanese knotweed in growth trials given 4 levels of fertilizer, over 3 annual harvests. https://www.w3.org/1998/Math/MathML"> H O O 3 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> unptake through the roots in willow and sunflower and effect of https://www.w3.org/1998/Math/MathML"> H O 2 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> uptake on the productivity of willow cuttings P. Pelkonen, E.M. Vapaaviori and H. Vuorinen The Firmish Forest Research Institute, Suonenjoki Research Station, SF-77600 Suonenjoki, Finland Sumary Abstract Young willow https://www.w3.org/1998/Math/MathML">   Salix   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 'aquatica gigantea') and sunflower (Helianthus apinus ber plants were grown in hydroponic cllture lasala, and 14 Clabelled sodium bicarbonate was fed to the roots. Uptake of theripels ( 6 in, https://www.w3.org/1998/Math/MathML"> 48   h )   T e a v e s   a n d   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> had been transfermed to the leaves and shoots. A second experiment was designed to test whether carbon uptake by the roots affects the growth of young willow plants. Rooted cuttings were grown in hydroponic cultures at five difterent levels of bicarbonate: 0,0.015, 0.147,0.737, and https://www.w3.org/1998/Math/MathML"> 1.473 m M N a H O O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> After a 4-week growing period we determined the biamass of leaves, shoots, roots and cuttings. Production of total dry matter (shoots, leaves and roots) increased with increasing bicarbanate concentration. Saturation of dry matter production was reached at 0.737 mM https://www.w3.org/1998/Math/MathML"> N a H O O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , but a higher cancentration of https://www.w3.org/1998/Math/MathML"> N a H O O 3 ( 1.473 m M ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> caused a slight decrease in the dry matter production. 1. INTRODUCITON In rapidly decomposing soils the concentration of https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be markedly higher than that in the atmosphere, fran 0.5 to https://www.w3.org/1998/Math/MathML"> 1.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by volume (1). Part of this https://www.w3.org/1998/Math/MathML"> ∞ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> equilibrates with the water of the soil to produce carbonic acid, which further dissociates to https://www.w3.org/1998/Math/MathML"> H C O 3 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C O 3 2 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The relative proportions of the ionic species depends on the https://www.w3.org/1998/Math/MathML">   3 p H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Many aquatic plants and algae are able to take up both https://www.w3.org/1998/Math/MathML"> H 0 O - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which obviously could make them photosynthetically more campetent'(2). In bean plants, uptake of bicarbonate was detected using https://www.w3.org/1998/Math/MathML">   11 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as a tracer with a decreasing gradient of label from roots to leaves (3). Several reports have indicated that high concentrations of bicarbonate (fram 5 up to https://www.w3.org/1998/Math/MathML"> 20 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in soils and irrigation waters inhibit uptake of other nutrient ions and dearease crop growth https://www.w3.org/1998/Math/MathML"> ( 4,5 , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , . These high https://www.w3.org/1998/Math/MathML"> H O O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentrations, reported for example in strongly anaerobic conditions in rice fields (6), are unlikely to occur in normal solls. The purpose of this experiment was to test, using radiotracer studies in hydroponic cultures, whether willow and sunflower plants take dissolved https://www.w3.org/1998/Math/MathML"> C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from nutrient solution and whether the availability of dissolved https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at lo concentrations in the medium would affect growth and biamass production of young willow plants. 8. MAIERTAL AND MEIHODS https://www.w3.org/1998/Math/MathML"> 1 N a H 14 C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> feeding experiment Cuttin's of willow (Salix 'aquatica gigantea') that were about equal in length and diameter were selected for the experiments. The cuttings were rooted in deionized water for about two weeks and then transferred to a nutrient solution (7), pH 5.5, for the experiments. Seeds of sunflower (Helianthus amuus L.) were sown in washed sand. At the cotyledon stage the plantlets were transferred into the above nutrient solution, pH 7.0, for furtiner growth and for the https://www.w3.org/1998/Math/MathML">   14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> uptake experiment. Using a rubber stopper, the plants were tightly sealed into https://www.w3.org/1998/Math/MathML"> 300 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> flasks with a small inlet for aeration of the solution with https://www.w3.org/1998/Math/MathML"> C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -free air. The outgoing air was led into a https://www.w3.org/1998/Math/MathML"> C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -trap https://www.w3.org/1998/Math/MathML"> ( 20 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of 2-thoxyethanol-ethanolamine mixture 7:1). Before the experiment, plants for 8 different treatments were incubated for 3 days in the nutrient solution with either 0.015 mM https://www.w3.org/1998/Math/MathML"> N a H O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (treatments 1 to 4 ) or https://www.w3.org/1998/Math/MathML"> 1.473 m M N a H C O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (treatments 5140 8). After this incubation period, https://www.w3.org/1998/Math/MathML"> 3.604 μ M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of either unlabelled or labelled https://www.w3.org/1998/Math/MathML"> N a H O O 3 N a H 4   W 3 53.5 m C i / m m o l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , The Radiochemical Centre, Amersham) was injected into the medium. After the 6 and 48 in feeding period the shoots were cut into pieces; each sample contained one leaf with the intermode below. Fresh and dry weights of the samples were measured, after which they were treated with https://www.w3.org/1998/Math/MathML"> 20 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> 5   N H C l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to free the inorganic carbon compounds from the plant material as https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The evolved https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was trapped into https://www.w3.org/1998/Math/MathML"> 20 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of 2-thoxyethanol-ethanolamine mixture https://www.w3.org/1998/Math/MathML"> ( 7 : 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The acid treated plant materials were collected on filter papers and washed twice with https://www.w3.org/1998/Math/MathML"> 5 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of distilled water, after which the samples were dried and finally burned in a combustion chamber. Radicactivities of the combusted samples were measured with a liquid scintillation counter (LKB Wallac 1215 Rackbeta Liquid Scintillation Counter). Samples of the 2-ethoxyethanol-ethanolamine mixture and of the acid with rashings were taken for radicactivity measurements on a liquid sointillation counter (LKB Ultrobeta 1210). 9. 2.2 Effect of carbon uptake on productivity Rooted willow cuttings of equal size were selected for the experiments. Rooting conditions were as in the https://www.w3.org/1998/Math/MathML">   14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> feeding experiment. The cuttings ( 7 cuttings for each treatment) were transfermed into Frlermever flasks and cultivated in https://www.w3.org/1998/Math/MathML"> 275 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the nutrient medium (7) in a greenhouse. To prepare a ∞-free nutrient medium the solution was boiled for 30 min and then tightly stoppered. The pH of the cooled media was rapidly adjusted to 7.00,7.00,6.90, 6.70 and 6.40 in Treatments 1,2,3,4 and 5 respectively. The media were aerated with https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -free air for 30 min. https://www.w3.org/1998/Math/MathML"> N a H C O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was then added to the media to bring the pH of the media to 7 and the https://www.w3.org/1998/Math/MathML"> N a H C O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration in Treatments 2,3,4 and 5 to https://www.w3.org/1998/Math/MathML"> 0.015 m M , 0.147 m M , 0.737 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 1.473 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. Treatment 1 served as a control. The nutrient media were changed every 2 days during the 24 -day experiment. After 2 days in all the treatments the pH of the media decreased to pH 0.4. During the growing period, daylight was supplemented with Osmam HQ1 400 W-71 lamps to give a photoperiod of https://www.w3.org/1998/Math/MathML"> 18   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and an air temperature between 20 and 15 C. After the 24-day growing period, the plants were harvested for determination 10. RESULTS AND DISCUSSION 11. https://www.w3.org/1998/Math/MathML"> 3.1 N a H 14 C O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> feeding experiment The https://www.w3.org/1998/Math/MathML">   14 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C label was detected in the leaves and shoots of willow and sumflower in both preincubation treatments even after a 6 h feeding period (Table 1). Our results with willows thus confirm the data for beans and Galenia pubescens (3) and show that https://www.w3.org/1998/Math/MathML"> H C O 3 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> moves from the soil into the shoot and leaves The rate of https://www.w3.org/1998/Math/MathML"> H C O 3   - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -uptake with willow and sunflower was dependent on concentration, since incorporation of https://www.w3.org/1998/Math/MathML">   14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> label, calculated both on the basis of fresh as well as dry weight, was higher in treatments preincubated at https://www.w3.org/1998/Math/MathML"> 1.437 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> N a H O O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> than at https://www.w3.org/1998/Math/MathML"> 0.015 m M N a H O O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . After the https://www.w3.org/1998/Math/MathML"> 6   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> feeding period, most of the 14 C label was found in acid-labile products. Incorporation of the label through the metabolisn into the acid-stable products was time dependent, which could be seen as a higher percentage of the label in acid-stable products after the https://www.w3.org/1998/Math/MathML"> 48   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> treatments (Table 1). Table 1. Rate of https://www.w3.org/1998/Math/MathML">   14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> uptake during on and https://www.w3.org/1998/Math/MathML"> 48   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> feoding periods in leaves Our https://www.w3.org/1998/Math/MathML">   14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> labelling data does not, however, allow us to determine what proportion, if any, of the https://www.w3.org/1998/Math/MathML"> 14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> label in the acid-labile and acid-stable products was derived from the https://www.w3.org/1998/Math/MathML"> H 14 C O - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -molecules transported to the site of synthesis in the shoots. Malate, which is thought to be formed in the roots by PEP carboxylase and/or PEP carboxykinase (8), may be decarboxylated again; and in this case the evolved https://www.w3.org/1998/Math/MathML"> O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> molecules would be transported to the site of synthesis in the shoots. 12. 3.2 Effect of carbon uptake on productivity Results from the experiment in which willow cuttings were grown in cultures with different concentmens of https://www.w3.org/1998/Math/MathML"> N a H O O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> show that the dry matter pmenucion of the whole plant (shoots, leaves and roots) increased by https://www.w3.org/1998/Math/MathML"> 31.1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in culture medium with https://www.w3.org/1998/Math/MathML"> 0.737 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> NaHOO https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and that even at the highest by https://www.w3.org/1998/Math/MathML"> 31.1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in culture medium with https://www.w3.org/1998/Math/MathML"> 0.737 m M N a H O O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and that even at the highest https://www.w3.org/1998/Math/MathML"> N a H O O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration https://www.w3.org/1998/Math/MathML"> ( 1.473 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mM) the biomass production was higher than in the control plants https://www.w3.org/1998/Math/MathML"> ( 26.8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> increase in dry weight, Fig 1.). The same trend was found separately in the dry matter production of leaves and shoots. In the roots such an effect of https://www.w3.org/1998/Math/MathML"> N a H O O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the dry matter production was not obvious, and at https://www.w3.org/1998/Math/MathML"> 1.473 m M N a H O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the ary weight increased only slightly (results not shown). Fig. 1. Effect of different concentrations of https://www.w3.org/1998/Math/MathML"> N a H W 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in matter production of whole willow plants (shoot, leaves, roots). Individual data points and the mean values for each treatinent are shown https://www.w3.org/1998/Math/MathML"> 1 = 0 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 2 = 0.015 m i ,   3 = 0.147 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> 4 = 0.737   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 5=1.473 mM https://www.w3.org/1998/Math/MathML"> N a H O O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The path of carbon through the roots to the sites of synthesis in the stems and leaves is difficult to trace. Our data with willows show that in plants grown in the culture media with the highest https://www.w3.org/1998/Math/MathML"> N a H C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentrations, which caused increased productivity, transpiration was highest, even though in the beginning of the 24-day growing period all treatments had similar rates of liquid consumption (Fig. 2) The average water consumption in plants varied from 800 to https://www.w3.org/1998/Math/MathML"> 1000   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> during the 24-day growing period. From this data we have calculated that with the highest https://www.w3.org/1998/Math/MathML"> N a H O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration the amount of carbon flow from the culture media into the shoots and leaves was about https://www.w3.org/1998/Math/MathML"> 1.2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total amount of carbon in the plants. Let us consider the effects of carbon supply with two different concentrations as percentages p1 and p2 (p=p1-p2). If the initial dry weight of the substances available for growth in plants is wo and dry weights at the end of the growing period W1 and W2, the ratio of dry weights https://www.w3.org/1998/Math/MathML"> ( x = W 2 / W 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be calculated according to the following formula: The values of dry weight ratio https://www.w3.org/1998/Math/MathML"> ( x ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as a function of relative groving time ( (W2/Wo)-1) using three different values for p have been presented in Fig.3. These theoretically calculated figures confirm our experimental data. Thus the https://www.w3.org/1998/Math/MathML"> D 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> molecules taken up by the roots and transported to the site of synthesis in the shoots have an inereasing effect on the productivity of willow plants. 13. REFERENCES (1) Larcher, W. (1975) Physiological Plant Ecology. Springer-Verlag, Berilin, Heidelberg, New York. https://www.w3.org/1998/Math/MathML"> 252 p p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (2) Lucas, W.J. (1983). Annual Review of Plant Physiology, 34, 71-104. (3) Wallace, A., Mueller, R.T., Wood, R.A. & Souf i, S.M. (1979). Plant and Soil, 51, 431-435. (4) Paliwal, K.V., Maliwal, G.L. & Nanawati, G.C. (1975). Plant and Soil, 43,523-536. (5) Andel, J. van, Bos, W. & Ermst, W. (1978) New Phytologist, 81, 763-772. (6) Yosinida, S. & Tanaka, A. (1969) Soil Sciences and Plant Nutrition, 15, 75-80 (7) Arnon, D.I. & Hoagland, D.R. (1943) Botanical Gazette, 104, 576-590. (8) Popp, M., Osmond, C.B. & Sumons, R.E. (1982) Plant Physiology, 69, 1289-1292. P. VENTAS, J.L. TENORIO, E. FUNES and L. AYERBE Dpto. Fisiología. Instituto Nacional de Investigaciones Agrarias Apdo, 8.111 Madrid-Spain 14. Summary Some experiments have been carried out, in controlled environment cham bers, to know the growth response of Euphorbia lathyris, in relation I with temperature and water stress. Four temperatures were tried out: 26, 21,16 and 11 두 during the day; night temperatures were five or ten degrees lower. Plants were sown in pots with a soil composed by a mixture of peat and sand. Controls were irrigated, whenever necessary, to maintain the soil at field capacity, other treatments suffered di fferent degrees of water stress. The optimum temperature for shoot growth was https://www.w3.org/1998/Math/MathML"> 21 % C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , being somewhat lower for root development. Leaf water potential decreased with progressive water stress, but never went below https://www.w3.org/1998/Math/MathML"> - 17 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bar, showing this species a drought avoiding pattern. According with that behavior, growth measured as dry matter production and as leaf area index, was very much restrained in stressed plants, furthermore, leaf diffusion resistance increased, favouring the maintenance of a good water status. Water stress induced a greater amount of sugars to be accumulated in the plants, specialiy in stems, although it did not increase hydrocarbon contents. 15. INTRODUCTION In the last years some studies have been developed in order to evaluate Euphorbia lathyris as an energy crop (1, 2,3,4), but few if any, have been devoted to analyze this species growth in a controlled environment. So we have tried to evaluate the effect of temperature and water stress, on the growth pattern and dry matter production of this plant, cultivated in pots in a climatic chamber. 16. MATERIALS AND METHODS We made two experiments (I and II), in the first one, four day temperatures were tried out: 26,21,16 and https://www.w3.org/1998/Math/MathML"> 110 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (night temperatures were https://www.w3.org/1998/Math/MathML"> 50 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lower in each case), day and night length were 12 hours each, relative humidity was https://www.w3.org/1998/Math/MathML"> 72 + 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> during the day and https://www.w3.org/1998/Math/MathML"> 86 + 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> during the night. Photosynthetic acti ve radiation (PAR), was https://www.w3.org/1998/Math/MathML"> 317 μ E m - 2 - - 3 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , measured at the top of the plants. Soil was a mixture of peat and sand https://www.w3.org/1998/Math/MathML"> ( 3 : 1 ,   V : V ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the soil had been previously calibrated by means of a pressure membrane to know its humidity content at field capacity https://www.w3.org/1998/Math/MathML"> ( C C = 1 / 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bar) , and in the nemmanent wilting point (wp - 15 bar). Forty pots (11,5 dm 3 capacity, one plant per pot), were assayed for each temperature, half of them were permanently maintained at cC whereas to the other half, a progressive water stress was imposed, adding no water for the whole experiment (18 weeks). Fresh and dry weight (DM), and height of the plants were measured periodically. Leaf diffusion resistance (RD) and leaf water potential (LwP), were also measured on leaves from the fifth or gixth ventiojl ounted fnom the youngest completely open leaf. Critical saturation deficit, was also evaluated on leaves. Total sugar contents and hydrocarbons were evaluated at the end of the experiment (5, 1). Tn experi ment IT, the effect of different degreps of water gtrese on plant gmowth ment II, the effect of different degrees of water stress on plant growth was investigated. Day (12 hours), temperature was https://www.w3.org/1998/Math/MathML"> 210 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the best one in the previous experiment; night (12 hours), temperature was lloc. Soil was a mixture of peat and sand https://www.w3.org/1998/Math/MathML"> ( 1 : 3 , V : V ) : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The other environmental conditions were the same as in experiment I. All the plants, as in experiment I, star ted with soil at field capacity, then the next three different irrigation treatments, were given to groups of twenty plants (one per pot), for 19 weeks : a/ The soil was maintained at CC for the whole experiment. b/ Soil was brought to CC whenever, available water went below five per cent. c/ Not irrigated; (available water was depleted by the 12 th week available water: water at cc minus water at wP). 17. RESULTS AND DISCUSSION Experiment I. According with soll calibration data, available water in stressed plants was depleted by week 11 th at 26 and https://www.w3.org/1998/Math/MathML"> 21 . C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , by week 13 th at https://www.w3.org/1998/Math/MathML"> 160 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and by week 17 th at https://www.w3.org/1998/Math/MathML"> 110 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Plants at field oapacity at any tempenatur re (except https://www.w3.org/1998/Math/MathML"> 11.0 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , grew better than plants, at the same temperature, under stress (fig. I a, b and c). Twenty one degrees centigrade was the best stress (fig. 1 as b and c). Twerty one degrees certigrade was the best treatment for shoot growth, reaching the plants 91 cm mean height and 40 g mean dry weight, per plant, at the end of the experiment. Leaf area index (LAI), at CC and https://www.w3.org/1998/Math/MathML"> 21 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was always higher than others with the same water regime, but different temperature, reaching at week l7th a value of https://www.w3.org/1998/Math/MathML"> 4.4 ; - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at the same time, well irrigated plants, at https://www.w3.org/1998/Math/MathML"> 160 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , showed a LAI of 3.8 (fig. https://www.w3.org/1998/Math/MathML"> 2 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Leaf area indexes for stressed plants were much lower, compa red, with well irrigated ones, and never reached a lui value of one (fig. 2b). On week 17 th, the best root dry matter yield was for plants at https://www.w3.org/1998/Math/MathML"> 160 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , that reached https://www.w3.org/1998/Math/MathML"> 17.7   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DM per plant at CC, and https://www.w3.org/1998/Math/MathML"> 4   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DM per plant under stress. Leaf diffusion resistance was almost always, lower in plants at CC than in stress, and grew higher with time in the last ones, going higher than 30 s cm-1 in plants at 26 and https://www.w3.org/1998/Math/MathML"> 210 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Lef diffusion resistance values at CC remai ned more or less constant until the end of the experiment (fig. I). Leaf water potential never went below - 10.5 bar in irrigated plants and -l7 bar in stressed ones (fig. lb). Critical saturation deficit, for leaf disks, was https://www.w3.org/1998/Math/MathML"> 41 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , this means that https://www.w3.org/1998/Math/MathML"> . lathyris can be considered as a xerophytic me-   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sophyte plant (6). Hydrocarbon content (week 17 th), was significantly (P = https://www.w3.org/1998/Math/MathML"> = 0.01 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , higher in leaves: https://www.w3.org/1998/Math/MathML"> 7.9 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of DM, than in stems: https://www.w3.org/1998/Math/MathML"> 3.1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Mean hydrocar bon content for the whole plant was https://www.w3.org/1998/Math/MathML"> 5.4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> There was no significant differen ce, nefther for different temperatures, nor for water stress treatments. other fraction containing also hydrocarbons, that according to Nemethy (l) can amount to https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total dry matter, was not evaluated. Sugar content was significantly https://www.w3.org/1998/Math/MathML"> ( P = 0.01 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , higher in stressed plants: https://www.w3.org/1998/Math/MathML"> 10.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the dry matter, than in irrigated ones: https://www.w3.org/1998/Math/MathML"> 5.8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Sugar in stems of unirrigated plants was also significantly https://www.w3.org/1998/Math/MathML"> ( P = 0.01 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , higher: https://www.w3.org/1998/Math/MathML"> 13.2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> compared with the leaves content: https://www.w3.org/1998/Math/MathML"> 7.8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Experiment II. Growth of plants permanently cultivated at CC (treat ment a), was not significantly different from that of plants stressed until only https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the available water was left (treatment b). Maximum mean height and dry weight of plants from treatments a and b, were 83 cm and https://www.w3.org/1998/Math/MathML"> 18   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per plant respectively, at the end of experiment II, these values, are lower than the corresponding in experiment I, at https://www.w3.org/1998/Math/MathML"> 21 ∘ c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and CC, this was probably - due, to the decrease in night temperature in the last assay. In the treat https://www.w3.org/1998/Math/MathML">   m e n t   t o   t h e   d e c r e a s e r i n   n i g h t   t e r n g e r a t u r e   i n   t h e   l a s t   a r a y   u n   t h e   t r e a t m o n t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> but in the not imrigated treatment (c), RD reached 32 s cm-1 in the last https://www.w3.org/1998/Math/MathML">   b u t   i n   t h e   n o t   i r r i g a t e d   t r e a t m e n t   ( c ) ,   R D   r e a c h e d   32   s o m e n t r i https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> week. Leaf water potential was not significantly different for the three treatments (a, b and c), being the lowest registered value: https://www.w3.org/1998/Math/MathML"> - 1.4 . 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bar (c). Hydrocarbon contents did not differ from those obtained in experiment I. The amount of sugars was also in this experiment significantiy (P = O.OL) higher in stressed plants (c): https://www.w3.org/1998/Math/MathML"> 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , compared with well irrigated ones (a): https://www.w3.org/1998/Math/MathML"> 6.6 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and it was also higher in stems: https://www.w3.org/1998/Math/MathML"> 9.9 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , than in leaves: https://www.w3.org/1998/Math/MathML"> 6.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the two last values are mean of a,b and c treatments. From all the above data, we can conclude that https://www.w3.org/1998/Math/MathML"> 21 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the best tempera ture for shoot growth, although somewhat lower seems better for root deve lopment. The combination https://www.w3.org/1998/Math/MathML"> 21 / 16 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (day/night), enhances also shoot growth verus https://www.w3.org/1998/Math/MathML"> 21 / 110 C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> As was expected, plants at cC grew better than stressed ones (experiments I and IIC), nevertheless, apparently medium stressed plants, from experiment IIb, did not decrease their dM production compared with plants constantly maintained at CC, this fact was probably due to the low https://www.w3.org/1998/Math/MathML">   p l a n t s   c o n s t a n t l y   m a i n t a i n e d   a t   C C ,   t h i s   f a c t   w a s   p r o b a b l y   d u e   t o   t h e   l o w i m e n t e   h u m e   t h e   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and perhaps because the roots thrive better in a well drained soil. It can be said that E. lathyris has behaved as an extremely drought avoiding plant. as the lowest leaf water potential never went below -17 bar (fig. https://www.w3.org/1998/Math/MathML"> 1 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). To this pattern, we think has contributed mainly the growth restraint exhibi ted by stressed plants (fig. la, b and c). Leaf area indexes were also much lower in stressed than in well irrigated plants (fig. 2a, b). Finally, leaf diffusion resistance also increased with progressive stress (fig. la, b), and differences found between well irrigated and stressed treatments showed at least the same degree of sensitivity as differences between dry matter production in wet and unirrigated treatments (fig. la, b and c). Plants grown at 11 으 suffered a negligible water stress (available water was not depleted until week 17 th), and leaf diffusion resistance and water poten tial values were alike in wet and dry treatments; in this case, low DM production, must be mainly atributed to a deficient temperature. It is also interesting to notice that water stress, in the assayed conditions did not increase hydrocarbon, but almost doubled sugar contents. 18. REFERENCES (1) NEMETHY, E.K., OTVOS, J,V., and CALVIN, M. (1981). Hydrocarbons from Euphorbia lathyris. Pure and Appl. Chem. 53, 1101-8. (2) KINGSOLVER, B.E. (1982). Euphorbia lathyris reconsidered: Its potential as an energy crop for arid lands, Biomass, 2, 281-98. (3) SACHS, R.M. et al. (1981). Euphorbia lathyris: A potential source of petroleum-iike products. Calif. Agric. 35,29-32. (4) AYERBE I. Et al. (1984). Euphorbia lathyris as an energy crop-Part l. Vegetative matter and seed productivity. Biomass, 4,283-93. (5) YEMM, E.W. and WILLIS, A.J. (1954). The estimation of carbohydrates in plant extracts by anthrone. Biochem. 57,508-14. (6) STREET, H.E. and OPIK, H. (1970). The physiology of flowering plants: Their growth and development, https://www.w3.org/1998/Math/MathML"> 236 p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Edward Arnold Publishers London. https://www.w3.org/1998/Math/MathML"> l 1 - W 0 ' s 2000481301   u 01 s n d H P   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 440 ∣ d / 6 ) + 4 b 10 MR ⊥ p + 0045 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> U० W https://www.w3.org/1998/Math/MathML">   1 - u v ∘ s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> esuptsised uolsntHp doe7 https://www.w3.org/1998/Math/MathML"> ( 3001   d , 6 ) + 46 ! k m p + 0043 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> บo N https://www.w3.org/1998/Math/MathML"> ( 1 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> us.s) 00404818×1 U01sndtip 1007 https://www.w3.org/1998/Math/MathML"> ( 4 ∪ 01 d / D ) + 4 b 1 ⋅ MK ⊥ 1004 = 400 W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Wo https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) 60 UDHSIS https://www.w3.org/1998/Math/MathML"> 1   U https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> u ˆ = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MICROPROPAGATION OF WILLOWS (SALIX SPP.) T. TORMALA and E. SAARIKKO Kemira Oy, Espoo Research Centre PO Box 44, 02271 Espoo, FINLAND Summary In the context of a breeding and testing program for short rotation biomass production of willows, 16 genotypes were micropropagated using a modification of Bhojwani's (4) method. The method can be simplified using same medium for initiation and proliferation phases and rooting the microshoots directly into soil in vivo. 19. INTRODUCTION The energy crisis in the early https://www.w3.org/1998/Math/MathML"> 1970 ∘ s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> launched many national and private short rotation energy forest programs. While in relatively few places the projects have resulted in large scale production, the interest in short rotation forestry has sustained and even broadened in scope. In addition to burning other alternatives such as landscape reclamation, production of biomass for pulp and feed stocks for chemical industry have received increasing interest. Willows (Salix spp.) are most promising species for short rotation forestry together with alders (Alnus spp.) and poplars (Populus) in the temperate zone. Salix is taxonomically and ecoiogically an extremely diverse genus offering an almost unlimited source for breeding and genetic improvement in general. The propagation and planting of most willows is easy using cuttings. The procedure can easily be mechanized. If so, one may ask, what are the incentives for using tissue culture propagation in willows? With micropropagation desired genotypes can be bulked up rapidly for cutting production Secondly, plantlets are more uniform and practical than cuttings in tests, especially in the laboratory environment. In this paper we describe our experiences in willow micropropagation which has been directed toward genotype improvement and field testing for short rotation forestry in mined peatlands in northern Finland. 20. MATERIALS AND METHODS The following clones were used in the experiments: https://www.w3.org/1998/Math/MathML"> s _ ⋅   dasyclados   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3 clones (V761, P6011, 196), S. aquatica (E4856), S. viminalis 2 clones https://www.w3.org/1998/Math/MathML"> ( S 15111 , E 7899 ) , S _ ⋅ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> myrsinaifolia https://www.w3.org/1998/Math/MathML"> ( V 78 ) , S _ ⋅ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dasyclados H3159 x trinadra P6010 (V777), S. purlamb H3172 x S. aquatica V768 (V778), S. dasyclados H3159 x S. aquatica E4856 (V779), S. vimina1is H3157 x aquatica E4856 https://www.w3.org/1998/Math/MathML"> ( v 780 ) , s _ ⋅   viminalis   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> H3157 x https://www.w3.org/1998/Math/MathML"> S _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . caprea E6762 (V781), S. viminalis H3157 x aquatica E4856 (V782), and S. viminalis H3157 x smithiana H3163 (three clones V783, V784, V785). Disinfestation was achieved by dipping the explants in https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol for 30 seconds, prior to soaking in https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sodium hypochlorite for 15-20 min. (a few drops of detergent added) and finally rinsing four times in sterile water. Two kinds of explants were used: shoot tips from soft vegetative growth and single node segments from hard wood cuttings (ca. https://www.w3.org/1998/Math/MathML"> 2.5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> long). The basal media tested were MS (1), half strength MS and woody plant medium (WPM) (2). https://www.w3.org/1998/Math/MathML"> N 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -benzyladenine (BAP) and 1-naphthalenacetic acid (NAA) were applied in different concentrations. The cultures were incubated in growth chambers (L:D 16:8h, Temp. https://www.w3.org/1998/Math/MathML"> 25 ∘ / 18 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The light intensity was ca. 2000 lux. 21. RESULTS AND DISCUSSION The success of surface sterilization depended highly on the source of explant. Using greenhouse stock plants, which had not receive overhead watering, a 95-100% rate of disinfestation was obtained. When material from the field was used the disinfestation procedure applied was not satisfactory. The use of excised buds as explants would probably have given better results (3). Of the three tested basal media WPM gave the best general response in initiation and multiplication phase (Table 1). The results were, however, dependent on the clone. There were no striking differences between the response of shoot tips and lateral buds. Table 1. Percentage of single node explants, which developed into a https://www.w3.org/1998/Math/MathML"> 2 - 3   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> shoots after (12-21 days) in vitro. BAP treatments (0.05, 0.2 and https://www.w3.org/1998/Math/MathML"> 0.5 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) pooled. https://www.w3.org/1998/Math/MathML"> N = 18 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> % transferred for multiplication https://www.w3.org/1998/Math/MathML">   Clone   1 / 2   MS   777   MS   78   WPM   83   x   _ 778 11 22 28 83 779 50 55 50 52 780 17 5 38 20 785 38 28 67 44   E4856   45 62 45 50 x ‾ 41 42 52 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Three levels of BAP were tested in an experiment. It seems that optimal concentration is ca. 0.1-0.2 mg/l for most clones (Table 2). No significant interaction between the basal medium and the growth regulators could be observed. The time elapsed from the initiation of the culture to the transfer of https://www.w3.org/1998/Math/MathML"> c a , 3 - c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> long shoots depended primarily on the genotype. The cytokinin level alone did not have any consistent effect on the bud break. A sma11 amount https://www.w3.org/1998/Math/MathML"> ( 0.05 m g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of NAA in addition to the BAP enhanced the bud break slightly in some clones (e, g. P6011, V761). The shoot proliferation was best on a similar medium as in initiation (BAP https://www.w3.org/1998/Math/MathML"> 0.1 - 0.2 m g / 1 w i t h / w i t h o u t 0.05 m g / 1 N A A https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Especially, in the presence of NAA, roots of ten developed in this phase. The multiplication rate was 1.5-5.0 depending on the clone. Similar rates have been obtained by other authors https://www.w3.org/1998/Math/MathML"> ( 3,4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Most of the clones rooted well in vitro (basal medium, 0.1 https://www.w3.org/1998/Math/MathML"> m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> NAA) and in vivo in greenhouse. E4856 and https://www.w3.org/1998/Math/MathML"> V 78 - 2   were hard to root.   - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> E4856 does not root well from the cuttings in the field, either. The proliferation of E4856 is poor, too, and probably a single node culture (3) could be better for this genotype. In 1984 all plantlets (ca. 450) grown in greenhouse a height of more than https://www.w3.org/1998/Math/MathML"> 5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> survived in the field. Table 2. Effect of BAP concentration on the bud break of single node segments. Data from 1/2 MS, MS and WPM pooled. https://www.w3.org/1998/Math/MathML"> N = 18 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> % transferred for muTtiplication Clone https://www.w3.org/1998/Math/MathML"> 0.05 777 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 88 0.2 0.5 778 28 88 72 779 30 12 22 780 22 50 45 785 50 33 5 E4856 66 55 28 https://www.w3.org/1998/Math/MathML"> x - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 52 72 12 52 30

CONCLUSIONS

Well fertilized (5) greenhouse grown stock plants not watered from above are preferable to field material as sources of explants.

Buds in large https://www.w3.org/1998/Math/MathML"> ( 2 - 3   c m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> single node explants develop into shoots that can be transferred faster than excised buds (3) or small bud explants https://www.w3.org/1998/Math/MathML"> ( 3,5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> without the stem. Some of the shoots can be transferred in fact already after one week and most in two weeks.

The same media can be used both for initiation and multiplication (BAP https://www.w3.org/1998/Math/MathML"> 0.05 - 0.2 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with/without https://www.w3.org/1998/Math/MathML"> 0.05 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> NAA).

Most genotypes can be rooted directly e.g. in peat-sand mixture in the greenhouse in high humidity. The hardened plantlets can be transferred into the field when they are at least https://www.w3.org/1998/Math/MathML"> 5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tall.

ACKNOWLEDGEMENTS Dr. Stephen Garton kindly commented on the manuscript. 22. REFERENCES (1) MURASHIGE, T, and SKOOG, F. (1962). A revised medium for rapid growth LLOYD, G. and MCCOWN, B. (1981). Commercially feasible micropropa- (2) LLOYD, G. and MCCOWN, B. (1981). Commercially feasible micropropagation of mountain laurel, Kalmia latifolia, by use of shoot tip (3) BERGMAN, L. V. ARNOLD, S. and ERIKSSON, T. (1984). Culture of Salix species in vitro. Energy Forestry Project. Uppsala, Sweden, Report 36 (4) BHOJWANI, S.S. (1980). Micropropagation method for a hybrid willow (Salix matsudana x a1ba N2-1002). New Zealand J. Bot. 18:209-214 (5) GARTON, S., READ, P.E. FARNHAM, R.S. (1983). Effect of stock plant nutrition on macro and micropropagability of Salix. Acta hort. 131: 141-151 THE USE OF PHOTOINTERPRETATION FOR BIOMASS EVALUATION AND POSSIBLE BIOMASS RECOVERY IN AN AREA OF THE LOMBARDY REGION Summary FOREWORD AND SCOPE OF RESEARCH Table 1 - Land breakdown by main crop, Lodi district: Comparisor of data Erom varlous sources (ha) CROP STATISTICAL DATA https://www.w3.org/1998/Math/MathML"> ( 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ESTIMATED DATA https://www.w3.org/1998/Math/MathML"> ( 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> PHOTOINTERPRETATION DATA https://www.w3.org/1998/Math/MathML"> ( 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Wheat Grain bar1ey 9,772 7,329 14,661.53 Rice 1,417 1,785 682.25 Graln maize 661 659 22,601.48 Forage crops 13,145 13,697 28,779.47 Wood crops, forest, 33,791 35,229 nurserles 4,789 4,789 3,661.43 Other 3,845 3,719 n.a. Tare 3,592 3,592 n.a. Total, 70,799 70,386.162 farmland & woods 71,012 (1) Lombardy Region, 1978 (2) 1980 estlmated data, based on 1978-80 percent. variations over the whole province of M1lan (3) Aerial photographs, Lombardy Region, 1980 . Table 2 - Cattle and swine farms in the sampled munfcipalities: Comparison of data from varlous sources STATISTICAL DATA TERRITORIAL DATA(3) PHOTOINTERPRETATION DATA(4) ZONES CATTLE (1) SWINE (2) CATTLE SWINE CATTLE SWINE FARMS FARMS FARMS FARMS FARMS FARMS (No.) (No.) (No.) (No.) (No.) (No.) ZONE A 21 8 16 3 20 7 ZONE B 39 19 20 5 30 6 ZONE C 15 3 9 4 8 4 ZONE D 31 7 14 8 30 11 ZONE E 81 13 53 19 59 21 ZONE F 89 15 22 8 41 14 (1) UNIONCAMERE-Lombardy, 1980 (2) Lombardy Regton, 1978 (3) Lodi District Survey, 1980 (4) Aerfal photographs, Lombardy Region, 1980. PHOTOSYNIHETIC SOLAR ENERGY CAPTURING IN A CROPPING SYSTEM WITH EXTENSIVE EXPLOITATION OF BIOMASS FOR FUEL PRODUCTION J. Zubr Copenhagen, Denmark Copenhagen, Denmark 23. https://www.w3.org/1998/Math/MathML"> Summary _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A cropping system designed for maximum capturing of solar photosynthetic energy by field crops has been under evaluation for three years. The capacity of crops to capture PAR was measured by LAI and by the production of TS. The biomass of selected crops has been investigated as a source of substrate for bioconversion into alcohol and biogas. Batch alcoholic fermentation of sugar beet (BETA VULGARIS) roots, Jerusalem artichoke (HELIANTHUS TUBEROSUS) tubers and potato (SOLANUM TUBEROSUM) tubers was performed in the laboratory at https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 72 hrs. Prior to the fermentation, potato mash was liquefied and saccharified by the enzyme THERMAMYL and AMG NOVO and as a variable treatment for all materials a specific enzyme SP 249 NOVO has been applied. The fermentation has been carried out by the use of an alcoholic strain of SACCHAROMYCES CEREVISIAE. Maximum yield of alcohol https://www.w3.org/1998/Math/MathML"> 0.531 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TS was achieved from sugar beet roots pretreated with the enzyme SP 249 NOVO. Methanogenic fermentation of crop residues has been carried out in the laboratory using batch system fermentation reactors operating under mesophilic conditions https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . From selected raw materials the highest yield of biogas https://www.w3.org/1998/Math/MathML"> 6381 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VS added and the highest yield of methane https://www.w3.org/1998/Math/MathML"> 4511 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VS added was obtained from ensiled cabbage (BRASSICA OLERACEA var. Capitata) leaves. When an extensive exploitation of the biomass for fuel production was considered, the gross energy yield of https://www.w3.org/1998/Math/MathML"> 251.555 G J / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the form of alcohol and methane produced from sugar beet roots and top, respectively, was the maximum achieved under the above experimental conditions. 24. INTRODUCTION During the last decade in Danish agriculture about 60 of the arable land has been used for growing grain crops such as barley, wheat, rye and oats (1). This large percentage of grain crops enforced new practices in agrioultural managernent making crop rotations one-sided. The specialization has led to development of an excesive production capacity contributing now to the surplus stock of grains. This controversial situation requires new strategies for the planing of crop production in the near future. At the same time, the economics forces develooment in the direction of efficient production while ecological considerations demand sustainable cropping systems safeguarding the environment. In future cropping systems which should be both economically and ecologically justifiable, the croo structure is to be adapted to the local climatic and soil conditions. Anyhaw, the maximum photosynthetic energy capturing by the crops remains still the primary demand. In this respect, long term crops with a high photosynthetic capacity, producing a biomass rich in carbohydrates are considered as a substitute for the excesive grain crops. These crops besides of the main products will yield large quantities of byproducts in the form of crop residues. The main crop products can be used as raw materials for industry while the byproducts offer the possibility of exploitation in an nontraditional way for production of fuel. With regard to abundance of the crop residues, the exploitation should be located in the rural area in order to keep the transportation expenses as low as possible. From an ecological point of view the most beneficial method for conversion of the biomass into fuel under this conditions seems to be the methanogenic fermentation. It has been recognized, however, that the economics of methanogenic fermentation is still the crucial problem. This depends on a number of factors such as the technology, quality of raw materials, biodegradability of the substrates etc. Although a certain progress has been made f. inst. with application of cellulolytic enzymes https://www.w3.org/1998/Math/MathML"> ( 2,3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , much remains still to be done concerning the specific problem of lignocellulosic compounds, the technology etc. 25. CIIIMATIC CONDITIONS The experimental area is located at https://www.w3.org/1998/Math/MathML"> 55040 ' N 12 ∘ 18 ' E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> about https://www.w3.org/1998/Math/MathML"> 20   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> west of Copenhagen at an altitude of https://www.w3.org/1998/Math/MathML"> 30   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a.s. 1 . The climatic conditions, mainly the temperature, delimit the duration of the growth seasons to the period fram 1. April to 31. October. The normal daily mean temperature is https://www.w3.org/1998/Math/MathML"> 7.5 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , during the growth season https://www.w3.org/1998/Math/MathML"> 11.9 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The available PAR amounts to 49 o of the global radiation having the maximum in the middle of summer (Fiqure I). The normal annual precipitations amount to https://www.w3.org/1998/Math/MathML"> 583   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of which https://www.w3.org/1998/Math/MathML"> 371   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> makes up rainfall for 7 months of the growth season (Figure II). Under normal conditions the rainfall compensates for the transpiration of intensive crops also during the surmer months. This allows a growth of long-term crops with maximum photosynthetic production during the summer. n P ห ป Figure I Figure 1. (1eft) Daily totals of photosynthetical Hhetically active radiation (1955-1979) Einstein https://www.w3.org/1998/Math/MathML"> m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (4). Figure II. (right) Monthly normal precipitations (1955-1979) mm (4). 26. CROPPING SYSTEM The predominating crop grown in Denmark is spring barley (HORDEUM VULGARE). As shown in Figure III, the growth cyclus of spring barley is short. This becomes important when such a crop is grown repeatedly without crop rotation. In this way the PAR available during the summer and the autumn is lost. To eliminate these losses and the drawbacks of the overspecialization as mentioned above, a field experiment with a cropoing system including 20 different crops and 18 crop rotation combinations was started in 1982 . The field experiment was designed to become a model for a liberal-ecological cropping system with production of biomass for energy purposes. In order to capture maximum of the PAR for a large part of the season as possible, long-term crops and catch crops were incorporated. The IAI and prodution of Ts were measured periodically and on this basis the cropping system has been evaluated. The leaves area distribution in the form of LAI of selected crops is shown in Figure III. 27. PRODUCTION OF BIOMASS The local climatic conditions give the theoretical possibility of photosynthetic production of biomass during the growth season of 7 months per year. Provided that all growth factors are optimal, then LAI of a crop can be considered as a measure of the respective crop capacity to capture the PAR. Different terms can be used to express the growth rate and the photosymthetic energy efficiency of a crop. Growth rate is usually cited as dry matter production per unit area per day while the photosynthetic energy efficiency is given by the TS production per unit of radiation https://www.w3.org/1998/Math/MathML"> ( 5,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The interrelation between these two parameters expresses the photosynthetic capacity of the crop in question. Thus, the crops with large IAI remaining photosynthetically active during the period of optimal growth conditions can be regarded as feasible for production of biomass. The evaluation of selected crops is sumarized in Tables I and II showing differences among these crops in the ability to accumulate photosynthetic energy and also to release this energy from the biomass. Evaluation of crops taking the only parameter of fuel production into consideration is of course not complex. From some of the crops only crop residues are used for production of biogas, nevertheless, the yield of TS namely https://www.w3.org/1998/Math/MathML"> 22.894 t / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of sugar beet roots and top and the yield https://www.w3.org/1998/Math/MathML"> 23.099 t / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Jerusalem artichoke tubers and stalks proved the superiority of these two crops in the cropping system. Both these crops can be classified as energy crops with a high energy potential of the products and byproducts. 28. EXPLOITATION OF THE BIOMASS The exploitation of both the main products and the byproducts for fuels has been performed experimentally in the laboratory. The economics of microbial conversion of biomass into fuel, although being decisive, has not been subject of consideration in this context. Production of alcohol from biomass is becoming actual with the increasing need for clean fuels for motor vehicles. One of the factors determining the applicability of a crop for the microbial conversion into alcohol is the yield of fermentable substrates. According to recent report the ethanol yield of crops such as f.inst. Jerusalem artichoke can reach https://www.w3.org/1998/Math/MathML"> 56 h l / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha (8). In connection with the field experiment a laboratory investigation was performed with a comparative production of alcohol from sugar beet roots, J. artichoke and potato tubers. All three crops were grown under similar conditions and were harvested in the last days of october 1984. In the laboratory the materials were boiled under pressure for https://www.w3.org/1998/Math/MathML"> 30   m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . and homogenized with a blender, finally the pH was adjusted to 4.5-5.0. The mash of potato tubers was liquefied and saccharified enzymatically by the use of THERMAMYL and AMG NOVO. All materials were then fermented without and with SP 249 NOVO enzyme, using the alcoholic strain SACCHAROMYCES CEREVISIAE under temperature of 30 o C during 72 hrs. Yield of alcohol was determined after distillation by using alcohol dehydrogenase (9). Table I. Production and yield of alcohol from selected crops. The table shows that sugar beet roots exerted the highest respons to enzymatic treatment. The effect of the enzyme SP 249 should be ascribed to the degradation of plant tissue (polygalacturonase, pectinase activity) releasing additional substrates for the fermentation. The yield of alcohol per area unit confirms that sugar beet root is a superior raw material for production of alcohol. The difference between J. artichoke and potato in yield of alcohol per area unit was mainly caused by the difference in yield of tubers. In order to evaluate the feasibility of crop residues for production of gasous fuel via bioconversion, a laboratory investigation has been carried out with anaerobic fermentation by the use of batch system reactors operating under mesophilic conditions https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The investigation included 30 different plant materials mainly crop residues (7) of which selected examples are presented in Table II. Table II. Production and yield of biogas from crop residues. RAW MATERIAL https://www.w3.org/1998/Math/MathML"> T S g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BG https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Y I E T D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Y I E L D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Y I E T D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1 / k g V S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1 / k g V S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> T S t / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> V S k g / h a C H 4   m 3 / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> SUGAR BEET fresh top 12.9 534±18.2 355 6.860 5214 1851 J. ARTICHOKE Sillage stalks 17.1 468±14.8 315 12.120 10787 2718 POTATO silage top 17.7 347±11.6 246 2.567 2026 498 WHITE CABBAGE silage leaves 10.4 638±15.9 451 6.720 5242 2364 MAIZE fresh stalks 24.8 378±7.8 257 7.315 6730 1730 SPRING BARLEY straw 89.4 427±16.3 274 5.784 5495 1506 As shown, the highest yield of https://www.w3.org/1998/Math/MathML"> C H 4 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VS added has been achieved from ensiled leaves of white cabbage. The yield of methane from potato top when expressed per area unit is not satisfactory in comparison with the other raw materials. This is mainly due to the very low yield of the top. The exploitation of crop residues for production of biogas is associated with specific problems of biodegradability, production rate as well as the handling of fermentation residues (7). From economical point of view the bioconversion of crop materials into gasous fuel via methanogenic fermentation needs further investigation. Table III. Yield of gross energy from selected crops. 6.GROSS ENERGY YIEID Proper experimental evidence proves that the main products rich in fermentable substrates as well as the byproducts from long term crops, both can be exploited for fuel production. Under climatic conditions of Norhern Europe, with the exception of seasons extraordinary dry, these crops can be grown with succes without irrigation. Anyhaw, a certain limit is given by the agrotechnical demands of crop rotation particularly in the case of sugar beet. For comparative purposes the gross energy yields in the form of alcohol and biogas from selected potential crops are presented in Table III. The highest gross energy yield was achieved from sugar beet which being used for alcohol and biogas production yielded https://www.w3.org/1998/Math/MathML"> 251.555 G J / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha equivalent to 706610. E. /ha/year. In a crop rotation with other field crops and with Jerusalem artichoke, which yielded https://www.w3.org/1998/Math/MathML"> 189.355 G J / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha equivalent to 5319 I O.E./ha/year, this crop combination appears feasible for incorporation into a cropping system designed for intensive capturing of PAR in the biomass of plants. 29. ACKNONLEDGEMENTS The experimental work was supported by The Royal Veterinary and Agricultural University, Copenhagen, and partly sponsored by the Danish Agricultural and Veterinary Research council. Linguistic revision of the text by E. Svenstrup. 30. REFERENCES (1) DANMARKS STATISTIK (1983). Landbrugs statistik, (Danish). (2) PAGUOT, M. , THONART, P., FOUCART, M., DESMONS, P, and MOTTET, A. (1984). Improvement of pretreatments and technologies for enzymatic hydrolysis of cellulose from industrial and agricultural refuse and comparison with acidic hydrolysis. In: Anaerobic digestion and carbohydrate hydrolysis of waste. Edit. FERRERO, C.L., FERRANTI, M.P., NAVEAU, H. Elsevier Appl. Publ. London, 112-124. (3) RIJKENS, B.A. (1979). Methane and compost from straw. In: Proc. of the third coordination Meeting of Contractors "ENERGY FROM BIOMASS" 6-8 June 1979, Taormina, Italy. (4) HANSEN, S., JENSEN, SV.E., ASLYNG, H.C. (1981). Jordbrugsmeteorologiske observationer statistisk analyse og vurdering 1955-1979, (Danish). Den Kgl. Veterinær-og Landboh ∅ jskole, кфbenhavn. (5) SIBMA, L. (1977). Maximization of arable crop yields in the Netherlands, Neth. J. Agric. Sci. 25,278-287. (6) SIENART, G.A. https://www.w3.org/1998/Math/MathML"> ( 1970 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . High potential productivity of the tropics for cereal crops, grass forage crops and beef. J. Austr. Inst. Agr. Sci. 36, 85-101. (7) ZUBR, J. (1985). Crop residues and energy crops as renewable sources of convertible photosynthetic energy for methanogenic fermentation. In: Biotechnology and enviromental systems, WISE, D.L., CRC Press. (8) WILLIAMS, L.A. and ZIOBRO, G. (1982). Processing and fermentation of Jerusalem artichoke for ethanol production. Biotechnol. Letters Vol. 41,45-50 (9) BERNT, E. and GUTMANN, I. (1974). Ethanol determination with alcohol dehydrogenase and NAD. In: Methods of enzymatic analysis, BERGMEIER, H.U., Acad. Press, N.Y. Vol. 3, 1499-1502. (10) BABA (1982), Anaerobic digesters, A code of practice on safety in and around anaerobic digesters. (11) BERG, P.S., HOLMER, E. and BERTILSSON, B.I. (1980) . The utilization of different fuels in a diesel engine with two separate injection systems In: Proc. of third International Symposium on Alcohol Fuel Technology, Asilomar, Califormia 29-31 May 1979. MICROPROPAGATION OF SOME FOREST TREE SPECIES G. SAVOIA and S. BIONDI Azienda Regionale delle Foreste dell'Emilia-Romagna, Bologna, Italy Summary In view of the need to increment biomass production for energy, the A.R.F.E.R. is examining ways to increase the productivity and economic viability of Regional forests by increasing the genetic gains. This can be achieved by selecting and cloning the best individuals within the best geographic sources of the best species. Using micropropagation as an in vitro technique of vegetative propagation, quality trees are selected and massproduced. In this way the rapid multiplication of selected genotypes which are scarce and/or difficult to propagate by rooted cuttings can be achieved. The species chosen to date for the micropropagation studies are chestnut, walnut, Douglas fir, wild cherry, alder and elm. Only mature trees, old enough to have demonstrated their superior characteristics, are propagated. This often requires the application of "rejuvenation" treatments on the donour-plant to improve the response of the explants to micropropagation. The field performance of the micropropagated plants will be evaluated in every case and clonal collections and seed orchards established. 1. INTRODUCTION The potential energy obtainable from forest biomass is impressive. For biomass production, the major objective is to obtain the maximum growth of the most desired wood in the shortest possible time at as low a cost as possible. With this objective in mind, the A.R.F.E.R. is examining ways to:

increase the yield on already good sites, and

develop trees capable of growing on marginal or non-productive areas that currently do not support an economical forest enterprise.

The A.R.F.E.R.'s project on the micropropagation of forest tree species is aimed at obtaining genetic gains from tree improvement by:

locating and using the correct species;

using the best geographic sources within the best species;

selecting and cloning the best individuals within the best sources of the best species. Hybrids especially developed in breeding programmes (elm) and elite cultivars (chestnut) are also used.

When the energy and fuel-wood species are selected, special consideration should be given to adaptability, rapid growth (short rotation), ability to coppice and production of wood of high calorific value (1). The micropropagation project has also taken into consideration those species which can assist in land consolidation on steep hillslopes (over https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the Regional forests are in hilly or mountainous areas), which can grow on clay soils and which provide high quality wood. This latter aspect is of fundamental importance since Italy imports https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of this wood and these imports weigh heavily in the country's foreign trade balance. Using in vitro techniques, quality trees and disease-resistant clones are selected and massproduced (this also ensures the conservation of our dwindling genetic reserves); also the risks associated with the collection and variable quality of seeds and with nursery practice are reduced. It is expected that this alternative approach to the vegetative propagation of elite trees or cultivats will consent the following: a) the rapid multiplication of selected genotypes especially when these are scarce, since tissue culture offers the advantage that a few explants are sufficient to produce several thousand propagules; b) cloning selected genotypes in species which are difficult to propagate by rooted cuttings; c) an improvement in the rooting percentage of cuttings. It has been reported that when micropropagated plants are used as ortets, the rootability of cuttings is higher (2). To date the following species have been considered for our micropropagation studies: https://www.w3.org/1998/Math/MathML">   Castanea   _   sativa, Juglans regia, Prunus avium, Pseudotsuga menziesii, Alnus cordata and Ulmus   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> spp. In line with the fore-mentioned objective of improving forest productivity and obtaining high genetic gains by using carefully selected genotypes, only mature trees old enough to have demonstrated their superior chatacteristics, are used as donour-plants. In view of the well known difficulties encountered when attempts are made to propagate mature clones, two solutions are being examined

pre-treatments on the donour-plant that convert mature tissues to a more juvenile state "'rejuvenation"");

propagation of adolescent trees (5-10 years old depending on the species). Theoretically the propagules can be kept in cold storage for several years during which time the quality of the donour-plants is evaluated. Subsequently, the propagules of the plus genotypes are masspropagated while the others are discarded.

In all cases, the field performance of the micropropagated plants is to be determined Seed orchards (as a complement to vegetative propagation) to supply genetically improved seed for the forest industry can be set up using micropropagated plants. As well, if in vitro mass propagation proves not to be economically viable with respect to other means of vegetative propagation, micropropagated plants can be produced in limited numbers to create clonal orchards from which classical cuttings can be taken for large-scale production. These clonal orchards will also play a role in germplasm conservation. 31. MATERIALS AND METHODS The micropropagation programme is subdivided into the following stages:

choice of donour-plants and explants

II. rejuvenation of donour-plants III. in vitro propagation IV. transfer of plantlets to soil and field trials V. clonal collections. The materials and methods used in each of these stages will be described briefly. I. Choice of donour-plants and explants As stated in the Introduction, our project makes use of high value donour-plants selected for specific genetic traits such as wood quality, form, growth rate, disease resistance, etc. They are located on the basis of:

a survey carried out in Emilia-Romagna in which the best individuals were selected; - ongoing breeding programmes (at the Istituto Sperimentale per la Selvicoltura of Arezzo and the Centro di Studio per la patologia delle specie legnose montane, C.N.R. of Florence in which different geographic sources are subjected to comparative tests or, as in the case of elm, in which new hybrids are being created and tested for their resistance to Dutch elm di sease.

For chestnut, elite cultivars which have been vegetatively propagated (by grafting) for many years in Tuscany and collected in trial areas set up by the Istituto di Selvicoltura of the University of Florence, are used as donour-plants. The choice of the explant (bud) refers principally to the part of the tree from which it is collected and the time of year it is collected. Bud break in culture occurs faster and better if the buds are in the predormant stage. It has been recognized that the rooting response of cuttings and the feasibility of in vitro propagation rapidly decline with increasing age of the donour-plant. Several approaches have been taken in recent years to overcome this obstacle and obtain physiologically younger or so-called "rejuvenated" material. First of all, some parts of adult trees are thought to be more juvenile, in particular those which are closer to the roots. Thus, buds or ramets taken from stump sprouts or root suckers of mature trees are more easily propagated. II. Rejuvenation When a mature tree does not spontaneously form juvenile material, several techniques can be applied to induce the process of "rejuvenation".

Grafting scions taken from the mature tree onto young rootstock.

It may be necessary to repeat the grafting cycle several times in succession ('successive grafting")

Nut-grafting. This approach is based on the same concept that grafting on a young rootstock tends to 'rejuvenate' mature scions. Nut-grafting can be applied to chestnut and walnut The scion is grafted on a germinated nut after removal of the radicle and part of the hypocotly, into a transversal slit cut across the nut. Alternately, only the apical part of the radicle is excised and the scion is joined onto the remaining part.

The release of suppressed buds, by hedging to form epicormic shoots which are frequently more jtivenile.

Cytokinin foliar sprays. Cytokinins are a class of plant growth regulators (phytohormones which, when applied at relatively high concentrations to a plant, release lateral buds from apical dominance. These compounds are used in tissue culture to induce bud break and shoot proliferation, but also to induce or maintain a rejuvenated phase. Indeed, studies carried out principally in France and the U.S.A., seem to indicate that several weekly applications of cy- tokinin foliar sprays prior to natural bud burst produce rejuvenated material which is more easily propagated both by rooted cuttings and by axillary bud cultures. IIJ. In vitro propagation

In our programme, in vitro propagation is carried out by means of axillary bud cultures This approach requires surface sterilization of buds collected preferably in the predormant stage, followed by bud scale removal, excision of the shoot apex with attached young leaf primordia and introduction in aseptic culture on an appropriate medium. The components of this medium must be empirically determined at each subculture to allow the following succession of events:

bud break (within approximately 4 weeks)

the development of lateral meristems and the outgrowth of small shoots (multiplication phase

the elongation of these shoots to at least https://www.w3.org/1998/Math/MathML"> 10   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lengths

the rooting of elongated shoots for plantlet formation. This technique is commonly referred to as "micropropagation" and has led to many recent successes in mass propagating woody species.

It must be emphasized that each species and sometimes each cultivar to be cloned more often than not requires the development of a specific procedure which can, with our present knowledge, only be derived empirically. IV. Transfer of plantlets to soil and field trials. Plantlets produced in vitro must be acclimated or hardened, i.e. they must undergo gradual transition to the lower humidity and higher light intensities existing in the open. Fhis is achieved by transplanting the plantlets into potting mixtures and placing them under warm and highly humid conditions, for example in a greenhouse under intermittent mist. However, different species require specific methods of handling, light and temperature regi mes, etc. which must be determined by trial-and-error. Upon transfer to nursery or field conditions, several points must be borne in mind: - the quality of the root system. This is important for nutrient absorption, wind stability and form. Sometimes what may seem like plagiotropic growth is due to a poorly balanced root-shoot system.

Plantlets are very vulnerable to pathogen attacks and must be treated with pesticides, fun gicides, etc.

Field performance is evaluated in terms of growth rate, topophysis, disease resistance, etc. and in comparison to seed-derived seedlings and rooted cuttings. V. Clonal collections In parallel to the studies linked to the micropropagation of the species under examina- tion, efforts are being made to set up clonal collections with the selected genotypes using grafting techniques in nurseries or plantations belonging to the A.R.F.E.R.. This scheme has a dual purpose:

to render the plants more accessible for the collection of material for propagation;

to ensure the conservation of unique genotypes even where micropropagated plants are not yet available. At the same time, the performance of clones or cultivars which have demonstrated their superior characteristics in other geographic locations can be tested in the Appenines of Emilia-Romagna where the future reforestation programmes are to be carried out.

32. RESULTS Castanea sativa. Varietal collections have been established by grafting scions of 8 elite cultivars on 1-year old seedlings or 2-year old stump sprouts. Various techniques related to the grafting operation and the incidence of ink disease and chestnut blight are examined. The method of nut-grafting in which the scion is grafted onto the radicle has given po sitive results but the use of extremely small scions to match the diameter of the radicle may carry epigenetic defects which impair the later development of the plant. Our micropropagation studies have proceeded with buds obtained from scions grafted several years ago on young and vigourous stump sprouts and pruned annually, The results obtained to date regard mainly one cultivar (Mozza). In the presence of a growth hormone (0.5 https://www.w3.org/1998/Math/MathML"> m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> benzyladenine (BA)) proliferation by axillary budding can be achieved. The multiplication rate is approximately 3:1 every 3-4 weeks. The subsequent elongation of the shoots thus obtained, which is enhanced by reducing the BA supplied to the medium, is somewhat erratic. Consequently, experiments aimed at inducing rhizogenesis in the shoots are limited. With the material available, numerous trials have been carried out varying the macro-and micro-nutrient formulas, the hormonal treatments, the physical support, etc., but as yet this phase of the micropropagation process remains to be accomplished. Prunus avium. Seven selected clones have been introduced in aseptic culture. Approximately 1000 micropropagated plants of each of 4 clones have been planted in the field for comparative tests on the performance of the different geographic sources. A further 1000 plants of the clone Paradisino have been planted out (November '84) for the purpose of creating a seed orchard. The micropropagation of this species followed the usual scheme of inducing axillary budding on a medium supplemented with BA https://www.w3.org/1998/Math/MathML"> ( 1.5 m g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The multiplication rate was rather high since several hundred plantlets can be obtained from one explant in 8 to 10 months. Fol lowing shoot elongation on a medium with reduced BA, rooting was induced in the presence of https://www.w3.org/1998/Math/MathML"> 3 m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> indole acetic acid. The rooting percentage varied from clone to clone https://www.w3.org/1998/Math/MathML"> ( 15 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 80 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Rooted plantlets were successfully hardened in a greenhouse (over https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> survival rate) and transferred to soil for field trials. Ulmus spp.. Two species and several elm hybrids with a good level of resistance to Dutch elm disease developed in the breeding programmes undertaken in Italy and abroad under the auspices of the EEC in order to combat this disease have been introduced in one of our nurseries by grafting on https://www.w3.org/1998/Math/MathML"> U _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . pumila seedlings. In the spring of ' 85 scions taken from ortets of U. carpinifolia and of their spontaneous hybrid U, carpinifolia x pumila which, as a survey in progress in Emilia-Romagna will demonstrate, have survived the Dutch elm disease epide mic will be added to the collection in order to preserve their germplasm for future breeding programmes in the hope that at least some of them are resistant. Another possibility is that in the future the Dutch elm disease epidemic may recede, or that effective chemical and biological controls for elm bark beetles will be found so that even the less resistant clones can survive. Buds were excised from the root suckers of a mature (ca. 100-year old) clone, free of Dutch elm disease. The buds were subjected to the normal sterilizing procedures and placed in culture on a suitable growth medium (1 mg/l BA). Shoot multiplication by axillary budding occurred in these conditions. Rooting was induced by adding https://www.w3.org/1998/Math/MathML"> 1 m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> naphthalene acetic acid and https://www.w3.org/1998/Math/MathML"> 100 m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> activated charcoal. Rooted plantlets were hardened in a greenhouse for 40 50 days with excellent survival rates. Over 1000 plantlets were transferred to soil in a nursery for field trials. Some of the resistant hybrids and species mentioned earlier have now been introduced in culture. In some cases (e.g. https://www.w3.org/1998/Math/MathML"> U _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , wilsoniana, https://www.w3.org/1998/Math/MathML"> U _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , villosa and "454 Lobel"), their micropropagation is already in the final stages. Pseudotsuga menziesii. Numerous North American and one Italian provenance of this species have been introduced in experimental areas via rooted cuttings for comparative tests between the various provenances. The cuttings from these superior provenances are part of a IUFRO programme aimed at comparing over 80 provenances. Another collection has been set up by grafting on 2 -year old seedlings scions taken from 20 individually selected phenotypically superior clones growing in the forest of Vallombrosa, Tuscany. These clones are approx. 60-80 years old and are currently subjected to progeny tests. Two approaches have been taken in order to rejuvenate the mature clones:

successive grafting

foliar applications of a cytokinin (BA).

Experiments to induce axillary budding are now in progress with buds collected from 6-7 years old trees of various provenances. Juglans regia and Alnus cordata. Work with these species has thus far proceeded as far as constituting clonal collections or sowing the seed of selected clones. Some mature walnut clones have been severely pruned to induce the formation of epicormic shoots which may provide "rejuvenated" material for propagation. For alder, scions from 42 plus ortets selected in the province of Florence were grafted on seedlings in the spring of '84. These have been planted out in the forest following an experimental design. 33. https://www.w3.org/1998/Math/MathML">   REFERENCES   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) DURZAN, D.J. (1982). Cell and tissue culture in forest industry. Tissue Culture in Forestry (J.M. Bonga and D.J. Durzan, eds), Martinus Nijhoff Publishers, The Hague 3671. (2) BOULAY, M. (1985). Some practical aspects and applications on the micropropagation of forest trees. International Symposium on In Vitro Propagation of Forest Tree Species, Bologna. II. CONVERSION (a) Anaerobic Digestion (b) Fermentation (c) Hydrocarbons (d) Combustion (e) Gasification and Pyrolysis (f) Lique faction (g) Chemicals (h) Enzymes ANAEROBIC DIGESTION IN THE FOOD PROCESSING INDUSTRY https://www.w3.org/1998/Math/MathML">   A   _   FEAS IBILITY   _   STUDY   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> D.J. https://www.w3.org/1998/Math/MathML"> C O X https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and D.R. NUTTALL Polytechnic of the South Bank, London SE1 OAA, U.K. 34. Summary Over 200 companies in the JK food and beverage sector were contacted and asked to collaborate https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a study of effluent treatment/disposal strategies. Flfty-one were ulstted and gentor personnel tnterviewed strategies. Flity-one were visited and sentor personne. literviewed questionnalres were completed (1n some cases) concerning strength, volume, nature of wastes, cooto 1 necurred and company perspectives and Wolume, hature of wastes, costs 1ncurred and company perspectives and strategies. The economics of on-site treatment were generaliy favourable w1th anaeroblc digestlon showlng most promlse. Pay back. of most gnaeroble systems was (or would be) withtn the 1 fmita of most anaerobic systems was (of would be) withla the limits considered sultable for commercial investment (2-5 years). However, a large proportion of Industrialists were not kindly dlsposed towards on-slte treatment of any type, and often preferred to reduce diaposnl costs through factory husbandry. Susplcion of on-site treatment was principally on aesthetic grotinds (particularly the prospect of malodorous emisstons) and also there were worrles about practlcality of operation, malntenance and monttoring. The prospects of blogas use for process or other heat was of peripheral interest to all but the most commltted devotees. Many s1tes were too restricted for space, or were unable to collect trade waste easily. Vegetable processing and malting seemed most sultable for on-site anaeroblc treatment In the UK. Meat and poultry processing least so. 35. INTRODUCTION The effluent disposal problems of the UK food processing and beverage sector has been evaluated on a number of previous occasions. (e.g. (l)), as often as not, however, the results of these surveys or evaluations have efther not passed lnto the publlc domaln (slnce they were sponsored by organlsations with commerclal interests in the results), or have been targetted to spectific subsectors (e.g.brewtng), or are reporto field trials of particular designs of plant. Many evaluations have been based on literature studies alone where speculatlve projections have been made Erom average cod/flow data, whth little attempt betag made to consider the needs, aspirations and problems of the actual end-users of plant. Generally speaking, the industry has not been well served by consultants In this fleld, whose experience ls rooted in domestic wastewater dogma. Thus there are several palnful examples of activated sludge-type processes befng installed to treat certain industrial wastes whlch are clearly unsulted to such treatment, resulting in a high waste activated sludge disposal problem. Similarly, poorly fteld-tested novel designs of plant have been installed on several occasions with exaggerated claims belng made for thelr capabllıtles. The subsequent lacklustre performance of these systems has done much to encourage susplcion among other potential Add1tlonal1y, WA offlcials in the UK malntain a regular presence in https://www.w3.org/1998/Math/MathML">   f a c t o r t e s   a n d   a r e   o f t e n   r e g a r d e d   a g   h o g t l t e   b y   c o m p a n y   p e r s o m n e l o n t a l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> companles had undertaken some form of evaluation of thel.r trade waste disposal and the majorlty had tnvited commercial representatlues to their premtses and requested quotatlong for treatment plant. In those cases premlses and requested quotatlons Lor treatinent plant. In those cases where a realistic economic assessment had been made (about https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), and where there were no spectal problems assoclated with the effluent itself, then anaeroble systems were overwhelmangly favoured over aerohtc. payt baele anaerobic systems were overwhelmingly favoured over aerobic. Pay back times of between 2-5 years had been calculated for the former, as opposed to 7-10 years for the latter. Interestingly, lnterviewees had accounted for the obvious fentures of for the obvious features of capleal cost and trade charge savings, and had also consldered labour charges, power costs and sludge disposal problems, but few had bothered to estimate the potential value of any biogas produced. There is evidence to suggest that since these savings would accrue to a different 'cost centre" with1n the company, then there was 1ittle incentive for the effluent treatment manager' to eate these savings highly in his own budgetting. Nevertheless, even 1n those cases where pay back times had been calculated as 2-3 years, companies were often reluctant to invest several hundred thousand pounds in treatment plant, arguing that a similar Investment In production plant would pay back even sooner. One of the most surprising conclusions of the survey was the extent to which companies were concerned with aesthetic and non-techntcal problems assoclated with on-site treatment plant. Most interviewees were very worrled that systems would produce malodorous emlsstons whlch would create ll1-reeling among local residents who were usually already mildly host11e to netghbouring factories. In the company's perception, anaerobic systems were favoured in thls regard since, belng enclosed, they would be less likely to generate smells. Balancing tanks, apart from belng very costly, are often the culprit https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> malodorous plants, and commercial prizes awalt the effluent disposal company which devises a system with a reduced or eliminated requirement for balancing. The oplnlon was also regularly votced that food processing compintes are not in the thisiness' of offluent disposal https://www.w3.org/1998/Math/MathML"> -   t h e y   a r e   n o t   l i s e d   t o   t o   t h e   t h e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> effluent disposal they are not used to lt, they do not have personnel trained in it, and the use of such operations may detract from the company's "image" In other words effluent treatment and for 'effluent" read "sewage"t) is not conslstent with food production. Flnally, 1 t was clear that a large number of factories elther did not have the space for on-site treatment plant, or did not have an adequate system of dratns. This was particularly so in brewerles (especially older breweries) which usually occupy urban s1tes several centuries old, and also in confectionery factories. The same problem also applied to poultry and meat processing factories, although to a lesser degree. In any case, the effluents generated by brewing and meat processing are not well sulted to on-site (anaeroblc) treatment, largely due to their inconsistent nature and extremes of pH, toxic content and so on. 36. CONCLUSIONS this survey are subjective and based on concensus views rather than tinassaliable solentific data. Moreover the gample gize was not large in unassallable scientific data. Moreover, the sample slae was not large in p1cture that had emerged after more than a year "on the road' 1 a true reflection of the prevalling vlens of putative practitioners of anderoble digestion In the food and beverage industries. We conclude that the 37. PURIFICATION OF BIOGAS K.EGGER, K. SUTTER and A.WELLINGER BIOGAS PROJECT, Swiss Federal Research Station for Farm Management and Agricultural Engineering. CH-8355 Taenikon 38. INTRODUCTION Biogas formed from any substrate is usually composed of methane, carbon dioxide, water vapor and trace amounts of hydrogen sulfide. Often the question is risen whether it would be of advantage to remove all gases but the energy rich methane. The scrubbing of coz as inert gas is of limited interest only. for applications where the gas is compressed or has to be brought up to pipeline qualities. For the hydrogen sulfide however. it is strongly recommanded to strip it off before any utilization of biogas. It is at the same time a nuisant and heavily toxic compound. The subject of the present study was to design H2S and CO2 purification plants for on-farm utilization. Construction parameters were defined in pilot plant experiments and consequently full-size installations have been built and monitored on the farm for about nine months. The purified gas was used to run a biogas tractor (see poster PIV/234).

CHEMISORPTION OF HYDROGEN SULFIDE

When protein or sulfate containing organic waste is anaerobicaliy degraded, trace amounts of hydrogen sulfide are formed. ranging in biogas from animal manure up to https://www.w3.org/1998/Math/MathML"> 0.5 % ( v / v ) . H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is not only a very toxic gas. it is also very corrosiv. Gas utilities therefore have stringent quality requirements:

For the use of biogas in internal combustion engines, manufacturers

usually require concentrations of less than 50 to https://www.w3.org/1998/Math/MathML"> 100 ppm . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

If biogas is used as boiler fuel. H2S causes an increase of the exhaust gas dew point (the so called acid dew point). With common concentrations of several hundred ppm's H2s in the biogas, the condensation temperature of the flue gas is increased up to 160 C. This value compares to natural gas with a dew point of 57 c only. The condensate formed is rich in sulfuric acid and leads to heavy corrosion of exhaust pipes, chimneys and parts of the heater.

Virtually all of the H2S has to be removed for the storage of biogas under high pressure (200bar). Together with traces of water. H2S leads to heavy corrosion of the pressure bottles within a few weeks.

The same is true for cooking where H2S is reduced to soz which is odourless but even more poisenous than the former.

Chemisorption: Proceedures to remove H2S from a gas phase have been known for many years however. they were hardTy applied with biogas. One of the oldest technologies is the chemisorption by iron oxide: https://www.w3.org/1998/Math/MathML"> F e 203 ⋅ 3 H 2 O + 3 H 2   S = F e 2   S 3 + 6 H 2 O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> With the addition of oxygen the iron sulfide is regenerated in a strongly exergonic reaction: https://www.w3.org/1998/Math/MathML"> F e 2 S O 3 + 3 / 2 O 2 + 3 H 2 O = F e 203 ⋅ 3 H 2 O + 3   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The pure sulfure formed during the reaction is an ecologically harmless compound and adheres usually to the iron oxyde. This dry purification process fits perfectly well into the requirements of agricultural biogas cess fits perfectly wellininto the requirements of agricultural biogas gas flow rates of 10 to https://www.w3.org/1998/Math/MathML"> 500   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per day. The market offers a variety of bas flow rates of 10 to 500 miz per day. to https://www.w3.org/1998/Math/MathML"> 30 mm https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and diameters around https://www.w3.org/1998/Math/MathML"> 12 m m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The water content of the different products varies from https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 20 % ( w / w ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Two process parameters essentially describe the behaviour of an adsorption column: the load and the zone of reaction. Both were defined in a pilot-size column of a height of https://www.w3.org/1998/Math/MathML"> 1   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a diameter of https://www.w3.org/1998/Math/MathML"> 65   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which was filled with 33 litres of iron oxide pellets (Hamm Chemie. Germany). Biogas with defined concentrations of H2S was added at the bottom and its adsorption meassured at different levels (C1...Cn) in the column (Fig.1). Fig. https://www.w3.org/1998/Math/MathML"> 1 H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> adsorption column: pilot plant. Load: The total amount of H2S which can react with iron oxide is a funct https://www.w3.org/1998/Math/MathML"> ion - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of H2S-concentration and reaction temperature. At https://www.w3.org/1998/Math/MathML"> 22 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the maximal adsorbtion determined in a single load without regeneration increased from 2 to https://www.w3.org/1998/Math/MathML"> 25   g H 2   S / 100   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of pellets with increasing concentrations (Fig.2). After every regeneration step a part of the active reaction surface was covered with adhering sulfure and hence, the potential of adsorption reduced. With the product investigated, the load was reduced by about https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after every oxydation. With an initial H2S-concentration of 3500 to https://www.w3.org/1998/Math/MathML"> 4000 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the total load per https://www.w3.org/1998/Math/MathML"> 100   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of pellets was about https://www.w3.org/1998/Math/MathML"> 50   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> H2S (Table 1). In a twocolumn full-size installation which was designed according to the parameters defined in the pilot-plant experiments for the treatment of about https://www.w3.org/1998/Math/MathML"> 100   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of biogas per day, the total load reached only about half that value (25g per loog pellets). Two parameters were probably responsible for that drop:

the ambient temperature on the farm was far lower than 22 C and 2 ) the gas was saturated with water vapor which condensed in the column and moistened the pellets which got caked.

Table 1: Total load of H2S after Repeated Regeneration Concentration of H2S https://www.w3.org/1998/Math/MathML"> p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3500-4000 1100-4000 Ambient Temperature C 18-24 20-23 Dry Pellets kg 3.51 1.4 H2S g 1790 644 Load https://www.w3.org/1998/Math/MathML"> g H 2   S / 100   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pellets 51 46 Zone of reaction: The span of the reaction zone was essentially defined by the temperature which determined the velocity of reaction of the iron sulfide formation (Fig.3). Other factors such as gas velocity in the column or initial H2S-concentration were of minor importance. https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ambient Temperature https://www.w3.org/1998/Math/MathML">   Fig.2     Adsorbtion of   H 2   S   in a single     load in function of   H 2   S-Conc.   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig. 3 Span of reaction zone in function of ambient temperature Continuous addjtion of air: If trace amounts of air are directly added to the biogas, both reactions, the reduction and the oxidation take place at the same time in the column. However. determinations revealed that the zone of reaction becomes increasingly longer without reaching the point of saturation in the lower part (Fig.4). Depending on the ambient temperature. the zone of reaction reached the top of the column within 30 to 100 hours with every concentration of air added from 0.9 to https://www.w3.org/1998/Math/MathML"> 9 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

SCRUBBING OF CARBON DIOXIDE

Removal of CO2 increases the energy content of biogas and hence, the storage capacity particularly at elevated pressure as it is required for the utilisation of biogas as tractor fuel. For that purpose a counter-flow water scrubbing column was developped for the purification of 5 to https://www.w3.org/1998/Math/MathML"> 10   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of gas perubbing column was developped for the purification of 5 th 10 miz of gas per hour. The column had a diameter of https://www.w3.org/1998/Math/MathML"> 20   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and was filled to a height of 1. 3m with plastic saddle bodies (Fig.5). Thanks to the fact. that co2 is about 25 times better soluble in water than methane, the two gases can about 25 times better solubles in water than methane, the two gases can easily be seperated. The raw biogas was compressed to approx. 9 bar and entered the column at the bottom. The water was sprayed at an equal pressure from the top onto the saddle bodies where the co? was disolved After having from the top onto the saddle bodies where the coz was disolved. After having decreased the pressure to ambient conditions the gas was reteased and the water could be recycled. The size of the expansion vessel did not allow an entire regeneration of the water. thus about https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of fresh water had to be added in order to achieve a constant rate of co2 disolution. The rate of co2 removal was influenced in decreasing order by the flow rate of water and the gas flow rate (Fig.6). To reach a methane concentration of https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which is an optimal value to run a dual fuel engine (biogas/diese1). 431 itre per minute of water had to flow through the washing column. However with such a high flow rate also the CH4 losses became important with https://www.w3.org/1998/Math/MathML"> 16 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Thus, from https://www.w3.org/1998/Math/MathML"> 7.7   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of raw biogas which were processed per hour, https://www.w3.org/1998/Math/MathML"> 4.6   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> left the column with a methane content of https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Beside https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> also H2S is disolved in the washing water. It's solubility is even three times better than that of Co2. In our experiments the initial H2S concentration was varied from 300 to 6600 pom. The scrubbing reduced the amount by 90 to https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . CONTRIBUTION TO COMPREHENSIVE ENGINEERING CONCEPTION OF METHANISATION BASED ON KINETIC APPROACH R. BACHER, F. YEBOUA AKA, M. EL-HOUSSEINI and G. GOMA Département de Génie Biochimique et Alimentaire, Institut National des Sciences Appliquées, ERA-CNRS https://www.w3.org/1998/Math/MathML"> N ∘ 879 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Toulouse, France 1. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Biological methanisation of biomass occurs after consecutive reactions (fermentation, acidogenesis, methanogenesis) complicated by semi parallel reaction (reduction of https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The rate of these reactions are described. The critical concentration of salts Na https://www.w3.org/1998/Math/MathML">   + , K + , C a + + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which become inhibitory on methanogenesis is high compared with other ones available in the literature. The effect of initial concentration of acetic acid has been demonstrated. Butyric acid concentration up to https://www.w3.org/1998/Math/MathML"> 20   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has no toxicity effect on the aceto- clastic methanogenesis in continuous fixed bed bioreactor. 2. INTRODUCTION Methanogenesis has traditiona1ly been viewed as a two-stage process, the acid forming and https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -methane forming stage (Toerien and Hatting, 1969 , Kirsch and Syke, 1971). Bryant (1976, 1979) proposed a scheme that attempts to syn- thesize informations on methanogenesis from organic matter. In general, the first stage involves species of fermentative bacteria, which, as a metabolic group, hydrolyse complex carbohydrates, proteins and lipids and ferment these products to fatty acids, https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The second metabolic group, called the hydrogen-producing acetogenic bacteria produces acetate, co 2 and Hz from the fatty acids generated in the first stage. The third stage involves the metha- nogenic bacteria that utilizes the products of the first two stages, mainly acetate, https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to produce https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Recently, an additional stage was added to this scheme. This metabolic group is called the homoacetogenic bac- teria which synthesize acetate using https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and formate (Zeikus, 1979 and Wolfe, 1979). The rates of the hydrolysis and acidogenic reactions are higher than the methane formation rates (Ghosh et al., 1975). There-fore the volatile fatty acids can be accumulated and have an inhjbitory effect on the methane forming bacteria if the equilibrium between these stages are not realised (Kroeker et a1., 1979). Also, the rates of reactions are inhibited by cations (Na*, https://www.w3.org/1998/Math/MathML"> K + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> C a + + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and toxicity effect is associated with the cation rather than anion portion of the salts (Pefefer, 1974). The present work is aimed to describe the dynamic behaviour of the diffe- rent consecutive reactions of the biomethanization process, to compare the critical concentration of cations, to demonstrate the effect of initial con- centration of acetic acid on the biodegradation of butyric acid and to study the effect of different concentrations of butyric acids on the acetoclastic and methanogenic bacteria. 3. MATERIALS AND METHODS Two laboratory batch experiments were made up in bottles of https://www.w3.org/1998/Math/MathML"> 500   m L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the first one, the degradation rate of sucrose, glucose (acid fermentors), lactic, butyric, propionic and acetic acid (methane fermentors) were studied. The second experiment was carried out to state the inhibitory effect of different cations on both acidogenic and methanogenic stages. Different .cation concen - trations of https://www.w3.org/1998/Math/MathML"> K + , N a + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C a + + ( 0.15,0.30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 0.65 mole/L) were used. These Figure 1. : Biodegradation of different substrates involved in biomethanization process. Table 1. Degradation rate and tag phase for ditterent termented substrates

Effect of different mineral salts on the biological activity of both acid and methane forming bacteria

The relation of VEA production per unit of initial sugar added is function of salt concentration as shown in figure? The regults indicate that the activity of cations is dependent on the nature of the associated anions. At the same cation concentration of all salts used, the inhibitory effect of NO 3 is higher than CL and this increases with higher concentrations of different cations. On the other hand, cations of Na , K + when associated with anions of https://www.w3.org/1998/Math/MathML"> S O 4 - - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> have a stinulatory effect. The second experiment is still going on; the first results indicate that there is no toxicity effect, but we have observed a low inhibition on the acetoclastic methanogenesis. 4. 3.- Methanogenesis of butyrate Biodegradation of butyrate in batch cuilture is affected by the initial concentration of acetic acid. Main results are described in figure 3 and Table 2. Concentrations of acetic acid up to https://www.w3.org/1998/Math/MathML"> 6   g / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has stimulatory effect on butvrate degradation. On the other hand, acetate concentration excess of 6 g/l. has an inhibitory effect and this increases with increasing the concentration of acetic acid. Similar result were obtained by Stafford (1982) and Laroche (1983) who found that concentrations of https://www.w3.org/1998/Math/MathML"> 1   g / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 5   g / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has an stimulatory effect on butyrate degradation respectively. On the other hand, Laroche (1983) showed that there was a low inhibition with concentration of https://www.w3.org/1998/Math/MathML"> 10   g / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> acetic acid. 461 https://www.w3.org/1998/Math/MathML">   Figure   2 :   Effect of different concentrations of cation in association with     different anions;   →   reference,   ◻ ◻ N O 3 , 0 - 0 S O 4 , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The main results obtained from the fixed bed reactor are Summarized in Table 3. Acetate accumulation begins with low initial concentration of butyrate. But butyrate accumtlation appears at https://www.w3.org/1998/Math/MathML"> 10   g / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> initial concentration. The gas production increases from 1 to 3.5 L/L/day with increasing butyrate concentration. On contrary, methane percentage decreases from 82 z to 75 ₹ when butyrate increases from concentration of 4 to https://www.w3.org/1998/Math/MathML"> 20   g / L . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

REFERENCES

1 - Bryant, M.P. In Schlegel, H.G. and Barnea, J. (eds). Microbial Energy Conversion, Pergamon Press. P. 107-117 (1976). 2 - Bryant, M.P. Theoretical aspects. J. Anim. Sci., 48, 193 (1979). 3 - Finck, J.D. These Laboratoire de Génie Biochimique, INSA. Toulouse France https://www.w3.org/1998/Math/MathML"> ( 1983 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4 - Ghosh, S. Conrad, J.R. and Klass, D.L.* J. Water Poll. Cont. Fedn. vol. 47,30-45 (1975) 5 - Kirsch, E.J. and Sykers, R.M. In Hockenhul1, D.J.D. and Churchill, A. (eds). Progress in Industrial Mícrobiology. London. (1971). 6 - Kroeker, E.J., Schulte, D.D., Spariing, A.B. and Lapp, M.M. J. Water Pol1. Contro1. Fedn. https://www.w3.org/1998/Math/MathML"> 51,518 ( 1979 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7 - Laroche, M. Thèse, Institut National de la Recherche Agronomique de Narbonne, France (1982). 8 - Miller, G.L. Anal. Chem., 31, 426-428 (1959). 9 - Pfeffer, J.T. Biotechnol. Bioeng., 16, 771-787 (1984). 10 - Stafford, D.A. Biomass, 2, 43-55 (1982). 11 - Toerien, D.F. and Hattingh, Water Res., 3, 385 (1969). 12 - Uribelarrea, J.L. Thèse, Laboratoire de Génie Biochimique, INSA, Toulouse France https://www.w3.org/1998/Math/MathML"> ( 1980 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 13 - Wolfe, R.S. In J.R. Quayle (ed). Microbial Biochemistry. Vol. 21 (1979) 14 - Yeboua Aka, F. Thèse, Laboratoire de Génie Biochimique, INSA, Toulouse, France (1984). 15 - Zeikus, J.G. First International Symposium on Anaerobic Digestion. Univ. Industry Center univ. Collège. Sept. 17-21, Cardiff Wales (1979). Table(3)Caracteristics of the fixed bed reactor feeding with differentconcentrations of butyric acid at retention time of 53 hoursRt 5. PERFORMANCE OF ANAEROBIC EXPANDED BED REACTORS P. GARCIA, L.J. REDONDO, I. SANZ and F. FDZ-POLANCO Dpto. Química Técnica, Universidad de Valladolid, Spain 6. Summary The performance of two laboratory scale anaerobic expanded bed reactors treating raw domestic sewage has been evaluated over a period of some nine months. The support media used were uniformly sized particles https://www.w3.org/1998/Math/MathML"> 0.14 - O . 28 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mm https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of red brick and clay. The temperature changed between https://www.w3.org/1998/Math/MathML"> 11 - 31 C ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , with daily variations of 7 o C. At a volumetric loading rate of https://www.w3.org/1998/Math/MathML"> 4 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COD https://www.w3.org/1998/Math/MathML"> m - 3   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (HTR https://www.w3.org/1998/Math/MathML"> = 4   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) the ave rage total coD-reduction was greater than https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and the so luble coD-reduction was in the range of https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Removal eff ciencies showed very little sensitivity to fluctuations in influent wastewater quality. A very high efficiency of removal of suspended solids was achieved, effluent tSS below https://www.w3.org/1998/Math/MathML"> 20 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were common. The stability of the reactors was very good, they were unaffected by fluctuations in temperature, flow rate, or ganic loading rate and suspended solids concentration 7. INTRODUCTION. Municipal wastewater treatment using conventional aerobic technology consumes a great deal of energy and produces large excesses of sludge. The development of new digester types as up flow Anaerobic Sludge Blanket (UASB) and Anaerobic Expanded or Fluidised Bed (AEB, AFB) reactors could allow the treatment of dilute effluents (ie coD https://www.w3.org/1998/Math/MathML"> < 200 m g 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) (1) (2) (3). Therefore, the general purpose is to develop a new approach to sewage treatment, that would minimize energy input while producing energy, and minimize excess biological solids production. The use of the AEB reactor for the treatment of domestic sewage has been studied by Jewell et al. (2) (4) and by Rockey (5). Jewell concludes that the process is effective at low temperatures with an organic loading rate of https://www.w3.org/1998/Math/MathML"> 4 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COD https://www.w3.org/1998/Math/MathML"> m - 3   d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> removal efficiences. Otherwise, the data of Rockey using unsteady-state conditions indicate that the process is unlikely to provide an effertive system for the treatment domestic sewage. 8. MATERIALS AND METHODS Two anaerobic expanded bed reactors were used. A diagram of the system is shown in Figure 1. A summary of design charac teristics of both reactors are shown in table I. https://www.w3.org/1998/Math/MathML">   Diameter (cm)     Length (cm)     Expansion (\%)     MaterialA     Diameter (mm)     Density (g/cm   3   )     Void fraction (\%)     Superficial velo     city (m s   - 1 )   Temperature     Moth   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Reactor 1 Reactor 233020Ar1itaO.14-0. 281.94570. 11ndedreiavreactors All analysis were determined by Standard Methods. All loa ding rates and retention times were calculated on an empty voIume basis that is occupied by the expanded media. The develop ment of the methanogenic biofilm on the support was very simiLar in both reactors. Domestic wastewater was obtained from a municipal sewer once or twice per week and stored at 4 oc. A degree of biode gradation occurred in the storage reservoir. Datly fresh feed was prepared and continuously pumped to the reactors, a littie biodegradation was also observed. No settled sewage was used, the feed system allowed solids to be pumped to the reactors. 9. RESULTS AND DISCUSSION. The variation in the experimental conditions of the sewage is shown in Figure 2. A large fluctuation in the COD, (maxi mum https://www.w3.org/1998/Math/MathML"> = 590 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , minimum https://www.w3.org/1998/Math/MathML"> = 110 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) was observed. This fluctua tion subjected the reactors to varying organic Ioading rates, so the system never achieved steady state conditions. The variation in the CoD of the sewage, and therefore the effluent, is shown in Figure 2. The COD of the effluent was di rectly measured without filtration or centrifugation. The effluent always had a very low turbidity. An examination of the COD removal versus organic loading rates (Figure 3) showed that, when organic loading rates are lower than https://www.w3.org/1998/Math/MathML"> 1 K g C O D / m 3   d , C O D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> removal greater than https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is - easily achieved. With loading rates of https://www.w3.org/1998/Math/MathML"> 4 K g C O D / m 3 ⋅ d   ( H R T = 4   h ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a COD removal of https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is achieved. Figure 3. The effect of OLR on organic removal efficiency The influence of temperature is shown in Figure 2. In the first period with average temperatures above https://www.w3.org/1998/Math/MathML"> 25 C ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the CoD-re duction was greater than in the second period. The stability of the reactors against temperature changes was very good. They have been operated between 11-31 oC with average daily changes of 7 웅 The suspended solids removal was very high in the whole range of operation. The average TSS-removal was https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Morris (6) suggests that the removal of the small particles of suspended solids is effected by both physical and biological phe nomena. It is possible that a little settling in the feed reservoir was achieved. The average value of all influent and effluent parameters during the period 245-260 day, are summarized in table II. Gas production rates were not easy to measure due to the size of the experimental system. It is interestings to note the effects of methane and carbon dioxide solubility on gas produc tion rates. Assuming a https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> solubility of https://www.w3.org/1998/Math/MathML"> 33.1 m l C H 4 / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> water, https://www.w3.org/1998/Math/MathML"> ( T = 20 @ C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a methane yield of https://www.w3.org/1998/Math/MathML"> 0.351 C H / g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COD and a https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of CoD removal, the lost of methane could be https://www.w3.org/1998/Math/MathML"> 33 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> 400 m g / I https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of influent COD and https://www.w3.org/1998/Math/MathML"> 66 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> when the influent COD is https://www.w3.org/1998/Math/MathML"> 200 m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . From this analysis it appears that energy recovery potencial for anaerobic systems treating low strength domestic wastewater is further diminished due to soluble methane loss in the effluent. 10. CONCLUSIONS. The results of this experimental study of the performance of the anaerobic expanded bed reactor suggest that the sys tem would be adecuate for the practical treatment of raw sewa ge at moderate temperatures. The reactors were unaffected by fluctuations in temperature, flow rate and organic loading rate. 11. https://www.w3.org/1998/Math/MathML">   REFERENCES.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) GRIN,P.C., ROERSMA, R.E. and LETTINGA, G. (1983) . Anaerobic Treatment of raw sewage at lower temperatures. Proceedings of the Anaerobic Waste Water Treatment European Symposium. Noordwijkerhout. (2) SWIT ZENBAUM, M.S. and JEWELL,W.J. (1980). Anaerobic attached film expanded bed reactor treatment. J. Wat. Pollut. Contro1 Fed. 52, 1953-1965. (3) KOBAYASHI,H.A., STENSTROM,M.K. and MAH,R.A. (1983) . Treat ment of low strength domestic wastewater using the anaero bic filter Water Res. 17,903-909. (4) JEWELL, W.J., SWITZENBAUM, M.S. and MORRIS, J.W. (1981). Municipal Wastewater treatment with the anaerobic attached microbial film expanded bed process. J. Wat. Pollut. Contro1. Fed. 53,482-490. (5) ROCKEY,J.S. and FORSTER,C.F. (1982). The use of an anaero bic expanded bed reactor for the treatment of domestic se wage. Environmental Technology Letters. https://www.w3.org/1998/Math/MathML"> 3 _ , 487 - 496 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (6) MORRIS, J.W. and JEWELL,W.J. (1981). Organic particulate removal with the anaerobic attached, film expanded bed process. 36 th Purdue Industrial Waste Conference. Purdue University . Indiana. ANAEROBIC STABILIZATION OF AGRICULTURAL AND FOOD-BASED INDUSTRIAL WASTES J. Winter and F.X. WildenauerUniversity of Regensburg, Department of Microbiology,Universitätsstr. 31, D-8400 Regensburg, FRG. Summary: Anaerobic fermentation of cattie manure (7 : total solids) in a mixed tank digester at a HRT of 15 d revealed o.7 l biogas/ https://www.w3.org/1998/Math/MathML"> 1 ⋅ d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a cod-reduction of 18 &. When most of the solids were removed by filtration (4: solids left) before digestion only 15 & less gas was produced https://www.w3.org/1998/Math/MathML"> ( 0.61 / 1 ⋅ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d). No improvement was observed when filtered cattle manure was digested in a fixed- film reactor. Although attachment of bacteria to the red brick material was observed the gas production was only insignificant- Iy higher than in the conventional system (O.64 versus o. 6 l/ l.d). Digestion of piggery waste with a solids content of 1.6 o at 10 d HRT resulted in 58 & COD-removal and produced o. 7 l biogas/1.d. Undiluted sour whey could be stabilized with 95 qoin-reduction and a gas productivity of https://www.w3.org/1998/Math/MathML"> 5.61 / 1 . d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in a fixed-film upflow Ioop reactor, operated with pH-controlled whey addition. At a pH of 6.7 a maximum loading of https://www.w3.org/1998/Math/MathML"> 14   k g C O D / m 5 ⋅ d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was obtained and dis- turbances by oxygenation or overloading were corrected auto- matically by the system. https://www.w3.org/1998/Math/MathML">   Introduction:     To   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> To prevent further pollution of the environment, not only sewage sludge and domestic refuse from big cities and rural communities should be extensively treated before final dis- posal, but also agricultural wastes and wastes based on farm product processing. Especially wastewater from plant and milk processing for human food is highly polluting and needs treat- ment before disposal. In this contribution we report on the anaerobic treatment of cattie manure and piggery waste in con- ventional digesters and fixed-film digesters and on the anaero- bic digestion of sour whey from cheese production in a pH-con- trolled fixed-film upflow loop reactor. Materials and Methods: Cattle manure, piggery waste and sour whey were frozen in portions to operate a digester 3-4 days. Cattle manure was homogenized with an Ultraturrax before freezing. Samples were thawed a day before use and stored in a refrigerator. For the digestion of diluted cattle manure (7 & solids content) filtered cattle manure (4 o solids content) and piggery waste mixed tank digesters (Biostat V, Braun Melsungen, 1.1 were used, which were operated at 30-33 o C. The operation mode was semi-continuously by manual sludge removal and sludge addition once a day, to maintain the desired HRT (hydraulic retention time). Steady state conditions were assumed when the time for 4 HRTs had passed. Filtered cattle manure was additionalıy digested in a fixed-film digester containing red brick material Table 1: Composition of raw materials for anaerobic digestion experiments n.d. = not determined; 1. undiluted cattle manure contained 12 o dry matter; https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Filtration was performed with a grid with pores of https://www.w3.org/1998/Math/MathML"> 1   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diameter. Manure samples were drawn during winter time, when the diet mainly consisted of roughage and mineral feed; 3 The diet for fattening pigsmainly contained barley residues from a brewery; https://www.w3.org/1998/Math/MathML">   4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> From cottage cheese production, undiluted. Storage of raw material was in a deep freezer in portions of the daily demand. Sour whey was continuously pumped into the reactor from a refrigerator. Sour whey additionally contained https://www.w3.org/1998/Math/MathML"> 6.8   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of lactate, the lactalbumine and lactglobuline content was https://www.w3.org/1998/Math/MathML"> 0.8   g / 1 . M i l k https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fat could not be detected. Table 2: Performance of cattle manure, piggery waste and sour whey digesters ANAEROBIC DIGESTION AND METHANE PRODUCTION OF SLAUGHTERHOUSE WASTES A. STEINER, F.X. WILDENAUER and O. KANDLER Bayerische LWF, Freisinger Landstr. 181, 8 Muenchen 45 Summary: Slaughterhouse wastes (2.9% up to 10.5% VS) were fed semicon- tinuously into 2 l fermenters and digested at https://www.w3.org/1998/Math/MathML"> 35   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 55 %C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Some of the experiments were carried out with added pathogenic organisms (Salmonella typhi. and E. coli) to check the efficiency of disinfection. The fermentation of slaughterhouse wastes led to digestion failure with an organic loading of more than 8.75 https://www.w3.org/1998/Math/MathML"> k g V S / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .d caused by enrichment of volatile acids. No differences were found in gas production, percentage of methane and VS or COD reduction in mesophilic and thermophilic digestions. At thermophilic conditions E. coli had a https://www.w3.org/1998/Math/MathML"> D 10 - value https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of 20 mins (Salmonella typhi. https://www.w3.org/1998/Math/MathML"> D 10 = 30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mins). Only a slow reduction https://www.w3.org/1998/Math/MathML"> D 10 = 10.5   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of E. coli occurred at mesophilic temperatures. Introduction: Because of their high organic matter slaughter- house wastes are potential sources for methane fermentation. In the FRG (1) about https://www.w3.org/1998/Math/MathML"> 5 × 10 5 t / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of slaughterhouse wastes have to be treated mainly in the form of waste waters with a COD of 1 to https://www.w3.org/1998/Math/MathML"> 10   k g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Previous work https://www.w3.org/1998/Math/MathML"> ( 2,3 , 4,5 , 6,7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> showed that anaerobic fermentation of slaughterhouse wastes under mesophilic and thermophilic (2) conditions is possible with organic loadings (OL) of 0.35 to https://www.w3.org/1998/Math/MathML"> 6.0   k g V S / m 3 . d . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Retention times of https://www.w3.org/1998/Math/MathML"> 12   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 30   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> led to a gas production of 0.27 to https://www.w3.org/1998/Math/MathML"> 0.55   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas https://www.w3.org/1998/Math/MathML"> / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> added VS. This paper reports the results of mesophilic and thermophilic digestion of slaughterhouse wastes under steady state condi- tions with special reference to high ol and hygienic qualities of the digested sludge. Substrates: The substrate contained rumen and intestine con- tents (13%), manure from the animal buildings of the slaughterhouse https://www.w3.org/1998/Math/MathML"> ( 25 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , surplus sludge from the aerobic sewage treatment plant https://www.w3.org/1998/Math/MathML"> ( 44 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and fat derived from the fat separator https://www.w3.org/1998/Math/MathML"> ( 19 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The mixture exhibited a coD of https://www.w3.org/1998/Math/MathML"> 165   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a BOD of https://www.w3.org/1998/Math/MathML"> 112   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a dry weight of https://www.w3.org/1998/Math/MathML"> 120   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a VS concentration of https://www.w3.org/1998/Math/MathML"> 105   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fat and https://www.w3.org/1998/Math/MathML"> 23 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> proteins. In order to guarantee waste of constant composition throughout the experiments, equal portions of a homogenized mixture were stored in plastic bottles at https://www.w3.org/1998/Math/MathML"> - 20   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> until use. The mixture was diluted with tap-water to allow variations in the oL at equal retention times. Table I gives some data of the substrates and the OL. Digersters: Cylindrical, complete mix (CSRT) 2 l fermenters (Biostat V, Braun Melsungen FRG) with a filling volume of 1.5 I were used. Mixing was performed with 3 propeller type stirrers each about https://www.w3.org/1998/Math/MathML"> 5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> apart from the others on the central shaft (mixing at https://www.w3.org/1998/Math/MathML"> 75 r p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). COD (g/I) 47 65 93 128 93 165 165 VS (g/I) 28 43 60 81 60 105 105 R T (d) 10 10 10 10 7 12 10 OL (g VS/I.d) 2.9 4.3 6.0 8.1 8.6 8.75 10.5 Table I : Composition of the substrates, retention times and organic loadings Experimental design: Fermentation was carried out in a semicontinuous mode. New feed was added every https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> subsequent to the removal of the desired volume of fermented sludge. Samples for the analytical procedures were withdrawn before the new substrate was added. Biogas was collected in a gasometer and measured once a day. The results shown were determined after the fermentation had reached steady state conditions. Thermophilic fermentations https://www.w3.org/1998/Math/MathML"> 55 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were carried out at all OL, mesophilic at OL of 2.9 and 8.1. Analyses were performed according to standard procedures. Results: Reduction of COD and VS High OL led at both temperatures to gradual decrease of COD and VS reduction. At OL of https://www.w3.org/1998/Math/MathML"> 10.5 V S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and COD reduction decreased drastically. The BOD reduction of https://www.w3.org/1998/Math/MathML"> 72 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at oL of 8.6 dropped to 64 % at of 8.75. Fig. 1: Reduction of COD and VS 12. Hygienic qualities 13. Résumé Un modèle de simulation du fonctionnement d'une installation de fermentation méthanique des fumiers a été élaboré. Adapté a l'utilisation de l'énergie pour le chauffage et l'eau chaude domestiques. intégrant les disponibilités pour le chauffage et laeau chaude dontestiques. Intégrant lws disponibilités en biomasse et en travail offertes par fagriculteur au cours du temps, il devrait permettre de mieux appréhender un grand nombre de situations réelles. Les installations sont ici sunposées fonctionner en discontinu, hypothèse Les installations sont ici supposéss fontcionner en discantinu, hyputhese classique a léchelle de la ferme. et pour les types de substrat les plus fréquents en France: en surmontant les difficultés mathématiques ainsi accrues. un tel modele, ì caractère technico-économique. devrait aider acclues. un tel middele, a caractere technico-économique. devrait aider apprécier le potentiel économique de la filière. Un module d'optimisation apprecicr le potentiel beonornique de la filiere. Un module dioptimisation associé au programme de calcul de la simulation donne un instrument plus performant. Tout en confirmant le faible intérêt économique de la filiere. le modele met en évidence en particulier l'intérêt relatif d'une utilisation du gaz "au fil" de la production. avec un stockage tampon du gaz de faible valume. 14. LE PROBLEME quotidiennes assez sensibles. température pour un cycle de praduction https://www.w3.org/1998/Math/MathML"> P [ T , t ] = P ∞ 1 - k 2 t 2 2 + kt + 1 e - kt ,  avec : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> T: température https://www.w3.org/1998/Math/MathML">   0 c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> t: temps [semaines] P: production cumulée de biogaz https://www.w3.org/1998/Math/MathML"> m 3   N / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MOl] https://www.w3.org/1998/Math/MathML"> P ∞ = 43 : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production cumulée à t=∞ https://www.w3.org/1998/Math/MathML"> k [ T ] = ko e - λ / ( T + 273,15 ] , k 0 = . 420910 6 , λ = . 413910 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> p [ T , t ] = ∂ P ∂ t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> [figure 1] production instantanée de biogaz Les etudes microéconomiques précédentes portant sur la fermentation méthanique des fumiers à la ferme avaient mis en évidence le probléme de l'ajustement des besoins et de la production d'énergie au cours du temps [1][2]. Mais les périodes retenues [l'année. le mois] pour le calcutéconomigue ne permettraient pas de mesurer limportance du phénomene. En effet, les besains en chauffage [cas étudié ici], avec les aléas climatiques, subissent des variations D'autre part. la forme des fonctions de production du biogaz [figure 1] nous complique la tâche lorsqu'on envisage un fanctionnement des réacteurs en discantinu. A partir d'un ajustement de données de la bibliographie [3], nous praposons une forme analytique de la production cumulée en fonction du temps et de la Le gestionnaire d'une installation de fermentation doit pouvoir décider à tout instant de la charge, de la mise en fonctionnement, de l'arrêt ou du déchargement des cuves de fermentation. Cela en fonction de ses disponibilités en temps de travail, en biamasse, de la capacité de son installation et de ses besoins en énergie. Une bonne connaissance de l'exploitation agricole est dono nécessaire. et tout modele d'analyse doit être asez souple vis a vis de ces caracteristiques pour prétendre à une certaine qénéralité. Il importe aussi de définir un "signal" qui dicte at gestionnaire la décision préférable qu'il peut prendre vis à vis de l'explaitation des cuves. Interprétable mathématiquement. ce signal. équivalent à une décision de gestion, pourra être intégré à taut modète d'analyse de notre problème. La finalité de notre étude étant d'évaluer fintérêt économique de la filiere il s'agit pour nous de retenir tout élérnent ayant une incidence sur linvestissement ou le cout de fonctionnement. imputable a linsertion d'une installation de fermentatian dans une exploitation agricole. Face à la complexité de linteraction technicoéconomique, deux hypothèses sont proposées :

les éléments constitutifs de l'installation de fermentation. ayant un rôle direct dans le probleme d'ajustement soulevé en préambule. sont ici limités aux digesteurs, à la capacité de stockage du gaz. à la puissance et au rendernent de la chaudiere brúlant le biogaz [figure 2].

on suppose que l'insertion de cette installation https://www.w3.org/1998/Math/MathML"> Π ' a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pas d'effet indirect suf I'économie de l'explaitation agricole, c'est-à-dire qu'elle n'a pas d'autre effet que la seule modification de la dépense d'énergie domestique. En particulier. on admet que la valorisation agronomique globale du fumier reste inchangée, qu'il y ait fermentation ou non [4].

15. SIMUL ATION ET OPTIMISATION : LE MODELE PROPOSE La méthode d'analyse retenue est fondée sur la simulation du fonctionnement de l'ensemble [digesteurs, stackage de gaz, chaudiere] par rapport à son environnement [température extérieure, travail et biomasse dispomibles. prix de fiénergie Substituée .... Lintervalle de temps au bout duquel les variables de la simulation sont modifiées est de préférence la journée: un intervalle "plus grand" ne permet pas de tenir compte des aléas climatiques et des variations de la production instantanée de biogaz; Un intervalle plus court conduirait a des difficuités de calcul thermocinétique. A chaque période, somt effectués des bilans d'énergie, de biomasse. de travail, de l'état dustockage [figure 3 ]. La regle de décisian quant au fonctionnement d'un digesteur consiste à décider du chargement, du démarrage, de l'arrêt et du déchargement de celujci. Une regle est choisie pour toute la durée de la simulation. Un ensemble de décisions possibles est propose. En particulier, pour l'arret d'un digesteur, citons deux cas extrêmes.

Si l'on veut maximiser l'énergie produite par unité de biomasse disponible. la regle de décision est d'arrêter le digesteur si la consommation c quotidienne pour son réchauffage dépasse la production p [le "signal" est alors calculé, comme la différence https://www.w3.org/1998/Math/MathML"> p [ θ ] - c [ θ ] = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , ou θ est le temps de séjour courant].

Si l'on veut maximiser l'énergie mayenne produite par unité de temps,la règle de décision est alors fixée par le signal https://www.w3.org/1998/Math/MathML"> p [ θ ] - P ( θ ) - C 0 ( t ) 2 = 0   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> [P production cumulée pour le cycle de durée θ, p production quotidienne. Co[t] coût initial de chauffage à la date https://www.w3.org/1998/Math/MathML"> t = t 0 + θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , to instant de démarrage du cycle courant].

Pour compléter cette analyse à caractère descriptif, un calcul d'optimisation est proposé selon le principe suivant. Celui qui décide d'investir dans une telle installation doit pouvair juger de l'efficacité de la solution qu'il aura choisie relativement à ces possibilités de choix. Efficacité que nous évaluerons selon deux criteres au choix:

maximisation du taux de substitution du combustible classique par le biométhane pour les besoins en chaleur domestique.

minimisation de la dépense moyenne annuelle actualisée relative à ces besoins. Parmi l'ensemble des paramètres de notre modèle initial, une sélection de variables est opérée, variables par rapport auxquelles sera effectuée l'optimisation. A chaque valeur de ces variables, la fonction d'objectif est calculée par le modèle de simulation. L'idée générale de l'algorithme est précisée (fiqure 4).

16. RESULTATSET LIMITES Le modèle est concrétisé par des programmes informatiques écrits en FORTRAN. Lensemble logiciel fonctionne actuellement sur du matériel Cll-HB [DPS-\theta. systeme d'exploitation MULTICS]. Ce modèle. explaité avec les conditions réelles correspondant à lélevage bovin de l'Ouest de la France. naus permet de tirer quelques enseignements. Tout d'abord. même dans un cas d'exces de biamasse disponible, la limitatian du volume de stockage de gaz conduit à une substitution partielle du combustible classique par le biomethane (ne depassant pas https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pour https://www.w3.org/1998/Math/MathML"> 100   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de stockagel. Lintéret économique optimal canduit meme au choix d'un stockage minimal malgré une chute sensible du taux de substitutian https://www.w3.org/1998/Math/MathML"> [ < 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pu B0 https://www.w3.org/1998/Math/MathML"> / / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> selon que la durée de vie des cuves est de 10 ou 15 ans]. Plus précisément. si optimum énergétique [en] et optimum économique [ec] s'accordent pour limiter le nombre de cuves [l ou 2], augmemter au maximum la charge du réacteur. il est plus difficile de conclure paur le choix de la température de fermentation [en général https://www.w3.org/1998/Math/MathML"> T * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> e < https://www.w3.org/1998/Math/MathML"> T * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en* https://www.w3.org/1998/Math/MathML"> T * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> température optimale] et pour le volume total de cuverie https://www.w3.org/1998/Math/MathML"> V *   e c < V * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en https://www.w3.org/1998/Math/MathML"> V * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volume total de cuverie optimal]. Par contre. les optima divergent totalement si l'on considère le volume de stockage du gaz. Ees premiers résultats n'aboutissent pas à une condamnation de la filière si f'on en juge par la seule compétitivité des vecteums énergétiques substitués et substituants. Mais les capacités financieres importantes mises en jeu et la moindre rentabilité supposée des capitaux investis ici comparée à celle d'autres investissements agricoles permettent d'expliquer qu'elle ne soit pas encore operatiannelle If convient cependant de souligner la grande sensibilité des résultats obtenus à la durée de vie de l'installation, du taux d'actualisation et aux investissements. et la dépendance à l'égard des fonctions de production technique dont il faudrait s'assurer de la fiabilité. 17. BIBLIOGRAPHIE [1] REQUILLART (V.) [1980]. Le biométhane : les problèmes liés à sa production à la ferme. Mémoire de fin d'études I.N.A.-P.G. - I.N.R.A. Laboratoire d'Economie Rurale de Grignon. [2] FLORENTIN [J.][19日1]. Analyse de Irajustement production - consommation d'une installation de fermentation méthanique à la ferme. Mémoire de DEA - INSTN-INRA - Laboratoire d'Economie Rurale de Grignon. [3] ZELTER [S.Z.] et coll. [197日]. Fermentation méthanique en discontinu des déchets agricoles. INRA - BERTIN - Compte-rendu d'une recherche DGRST Comité VEDA - Station d'élevage porcs INRA - Jouy-en-Josas. [4] lJSTE [C.] et coll. [1981]. Influence de la fermentation méthanique sur la valeur fertilisante de divers déchets organiques. Académie d'Agriculture. 13 Mai 1981 ... pp. 782-790. Fig. I : Fonction de production de biagaz pour un cycle Figure 2 - Schéma de principe du fonctionnernent du système Figure 3 - Principe du calcul de simulation Figure 4 - Principe de calcul d'optimisation sous contraintes THE PRODUCTION OF METHANE FROM BIOMASS IN THE UNITED STATES: ECONOMICS, TRADEOFFS, AND PROSPECTS J.R.FRANK AND T.D.HAYES GAS RESEARCH INSITUTE P.H.SMITH UNIVERSITY OF FLORIDA 18. Summary Methane produced from dedicated blomass facillties can play an Lmportant role in supplylng a slgniflcant fraction of future methane demand in the U.S. If improvements can be made which reduce nethane costs between https://www.w3.org/1998/Math/MathML"> $ 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> $ 7 / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at the city-gate. Both applied and fundamental research focused on speciflc reactor and plant systems w111 be needed https://www.w3.org/1998/Math/MathML"> 1 f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> this goal is to be achleved. A systems approzch https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> used which restlts in a continuous assessment of research progress and requirements and alds in the development of cooperative research efforts. In 1983, supplemental supplies constitute approximately 6 percent of the U.S. gas consumption (1). A recent study indicates that the avallabllity of gas from the conventional gas resources ln the lower contiguous 48 states w111 contlnue to decline and that supplemental gas Bupplies (e.g. forelgn imports, Alagkan gas, coal gas and LNG) will provide an increasing percentage of the gas that Is used (1). If only currently avallable technologies are titilzed, 1t 1s estlmated that supplements will provide almost https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the U.S. gas supply by 2000 and 40 percent by 2010 (1). If nex technologles are developed providing lower cost unconventional natural gas, gas from advanced coal gasiflcation processes and methane from blomass, these sources w111 become major supplements. Another study that consldered the potentlal Impact of blomass-to-methane systems 1 ndicates that https://www.w3.org/1998/Math/MathML"> 1 f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pipeline quality methane from blomass could be avallable at the city-gate for https://www.w3.org/1998/Math/MathML"> $ 6.80 / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1n 1983 Levellzed constant dollars), by the years 2010 and 2030 , a gas demand could exist for up to 1 quad https://www.w3.org/1998/Math/MathML"> 1.06 x 10 9 G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and over 4 quads (4.2 x 109 GJ) respectively (K. Darrow, personal communication). This study assumed that GRI' s research in producing gas from unconventlonal gas sources and coal gasification would be successful. If a price closer to https://www.w3.org/1998/Math/MathML"> $ 5 / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be attained or the promise of these latter technologles Is not fully reallzed, the lmpact of blomass could be slgnificant much earlier. These estimates do not include the potentlal nearer term lmpact of up to 1.8 quads (1.9 x 10 9 GJ) of plpeline quality methane which may be contributed from non-agricultural wastes (2). To make a s1gnificant energy 1 mpact, substantial amounts of land must be avallable for energy crop production. In the Unlted States, 1 t has high sollds conversion processes, improving the biomass and methane ylelds of promising biomass feedstocks through Improved crop management and genetic selection, the application of new biotechnologies to promising production and conversion systems, and continued development, valldation, and evaluation of the system models. REFERENCES (1) HOLTBERG, P.D., et al. (1984). 1984 GRI Baseline Projection of U.S. Energy Supply and Demand, 1983-2010. Gas Research Insights, (October 1984). (2) LIPINSKI, et al. (1983). Review of the Potential for Blomass Resources and Conversion Technology. Final report to Gas Research Institute. GRI-83/007. (3) BIRD, K.T. and A.B. ASHBY. (1984). Recent Economic Results of Converting B1omass to Methane. IGT Symposium on Energy from Biomass and Wastes VIII, Ed, D, K1ass. (4) WARREN, C.S. et a1. (1984). The Methane from Biomass and Wastes Program: Evaluation of the Lake Apopka Natural Gas District. Gas Research Institute Top1cal Report. GRI 84/0015.1. (5) HINTON, S.W. and C.S. WARREN (1985). The Methane from Biomass and Waste Program: Blomass Resource Assessment Belle Glade Area. Gas Research Institute Topical Report (In Press). (6) SMITH, W.H. (1985). Methane from Biomass and Wastes: Annual Report for 1984. Gas Research Institute Report (In Press), (7) CHYNOWETH, D.P. et a1. (1984). Biogasification of Water Hyacinth and Primary Sludge. Proceedings of the International Gas Research Conference. Government Institute, Inc. (In Press). (8) LIU, Y. et. al (1985). Methanosarcina maze1 LYC, A New Methanogentc Isolate which produces a disaggregating enzyme. Applied and Environmental Microblology. (In Press) ANAEROBIC DIGESTION OF PIG MANURE RESULTS ON FARM SCALE AND NEW PROCESS C. AUBART, F. BULLY Research Laboratory on Fermentation B I OMAGAZ Aspach le Bas - 68700 CERNAY - France Té1. (89) 48.96.11. 19. Summary The economical profit of pig manure biogas plants requires an optimisation of the process. Since July 1981 we carry out a scientific follow up of a https://www.w3.org/1998/Math/MathML"> 200   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> experimental biogas unit (completely mixed) which is loaded with a pig manure daily flow of https://www.w3.org/1998/Math/MathML"> 18.5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The capacity of this plant has been determined by the results of experiments made on six litre digesters (completely mixed). The net production of biogas is processed in a gas engine generator without treatment. It produces 71,958 Kwh/year. Chemical oxygen demand decrease and deodo- risation occuring in pig manure anaerobic digestion permit to sup press the aerobic treatment and economize https://www.w3.org/1998/Math/MathML"> 94,900 K w h / y e a r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the consumption of electricity. Complementary laboratory experiments were carried out to decrease the retention time and in consequence the digester capacity and investment cost. Retention times tested are 7.5 and 5 days. Results show that to obtain about same performances on energy production and pollution control a digester capacity of https://www.w3.org/1998/Math/MathML"> 139   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is sufficient. A digester capacity of https://www.w3.org/1998/Math/MathML"> 93   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> permits to obtain 86 % of the precedent production. From the results presented above, we can conclude:

Eirst : possibility to decrease investment cost of biogas plant,

second: possibility with the same system to treat the daily fiow of a very large pig farm.

The new process permits to decrease investment cost and to increase biogas production and the annual economy. 20. INTRODUCTION The energetic aspects of an anaerobic unit for biogas production (useful capacity https://www.w3.org/1998/Math/MathML"> 200   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) have been presented (C. AUBART, F. BULLY, 1984). The digester is functionning in a pig farm (3.000 pigs) without break since July 1981 . The retention time is 10.8 days and the annual mean biogas production is https://www.w3.org/1998/Math/MathML"> 208   m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day. The biogas is used in a generator set ( 35 Kva) which produces annualy 71,958 Kwh. The electricity consumption of the previous aerobic process is https://www.w3.org/1998/Math/MathML"> 95,000 K w h / y e a r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which present now an economy. This biogas unit gives entirely satisfaction on the technical point of view. However, laboratory studies are carrying out to decrease size of the digester and in consequence the investment cost and to increase results obtained from completely mixed digesters. The used digester is a new process and the patent is in writing elaboration (second generation) The scientific approach has been previotsly presented (C. AUBART, 1982). Three different pig manures are tested. The characteristics are described in table 1. Two retention times are used on the laboratory digesters : 7.5 and 5 days.

CONCLUSION

The application of biotechnological researchs and fundamental studies on bioconversion mechanisms have permitted to perform a new process. The new process does not involve annual running cost and the investment cost is lover. The obtained results indicate that improvement in pig manure anaerobic digestion can be brought. Consequences on investment cost and economy project in the future the development of this technology. 21. REFERENCES (1) AUBART, C., Mise au point industrielle de production d'énergie par méthanisation des déchets agricoles et des résidus agro-alimentaires. Exposé CCE, Wageningen, 3 mars 1982. (2) AUBART, C., BULLY, F.. Development of installations for the production of biogas from stock-farming waste. Anaerobic digestion and carbohydrate hydrolysis of waste. Elsever Applied Sciences Publishers Pp. 318-322,1984. (3) AUBART, C., FARINET, JL., Anaerobic digestion of pig and cattle manure in large scale digesters and power production from biogas. IGT SYMPOSIUM "Energy from Biomass and Wastes VII", Orlando, 24-28/1, pp. 741-766,1983 (4) AUBART, C., BULLY, F., REISINGER, O., Anaerobic digestion of mixed animal wastes/Biogas production and approach of bioconversion mechanisms. Poster session, Bio Energy'84, Göteborg, Sweden, June 18-21, 1984. 22. Table 1 CHARACTERISTICS OF TESTED PIG MANURE STUDY COMPLETELY MIXED NEW PROCESS Retention time days 7.5 5 7.5 Total solids % 3.70 3.37 3.97 Volatil solids % 2.71 2.65 2.83 C.0.D. https://www.w3.org/1998/Math/MathML"> m g O 2 / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 45,312 34,459 49,535 Total solids % 1.14 0.84 1.30 (supernatant) % 0.60 0.49 0.73 Volatif solids (supernatant) Table 2 LABORATORY RESULTS B.U. : Biogas Unit (useful capacity https://www.w3.org/1998/Math/MathML"> 200   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) C.M. : Completely mixed L.D. : Laboratory digesters C.M. : CompletelyN.P.: New process Table 3 RESULTS EXTRAPOLATION TO INDUSTRIAL SCALE B.U. : Biogas Unit (usefu1 capacity https://www.w3.org/1998/Math/MathML"> 200   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) L.D. : Laboratory digesters C.M.: Completely mixedN.P.: New process 23. AN ECONOMIC APPROACH TO BIOGAS GENERATION AND USE 24. D.J. Pícken Leicester Polytechnic 25. Summary The economic returns on the production of biogas in developed countries have been generally disappointing. Many studies have shown that even when the problems of digester design and operation have been satisfactorily solved the payback from the use of biogas has been well below expectation. Sometimes this has been due to plant unreliability or incorrect operation. More often it has been due to the continuous production of biogas not matching the fluctuating demands for energy near the plant. This is possibly due to the digester system being designed to deal with the available biomass supply. An alternative approach to design is to consider the energy needs and possible savings and match this to the investment available for building the digester system. This paper attempts to show the results of such design considerations. Before any sensible costings can be made it is essential to decide what base load of continuous power can be usefully used at or near the digester site. This can include the generation of electricity to sell back to the electricity supply company, but the price offered is generally not attractive. Having decided on the power rectuirement from the digester, an estimate must be made of the value of this power in terms of annual income. This can best be calculated by taking the cost of the fuel supply which is to be replaced, or which offers the most likely alternative to biogas. Depending on the particular location of the plant, and on the type of energy to be used, this can either be solid fuel, natural gas, mains electricity or diesel oil. Unfortunately each of these fuels is normally priced in a different way, and the price will vary with location as well as from one year to another. It is a fairly simple calculation however to put fuel costs in terms of cost per kW hr so that direct comparisons can be made in UK the following costs are normal:- (i) Electricity cost https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fo.03/kWhr (average) If biogas is to be used to generate electricity then the amount of biogas required is that which when used as a fuel for an engine generator set to produce electricity As a general rule we may take the efficiency of such a set as https://www.w3.org/1998/Math/MathML"> 20 % . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Thus bíogas energy required https://www.w3.org/1998/Math/MathML"> = 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> x electrical energy required. https://www.w3.org/1998/Math/MathML"> ∴ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Biogas value per kW/hr https://www.w3.org/1998/Math/MathML"> = E O . 03 / 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> EO.006 per kWhr. Thus if biogas is to replace electrical energy its annual value is https://www.w3.org/1998/Math/MathML"> E O . 006 × 8760 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per kW Now if we assume that the specific energy of biogas is https://www.w3.org/1998/Math/MathML"> 25 M J / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> then the gas production rate to produce a power of https://www.w3.org/1998/Math/MathML"> 1   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is https://www.w3.org/1998/Math/MathML"> 1 × 3600 × 24   m 3 /   day   25000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 3 = 3.46   m / d a y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 25000 Each m of dígester capacity will normally produce between 1 and https://www.w3.org/1998/Math/MathML"> 1 1 2 m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas per day. If we assume a well designed digester producing latimes its volume of biogas per day, then per kW output its volume times its volume of biogas per day, then per kW output its volume Will be 2.3 m We can therefore expect an annual return (saving) of https://www.w3.org/1998/Math/MathML"> f 52.56 / 2.3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> f22. 85 perm of digester volume (ii) If the fuel to be saved is diesel fuel (i.e. in an exísting diesel generator), for which a typical cost is fl per gallon, taking the energy content of diesel fuel as https://www.w3.org/1998/Math/MathML"> 44 M J / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and taking 1 gallon as https://www.w3.org/1998/Math/MathML"> 3.36   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> we arrive at a price of diesel fuel of fO. O24/kWhr (annual value https://www.w3.org/1998/Math/MathML"> { 212,8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per kw) The same calculation as above suggests an annual return on biogas as https://www.w3.org/1998/Math/MathML">   f92.   52   per m   3   of digester volume.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (iii) A typical cost of natural gas is £0.11 per m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (UX prices). The best biogas has a calorific value of about https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of natural gas. Thus its value is https://www.w3.org/1998/Math/MathML"> E O . 077 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per m Thus its annual return is fo.077 https://www.w3.org/1998/Math/MathML"> × 365 × 1.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per m digester volume (ammuat value equelper m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester volume With these figures it is easy to calculate the maximum cost of a digester system for a given pay-back time Thus using Graphs 1 and 2 it is possible to find the limits of cost for a particular proposed installation. e.g. (1) A farm has a requirement for a constant https://www.w3.org/1998/Math/MathML"> 20   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of heating. at present supplíed by gas oil: A Pay back time of 3 years is required. From graph 1 digester size must be https://www.w3.org/1998/Math/MathML"> 50   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Maximum cost of digester system is https://www.w3.org/1998/Math/MathML"> f 220 / m 3 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> I..e. system must cost less than https://www.w3.org/1998/Math/MathML"> £ 11,000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . e.g. (2) An alternator has a constant electrical demand of 20 kW and requires an energy pay-back of 3 years. Digester size must be https://www.w3.org/1998/Math/MathML"> 230   m 3 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Digester cost must be less than https://www.w3.org/1998/Math/MathML"> f 70 / m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Digester system must therefore cost less than 16,100. Note that although pay-back time is relatively short, no allowance has been made for maintenance, or breaks in demand. In particular the costs are for the whole system (including pumps. pipework, engine-generator sets etc). 26. METHANE FROM BIOLOGICAL ANAEROBIC TREATMENT OF INDUSTRIAL ORGANIC WASTES R. Campagna, G. Del Medico, M. Pieroni Istituto G.Donegani S.p.A.,Via Fauser, 4-I 28100 Novara (Italy) Organic wastes ot various industrial origin were char acterized, desk evaluated and then tested in batch di gesters, either alone or in co-digestion with other wastes, at the aim to check their amenability to anaerobic biotreatment. Finally, microorganisms were gradually acclimated and fed, in bench scale anaerobic digesters, with most ot these wastes. A good agreement was obtained between results from batch and continuous tests. Each industrial waste was found to be a unique case but generally it was concluded: (I) primary sludges f゙rom wastewater treatment plants are seldom bioanaerobically treatable; (II) secondary https://www.w3.org/1998/Math/MathML"> ( i . e . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biological https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sludges trom well operated wastewater treatment plants are otten amenable to anaerobic biotreatment, with the same degree ot gasitication and specitic rate of reaction of secondary sludges of domestic onigin; (III) organic process wastes and wastewaters frequently can be treatable and, it so, with high yields; (IV) anaerobic co-bio treatment of wastes ot different origin is often bet ter' than the separate treatments. 27. INTRODUCTION Anaerobic biological puritication plants are becoming more and more widespread and they could be safely and economically applied to a broader class ot organic wastes of industrial origin The wastes considered in this work included:

primary sludges from industrial wastewaters treatment plants; - secondary sluderes, as above

organic industrial process wastes and wastewaters.

Products were first characterized, desk evaluated and then tested, with controls, in batch digesters, tig.1, to check their amenability to anaerobic biotreatment. The most ot these wastes were also semi-continuously fed to laboratory completem ly mixed mesophilic anaerobic digesters, EIg.2, allowing for the acclimation ot microorganisms. 2. RESULTS Ihe experimental main results obtained are listed in tab I and II. Each waste was found to be a unique case but the fol Lowing general remarks can be concluded:

primary sludges from industrial wastewaters treatment plants are seldom bioanaerobicaliy treatable as such; sometimes ma jor pretreatments (dilution, washing, hydrolisis, specific

toxic removal, etc.) may remove the cause of inhibition and/ or improve the bioanaerobic treatment but are usually expen sive.

Secondary (i.e.biological) sludges from well operated industrial wastewaters treatment plants are, instead, usually bio treatable as such or only with minor pretreatments; their kinetics and degree of gasification are in the same range of those of domestic origin.

Organic industrial process wastes and wastewaters Erequently can be treatable and, if so, often with high yields.

Anaerobic co-biotreatment of wastes of ditterent origin is almost always better than the separate treatments.

DISCUSSION

Biological anaerobic treatment can be applied to a wide range ot industrial organic wastes, obtaining usetul methane while reducing pollution load. Industrial factories have, or may rapidly have, the neces sarily expertise to do so; the methane produced could be en tirely used tor other more useful purposes than that ot digest er heating, having for this wastewheat to use; furthermore, the methane in the developed biogas is usually much Iess than that required (and commonly used) for the tactory activities and so the biogas could be used as such or only with minor pre treatments in the tactory utilities. An improved stability to the process is obtained it wastes of ditferent origin are biotreated together (co-biotreatment); important is the choice ot the plant location, its size and its integration with other nearby existing facilities; other advantages include:

more than proportional methane production, due to the positive synergistic eftects ot a more complex and better balanced environment; this leads also to:

minor pretreatments need, due especially to the dilution and, otten, to the complementarity effects;

savings in chemicals to be eventually added;

minor posttreatments (especially for N and P) eventually required. TAB. I-MAIN CHARACTERISTICS AND RESULTS OF THE WASTES TESTED WITH BATCH DIGESTERS

TAB.II-MAIN CHARACTERISTICS AND RESULTS OF THE WASTES TESTED WITH LABORATORY COMPLETELY MIXED SEMI-CONTINUOSLY FED MESOPHILIC ANAEROBIC DIGESTERS FIG. 1 - ANAEROBIC DIGESTERS FOR BATCH TESTCNG FIG. 2 - LABORATORY COMPLETELY MIXED ANAEROBIC DIGESTERS EXPERIENCES WITH ANAEROBIC DIGESTION OF VARIOUS CASSAVA RESIDUES IN INDONESIA R. Wurster EAT-Systemtechnik GmbH, D-8012 Ottobrunn Abstract SUMMARY Geographical, environmental and climatic factors proved to be very much in favor of the application of anaerobic digestion processes in Indonesia. From a large number of digestible substrates originating from agro-industries (4), cassava derived residues were selected for digestion experiments. The digestibility of solid tapioca residue could be demonstrated in different types of digesters. An alternative of improved recovery of energy from this residue is sketched, and first Indonesian digestion results with cassava derived ethanol slop are reported. 1. INTRODUCTION On the basis of the cooperation agreement for scientific research and technological development between the F.R. of Germany and the Republic of Indonesia, a joint project called "Solar Village Indonesia", was established in 1979. In the scope of this project EAT was asked in 1983 to promote the experience in the use of biomass for anaerobic digestion in Indonesia. The original goal of the project was to assist the Indonesian partner (B.P.P.Teknologi) in the final design, construction and operation of a large-scale experimental biogas plant, as well as to carry out a study on the biomass potential for anaerobic digestion in Indonesia in general. As first step, laboratory digestion tests with various substrates should be performed and an investigation on the general feasibility of anaerobic digestion processes should be carried out, leading to recommendations how to proceed. The experiments were scheduled to be carried out by BPPT-staff. Assistance from the German side should take place on site during the stays of the visiting experts as well as by monitoring the test results continuously from abroad The BPPT-staff involved in the activities should have been sent to Germany for a six weeks training program on biochemical analysis and on anaerobic digestion. 28. MATERIALS AND METHODOLOGY The digestion tests in Indonesia were carried out with an experimental set-up consisting of 8 batch digesters of 601 each and of 4 semi-continuously fed https://www.w3.org/1998/Math/MathML"> 40 l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digesters. Four of the batch digesters were equipped with a simple device for up- and downward stirring. Two of the 401 digesters were of the so-called two phase type, where the feed intake also serves as a hydrolysis and acidification section. The volumetric ratio of acetogenic to methanogenic section was of about 1 to 8 . In contrary to this, the both socalled one phase digesters have a volumetric ratio of about 1 to 30 . Main efforts were laid upon experiments with the semi-continuously fed digester type, because it is better suitable for practice oriented operation. Simple measuring equipment was provided only for the determination of the total organic solids (TOS) content, the pH-value of the substrate and for the https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -content in the biogas. More detailed analyses should be regularly performed by specialized institutions. The following operational parameters were measured and recorded daily: substrate feed, gas production, gas quality; furthermore the pH-value of substrate, digester contents and digester effluent. The digester temperature was controlled thermostatically and kept at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . For the start-up of the digestion process with solid tapioca production residue (STR), cattle manure was used, since no sewage sludge as inoculum could be obtained, because in Indonesia waste water treatment plants are lacking almost completely. The digestion tests performed during the training program at the University of Regensburg, Germany, were carried out in https://www.w3.org/1998/Math/MathML"> 1 l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> continuously stirred, semi-continuously fed cylindrical laboratory digesters at https://www.w3.org/1998/Math/MathML"> 35 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> As starter substrate cattle manure as well as sewage sludge were applied. The digestion tests were supported by all necessary analysis activities like gaschromatography, https://www.w3.org/1998/Math/MathML"> C O D - , N H 3 - , N k - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -determinations. 29. EXPERIMENTAL EXPERIENCES -FIRST TEST AND ANALYTICAL RESULTS During initial digestion tests in Indonesia using cattle manure it was decided to focus future efforts on substrates which are locally concentrated (e.g. from industrial plants) and cause harm to the environment. centrated (e.g. from industrial plants) and cause harm to the environment. From this group of materials, solid tapioca production residue (STR) was chosen. The TOS-content of the diluted STR fed to the digester was increased step by step from https://www.w3.org/1998/Math/MathML"> 0.68   k g - T 0 S / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 2.0   k g - T 0 S / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in order to increase the gas production rate. As a result the daily gas production rate was raised from poor https://www.w3.org/1998/Math/MathML"> 9 l / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to moderate https://www.w3.org/1998/Math/MathML"> 251 / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and the fluctuating specific gas yields consequently varied between https://www.w3.org/1998/Math/MathML"> 2361 / k g - T O S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 3771 / k g - T O S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The initial pH-value of the STR measured some hours after the termination of the production process, normaliy dropped to around pH 4 . Thus the substrate was very acidic. Due to this low pH-value, due to the organic overload which sometimes occured, and due to repeated and excessive curtailing of the digestion starting phase to less than two weeks, overabundant acidification of the digester contents was caused very easily (for the minimum time requirement of the start-up, https://www.w3.org/1998/Math/MathML"> cf . 8 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This retardation or obstruction of the anaerobic process mainly was attributed to the insufficient growth of the methanogenic bacteria and thus to an accummulation of acids and of hydrogen. Most of these operational disturbances have been avoided during a thoroughly monitored training program on anaerobic digestion of STR which was performed in Germany. Gas yields of https://www.w3.org/1998/Math/MathML"> 0.8   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -biogas per kg-TOS (added) proved to be realistic. The mean methane content reached https://www.w3.org/1998/Math/MathML"> 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the COD-reduction of the originally highly polluted substrate https://www.w3.org/1998/Math/MathML"> ( 120 - 140   g - C O D / l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reached https://www.w3.org/1998/Math/MathML"> 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Also during these tests, which were continued after the end of the training program for another two months, a severe deficiency of nitrogen in the STR was observed. Therefore the addition of nitrogen sources is suggested to avoid obstruction of bacterial build-up. The most essential analysis and performance data, acquired during the above mentioned training program, are summarized in the following tables I and II : Table II : Mean Values of Experimental Digester Performance

DISCUSSION OF EXPERIMENTAL AND STUDY RESULTS

4.1 Experimental Results: During the one year's experimental digestion phase in Indonesia it turned out that reliable chemical analyses neither could be carried out on-site, nor could be obtained at short notice and completely enough from specialized private or university institutes due to organizational difficulties. Many of the problems which occured were related to this fact. On the other hand the digestion tests were performed with a still rarely known substrate: solid tapioca residue (STR). As a result of the training program for Indonesian staff in Germany, it was decided to provide additionally the necessary analytical equipment for the determination of https://www.w3.org/1998/Math/MathML"> T O S , C O D , N H 3 ,   N , S O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and volatile acids to ensure an improved continuation of the tests with this extraordinarily well suited substrate in Indonesia. Regarding the requirements of the biogas process on one hand, and the conditions of a tapioca factory on the other, for practical application, it is recommended to dilute the STR with the liquid effluent of the tapioca factory due to its very high TOS-content. Notwithstanding, STR obviously has a very high starch content of more than https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and therefore it would be even more advisable to carry out alcoholic fermentation. By doing so, prior to an anaerobic digestion step performed on the liquid effluents from both, alcoholic fermentation and tapioca production, a more versatile applicable energy can be recovered. 29.1. Study Results : In parallel to the digestion experiments the biomass potential suitable for anaerobic degradation was investigated. Further the impacts caused by the application of this technology were studied (4). The study concludes that conversion of agricultural residues, forest residues, weeds, and municipal wastes to biogas roughly can substitute as much as 3.5 Mtce/a or https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the present Indonesian primary energy consumption. Furthermore the very favorable effects of biogas technology concerning its net-potential for job creation and its possible benefits to an increasingly polluted environment are presented. All these effects count even higher in a basically still agrarian society with an actual growth rate of https://www.w3.org/1998/Math/MathML"> 2.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 160 mio. inhabitants, of which more than https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> live in an average density of more than 750 inhab. https://www.w3.org/1998/Math/MathML"> / k m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the island of Java, whereas the rest of the population lives scattered over approx. 2,000 inhabited islands with an average density of 34 inhab. https://www.w3.org/1998/Math/MathML"> / k m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 30. PROSPECTS OF ANAEROBIC DIGESTION OF CASSAVA DERIVED SUBSTRATES Since 1984 new environmental laws are enacted in Indonesia, forcing major polluters to purify their production effluents to a maximum organic load of https://www.w3.org/1998/Math/MathML"> 2,500 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -COD/ 1 before discharge to publ ic waters. The existing large tapioca factories as well as the numerous ethanol distillation plants conceived by the government, produce large quantities of concentrated organic effluents or residues. Aerobic treatment for the purification of these effluents would require a large amount of energy, mainly electricity. since the ethanol plants will be located in remote transmigration areas, energy supply will be both, difficult and expensive Therefore anaerobic treatment of the ethanol stillage is suggested, to provide purification capacity and to substitute process energy. Digestion experiments with cassava distillation slop (TOS: https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) were carried out by BPPT. The diluted slop (BOD: https://www.w3.org/1998/Math/MathML"> 20   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) was fed to the digester at a load ratio of https://www.w3.org/1998/Math/MathML"> 5   k g - T O S ⁡ / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The yield at a HRT of 4 days was https://www.w3.org/1998/Math/MathML"> 0,7   m 3 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas per kg-TOS. As known from experiments with distillation stillage in upflow anaerobic filter reactors https://www.w3.org/1998/Math/MathML"> ( cf , 6,7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , C00-degradation of up to https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be regarded as feasible, if the percentage of SS is low. Considering these benefits, aerobic posttreatment seems to be unnecessary for many applications in Indonesia in the short run. To realize this idea, a biogas pilot plant is under planning as an integral part of the almost finished ethanol complex at Tulang Bawang Transmigration Area in Sumatra. For the design of the plant the following input/output ratio is taken as a basis : https://www.w3.org/1998/Math/MathML">   daily Input   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

daily Input

90.0 t of cassava or sweet potato https://www.w3.org/1998/Math/MathML"> 10.0 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of cassava or sweet potato https://www.w3.org/1998/Math/MathML"> 7.5 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of cassava or sweet potato daily Output of ethanol (95%) https://www.w3.org/1998/Math/MathML"> 2 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of high fructose syrup https://www.w3.org/1998/Math/MathML"> 1 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dry yeast solids approx. https://www.w3.org/1998/Math/MathML"> 200   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of ethanol slop 31. CONCLUSION The recent difficulties encountered in the digestion of cassava processing residues in Indonesia were more related to infrastructural and organizational shortcomings, as well as to shortages in equipment, than to technological problems. These circumstances became obvious within the the training program. Cassava is arable under a wide range of climatic and soil conditions (from arid to tropical), furthermore it is rich in starch content, and it has a high latent potential for increased root yield. Therefore it will be a very important food a/o energy crop also for Indonesia (cf. 2). An envisaged wider utilization of cassava and other crops in industrialized production processes, like used in tapioca factories, ethanol plants, palm oil mills, sugar factories, canneries, paper mills, etc., will cause locally concentrated effluents of high organic pollution potential. This will result in a severe environmental impact, if effluents are discharged to public waters without any treatment. Modern anaerobic digestion technology can provide very reasonable means of waste water purification and will further make available a strongly needed auxiliary energy source and an energy-saving natural fertilizer. Both, the environmental and the energetic aspect will gain increased importance in Indonesia. On the overcrowded island of Java the pollution potential is very high due to almost complete lacking of industrial and municipal purification plants. On the scarcely populated and often poorly developed other islands, the supply of energy can be difficult, timeconsuming, and thus costly; all this is of even greater significance in transmigration areas. Additional advantage of the biogas technology is the limited level of technology which will be required with regard to fabrication and plant installation. Therefore a wider application of this technology will be feasible, when mainly using indigenous capacities. On the other hand, skilled personnel is required for plant operation. Considering rural applications, the acceptance of the biogas technology has to be investigated for each special case separately, to prevent probable failures. 32. REFERENCES

"US-ASEAN Seminar on Energy Technology, LIPI, Bandung, Indonesia, 7 - 18 June 1982

"Cassava as an Energy Crop for arid and semiarid Lands", by Porto/Marcarian, 2nd EC-Conference, Berlin, 1982

Statistik Indonesia, Biro Pusat Statistik, Jakarta 1982

"On the Prospects of the Anaerobic Digestion Technology in Indonesia", by 0. U1lmann, EAT-Systemtechnik GmbH, Dec. 1984

"Results of Cassava Digestion Experiments", Universität Regensburg, 1984 - not yet published

"A Pilot Scale Anaerobic Upflow Reactor treating Distillery Waste Waters", by Pipyn/Verstraete, Rijksuniversiteit Gent

"Anaerober Abbau von Weinschlempe", by Dr.M.Morper, Linde AG, 1982

"The Prospects of Anaerobic Waste Water Treatment", by G.Lettinga, Agric. Univ. Wageningen, CEC-Conference, Luxembourg, May 1984

BIOGAS TECHNOLOGY DEVELOPED AND EVALUATED BY ENADIMSA A.J. GARCIA, S. CUADROS and R. FERNANDEZ Unidad de Residuos sólidos, ENADIMSA Empresa Nacional ADARO de Investigaciones Mineras, S.A. Madrid - SPAIN Summary A wide program of studies and project oriented towards the better use of the residual biomass as energy source, has been taking place since 1978. The first studies were oriented towards the estimation of the potencial residual bicmass in Spain, using detailed inventories from various provinces. Subsequently, studies have been made regarding the technical-econamical viability towards establishing practical applica tions and developing the technology for the employment of energy coming from the residual biamass. Among the studies which ENADIMSA has carried out in this field, the following are examples:

Use of gas fram rubbish landfill as energy.

Use of the residue from an alcohol factory as energy.

Development of technology for the anaerobic digestion of farmwastes and self-supply of energy.

Use of crop residues as energy.

Use of forest resiale as energy sorrce through charcoal.

Program and practices in the field of biomass in different countries. - Economical aspects of the use of biamass residue.

These studies have led to the installation of demostration units for the different technologies used in the conversion of biamass into energy. 33. BIOGAS TECHNOLOGIES EVALUATED Within different PEN (National mergy Plan) projects (References 1,2, 3,4) various installations for the production of biogas have been constructed and are currently in a follow-up phase, in collaboration with the INIA (Instituto Nacional de Investigacion Agraria) and the "Instituto de la Grasa y sus Derivados, CSIC", with the objective of evaluating different technologies for the treatment of organic residues and wastes. Within the framework of these projects, ENADIMSA has achieved a technology of its own, developing three systems: rural, DAC and DAL. The systems and installations evaluated are described as under. 34. - Discontinuous system For the treatment of cattle-manure ( https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at solids), ENADIMSA has perfected a rural technology dry route discontinuous system, in two modu les of https://www.w3.org/1998/Math/MathML"> 50   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> constructed in Gerona. The biogas is exploited in a Totem Co-generator. The results achieved are of a 48 hour cycle for the aerobic phase and 15 days for the anaerobic phase, with biogas yields of https://www.w3.org/1998/Math/MathML"> 0,6   m 3 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester/day.

Mixed System

Filter SystemThis system has been evaluated in a pilot plant of https://www.w3.org/1998/Math/MathML"> 20   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in soria andin an industrial instalation of https://www.w3.org/1998/Math/MathML"> 120   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in Toledo, constructed by SUFISAwith the technology of S.G.N. (France) The results achieved in thedigester operating with slurry fram 4.000 pigs are:

Loading rate: https://www.w3.org/1998/Math/MathML"> 3,75 - 6,00   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vs/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester/dayBiogas yields: https://www.w3.org/1998/Math/MathML"> 3 - 4   m 3 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester/day

Process efficiency: 608

Hydraulic retention time (HRT) : 3-5 days

CURRENT PROGRAMThe objectives of ENADIMSA are to continue the follow-up of the differenttechnologies tested for the treatment the residues of farming, and toiniciate a program of evaluation of new systems, developing downflowstationary fixed film technology and to extend the range of the organiceffluents tested.REFFERENCES(1) Aprovechamiento energetico de residuos de alccholeras(Project PEN, 1980 ).(2) Desarrollo de Tecnologia para la digestion anaerobia de residuos ganaderos (Project PEN-MAPA, 1981 ).(3) Autoabastecimiento energético en explotaciones agropecuarias(Project PEN-MAPA, 1982 ).(4) Digestion anaerobia natural de residuos ganaderos en digestores ru-rales (Project PEN, 1983 ).

DIGESTER https://www.w3.org/1998/Math/MathML"> 2 × 50   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , RURAL SYSTEM (Gerona) DIGESTER OF https://www.w3.org/1998/Math/MathML"> 500   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , D.A.L. SYSTEM (Merida) DIGESTER OF https://www.w3.org/1998/Math/MathML"> 500   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , D.A.C. SYSTEM (Badajoz) INFLUENCE OF HYDROGEN ADDITION ON THE POTENTIAL OF METHANOGENIC ECOSYSTEMS R. MOLETTA https://www.w3.org/1998/Math/MathML">   ( 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , J.D. FINCK https://www.w3.org/1998/Math/MathML">   ( 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , G. GOMA https://www.w3.org/1998/Math/MathML">   ( 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and G. ALBAGNAC https://www.w3.org/1998/Math/MathML"> ( 4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) and (4) STATION DE TECHNOLOGIE ALIMENTAIRE - I.N.R.A. 369, Rue Jules-Guesde https://www.w3.org/1998/Math/MathML"> F - 59650 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VILLENEUVE D https://www.w3.org/1998/Math/MathML"> A S C Q https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) present address : STATION D'OENOLOGIE ET DE TECHNOLOGIE VEGETALE - I.N.R.A. - Bd du Général de Gaulle F 11.100 NARBONNE (2) and (3) Département de GENIE BIOCHIMIOUE ET ALIMENTAIRE ERA - CNRS 879 - Avenue de Rangüeil F - 31077 TOULOUSE (2) present address: ELF BIO RECHERCHES La Grande Borde, BP 62, Labèe F https://www.w3.org/1998/Math/MathML"> - 31320 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CASTANET-TOLOSAN Summary In microbial ecosystems of anaerobic digesters, reduction of carbon dioxide into methane by exogenous hydrogen may be of economic inte- rest. According to thermodynamical considerations, a partial hydro- gen pressure of https://www.w3.org/1998/Math/MathML"> 10 - 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> atm may lead to a total arrest of propionate degradation and thus reduce the admission of that gas into the digester. Supply of hydrogen to the gas phase at a very high partial pressure https://www.w3.org/1998/Math/MathML"> ( 0.24   a t m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> inhiblted the degradation of propionate by anaerobic sludge without fully stopping it. This event may be explained by a limitation of hydrogen transfer from the gas phase to the 1 iquid phase. The propionate degradation rate varied linearly with the logarithm of hydrogen partial pressure. Admission of hydrogen into an anaerobic digestor ensuring a discontinuous methanisation of dung led to a slighty lower biogas https://www.w3.org/1998/Math/MathML"> C O 2 + C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production, but the final yield was the same. When the hydrogen supply was adjusted to the consumption capacity of the system, the produced biogas contained https://www.w3.org/1998/Math/MathML"> 98.6 p . 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> methane, https://www.w3.org/1998/Math/MathML"> 0.4 p . 100 C O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 1 p . 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> residual hydrogen. Combined with hydrogen producing reactions, e1ther by fermentation or via chemical pathways, this procedure allows to recover energy and to store it as methane. I. INTRODUCTION During anaerobic digestion of organic matters, volatile fatty acids (especially acetate) are the main intermediates of the energy flow. Among these acids, propionate exerts the largest inhibition of the biological reaction (1) and plays a fundamental role in methane fermenta- tion (2). During anaerobic digestion of cow dung, acetate, propionate and butyrate, are respectively the intermediates for 72-75,13, and 8 p. 100 of the methane (3). Proplonate and butyrate degradation leads to production of hydrogen (Table 1), which concentration plays an important role in thereaction energetics (Fig. 1). Partial pressure Iower than lo 4 atm are 512 Fig. 1. Influence of https://www.w3.org/1998/Math/MathML"> p H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the https://www.w3.org/1998/Math/MathML"> Δ G ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( Kj ) on hydrogen production and consumption. The gas phase is in equilibrium with the https://www.w3.org/1998/Math/MathML"> 11 quid https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> phase. The concentrations selected were for the acids https://www.w3.org/1998/Math/MathML"> 10 - 3 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and for https://www.w3.org/1998/Math/MathML"> H C O 3 50 × 10 - 3 M . p C H 4 = 0.5   a t m . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) Degradation of propionate. (2) Degradation of butyrate. (3) Reduction of https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (4) Homoacetogenesis. Stoichiometry of the reactions are described in Table 1. Fig. 2. 100 litres reactor used for the digestion of cow dung in the presence of hydrogen. (1) Transparent PVC tank. (2) Heating pipe. (3) Recycling circuit. (4) Temperature sensor. (5) temperature controller. (6) Heating tank. (7) Discharge. (8) Hydrogen inlet. (9) Gas meter. Fig. 3. Influence of addition of hydrogen on propionate consumption.Temperature: https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) Degradation of propionate in thepresence of hydrogen. Initial concentration So https://www.w3.org/1998/Math/MathML"> = 474   g / 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Degradation of propionate in the absence of hydrogenSo https://www.w3.org/1998/Math/MathML"> = 0.406   g / 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig. 4. Propionate degradation rate https://www.w3.org/1998/Math/MathML"> r pr   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (mmoles.1 https://www.w3.org/1998/Math/MathML">   - 1 ⋅ h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) against log Fig. 5. Cumulated production of biogas https://www.w3.org/1998/Math/MathML"> C H 4 , C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the presence https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or absence (T) of hydrogen. Substrate cow dung containing 10 p. 100 dry matter. Temperature: https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig. 6. Anaerobic digestion of cow dung in the presence of hydrogen. Evolution of the hydrogen input flow rate (O), partial pressure in the effluent gas ( Q ) and consumption rate (O). REFERENCES BUTYRATE PRODUCTION AND VOLATILE FATTY ACIDS INTERCONVERSION DURING PROPIONATE DEGRADATION BY ANAEROBIC SLUDGES R.MOLETTA https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , H.C.DUBOURGUIER. G.ALBAGNAC STATION DE TECHNOLOGIE ALIMENTAIRE - I.N.R.A. 369 , Rue Jules Guesde F - 59650 VILLENEUVE D https://www.w3.org/1998/Math/MathML">   + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ASCQ STATION D'OENOLOGIE ET DE TECHNOLOGIE VEGETALE - I.N.R.A. Bd du Général de Gaulle https://www.w3.org/1998/Math/MathML"> F - 11100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> NARBONNE 1. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Discontinuous degradation of propionate by anaerobic sludges of an industrial digester of vegetable cannery waste waters led to a transitory accumulation of butyrate and acetate. For an initial concen tration of https://www.w3.org/1998/Math/MathML"> 32 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> proplonate, the maximum concentrations reached were https://www.w3.org/1998/Math/MathML"> 3.5 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> butyrate and https://www.w3.org/1998/Math/MathML"> 0.8 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> acetate Introduction of carboxyl https://www.w3.org/1998/Math/MathML"> 1.4 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> labeled propionate showed that the speciflc radioactivity of acetate was half that of propionate. This seems to confirm that propionate is degraded through a randomizing pathway. The specific radioactivity of butyrate was almost similar to that of propionate. During propionate degradation, addition of https://www.w3.org/1998/Math/MathML"> 14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> labeled butyrate or acetate showed the existence of metabolic pathways of V.F.A. (acetate. propionate. butyrate) interconversion. The degradation of one molecule of propionate led to the production of https://www.w3.org/1998/Math/MathML"> O . 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> molecule of butyrate. This study made on a mixed population inciuding O.H.P.A. bacteria analogous to Synthrophobacter or Synthrophomonas did not allow to determine whe ther butyrate proceeded from the condensation of two acetate molecules or it was directly derived from a symmetrical intermediate with four carbon atoms. 2. INTRODUCTION Propionic acid is an important intermediate in the microbial ecosys tems of anaerobic fermentation (1), (2), (3) and its inhibitory effect is larger than that of the other V.F.A. (4). In the conventional metabolic pattern this acid is converted into acetic acid,carbon dioxide and hydrogen by acetogenic bacteria (O.H.P.A.). Synthrophobacter wolinii was identified as responsible for this conversion in the presence of a Hz using bacterium (5). In methanogenic ecosystems the energy flows producing methane from propionate are sometimes more complex. In fact, propionate degradation in municipal waste water treatment may lead to a transitory butyrate accumulation (6). In the present study, we showed that this also occurred with another kind of sludge and that propionate degradation could be accompanied by a V.F.A. (acetate, propionate and butyrate) interconversion. II. MATERIALS AND METHODS Sludges studied came from an industrial digester producing methane from waste waters of a vegetable cannery. Reactors used were https://www.w3.org/1998/Math/MathML"> 100 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> penicillin flasks (drained by an oxygen free gas, https://www.w3.org/1998/Math/MathML"> N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at 80 and https://www.w3.org/1998/Math/MathML"> 20 p . 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively) into which 10 ml of sludge were added. Eight flasks were prepared to duplicate each Fig. 1. Variation in the VFA concentrations during discontinuous Fig. 2. Discontinuous degradation of propionic acid: variation in the vFA radioactivity with time during addition of 25 pmole/1 of carboxy 1 14c labeled propionic acid at time zero. Fig. 4. Discontinuous degradation of propionic acid: variation in the VFA radioactivity during addition of https://www.w3.org/1998/Math/MathML"> 25 μ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mole https://www.w3.org/1998/Math/MathML"> / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of carboxy 1 https://www.w3.org/1998/Math/MathML"> 14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> labeled butyric acid after https://www.w3.org/1998/Math/MathML"> 9.30   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of culture. Fig. 5. Discontinuous degradation of propionic acid: variation in the VFA radioactivity during addition of https://www.w3.org/1998/Math/MathML"> 25 μ m o l e / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of carboxyl https://www.w3.org/1998/Math/MathML"> 14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> labeled acetic acid aften https://www.w3.org/1998/Math/MathML"> 9.30   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of culture Fig. 6. Discontinuous degradation of propionic acid. Variation in the propionic and butyric acid consumption rates and butyric acid production with time during addition of https://www.w3.org/1998/Math/MathML"> 25 μ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mole https://www.w3.org/1998/Math/MathML"> / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of carboxy 1 14C labeled butyric acid after https://www.w3.org/1998/Math/MathML"> 9.30   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of culture. TABLE 1 REFERENCES IARGE SCALE ANAEROBIC DIGESTION OF ANIMAL WASTES IN IHE NETHERLANDS F.M.L.J. CORTHUYS - H.J.W. POS'IMA Grontmij n.v. consulting engineers, the Netherlands presentation: H. Snoek - P.H.A.M.J de Bekker 3. Summary About 25 Dutch biogas plants on individual farms aigest various types of animal waste slurries. Considerable operational ano technical problems turned the economic balance negative in most cases. In spite of the governent's financial support, the development and wide application of these small scale biogas plants is now impeded Large scale biogas plants were recently studied by Grontmij based on national and foreign practical experience with anaerobic digestion of animal wastes. These plants are generally found to be economically and technically feasible. Several projects are preparea for central processing of manure which originates from large numbers of livestock units. It is foreseen that 35 to 45 large scale biogas plants may be implemented in the next decade, to process about 10 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of animal wastes annually. Nett generation of biogas may reach 100 to 200 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> annually, equivalent with 55 to https://www.w3.org/1998/Math/MathML"> 110 K t . O . e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The paper covers a case study of central anaerobic digestion of https://www.w3.org/1998/Math/MathML"> 100.000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of pig wastes and https://www.w3.org/1998/Math/MathML"> 50.000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of poultry wastes per year simultaneously. The nett biogas production is estimated to be 3.0 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per annum (appr. 1,5 Kt.o.e.)

INIRODUCTION

In the Netherlands livestockfarming is concentrated in several regions causing detoriation of the environnent by uncontrolled disposal of animal wastes and overfertilization. In an ever increasing number of occasions during the past decade acid precipitation, nuisance and nitrates present in groundwater, which is a source of drinking water, were related hereto. On the other hand areas used for arable farming require conmercial and organic fertilizers. The long term purpose is to use the surplus of animal waste to balance the need for fertilizers. Large scale central anaerobic digestion of animal wastes may support the development of centrally managed recycling of manure surplusses as a first step in a serie of unit operations, providing the energy that is required for further processing. 4. PROBLEM Argicultural manure surplusses in the Netherlands. https://www.w3.org/1998/Math/MathML">   Manure surplus in total manure production     million tons per yr in million tons per yr   -   cattle   7.5 67.0 -   fattening calves   1.0 1.7 -   pigs   7.5 14.6 -   poultry   : 2.0 2.7 18.0 - 10 6   T / a 86.0 - 10 6   T / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 5. ENERGY RECOVERY About 25 Dutch biogas plants on individual farms digest various types of animal waste slurries. Considerable operational and technical problems turned the economic balance negative in most cases. In spite of the goverment's financial support, the development and wide application of these small scale biogas plants is now impeded. Large scale biogas plants were recently stuaied by Grontmij based on national and foreign practical experience with anaerobic digestion of animal wastes. These plants are generally found to be economicaliy feasible (gas-utilisation through production of electricity and heat). Several projects are prepared for central processing of manure which originates from large numbers of livestock units. A number of large scale biogas plants may be implemented in the next decade to treat about 10 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of animal wastes anually. Nett generation of biogas may reach 100 to 200 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> annually, equivalent with 55 to 110 Kt.O.e. (*). In this paper a case study on central digestion and further handling of yearly https://www.w3.org/1998/Math/MathML"> 150.000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of animal wastes is presented. In the Netherlands the present project is considered to be in the most advanced stage and can be implemented as a suitable energy demonstration project for large scale anaerobic digestion of anima. wastes, including large scale manure processing. The plant is projected in the industrial zone near the harbour of Meerlo-Wanssum's municipality (Province of Limburg, in the southern region of the Netherlands). 6. DEMONSTRATION PRAJECT WANSSUM (NL) By order of "stichting Mestbank Limburg", Grontmij designed a large scale plant for transhipment and anaerobic digestion of animal wastes. The manure is supplied by tanker-lorries, while the residue is conveyed by tanker-vessels or tanker-lorries. Storage tanks are applied to tune both flows. The anaerobic digestion plant is fed with fresh manure taken from the storage tanks. Biogas generated is utilized in several ways:

for energy consumption of the digestion plant (electricity and heat); for energy consumption of the transhipment plant (electricity).

Note: one t.0.e. https://www.w3.org/1998/Math/MathML"> = 4.19 * 10 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Joule.

DETAILED DESIGN OF MANURE DIGESTION PLANT WANSSUM (Variant C)

PROCES FLON DIAGRAM

COSTS ASPECTS

Investment for complete digestion plant excluding transhipment plant, including https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> subvention on investment Yearly capital costs: (15 years, 98 interest) : Dfl. 470,000.- Yearly running costs (excluding external transports) : Operation : DEl. 60,000. Maintenance Chemicals Digestion costs per ton of raw manure Running benefit https://www.w3.org/1998/Math/MathML"> 3,000,000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas/a ( https://www.w3.org/1998/Math/MathML"> 750   k W e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> 1650 t . 0 . e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per year) 7. REIFERRENCES Large scale transhipment and anaerobic aigestion of manure at Wanssum (Nu) Grontmij n.v. consulting engineers 1984 (in Dutch). THE ANOXAL PROCESS ANAEROBIC TREATMENT OF LIQUID INDUSTRIAL EFFLUENTS J.M. CUTAYAR L'Air Liquide Centre de recherche CLAUDE DELORME BP 126. 78350 Les Loges en Josas FRANCE M. MOULINEY L'Air Liquide D.C.V.M, CP 26,57 avenue CARNOT 94503 Champigny sur Marne FRANCE Abstract Summary Biological treatments of industrial effluents usually consisted in aerobic fermentation or in unoptimized anaerobic fermentation techniques (cSTR process, Contact process...). The main 1imitations of these techniques are economic or technical ones. The aerobic treatments cause important invest- ments and high operating costs;the first generation of methanization pro- cesses cannot accept high dilution rates because of the washing out of the microorganisms. The Anoxal process developped by https://www.w3.org/1998/Math/MathML"> 1 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> AIR LIQUIDE is an upflow anaerobic filter;the reactor is loosely packed with an inert plastic media which induces microorganisms retention. Since high active biomass concentrations can be reached, the process allows the anaerobic treatment of any kind of industrial effluents with important coD loading rates and methane productions. Several studies carried out from laboratory to full scale plant have established the efficiency and the reliability of the Anoxal process. 8. Introduction The anaerobic treatment of liquid industrial effluents is developped by https://www.w3.org/1998/Math/MathML">   * A T R https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> LIQUIDE since 1981. A two years basic research in our research center completed by several pilot plant studies (from 3 to 10 m 3 ) led us to the definition of the Anoxal process. It consists in an upflow anaerobic filter, loosely packed with an inert material (polypropylene pali rings) which induces microorganisms retention.Most of the biomass is present in suspended form in the intersticial void spaces within the media matrix and only a small portion of the biomass is attached to the packing surfaces. Since the suspended growth tends to collect in the bottom of the reactor,most of the activity is in the bottom of the fermentor and the attached growth has a polishing action(see pictures 2 and 3 ). In most of anaerobic digestion processes transport of unattached biologi- cal solids occurs because of hydraulic lifting and flotation due to attached gas bubbles, the consequence is a physical biomass washing out. In the Anoxal PICTURE 1: THE ANOXAL PROCESS PRINCIPLE The first full scale Anoxal plant was built in 1983-84 for FLODOR SA (potato industry) at Peronne in the north of France and was started in June 1984. This plant currently treats potatoes bleaching water,featuring a 13 tons of COD (chemical oxygen demand) daily load. A second full scale plant has been sold to "La Cellulose du Pin" at Tartas in the south west of France;this unit will be started on a sulfite evaporator condensate effluent.The previous load is 21 tons of CoD per day.

Anoxal process references

1 Treatment of a potatoes bleaching water

This waste water which mainly corrsists of starch, represents an organic load of 13 tons of COD per day. Its chemical and physical characteristics vary a lot however, the mean ones are:

COD (chemical oxygen demand) https://www.w3.org/1998/Math/MathML"> = 2000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to 10000 mg/1

BOD5 (biological oxygen demand) https://www.w3.org/1998/Math/MathML"> = 1500 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 8500 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Dry matter https://www.w3.org/1998/Math/MathML"> = 1500 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 6000 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Total nítrogen

https://www.w3.org/1998/Math/MathML"> = 1500 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 6000 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> = 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 100 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

pH

https://www.w3.org/1998/Math/MathML"> = 50 t 0100 m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> = 25 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 40 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> After a one year pilot plant study (on a https://www.w3.org/1998/Math/MathML"> 5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> unit), the full scale plant was built and started in June 1984. The applied pretreatment only consists of a temperature control.The anaerobic digestion occurs in a https://www.w3.org/1998/Math/MathML"> 1750   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cylindrical reactor (13 m x https://www.w3.org/1998/Math/MathML"> 13   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The hydraulic retention time is about 24 hours and the loading rate about https://www.w3.org/1998/Math/MathML"> 8   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> C O D / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . day. During the last ten months, the results observed were showing COD and FSS degradation values of respectively 95 and https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (see pictures 2 and 3 ) The medium daily biogas production https://www.w3.org/1998/Math/MathML"> 65 % C H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is about https://www.w3.org/1998/Math/MathML"> 5800   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 4 PICTURES 2&3 : THE TSS AND SOLUBLE COD PROFILES IN THE REACTOR 9. 2 Treatment of a sulfite evaporation condensate Evaporation of the spent 1.iquors from sulfite pulp mills produces sulfite evaporator condensates. This type of effluent has the following composition and characteristics; The complex chemical composition and the presence of substances which may be toxic for the methanogenic bacteria (phenols, polyphenols,free or combined SO. require an adapted population to the substrate. A. 14 months pilot plant study was carried out on a https://www.w3.org/1998/Math/MathML"> 5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> unit on the industrial site. A long period of time (about 2 months) appears to be required for the start up.The organic loadings to the reactor were slowly increased in steps,allowing time for acclimatation and growth of adapted populations. The optimum loading rate was https://www.w3.org/1998/Math/MathML"> 8   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COD/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .day with an hydraulic retention time about one day. The COD degradation was https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the biogas productivity from 2 to https://www.w3.org/1998/Math/MathML"> 3   m 3 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . day. The full scale plant is today under construction;the fermentor will be a https://www.w3.org/1998/Math/MathML"> 2900   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volume. This unit will treat 21 tons of COD and produce 7800 m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of biogas per day The energetic balance of the operation is as follows: https://www.w3.org/1998/Math/MathML">   biogas produced     autoconsumption     electric consumption     operating costs saved by anaerobic     treatment in compare to aerobic one   = - 1500   toe/year   = 150   toe/year   + 100   toe/year     The economic balance will include the pH neutralization and the nutri-   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ments requirements. 10. Conclusions During the last ten years, there have been numerous laboratory studies to demonstrate the various anaerobic treatment systems feasibilities. In view of the differents pilot plant studies and the full scale plant realizations, the upflow anaerobic filter seems to be the fittest anaerobic treatment pro- cess for most industrial wastawaters. In spite of all these advantages, the anaerobic filter isn't the easier process to scale up; lack of design experiences can lead to hydraulics problems like channeling, dead-zones ... In the Anoxal process, these problems are avoided owing to an optimized hydraulic regime (improved liquid distribution system...). The first full scale Anoxal plant has confirmed the realiability of the process;the second one has shown a great methanization potential for pulp and paper wastewaters. BIOGAS PRODUCTION FROM SOLID PINEAPPLE CANNERY WASTE AT ELEVATED TEMPERATURE M. TANTICHAREON, S. BHUMIRATANA, T. UTITHAM and N. SUPAJUNYA King Mongkut's Institute of Technology, Thonburi Bangkok 10140, Thailand https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The results reported herein are methane production using solid waste from pineapple cannery for industrial purpose. The experiments were from pineapple cannery for industrial purpose. The experiments were and amount of loading. The investigations were run at mesophilic and thermophilic temperature https://www.w3.org/1998/Math/MathML"> 32,37,45,50,55 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 60 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The reactor was 1 gallon glas bottle with 3 litre working volume. Each reactor re- ceived seeding from digester previously operated at ambient tempera- ture with pineapple waste. To minimize the effect of temperature shock, the cultures were acclimatized to the incubation temperature by increas- ing the digester temperature approximately https://www.w3.org/1998/Math/MathML"> 1   ∘ C / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day. Increasing the feed concentration from 12.5 to 17.5 gm. wet weight/litre of reactor volume per day at 50 day retention time increased methane production from 1.27 to 1.79 litre of reactor volume per day at https://www.w3.org/1998/Math/MathML"> 55 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 1.22 l. to 1.46 l. at https://www.w3.org/1998/Math/MathML"> 37 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> At high feed concentration, the ratio of gas production to total solid added at mesophilic temperature was lower than at thermophilic temperature. Increasing the feed concentration beyond those values indi- cated above resulted in decreased methane production, pH instability, and subsequent digester failure. The studies indicated that loading rates and organic destruction were higher at thermophilic range than at mesophilic range. The energy required, to maintain the system at higher temperature, is offset by energy gained from the operation. 11. INTRODUCTION Thailand pineapole-canning industry has grown rapidly. In a factory, 50 percent of the pineapple is left over as fruit waste. It is essential that these solid waste composed of peel and core are disposed of properly. Preliminary studies in our laboratory and subsequent pilot tests in https://www.w3.org/1998/Math/MathML"> 5 M 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digestor at ambient temperature indicated the possibility of producing methane from this waste in large scale. The gas production was approximately https://www.w3.org/1998/Math/MathML"> 1   m 3 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of reactor volume (1). The results showed that the organic loading was limited to as low as https://www.w3.org/1998/Math/MathML"> 10   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wet waste/m 3 -day If the gas produced was fully and properly utilized, the large scale prom duction would have a relatively short economic returns. However, to treat the amount of waste left over, the system would be very large and cumber- some. Effect of temperature on rate and degree of conversion on the anaerobic digestion have been reported in 1.terature https://www.w3.org/1998/Math/MathML"> ( 2,3 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Within each temperature range (mesophilic and themophilic), the reaction rate in- creased as the temperature increased. But the temperature effects on reaction rates vary depending on the domposition of the substrate used (4). This paper describes the effect of temperature on anaerobic diges- tion from low to high feed concentrations, using fresh waste of solid pineapple. The net energy return was investigated to examine the feasibility of thermophilic fermentors. MATERIALS AND METHODS At the higher feed rate, a slight decline in rate of gas production was observed, for the shortest RT.

Effect of temperature and feed concentration

Table 3 shows the effect of temperature on the highest possible organic loading at 50 days retention time. For both temperature ranges, the gas yield increased proportionally to the loading rate up to the loading of https://www.w3.org/1998/Math/MathML"> 17.5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wet weight/l of reactor volume-day But the efficiency of the mesophilic system decreased with increasing loading rate where as the efficiency of the thermophilic system remained constant. Another point in favor of thermophilic digestion was the favorable physical of sludge residues. Many investigators (6, ) reported the problem of thick scum when plant materials were used. We found that the layer of solids in thermophilic digestion was only bed that occured in mesophilic digestor. The interaction of mixed population of microorganism involved in the process of methane formation is complicated subject. The unbalance in the growth of bacterial subpopulations may cause the frequent failure of domestic waste water fermentors (8). As far as coD is concerned, our results raised another speculation on the numbers of bacterial subpopulations actively involved at each selected temperature. We observed a high COD value of liquid effluent with a greater total solid destruction at https://www.w3.org/1998/Math/MathML"> 55 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which may predict a more active hydrolytic microorganism in the thermophilic range in comparison with mesophilic temperature range. Identification of bacterial subpopulation and chemical analysis of intermediate product would be of interest. 12. System Energy Balance To determine net energy gained at elevated temperature, an energy balance on a system was carried out with the following assumptions: A feed rate of https://www.w3.org/1998/Math/MathML"> 17.5   k g / m 3 - d a y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , for which the rate of gas production at https://www.w3.org/1998/Math/MathML"> 55 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is https://www.w3.org/1998/Math/MathML"> 5.39   m 3 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -day and the rate of gas production at https://www.w3.org/1998/Math/MathML"> 37 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is https://www.w3.org/1998/Math/MathML"> 4.12   m 3 / m 3 - d a y . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The system is equiped with a heat exchange to transfer heat from effluent stream to the inlet stream. The exit stream from the exchanger is assumed to be https://www.w3.org/1998/Math/MathML"> 5   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> higher than the inlet stream to the system (at ambient https://www.w3.org/1998/Math/MathML"> 32   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). This condition implies that the inlet stream into the reactors is at https://www.w3.org/1998/Math/MathML"> 48 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 7 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> below the reactor temperature), thus energy needs to be added to this stream.

All heat capacities are the same as that of pure water

The reactor is insulated so that total heat of pure water than https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of total heat content of the reactor (sensible heat only) over 24 hours period.

Heat of reaction is negligible.

With the above assumptions, Table 2 summarized net energy gain for various reactor volumes. It is cleared that the energy required by the systern is offget by the energy gained from operating at higher temperature. The bigger the reactor, the smaller heat loss per unit volume, thus improved in term of energy. Obviously the final decisions will have to be based on economic considerations. Table 1 Daily gas production from anaerobic digestor incubated at elevated temperature and fed with 18.75 gm wet waste in every 4 day. The daily gas production were averaged from 5 values. day after fed batch litre of gas/3 L. reactor volume-day at c 32 37 45 50 55 60 1 3.74 3.76 2.62 2.98 3.27 3.72 2 2.33 2.29 1.71 1.82 2.26 2.40 3 0.87 1.00 1.42 1.47 1.56 1.19 4 0.51 0.56 1.24 1.23 1.04 0.42 Total gas 7.45±0.21 7.61±0.44 6.99±0.59 7.5±0.14 8.13±0.16 7.73±0.19 production(L.) Table 2 Energy analysis of biogas production at https://www.w3.org/1998/Math/MathML"> 55   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for various reactor sizes. (ambient temperature https://www.w3.org/1998/Math/MathML"> = 32 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) Table 3 Effect of loading concentration on anaerobic fermentation of pineapple waste at different temperature lioading once a day, RT 50 day) Loading gm. wet waste/L. of reactor volume Temperature https://www.w3.org/1998/Math/MathML">   C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas production ototal solid pH https://www.w3.org/1998/Math/MathML"> L . / g m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TS https://www.w3.org/1998/Math/MathML"> L . / L . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of reactor volume-day 12.5 32 0.49 1.17±0.07 86.48 7.25 37 0.51 1.22±0.09 88.85 7.25 55 0.53 1.27±0.02 90.78 7.60 60 0.51 1.22±0.10 89.40 7.6-7.7 15.0 32 0.44 1.24±0.09 80.26 6.9 37 0.44 1.24±0.09 80.19 7.0 55 0.54 1.54±0.09 92.87 6.95 60 0.54 1.55±0.09 93.28 7.35 17.5 32 0.43 1.42±0.05 80.28 6.9 37 0.44 1.46±0.07 80.30 7.0 55 0.54 1.79±0.08 91.99 6.9 60 0.54 1.79±0.12 92.24 7.35 Loading with https://www.w3.org/1998/Math/MathML"> 20.0 g m / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of reactor volume were not possible in every digester. pH dropped from 7.0 to 5.4 with gas production approximately https://www.w3.org/1998/Math/MathML"> 0.2 - 0.4   L / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . REFERENCES (1) TANTICHAROEN, M., BHUMIRATANA, S., TIENTANACOM, S. and PENSOBHA,L. (1982. Biogas production from solid pineapple waste. Proceedings of the National Workshop on Agricultural and Agro. Industrial Residue Utilization. Petch-Buri, Thailand, December 13-18, 1982 . (2) COONEY, C.L., and D.L. WISE. (1975). Thermophilic anaerobic digestion of solid waste for fuel gas production. Biotechnol. Bioeng. https://www.w3.org/1998/Math/MathML"> 17 : 1119 - 1135 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (3) PEEFFER, J.T. (1974). Reclamation of energy from organic refuse. Final report EPA-R-800776. Department of Civil Engineering University of Illinois, Urbana. (4) Adams, K.H. Optimization of net energy return. The effect of temperature on rate and degree of conversion in anaerobic digestion. Proceeding First Asean Seminar Workshop on Biogas Technology. 16-20 March 1981, Manila, Philippines. (5) Pfeffer, J.T. (1974). Temperature effects on anaerobic fermentation of domestio refuse. Biotechnol and Bioeng. XVI:771. (6) TANTICHAROEN, M. and CHUNTRANULUCK, S. Biogas production from aquatic weeds. Proceeding of the International solar Eneroy Society Congress, Brighton, England 23-28 Aug. 1981 . Edited by David O. Hall and June Morton. Pergamon Press. (7) CHITTENDEN. A.E., HEAD, S.W. and BREAD, G. Anaerobic digestorsfor smal.l-scale vegetable processing plants. Tropical Product Institute https://www.w3.org/1998/Math/MathML"> G 139 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> August 1980 . (8) CHYNOWETH , D.P., and R.A. MAH. (1977). J. Water Pollut. Control Fed ADHESION OF ANAEROBIC BACTERIA FROM METHANOGENIC SLUDGE ONTO INERT SOLID https://www.w3.org/1998/Math/MathML">   SURFACES   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> D. VERRIER and G. ALBAGNAC Institut National de la Recherche Agronomique BP 39 - 59651 VILLENEUVE D'ASCQ Cedex - France 13. Summary The mechanisms of bacterial adhesion on solid surfaces in anaerobic fixed film reactors remain poorly understood. The influence of the most significant parameters on the adhesion kinetics are presented as a preliminany contribution hinetice of biofilm formation wene a preliminary contribution. Kinetics of biofilm formation were obtained during 3-months experiments using methanogenic conmunities continuously fed with a mixture of https://www.w3.org/1998/Math/MathML"> V . F . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A. The fixation of the first bacterial layer was characterized using short submersion times of the bacterial layer was characterized using short submersion times of the slides was quantified using measurement of microbial proteins and microsconic techniques. A rapid initial adsorption (a few hours) is followed by a rather slow thickening of the biofilm. On P.V.C. Slides, it was determined during a 60-days experiment that biofilm growth was https://www.w3.org/1998/Math/MathML"> 0.13 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of protein per mm per day. Tnitial adsorption was ontimal at https://www.w3.org/1998/Math/MathML"> p H 7.4 : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> more than https://www.w3.org/1998/Math/MathML"> 4 × 10 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bacteria per mm were counted within four hours while less than https://www.w3.org/1998/Math/MathML"> 5 × 10 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bacteria/mm were fixed when the pH was adjusted above 6.8 or above 7.8. Calcium and sodium up to 4 milliequivalents per liter had a rather positive effect on the microbial attachment. Scanning electron microscopy showed the prevalence of filamentous acetoclastic methanogens in the fixed biomass. These results are discussed in confrontation with the physico-chemical theories of adhesion. 14. INTRODUCTION Bacterial adhesion onto solid surfaces have been studied in relation with human diseases, dental plaque formation, fouling in marine environments, etc.). However, mechanisms involved in anaerobic fixed film reactors remain poorly understood. General theories (DLVO theory, thermodynamics approach) cannot be useful without previous studies in this particular ecosystem. As a preliminary contribution, the influence of significant parameters on kinetics of anaerobes attachment on inert supports are presented here. 15. MATERIAL AND METHODS Glass and grey Polyvinyl Chloride (P.V.C.) slides were used as supports. Before each experiment, new slides were carefully cleaned and rinsed in distilled water. The device schematized in figure 1 was used for long-term adhesion experiments. It consists mainly of a https://www.w3.org/1998/Math/MathML"> 750 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> column with four sampling ports specially designed to facilitate the removal of plane supports without damaging the fixed biomass. Methanogenic bacterial suspensions were from a completely mixed reactor continuously fed with a Figure 1 : Device for the study of anaerobes adhesion rate I- Column: https://www.w3.org/1998/Math/MathML"> H = 50   c m ; D = 4,5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2- Sampling ports 3- Recyciing pump 4- Feeding pump B- Bakelite stopper J- Buty 1 joint L- Slide Abstract The formation of the first bacterial layer was studied in anaerobic flasks (500 m.l or more) filled with the bacterial suspensions adapted to V.F.A. The P.V.C. slides were submerged and fixed to the flask stopper during the incubation time (0.5 to 8 hours). Then, they were sampled, rinsed with 0.1 M cacodylate buffer and stained with acridine orange. They were rinsed in distilled water and viewed at https://www.w3.org/1998/Math/MathML"> 1000 x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> using a https://www.w3.org/1998/Math/MathML"> N A C H E T N S - 400 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> microscope equipped for epifluorescence. Numerations were done on a minimum of ten fields for each slide. All the experiments were performed at https://www.w3.org/1998/Math/MathML"> 35 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3. RESULTS AND DISCUSSION Long-term experiments showed that bacterial attachment on glass slides was very fluctuating and remained always low. On the other hand, it was higher and increased constantly with time on P.V.C. slides (Table 1). The average rate of biofilm formation was O.13 \mug of protein (expressed as equivalent B.S.A.) per https://www.w3.org/1998/Math/MathML"> 100   m m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of P.V.C. and per day. As 1 g of protein was equivalent to 5-6 https://www.w3.org/1998/Math/MathML"> × 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bacteria in this case (data not shown), we could calculate that https://www.w3.org/1998/Math/MathML"> 7 × 10 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bacteria adhered per mm of P.V.C. and per day, Scanning electron microscopy evidenced that the spatial distribution day. Scanning electron microscopy evidenced that the spatial distribution the predominant bacteria were filaments with septa and irregular surfaces tentatively identified to Methanothrix soehngenii. Table 1 : Biomass fixed on glass and P.V.C. slides in relation with incubation time (results are expressed as g protein equivalent sab per https://www.w3.org/1998/Math/MathML"> 100   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; average of two slides ) Incubation time (days) 19 63 Glass 1,61 1,22 https://www.w3.org/1998/Math/MathML"> P ⋅ V ⋅ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2,50 8,33 Short-term experiments evidenced that initial fouling was a rapid adsorption (a few hours) followed with a rather slow thickening of the bacterial layer (Fig. 2). Rates can be expressed by the relation X https://www.w3.org/1998/Math/MathML"> k , t 2 + k 2 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where k is the initial adsorption rate. In subsequent experiments, incubation time was therefore fixed to four houns. Influence experiments, incubation tine was therefore fixed to four hours. Influence of pH was studied in the range 6.5-8.O, pH being adjusted with https://www.w3.org/1998/Math/MathML"> 6 N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> HCl or ln NaOH. Optimal pH for injtial adsorption was 7.2-7.4 with more than 4 x lo bacteria counted per https://www.w3.org/1998/Math/MathML"> m m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while less than https://www.w3.org/1998/Math/MathML"> 5 × 10 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bacteria per mm were adsorbed for pH values below 6.8 or above 7.8 (Fig. 3 ). Influence of cation concentration was then examined using calcium chloride or sodium chloride https://www.w3.org/1998/Math/MathML">   a d d i t i o n s   a n   a n t i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> additiors. A strong influence of calcium concentration on bacterial adhesion was observed with an optimal effect at about https://www.w3.org/1998/Math/MathML"> 2 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Ca . Above this concentration a negative effect appeared due to bacterial aggregation (Fig. 4). Sodium additions were less effective. very similar influences of pH and calcium have been reported with marine bacteria (2, 3, 4). The same effect of calcium on methanogenic granular sludges formation was reported by HULSHOFF POL et al. (5). Nevertheless, the exact mechanisms involved in bacterial adhesion in anaerobic fermenters remain unknown. Three hypothesis at least must be further examined to underline the prevalent one:

As suggested by DLVO theory, electrical double layer must decrease when ion concentration increases in the liquid medium, thus reducing repulsion electrostatic forces provocated when a negatively charged bacteria approaches a surface and allowing attractive VAN DER WAALS forces to predominate. As a consequence, the number of attached bacteria will to predominate. As a consequence

Divalent cations may play an active role in the formation of hydrogen bonding between negative surface charges.

Cations may indirectly interact to increase hydrophobicity of surfaces, as suggested by FATTOM and SHILO (6).

Moreover, it will be necessary to examine how acid on basic pH modtfy the polysaccharidic sheath of the bacteria. Though this was not the goal of this study, a great difference was observed between supports like glass and P.V.C. and it will be important to define their surface characteristics in relation with their ability to promote bacterial adhesion. This study was partly supported by a pluriannual agreement between the French A.F.M.E. and I.N.R.A. (1) BRADFORD, M.M., 1976. A rapid and sensitive method for the quantitation of microgram quantities utilizing the principle of protein-dye binding. Anal. Biochem. 72,248-254. 16. ACKNOWLEDGEMENTS 17. https://www.w3.org/1998/Math/MathML">   REFERENCES   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (2) FLETCHER, M. (1977). The effects of culture concentration and age, time and temperature on bacterial attachment to polystyrene. Can. J. Microbiol. https://www.w3.org/1998/Math/MathML"> 23,1 , 1 - 6 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (3) STANLEY, P.M., 1983. Factors affecting the irreversible attachment of Pseudomonas aeruginosa to stainless steel. Can. J. Microbiol. 29, 11, 1493-1499. (4) GORDON, A.W, and MILLERO, F.J, 1984. Electrolyte effects on attachment of an estuarine bacterium. Appl. Environ. Microbiol. https://www.w3.org/1998/Math/MathML"> 47,3 , 495 - 499 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (5) HULSHOFF POL, L., DOLFING, J., DE ZEEUW, W., LETTINGA, G., 1982. Cultivation of well adapted pelletized methanogenic sludge. Biotechnology Letters https://www.w3.org/1998/Math/MathML"> 4 _ , 5,329 - 332 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (6) FATTOM, A., SHILO, M., 1984. Hydrophobicity as an adhesion mechanism of benthic cyanobacteria. Appl. Environ. Microbiol. https://www.w3.org/1998/Math/MathML"> 47,1 , 135 - 143 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 2 : Medial nymber of attached bacteria vs incubation time in a https://www.w3.org/1998/Math/MathML"> 2.2 × 10 bact.   / ml https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> suspension Figure 4 : Medial number of attached bacteria vs https://www.w3.org/1998/Math/MathML"> C a + + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> N a + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> GRANULAR METHANOGENIC SLUDGE : MICROBIAL AND STRUCTURAL ANALYSIS H.C. DUBOURGUIER https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , G. PRENSIER https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , E. https://www.w3.org/1998/Math/MathML"> S A M A I N 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , G. ALBAGNAC https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> I Institut National de la Recherche Agronomique BP 39 - 59651 VILLENEUVE D'ASCQ Cedex - France 2 I.N.S.E.R.M. - U 42 - CERTIA - 59650 VILLENEUVE D'ASCQ - France 18. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In granules sampled from an upflow sludge bed reactor, glucose and In granules sampled from an upflow sludge bed reactor, glucose and lactate were mainly fermented by Propionibacteriaceae. Acetogenesis with obligate hydrogen transfer was performed either by su.lphate reducers (lactate) or syntrophs (ethanol, butyrate, propionate). The hydrogen scavenger was Methanospirillum hungatei and the prevalent acetoclastic methanogen was a filamentous organism similar to Methenothmix goehngenii. Soanning electron micmoseopy mevealed network of Methanothrix entrapping various rod-shaped bacteria, Methanosarcina packets and cell debris. Transmission electron microscopy evidenced a matrix of cell debris entrapping mineral precipitates and individual small colonies made of pure or associated bacteria. Many cells were surrounded by abundant exopolymers appearing as fimbriae, capsules or fibrous glycocalyces. Methanothrix filaments were sometimes observed as winded into balls. Cells of Methanosarcina contained high amounts of cytoplasmic polysaccharidic inclusions. Other bactersa contained cytoplasmic inclusions (polyglucose or polyhydroxybutyrate). Thus, structure of cytoplasmic inclusions and cell morphologies allowed localization and presumotive identification of syntrophs and methanogens. The granules appeared as heterogeneous aggregates including the major trophic groups performing acetogenesis and methanogenesis. In this microecosystem, ultra-structural studies suggest that interspecies transfer of hydrogen and metabolites occured within the granules rather than through the liquid phase.

INTRODUCTION

In anaerobic ecosystems, bacterial interactions such as interspecies hydrogen transfer and cometabolism may be dependert on the microenvironment. In second generation digesters including anaerobic sludge blankets or fixed-film reactors, bacterial pelletization or formation of biofilms enhance retention of bacterial biomass. But little basic research has been done on the structure of these bacterial aggregates. 19. MATERIAL AND METHODS Anaerobic sludge was sampled from a https://www.w3.org/1998/Math/MathML"> 5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pilot upflow sludge bed treating wastewaters from corn starch industry. Enumerations were done by the MPN method as previously described (5) and quantified by recording growth, microscopic appearance, gas and VFA analysis of the cultures after incubation for 2 to 14 weeks at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . For microscopy, samples were fixed by ruthenium red and glutaraldehyde and postfixed by https://www.w3.org/1998/Math/MathML"> O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1). Ultrathin sections for TEM were stained with uranyl acetates and lead citrate. Scanning electron microscopy was performed on samples post-treated with ret. 20. 3. - RESULTS AND DISCUSSION By the acridine orange method, total counts were between https://www.w3.org/1998/Math/MathML"> 10 10 - 10 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cells per ml. Enumeration (Table 1) on lactate and glucose indicated that acidogenesesis was mainly due to Propionibacteriaceae. This could be explained by their low K for these substrates which confeng an ecologioal explained by their low K for these substrates which confers an ecological advantage compared with C. propionicum and M. elsdenii. in substrate-limited conditions. Methanogen numbers were very high (10 cells/ml) and the dominant acetodiastio species was filamentous and monphologionly similan dominant acetoclastic species was filamentous and morphologically similar to Methanothrix soehngenii. In the prime subcultures, these organisms presented particular surface properties since numerous rods sticked to thein filaments: they also agelutingted prepipitates of fermous sulphide their filaments; they also agglutinated precipitates of ferrous sulphide. Although they were never observed in numeration flasks, the presence of Methanosarcina sp. was pointed out ejther by light microscopy on by electron microscopy. The main hydrogenophilic methanogen was a long curved motile rod identified as Methanospirillum hungatei. Short pointed-end rods were also identified as Methanobrevibacter sp. Acetogenesis from lactate was performed by motile curved sulphate reducers (Desulfovibrio ?, https://www.w3.org/1998/Math/MathML"> 10 - 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per ml). In contrast, ethanol, propionate and butyrate were mainly catabolized with obligate hydrogen transfer by syntrophic association of rods with M. hungatei. Numbers of sulphate reducers degradjng these substrates were lower than those of syntrophs https://www.w3.org/1998/Math/MathML"> 10 6 - 10 7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 10 8 - 10 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cells per ml respectively). Direct optical microscopy and SEM were difficult to perform (Fig. because of masking by exogenous polymers or numerous minerals and cell debris. But in some areas, a network of Methanothrix sp. entrapping other bacteria has been observed. Microcolonies of Methanospirillum sp. or Methanobrevibacter sp. associated with rod-shaped bacteria were evidenced (Fig. 3,4,5). Methanosarcina sp. appeared as small aggregates of pairs of spherical cells (Fig. 6). Thin sections stained with toluidine blue showed patches of various colonies included in a light material with some deposits of ferrous sulphide (Fig. 2). Electron microscopy evidenced that the light material was mainly composed of a matrix of cell debris entrapping mineral precipitates and colonies of bacteria. In general, cells presenting cytoplasmic inclusions of polyhydroxybutyrate formed pure colonies (Fig. 7). In contrast, cells with a clear cytoplasm and polyglucose inclusions were often associated with short rods morphologically similar to Methanobrevibacter sp. (Fig. 8). In addition, numerous cytoplasmic polysaccharidic inclusions were also observed in Methanosarcina cells. Methanothrix was evidenced either as individual filaments or as filaments winded into balls (Fig. 9). The presence of high amounts of exopolymers was significant in granules. Indeed, numerous individual bacterial cells and microcolonies were surrounded or included in a glycocalix matrix as described in the rumen (1). These exopolymers appeared as fimbriae (Fig. 10), capsules (Fig. 11) or fibrous glycocalyces (Fig. 12) depending on the morphology of bacterial cells. Such exopolymers have already been mentioned in granules (4) and in biofilms (3) Thus, the granules which are present in the upflow sluage bed reactor appear as heterogeneous aggregates including all the major trophic groups performing acetogenesis and methanogenesis. They are a more complex microecosystem than described by other authors (2). Our results point out several fundamental developments. First, in order to specify the identity and the metabolic function of the various morphotypes, immunological 21. REFERENCES Table 1 Bacterial counts in the upflow anaerobic sludge bed. Prop, = Propionibacteriaceae ; M. elsd. = Megasphaera elsdenii Fig. 1 : SE Micrograph of a granule ( https://www.w3.org/1998/Math/MathML"> × 280 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) Fig. 2 : Thin-section stained by toluidine blue. Note the presence of Methanosarcina sp. ( × I800). Fig. 3 : SE Micrograph of M. hungatei associated with curved rods https://www.w3.org/1998/Math/MathML"> ( x ) 250 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig. 4 : SE Micrograph of Methanobrevibacter associated with rod-shaped bacteria. Note also the presence of ferrous sulphide and of Methanothrix sp. ( x7250) Fig. 5 : Network of Methanothrix sp. entrapping various rod-shaped bacteria Fig. 6 : SE Micrograph of Methanosarcina sp. cells ( x 22000). Fig. 7 : Needles of ferrous sulphide and microcolonies of cells accumulating polyhydroxybutyrate (x 6300). Fig. 8 : Mixed colony of cells accumulating polyglucose and Methanobrevibacter sp. (x 8800). Fig. 9 : Methanothrix sp. winded into a ball (x 9I00) Fig. 10 : A rod showing fimbriae-like exopolymer (x 22000). Fig. 11 : Exopolymers appearing as capsule (x 22000). Fig. 12 : Fibrous glycocalyces (x 22000). FULL-SCALE METHANIZATION OF SUGARY WASTEWATERS IN A DOWNFLOW ANAEROBIC FILTER D. VERRIER https://www.w3.org/1998/Math/MathML">   * , J , P , L E S C U R E * * , B , D E L A N N O Y * * , G . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ALBAGNAC https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Institut National de la Recherche Agronomique BP 39 - 59651 VILLENEUVE D'ASCQ Cedex - France I.R.I.S. - CERTIA - 59650 VILLENEUVE D'ASCQ - France 22. Summary Methane fermentation of wastewaters in one beet sugar factory located in Northern France (THUNERIES) is performed in a https://www.w3.org/1998/Math/MathML"> 1.100   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> downflow anaenobic plant packed with plastio ninge The incoming waetewaters anaerobic plant packed wi.th plastic rings. Ho incoming wastewaters https://www.w3.org/1998/Math/MathML"> ( 2,000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to 5,000 mg COD.L are pumped from the settling ponds and heated with warm condensates through an external heat exchanger allowing an accurate control of the fermenter temperature at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The allowing an accurate control of the fermenter temperature at 350C. ITRE biogas is burnt for process steam generation. Fermentation balances obtained during the first start-up procedures are presented. Briefly, very short hydraulic retention times (abqut 8 hours) and high volumetric loading rates (13 kg coD.m .day ) were reached within 3 months. More than https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> removal of the total coD was achieved with a https://www.w3.org/1998/Math/MathML"> 3,000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> daily methane production. A survey of the vFA concentration along the reactor height showed a complete elimination in the upper part. As a consequence, a significant bacterial colonization was only observed on the rings sampled at the top of the reactor. V.S.S. concentration in the interstitial medium was low, except in the sludge deposit at the bottom of the reactor. The fixed film observed by scanning electron microscopy revealed a network of filamentous bacteria identified as Methanothrix soehngenii and colonies of coccoid bacteria. 23. INTRODUCTION Methane fermentation of wastewaters arising from the beet sugar factory BEGHIN SAY in THUMERIES (Northern France) is performed for two campaigns using a downflow anaerobic filter built by s.G.N. according to a process perfected on distillery slops (1). It has to be considered as the first step of a complete wastewater treatment including a nitrification post treatment. This is presently studied at the pilot-scale in fixed film processes. As shown in the flow-sheet (Fig. 1), the anaerobic filter serves as a substitute for the aerobic lagoon. It is fed with the supernatant of the settling pond heated through an external heat exchanger for an accurate control of the temperature to https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Calorific energy is supplied by hot condensates. The reactor is a steel cylindrical tank of https://www.w3.org/1998/Math/MathML"> 12   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diameter with a https://www.w3.org/1998/Math/MathML"> 1,400   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> total volume packed with https://www.w3.org/1998/Math/MathML"> 1,100   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FLOCOR R plastic rings. A centrifugal pump (nominal flow https://www.w3.org/1998/Math/MathML"> = 60   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per hour) ensures the downflow recirculation of waters. The generated biogas is immediately used without any storage nor treatment. It is burnt in a special burner for process steam oroduction. 2. START-UP PROCEDURE AND 1983 BEET CAMPAIGN The anaerobic filter was started in october 1983, after inoculation with 500 tons of anaerobic sludge from MARQUETIE urban digester (31.4 g SS.1 https://www.w3.org/1998/Math/MathML">   - 1 ; 12.7   g V S S . 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 67 tons of sludge from an anaerobic IRTS plant located in another sugar factory https://www.w3.org/1998/Math/MathML"> 7.8 g S S . 1 - 1 ; 3   g v S S . 1 - 1 . M e t h a n o g e n i c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> activities of these inocula were 0.25 and https://www.w3.org/1998/Math/MathML"> 0.05   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> coD. https://www.w3.org/1998/Math/MathML"> k g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vSS. day respectively and were used to define the initial Ionding nate a few days thespectively and were lised to define the initial loading fate. before starting the wastewater feeding, a small amount of concentrated distillery slops was introduced in the fermenter in order to start methanogenic activity without sludge losses, Then, the incoming wastewater flows were gradually increased. As it appears in figure z. influent cop increased during this campaign from 2,000 to 5,500 mg. 1 . Soluble coD represented more than https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of total coD and was nearly exclusively due to V.F.A. (acetic, propionic and butyric acids). At the end of this first campaign which lasted two months, the obtained penfommances were as follow:

1,500 m of wastewaters containing https://www.w3.org/1998/Math/MathML"> 5,500 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cOD. https://www.w3.org/1998/Math/MathML"> 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> could be treated daily with https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gOD removal.

https://www.w3.org/1998/Math/MathML"> - 2,500 N m 3 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of methane were produced daily, i.e. about https://www.w3.org/1998/Math/MathML"> 3   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of biogas https://www.w3.org/1998/Math/MathML"> ( 80 % C H ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per m of fermenter per day.

residual VFA represented less than https://www.w3.org/1998/Math/MathML"> 200 m g . 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while cod of the guspended solide was leas than 500 mgul

total nitrogen was about 120 mg.1 https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and ammonia-nitrogen about https://www.w3.org/1998/Math/MathML"> 75 m g . I - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the treated effluent.

The survey of VFA concentrations and pH along the reactor height revealed a gradient as illustrated by figure 3a. The majority of substrate elimination was realized in the upper part of the reactor. As a consequence, a significant bacterial colonization was only observed on the rings sampled at the top of the reactor (Fig. 3b). Volatile Suspended Solids concentration was low in the interstitial medium, except in the sludge deposit observed at the bottom of the reactor. Sampled colonized rings were prepared for Scanning Electron Microscopy according to cosTERToN technique (2). As shown in figure 4 , the biofi. Ims observations revealed a network of filamentous bacteria identified as Methanothrix soehngenii, sometimes forming microcolonies (A); in the upper part of the reactor, colonies of coccoid bacteria (presumably Methanosarcina sp.) were simultaneously observed (B). Consortia of hydrogenophilic Methanobrevibacter-like (C) with ovolld bacteria (D) presumably OHPA species, were also noticed. This ecology results of the particularity of the substrate in which the soluble fraction is only composed of https://www.w3.org/1998/Math/MathML"> V . F . A . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and is related to gradient in the reactor. 24. RESTART-UP DURING 1984 SYRUP AND BEET CAMPATGNS After two months starvation, the fermenter can be heated again during the syrup crystallization campaign producing low-temperature lost calories. Restart-up was very quick and wastewater flow rates were increased to reach very short hydraulic retention times (about 8 hours) and high volumetric loading rates (1.3 kg COD per m per day). Nevertheless, COD removals were somewhat reduced to about https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> due to a loss of suspended solids in the effluent and the recycling pump was therefore stopped. Biogas and methane yields were 370 and https://www.w3.org/1998/Math/MathML"> 320 l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per kg removed COD respectively. It shoud be stressed that the methane content of the gas was very high (87-88%) and very constant during this 40 days-campaign. The combustion of this gas produced 30 tons of steam daily. At the end of this campaign, new sampling of the rings and of the interstitial medium allowed the estimation of the biomass stock accumulated https://www.w3.org/1998/Math/MathML">   Figure   1 _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : Flow-sheet of wastewater treatment plants Figure 2 : Influent and effluent COD during first start-up Figure 3 : V.F.A. and biomass gradients along the fermenter Figure 4 : Interior of a biofilm sampled at the top of the fermenter (SEM JEOL JSM-35 CF) Table 1 : Carbon balance https://www.w3.org/1998/Math/MathML"> ( k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C) obtained during 1984 syrup campaign METHANE FERMENTATION OF DISTILLERY WASTE WATER OF SUGAR CANE ALCOHOL ON A FIXED BIOMASS PILOT A. BORIES*, F. BAZILE**, J. RAYNAL*, E. MICHELOT** INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE

Station d'Oenologie et de Technologie Végétale F- 11104 NARBONNE

** Station de Technologie F-97170 PETIT-BOURG 25. Summary Feasability of the methane fermentation for waste treatment and energy recovery of molasses sugar cane stillage is studied at pilot scale on a fixed bed reactor (10 m ) with plastic support (FLOCOR). Reactor gerformance data are particularly good https://www.w3.org/1998/Math/MathML"> = 10 ad : 14.2 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 20.4   k g D C O / m . d . , H R T : 3.2 - 2.5   d . , b i o g a s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> productivity : 6.5- https://www.w3.org/1998/Math/MathML"> 8   m / m . d . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CoD elimination rate are optimal for this type of waste water: https://www.w3.org/1998/Math/MathML"> 60 - 73 p . 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and BOD rate are better than https://www.w3.org/1998/Math/MathML"> 90 p . 100 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The biofilm measurement after one year of experimentation shows a great concentration of fixed matter, equivalent to https://www.w3.org/1998/Math/MathML"> 47   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of reactor and confirms the good ability of this support for micriobial biomass Biogas production from molasse stillage (22 m /m of stillage) is able to account for https://www.w3.org/1998/Math/MathML"> 48 p . 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the distillation energy consumption 26. INTRODUCTION La production d'alcool à partir de canne á sucre (alcool industriel, rhums) et notamment des mélasses est une activité à fort potentiel de pollution. Les effluents sont particulierrement concentrés en matieres organiques https://www.w3.org/1998/Math/MathML"> ( D C O = 60 - 100   g / l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et minérales. En outre la distillation s'effectue sur des milieux à faible degré alcoolique, https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 'où d'importants volumes de rejets et des besoins énergétiques élevés. La fermentation méthanique peut s"appliquer à ces eaux résiduaires avec les objectifs : deppollution - valorisation énergétique. Cependant, les technologies classiques de fermentation : mélange complet, contact anaérobie, sont limitées dans leur performance par des aspects d'ordre biologique : faible taux de croissance des bactéries méthanogènes. La conception de réacteurs améliorant la rétention des micro-organismes permet de contourner ces limitations et d'augmenter les capacitess de traitement : réacteurs à lit fixé, réacteursà lit fluidisé (1). Gráce au développement de nouveaux supports (matières plastiques) présentant des avantages par leur surface spécifique, leur indice de vide, et leur poids, les réacteurs à ilt fixé ont montré des performances élevées (2) L' expérimentation à I'échelle pilote d'un réacteur à film fixé sur support plastique est réalisée en méthanisation de vinasse de mélasse de canne à sucre. L' étude vise à préciser la faisabilité de la dépollution de ce milieu par fermentation et à déterminer les performances du réacteur en regard de résultats acquis par ailleurs (2). 27. MATERIEL ET METHODES 2.1. Fermenteur à film fixé sur support plastique La plateforme experrimentale https://www.w3.org/1998/Math/MathML"> ( + ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> comprend un fermenteur de https://www.w3.org/1998/Math/MathML"> 10   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , contenant un support en PVC, sous forme d'anneaux (FLOCOR R.), dont la surface spécifique est https://www.w3.org/1998/Math/MathML"> 230   m 2 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et la porosité de https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (pourcentage de vide) Le réacteur est alimenté en circuit down-flow, avec une boucle de recirculation de la phase liquide, egalement en down-flow, pour assurer lhomogénéisation du milieu de fermentation. La fermentation est effectuée à https://www.w3.org/1998/Math/MathML"> 37 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> La plateforme dont la conception générale est analogue à celle décrite précédemment (2) est équipée d'un gazomètre souple (IO m , d'un moteur à biogaz, et d'un ensemble de régulations et de mesures: températures, débits gazeux, liquides. Elle est implantée en Guadeloupe (France) à la Société Industrielle de Sucrerie. 2.2. Substrat Les vinasses de mélasse de canne a sucre sont collectées en sortie de distillation, refroigies dans une tour à ruissellement, puis dirigées vers une cuve tampon (1 https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) en amont du réacteur, Un lot de vinasse de mélasse a été stocké afin d'assurer la continuité des essais hors périodes de distillation. Les vinasses ne subissent aucune correction de composition me pl, sauf lors de la phase d'ensemencement du réacteur https://www.w3.org/1998/Math/MathML"> p H ' 7,5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . La composition moyenne des vinasses est mentionnée dans le tableau 1. 2.3. Méthodes analytiques La fermentation méthanique est suivie par détermination du pH, de la demande chimique en oxygène (DCO) sur les milieux brut et centrifugé, de la demande biochimique en oxygène (DBO) sur les milieux brut et centrifugé, des acides gras volatils (AGV) par chromatographie en phase gazeuse. Les matiêres en suspension (MES) sont mesurées après centrifugation et sêchage du culot a https://www.w3.org/1998/Math/MathML"> 105 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> La composition du biogaz est déterminée par la mesure du https://www.w3.org/1998/Math/MathML"> C O 2 , C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et hydrogène sulfuré après chromatographie en phase gazeuse et détection par catharometre. L'analyse du substrat et du digestat porte également sur 1 'azote total Kjeldahl (NTK), et les éléments minéraux: Phosphore total, sulfate, calcium, potassium, sodium. 28. RESULTATS

Ensemencement.

La fermentation méthanique des vinasses de mêlasse est operrée à partir de flores anaérobies issues de milieux naturels, préalablement sélectionnés par des tests def fermentation. L' ensemencement gu réacteur est effectué par https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> apport de https://www.w3.org/1998/Math/MathML"> 4   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de suspension de boues, de https://www.w3.org/1998/Math/MathML"> 1   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de substrat neutralisé à https://www.w3.org/1998/Math/MathML"> p H 7,5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et un complément d'eau. Pendant la phase d'adaptation des populations, 1 'alimentation du réacteur est assurée a la charge volumique de 1,5 à https://www.w3.org/1998/Math/MathML"> 6   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DCO/m I. Durant cette période d'environ 40 jours, on note l'accumulation dans le milieu de la DCO : jusqu'à https://www.w3.org/1998/Math/MathML"> 20   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , et des acides gras volatils: acétate : 5,5 https://www.w3.org/1998/Math/MathML"> 1   g / 1 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> propionate : https://www.w3.org/1998/Math/MathML"> 1 - 1,9   g / 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> La diminution brutale observée par la suite sur ces paramètres témoigne de l'acclimatation complète des populations (DCO résiduelle https://www.w3.org/1998/Math/MathML"> ≠ 16   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , acétate : https://www.w3.org/1998/Math/MathML"> 300 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , propionate : 200 mg/1). Dès lors, l'expérimentation consiste à augmenter la quantité de substrat apporté, par palliers. Sur une pêriode ininterrompue de 180 jours, la charge volumique a été augmentée jusqu'à https://www.w3.org/1998/Math/MathML"> 20,4   k g D C O / m j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , et le temps de séjour hydraulique diminué de 20 à 2,5 j. Le tableau 2 rassemble les moyennes des valeurs obtenues dans la période d'essais à fortes charges. HEociété Générale Pour Les Techniques Nouvelles - Saint Quentin les Yvelines FRANCE. Table 2 : Performance evaluation of the methane fermentation of rum stillage on fixed film reactor (10 m) with plastic support nd : no determination 1. FOR THE METHANE FERMENTATION OF INDUSTRIAL WASTE WATER A. BORIES* M. DUVIGNAU et N. CATHALA INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE Station d'oenologie et de Technologie Végétale F. 11104 NARBONNE 2. Summary Lignocellulosic supports are used for micro-organisms fixation in two reactors design fluidized bed and fixed bed Comparison between 1ignocellulosic (wood, vine shoot) and inert (sand, PVC) media shows better fixation on the first type of supports. The effect of adjuvants: methanol, biopolymers, on microbial adhe- sion is studied. Alginate and pectin addition (O.1 - 10 mg/1) improves adhesion to wood particles. A fluidized bed reactor with cork support is experimented for the methane fermentation of dairy by-product (deproteinized whey). After three months, reactor performance data are: https://www.w3.org/1998/Math/MathML"> 10 ad : 7.48 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> g https://www.w3.org/1998/Math/MathML"> C O D / 1 . d . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> HRT https://www.w3.org/1998/Math/MathML"> : 2.8   d . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , productivity https://www.w3.org/1998/Math/MathML"> : 3.8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> l biogas/l. d., COD elimination rate: https://www.w3.org/1998/Math/MathML"> 96 p . 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . For the fixed bed reactor, the selected filling matter is an a- gricultural by-product: rape of grapes. The methane fermentation is achieved on a distillery waste water (wine stillage). Performance data, after 8 months are: load: https://www.w3.org/1998/Math/MathML"> 5.1 , C O D / 1 ,   g , H R T : 3.2   d . C O D e l i m i - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> nation rate: https://www.w3.org/1998/Math/MathML"> 93.8 p . 100 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fixed matter is well distributed all over the reactor height (0.6 to 1.1 g dry fixed matter/g support). Lignocellulosic matter seems to be interesting supports for performant and rustic design reactors (low weight, wide variety and cost : low to non-existent). 3. INTRODUCTION Les réacteurs à biomasse fixée apportent des gains très appréciables sur les performances cinetiques de la fermentation méthanique. Les supports de fixation varient dans leur conception: fixe, mobile, dans leur agencement: vrac, orienté, dans leur nature (1). De tress nombreux matériaux ont été proposés: -matières minérales : galets, supports d'argile orientés pour les lits fixés, sable pour les lits fludisés, -matieres de synthèses : chlorure de polyvinyl, polyuréthane, .., ou encore Les matières lignocellulosiques peuvent aussi être proposées comme sont en général très difficilement dégradées en anaérobiose et se rencontrent sous des formes trẻs diverses : biomasses végétales (bois, .) dé- Dans la présente étude, nous avons examiné la fixation des micro-orga- types de réacteurs: lit fluidisé, lit fixé, en fermentation d'eaux résitupesteres ditndustries agno-alimentaines Pour le lit fluidisé, un support végétal très léger, le liège, a été utilisé. Les performances du réacteur ont été évaluées en fermentation de lactosérum déprotéinisé. En lit fixé, le garnissage retenu est un sousproduit agricole : rafle de raisin, et l'étude de la fermentation porte sur un effluent de distillerie. MATERIEL ET METHODES 2.1. Matériel de fermentation Il est constitué par une colonne en verre de diamètre intérieur 6,7 cm et thermostatée à https://www.w3.org/1998/Math/MathML"> 37 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A la partie supérieure de la colonne un tamis de maille https://www.w3.org/1998/Math/MathML"> 0,2   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> retient les particules de support. Le support est du liège de granulonietrie: https://www.w3.org/1998/Math/MathML"> 0,2 - 0,35   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , à la concentration de https://www.w3.org/1998/Math/MathML"> 20   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , La fluidisation est assurée par recirculation de gaz (O,1 1/mn) injecté au bas de la colonne. Le substrat est introduit au même niveau et réparti de façon homogene au sein du réacteur par recirculation du milieu de fermentation à contre-courant du gaz, à égal débit.

Reacteur à lit fixé

Il consiste en une colonne en PVC, de https://www.w3.org/1998/Math/MathML"> 20   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de diamètre, thermostatée à https://www.w3.org/1998/Math/MathML"> 37 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Le volume total liquide du réacteur est de 34,9 le garnissage lignocellulosique expérimenté est un sous-produit de la vigne : rafles de raisin qui sont sous forme de tiges de 2 à 8 cm de longueun et quelaues millimètres de diamètre. Le poids de support initialement introduit est de https://www.w3.org/1998/Math/MathML"> 1725   g . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Le substrat de fermentation est apporté en continu a la partie inférieure du réacteur qui fonctionne en circuit up-flow. La phase https://www.w3.org/1998/Math/MathML"> 1 iquide https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est recyclée à 1 l/hr également en up-flow.

Dispositif d'étude de la fixation sur divers supports

Les fermentations sont réalisées en fioles de https://www.w3.org/1998/Math/MathML"> 500 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , disposées sur table d'agitation orbitale a https://www.w3.org/1998/Math/MathML"> 37 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , contenant la suspension microbienne https://www.w3.org/1998/Math/MathML"> ( 200 m l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et le support https://www.w3.org/1998/Math/MathML"> ( 8   g ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> L'alimentation en substrat est séquentielle : https://www.w3.org/1998/Math/MathML"> 20 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tous les trois jours soit https://www.w3.org/1998/Math/MathML"> 1.2   g D C O / 1 . j . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de facon à maintenir l'activité tout au long de l'essai (30j). Les supports testés sont : le bois, le sarment de vigne, le PVC, le sable. Leur granulométrie est o,2 -2 mm. 2.2. Substrats de fermentation Les fermentations avec biomasse fixée sur particules mobiles sont menées sur lactosérum déprotétnisé. Ce milieu est conservé au froid sous forme concentrée, puis dilué a la concentration souhaitée au moment des essais. Le substrat utilisé avec le réacteur à lit fixé est une eau résiduaire de distillerie: vinasse de vin rouge, obtenue dans plusieurs établissements et dont la DCO varie de 16 à https://www.w3.org/1998/Math/MathML"> 36   g 02 / 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.3. Populations microbiennes La fermentation méthanique du lactosérum déprotéinisé est opérée à partir d'une flore issue d'un digesteur de boues de station d'épuration d'eaux usees urbaines, adaptées au laboratoire sur le substrat pendant plusieurs mois. La flore microbienne utilisée pour la fermentation de l'effluent de distillerie provient d'une population d'un digesteur pilote industrieletest entretenue sur ce substrat en réacteur mélangé. 2.4. Méthodes analytiques Le suivi des fermentations porte principalement sur les paramètres pH, demande chimique en oxygène (DCO), acides gras volatils (AGV), volume et composition du biogaz, matieres en suspension (MES). La DCO est dosée selon la norme AFNOR sur un échantillon centrifugé à https://www.w3.org/1998/Math/MathML"> 10000 t / m n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pendant https://www.w3.org/1998/Math/MathML"> 10 m n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Les AGV sont dosés par chromatographie en phase gazeuse sur colonne SP 1200 (SUPELCO Inc.), à https://www.w3.org/1998/Math/MathML"> 1.05 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en présence d'acide éthyl, butyrique comme Le volume de biogaz est mesuré par compteur volumétrique de type SCHLUMBERGER. Sa composition est déterminée par analyse en chromatographie et détection par conductibilité thermique, après séparation des composants sur deux colonnes : silicagel, tamis moléculaire https://www.w3.org/1998/Math/MathML"> 5 x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , montées en séries. La mesure des matieres fixees sur les supports mobiles est effectuée après séparation des bioparticules par filtration sur tamis de o,2 mm et séchage à https://www.w3.org/1998/Math/MathML"> 105 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . la biomasse fixée est évaluée par le dosage de la teneur en azote total (Kjeldahl). La valeur de réference de la composition des bactéries est mesurée sur une culture tëmoin, sans support. La composition du support en azote est également déterminée. Cette démarche est pratiquée pour les supports organiques : bois, sarment, PVC. Pour le sable, les matières fixées sont mesurées directement par les matières volatiles après passage au four à https://www.w3.org/1998/Math/MathML"> 550 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Pour le support en lit fixé, le biofilm est séparé par agitation dans 1'eau et les matières détachées sont mesurées après centrifugation. 4. RESULTATS. DISCUSSION 3.1. Adhésion bactérienne sur supports lignocellulosiques L'étude comparative de la fixation des micro-organismes sur des supports lignocellulosiques et sur des supports inertes (PVC, sable) montre qu'après 30 jours de culture, les résultats les meilleurs sont enregistrés avec les particules végétales : bois, sarment (fig. 1 ), et dans une propor- L'influence d'adjuvants connus pour leur effet favorable sur les phénomenes d' adhésion a été examinée. Le méthanol stimulerait la synthèse de polysaccharides de bactêries méthanogènes (5). L'addition de méthanol dans nos cultures, à doses similaires a celles mentionnées, se solde par un effet defavorable sur la quantité de matière fixée, pour les divers supports hormis le PVC. On peut penser que les populations ne sont pas suffisamment adaptées à ce composé et/ou a un effet toxique. Des biopolymeres participent aux phénomennes d'adhésion. Les alginates sont des agents adhésifs en milieu marin (6). Les polyosides interviennent dans des pontages bactéries-végétaux (7). L'apport de pectines et d'alginates dans nos cultures en présence de support lignocellulosique (bois) amélione nettement les quantités de matienes fixées z gain de 19,6 et 37,5 p.cent respectivement, après 30 jours. 3.2. Réacteur à lit fluidisé sur support liège La montée en charge volumique du réacteur a été effectuée en maintenant le temps de sejour hydraulique, constant de 10 jours, et en augmentant par palliers la concentration du lactosérum. Pour la gamme de charge étudiée, 1,84 à https://www.w3.org/1998/Math/MathML"> 7,48   g D C O / 1 . j . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on observe un taux optimal d'élimination de la pCo (tabl. 1) s'améliorant avec l'augmentation de la charge, ce qui indiquerait une acclimatation progressive de la flore au substrat. La productivité du réacteur en biogaz est augmentée de 1 à 3,89 1/1.j. Dans une seconde phase d'étude, la charge volumique précédemment atteinte a eté maintenue constante, et le temps de séjour hydraulique diminué de 10 à 5 à https://www.w3.org/1998/Math/MathML"> 2,5 j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (tabl. 1). Cette forte diminution du temps de séjour n'affecte pas les performances de la fermentation, ce qui suppose une rétention efficace des micro-organismes par fixation sur le support liege. De très faibles teneurs en AGV soulignent la stabilité du processus. La légère diminution de la productivité en biogaz observée pour Tsh 2,5 j est due à des composés lentement hydrolysables ou fermentescibles. Ces résultats sont très encourageants car obtenus après seulement trois mois de fonctionnement du réacteur fiuidisé, ce gui est relativement stalon interne. tion importante. court pour ce type de réacteur. Ils sont en accord avec ceux mentionnés par SUTTON et LI (1982) (8) dont 1'étude portait sur un substrat identique mais en réacteur fluidisé avec le sable comme support. Des performances plus élevées sont signalées par (9) en fermentation de lactosérum acide, mais après une année de fonctionnement https://www.w3.org/1998/Math/MathML"> ( C V = 37,6   g D C O / 1 . j . ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 3.3. Réacteur a lit fixe Le réacteur a garnissage lignocellulosique: rafle de raisin, montre de bonnes performances en fermentation méthanique de vinasse de vin. Après 8 mois de fermentation, les valeurs optimales sont : temps de sejour hydraulique: 3,2 j, charge volumique: 5,1 g DCO/1.j. pour un taux d'Epuration de la DCO de https://www.w3.org/1998/Math/MathML"> 93,8 p . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cent. La productivité volumique atteint 2,07 l biogaz https://www.w3.org/1998/Math/MathML"> 11 ⋅ j ⋅ ( tab ] ⋅ 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . L'étude du profil de matieres fixées sur ce support lignocellulosique montre pour ce systeme de réacteur up-flow recirculé une répartition des boues dans toute la hauteur du lit, avec cependant une plus grande quantité en partie Inférieure (tabl. 3). La quantité de biomasse retenue par le support est importante : 0,6 á https://www.w3.org/1998/Math/MathML"> 1,1 g / g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de support. L'observation du support montre un biofilm enrobant les tiges de rafles. Après lavage, aucune dégradation importante n'est relevese et lanalyse de fibres confirme de faibles modifications de sa composition après 8 mois de séjour dans le réacteur. Ce type de support peut être envisagé pour des utilisations à plus long terme. 5. CONCLUSION Les matériaux lignocellulosiques s'avërent de bons supports de fixation de micro-organismes. Leur potentialité vis à vis de https://www.w3.org/1998/Math/MathML"> 1 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> adhésion bactérienne semble superrieure à celle des supports inertes, géneralement utilisés : sable, PVC. Par leur composition, ils peuvent offrir des possibilités d'amelioration de la colonisation du support, par utilisation d'adjuvants. Cette phase est la plus importante dans la mise en oeuvre de réacteur fluidisé. Sur le plan de la technologie des réacteurs, la diversité des matieres lignocellulosiques permet de multiples solutions

support léger, rendant le réacteur fluidisé plus abordable.

support fixé concourant a des réacteurs rustiques et performants.

Les performances obtenues dans les deux cas soulignent https://www.w3.org/1998/Math/MathML"> 1 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> interet de tels réacteurs, dans le traitement anaérobie d'effluents agro-industriels. 6. BIBLIOGRAPHIE (1) BORIES A., VERRIER D., 1984. Ind. Alim. Agric., 6, 493-497. (2) BORIES A., RAYNAL J., JOVER J.P., 1982. In STRUB A., CHARTIER P., SCHLESER G. , Energy from biomass, 2nd EC. Conference, BERLIN. Applied Science Publishers, London. (3) HENZE M., HARREMOES P., 1983. Wat. Sci. Technol., 15, 1-101. (4) SWITZENBAUM M.S., 1983. Wat. Sci. Technol., 15, 345-348. (5) BULL M.A., STERRIT R.M., LESTER J.N., 1982. Trans. I. Chem. E., 60,373-376 (6) MORRIS E.R. REES D.A., YOUNG., WALKINSHAW M.D. DARKE A. 1977 . https://www.w3.org/1998/Math/MathML"> J . M o l . B i O l , 110,1 - 16 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (7) FLETCHER M. FLOODGATE G.D., 1973. J. Gen. Microbiol., 74, 325334. (8) SUTTON P.M., LI A., 1982. Proc. 36th. Purdue Indust. Waste Conf. 665-677. (9) HICKEY R.F., OWENS R.W., 1981. 3rd Symp. on biotechnology in energy production and conservation. May 12-15, GATILNBURG, Tenessee, TWO-PHASE DIGESTION OF DISTILIERR SIOPS USING A FIXED BED REACTOR FOR BIOMETHANATION K. Wulfert and P. Weiland Institute of Technology, Fed. Res.Centre of Agriculture (FAL) D-3300 Braunschweig (FRG), Bundesallee 50 7. Sumaxy In order to determine the most important factors for obtaining a high efficient biomethanation of potatoe distillery slops, the influence of pre-acidification, support media type for anaerobic fixed bed and varlous operational conditions were tested in different laboratoryscale reactors. Results show, that random packed reactors operate with higher performance and greater stability than reactors with channeled packing. Surface roughness and porosity of the support material is important for the colonization velocity and total biamass content in stationary state, especially in the case of channeled packing materials. Acid concentration in the effluent of the acidification stage depends strong on the residence time but the influence on COD degradation and biogas yield in the biomethanation stage is only of minor importance. 8. INTRODUCTION The production of ethanol from renewable sugary and starchy raw mate rials gains increasing inportance because the surplus in food-production can be reduced and the availability of fuels and chemical feed stocks can be improved. One of the vital points for an economic ethanol production is the good use of the distillery slops, which are generated as a by-product in an amount of 10-12 times the production volume of ethanol. The slops are highly polluted with yeasts and non-converted organic compounds of the raw materials which results in a chenical oxygen demand (COD) of 20.000 https://www.w3.org/1998/Math/MathML"> 100.000 m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Anaerobic digestion of the slops offers the most profitable use, because on the one hand side production of biogas can supply up to 80 : of the energy demand for downstream processing of the fermentation broth and on the other hand more than 85 of cOD can be removed. For a large demonstration plant which will produce daily 48.0001 ethanol from a raw material mix of potatoes, sugar beets and corn-cob-mix, a concept for slops disposal was developed, according to that the slops are separated in a solid enriched phase for feed production and a nearly solid free liquid phase for biomethanation [1]. The main effort of this work was to improve the biomethanation process with respect to space time yield of biogas and COD elimination. For investigating the technical and econonic feasibility of treating slops in a two-phase process using a fixed bed reactor for biomethanation. experimental studies were performed on laboratory and pilot scale units [2]. In order to get specific data for process evaluation and design, the process behaviour in the acidification and biomethanation stage was studied as also the effect of different support materials and operational conditions. The experimental results of the laboratory tests will be discussed in the following. 9. MATERIAL AND METHODS Three fixed bed colum reactors were utilized, one randam packed with foamed clay https://www.w3.org/1998/Math/MathML"> ( d = 8 - 16   m m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , two other units equipped with vertical laminates of porous plastic webs. A schematic drawing of the units is shown in Fig. 1. Fig. 1: Schematic drawing of the fixed bed reactors Reactor 1 was operated in upflow mode without pre-acidification, because flow pattern shows almost plug flow behaviour. Reactor 2.1 and 2.2 were operated in up- and downflow mode using a separated well-mixed preacidification stage. The typical camposition of the potatoe slop used is shown in Table 1. The laboratory tests were carried out at https://www.w3.org/1998/Math/MathML"> 350 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . https://www.w3.org/1998/Math/MathML">   Table 1: Composition of a typical thin potatce slop     coD   N tot   N H x   tot   P K   total soluble   [ g / l ] [ g / I I [ g / 1 ] [ g / 1 ]   [ g / l ] 36 1,0 0,17 0,43 4,0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 10. RESULTS 10.1. ACIDIFICATION The objective of the hydraulic separation of the acidogenic and methanogenic phase is the creation of optimum conditions for acidogenic and methanogenic microorganisms. The influence of residence time on acid formation was studied. Fig. 2 illustrates, that up to hydraulic residence times of about https://www.w3.org/1998/Math/MathML"> 36   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the concentration of acids formed is strong dependent on residence time, whereas at higher values the acid composition is independent on residence time. Production of acetic and n-valeric acid dominates at residence times below https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> without a degradation of the influent lactic acid. At longer residence times lactic acid is degraded to butyric acid and the formation of acetic and valeric acid is diminished. The degradation of butyric acid is accompanied by a shift in pH and gas production. The degree of acidification is about 70 of for residence times above https://www.w3.org/1998/Math/MathML"> 1   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig. 2: Influence of residence time on the acidification of potatoe slops It is evident from biamethanation, that the change in acid camposition at residence times of about https://www.w3.org/1998/Math/MathML"> 36   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is of minor influence on biogas yield and COD reduction. The only consequence of the increasing butyric acid concentration is a shift in the methane content of the biogas fram 60 to 69 o. 11. 3.2 COLONIZATION BEHAVIOUR OF SUPPORT MATERTALS An important aspect for start-up of anaerobic fixed bed reactors is the colonization velocity of the support materials for methanogenic biamass. For studying the influence of the surface properties, reactors with randam and channeled packing configurations were investigated. Results show, that the surface properties of packed bed materials are of minor influence with respect to start-up, because a relative large amount of bicmass is entrapped in the interstial void spaces after seeding the reactor. In the case of film support materials the surface properties determine the colonization velocity and biomass concentration in stationary state. Fig. 3 shows the daily gas production within 100 days after seeding for four identical biogas reactors filled with different support materials. The gas production is considered to be proportional to the biamass density, so that the rate of colonization is reflected by the increase of the daily gas production. Results show, that the gas production for the non-porous support materials is nearly constant during the course of the experiment. This demonstrates, that no colonization occurs and gas production results only fram suspended biomass. The most rapidly colonization could be obtained with the cpencell foamed plastic. The gas production of the reactor with the glas fabric support rises in a similar rate but the total amount of fixed biom mass on the rough, but non-porous surface is smaller than in the case of open cell materials. Fig. 3: Influence of support material on biamass colonization 12. 3.3 REACTOR PERFORMANCE In order to obtain basic data for reactor design and operation behaviour reactors of Fig. 1 were investigated for more than 120 days at varius con laading rates. The results show that the reactor behaviour is strong dependent on support material used. The random packed reactor leads to a flow behaviour similar plug flow. As a consequence, strong dependence of COD removal and biological solid distribution throughout the reactor height results. Up to COD loading rates of https://www.w3.org/1998/Math/MathML"> 5   k g / m d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> more than 90 of the influent COD is removed in the lower one-third of the reactor but the contribution of the upper reactor zones on COD degradation increases with increasing loading rates. As a result the degree of COD degradation is constant 99 o up to loading rates of https://www.w3.org/1998/Math/MathML"> 12   k g / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Fig. 4). At higher loadings the degree of CoD removal gradually decreases but even at high loading rates in excess of https://www.w3.org/1998/Math/MathML"> 45   k g / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the biomethanation process is not inhibited. In contrast to the random packed reactor the liquid phase in the reactor filled with channeled packings is almost ideally mixed and a significant part of the biamass is attached on the support media. As a consequence the COD degradation is strang dependent on COD loading rate and the process breaks down above a critical loading rate of about https://www.w3.org/1998/Math/MathML"> 10   k g C O D / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Fig. 4). The performance of the upflow and downflow unit is comparable but the downflow unit shows a better restart behaviour after overloading. Independent on reactor type the methane yield per kg COD removed was approximately https://www.w3.org/1998/Math/MathML"> 400 l / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COD. The methane concentration varied between https://www.w3.org/1998/Math/MathML"> 60 - 69   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , dependent on the residence time of the acidification staqe. A maximum biogas production rate per unit volume of https://www.w3.org/1998/Math/MathML"> 8   m 3 / m 3 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was maintained in the random packed reactor at a volumetric COD loading rate of about https://www.w3.org/1998/Math/MathML"> 16   k g / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig. 4: COD degradation as function of loading rate 13. CONCLUSIANS Although this study is still on-going on pilot-scale, it is evident from the results obtained, that media type, shape and surface characteristics are important factors in determining the start-up and operational efficiency. Randam packed bed reactors exhibite better degradation performance and greater operational stability than reactors with film support materials. The acid camposition of the preacidified slops is only of minor influence on CoD degradation and biogas yield. The optimum residence time of the acidification stage is lower than 1.5 days. 14. REFEERENCES (1) BAADER, W., WULFERT, K., MICHAETSEN, Th. , KLOSS, R.; WEILAND, P.: Gewinnung von Biogas und festen hertstoffen aus Ruickstanden der Ethanol-Destillation und pflanzlichen Zuschlagstoffen. BML-Statusseminar "Nachwachsende Rohstoffe", Bonn 26.-27.11.1984. (2) WU FERT, K, WETI AND, P. Betriebsverhalten von Festbettreaktoren zur Biamethanisierung ver Abläufen der Gärungsindustrie. Chem-Ing. Techn. 57 (1985), No. 5, in press. BIOGAS FROM GREEN AND SILAGED PLANIS IN A DIGESTER WITH INIERRAL LIQUID CIRCUIT W. BAADER Institute of Technology, Fed.Res.Centre of Agriculture (FAL) D-3300 Braunschweig (FRG), Bundesallee 50 15. Summary Green and silaged plants are, in principle, well suited to serve as a source for biogas. Besides of vegetable residues also crops especially grown for energy purposes may have a chance for biogas production, provided there are no problems of supplying the digester with liquid and of handling the liquid effluent. A system was developed and tested for digesting continuously vegetable matter unless to mix it before with water or any kind of slurry. In the digester a constant volume of liquid was stored. Both the feed and the residual matter after conversion consist in solids. For nearly 1 year a https://www.w3.org/1998/Math/MathML"> 6   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester was fed only with grass-silage (average IS https://www.w3.org/1998/Math/MathML"> 508 , p H 4.5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The liquid, separated from the effluent by a screw press, was recycled to the digester. Apart fram adjusting occasionally slight deviations of liquid volume in the digester - depending on the moisture content of the silage - the liquid in the digester has not be renewed or diluted during a 290 days period. The methane yield from VS added ranged from https://www.w3.org/1998/Math/MathML"> 280 l / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (VS-laading rate B https://www.w3.org/1998/Math/MathML"> = 1   k g / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and https://www.w3.org/1998/Math/MathML"> 2001 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( https://www.w3.org/1998/Math/MathML"> B y S = 3   k g / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Corresponding with increasing loading rates Bus from 1 to https://www.w3.org/1998/Math/MathML"> 3   k g / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the gas production rate per volume digester increased fram 0.6 to https://www.w3.org/1998/Math/MathML"> 1.2   m 3 / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of 54-568 methane. 16. INIRODUCTION The conventional way of utilizing vegetable matter for biogas production is to mix it as an additive with liquid manure or similar organic slurries used as the main substrate. In this case the biogas plant is part of a liquid handling and treating system. However, if biogas is to be produced from green crops only, which are grown exclusively for this purpose, the vegetable matter is the predaminant substrate and every additional liquid may cause costs and management need with respect to provide the liquid as well as to handle and to dispose the effluent. In order to eliminate these problems, an integrated system for bianethanation of crops only was defined and estimated to be an appropriate one consisting in the elements A Crop harvesting by conventional methods (chopped forage). B Ensiling nearby the biogas plant. C Once daily feeding the digester with silage or, during harvest, with green crop, whenever energy is needed. D Digestion in fluidic state. E Retaining the liquid separated from the effluent in the digester, hence Abstract no need to provide permanent fresh liquid for supplying the digester and to dispose slurry. F Stocking the dewatered undigested fibrous residue for further utilization as animal feed additive or as fertilizer. Fram numerous research works it was known, that green and silaged crops are well digestible https://www.w3.org/1998/Math/MathML"> ( 1,2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . But no information has been given on the process stability, if liquid is recycled for a longer period instead of being renewed. In particular it was not clear, whether the acidic substrate will drop the pH in the digester, thus the performance of the process is limited by the feed rate, and whether accumulations of TS, https://www.w3.org/1998/Math/MathML"> N H x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and other components in the retained liquid will limit the process. A further problem was, how to control the flow of the substrate, rich in fibrous and floatable matter, through the digester. With regard to the real operation conditions in material properties and controlling the mass-flow, the research work on which is being reported in following, was conducted in a medium scale. 2. INSTALLATION AND MATERIAL FLOW The digester (Fig. 1) adapted to handle liquid substrates with a high content of fibrous matter was a cylindrical tank (a) with conical shape of both the bottam and the cover, inlet tangential at the lower section of the cylinder, outlet at the top, totally filled, with a loop flow of the mixture induced by a rotating screw (b) acting downward in a central tube (ç). This new type of digester has been tested successfully in https://www.w3.org/1998/Math/MathML"> 6   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 100   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> size with animal manure https://www.w3.org/1998/Math/MathML"> ( 3,4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig. 1: Configuration and flow sheet of the experimental installation a digester https://www.w3.org/1998/Math/MathML"> 6   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vol., https://www.w3.org/1998/Math/MathML"> 1.8   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diam. https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , b screw agitator ( https://www.w3.org/1998/Math/MathML"> 90 r p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), c guide tube https://www.w3.org/1998/Math/MathML"> ( 0.4 / 0.6   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diam.), d screw press, e holding tank (300 1 net vol.), f dewaterer (6 mm mesh). The silage is pushed into the digester by a screw press (d), supported by liquid which is pumped from the bottom of the digester during feeding. Before feeding (once per day), liquid stocked in a high positioned holding tank (e) is fed at the inlet. This results in a overflow of solid-liquidmixture, from wich the free liquid is separated subsequently by a screwtype dewaterer (f) and is given back to the holding tank (e). This cycle of liquid flow is repeated depending on the provided solids retention time. 17. MATERIAL AND METHODS The grass-silage was taken every 2-3 days from tower silos of the FALExperimental Farm. Due to the previous harvesting conditions variation in the material properties (Table I) had to be tolerated. Table I: Substrate data Vegetable matter grass-silage Particle length mm 20-80 Content total solids (TS) 8 42-77 Content volatile solids (VS) 8 34-62 pH-value https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4.5-5.0 Concentr. volatile fatty acids (VFA) https://www.w3.org/1998/Math/MathML"> m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 8000-22000 Concentr. acetic acid (AA) https://www.w3.org/1998/Math/MathML"> m g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3500-5500 The material properties were determined according the methods mentioned in Table II. The gas flow was measured continuously by a water desplacement https://www.w3.org/1998/Math/MathML">   T h b l e   I I ,   I h e   g a s   f l o w   w a s   m e a s u r e d   c o n t i n u t a r l y   b y   a t e r   d e s p l a c e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Gas flow rate, methane content, temperature in the digester and the accumulating weight of separated liquid were recorded continuously. Table II: Determination of material properties Data Methods Material Frequency Total solids (TS) https://www.w3.org/1998/Math/MathML"> T = 105 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> silage each charge Volatile solids (VS) https://www.w3.org/1998/Math/MathML"> T = 550 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> liquid daily Volatile fatty acids (VFA) chromatography silage, liquid weekly Ammonia nitrogen (NH_) distillation silage, liquid weekly Methane content (c https://www.w3.org/1998/Math/MathML">   CH   4 didily   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> IR gas daily For starting the experiments the digester was filled with https://www.w3.org/1998/Math/MathML"> 5.5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> effluent For starting the experthents the digester was filled with 5.5 morse suspended solids separated, TS 4,5 of) than https://www.w3.org/1998/Math/MathML"> 78   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is of grass-silage were added in portions during 4 days. After further 6 days https://www.w3.org/1998/Math/MathML"> 0.3   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> recycled liquid and in portions during 4 days. After further 6 days 0.3 mi recyeled liquid and tion of a methane yield of https://www.w3.org/1998/Math/MathML"> 2801 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (VS) was reached (begin of trial no. 1 ). tion of a methane yield of https://www.w3.org/1998/Math/MathML"> 2801 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (VS) was reached (begin of trial no.1). lic retention time of solids rsp., several trial runs each of a defined quantity of moist vegetable matter corresponding with a defined volume of recycled liquid were carried out (Table III) . Table III: Operating data Trial Feed rate No. Veget. matter (moist) Recycl. liquid Concentr. veget.matter i.digester https://www.w3.org/1998/Math/MathML"> k g / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> m 3 / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Hydr. ret. time solids Termp. 1 7.5 0.3 25.0 20 https://www.w3.org/1998/Math/MathML">   d C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 15.0 0.6 25.0 10 36 3 22.5 0.9 25.0 6.6 36 4 22.5 0.6 37.5 10 36 5 33.8 0.9 37.5 6.6 36

RESULTS

1 Process Efficiency

The influence of the volumetric organic loading rate, based on vs input of silage, on gas production is shown in Fig. 2. It could be determined that with increasing loading rates up to https://www.w3.org/1998/Math/MathML"> 3.2   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (VS) https://www.w3.org/1998/Math/MathML"> / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the gas production rate per unit reactor volume raised to https://www.w3.org/1998/Math/MathML"> 1.2   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (gas) https://www.w3.org/1998/Math/MathML"> / m 3   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . However, corresponding herewith the methane yield per unit vs added dropped from 0.360 to https://www.w3.org/1998/Math/MathML"> 0,170   m 3 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (VS). The methane content always differed between 548 and 568. Beetween 608 and 708 of vs input have been digested, thus follows that the methane yield per unit VS digested differed between 0.240 and https://www.w3.org/1998/Math/MathML"> 0.490   m 3 / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (VS). Fig. 2: Gas production vs. organic volumetric loading rate 4.2 Process stability (Fig. 3) During continuous operation of 290 days the composition of the recycled liquid changed in content of IS from 4.5 to https://www.w3.org/1998/Math/MathML"> 9.0 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration of https://www.w3.org/1998/Math/MathML"> N H X - N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from 2000 to https://www.w3.org/1998/Math/MathML"> 4000 m g / I https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration of acetic acid from 100 to https://www.w3.org/1998/Math/MathML"> 550 m g / 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> No accumulations of https://www.w3.org/1998/Math/MathML"> P , N a , K , M g , C a , Z n , F e , M n , C u https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> could be found. The pH ranged all the time between 7.5 and 8.0. 571 Fig. 3: Camposition of the recycled liquid during the total period of experimental operation. T1 - T5 duration of trials 4.3 Mechanical effects After separating of liquid the fibrous residues consist in 20 of TS (average). During the 290 days of operation only in total 8601 of surplus liquid were yielded, whereas in the same time 2.8001 water must be added. The totally filled loop-flow digester rendered a controlled continuous flow of the fibrous solids through the tank up to a concentration of vegetable matter in the digester of https://www.w3.org/1998/Math/MathML"> 37   k g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (liquid of https://www.w3.org/1998/Math/MathML"> 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> IS) .

CONCLUSIONS

Silage of creen crops can be digested for a lang period unless to substitute continuously the liquid. However, for dilution with respect to Is and https://www.w3.org/1998/Math/MathML"> N H x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , exchange of limited quantities of liquid by water is necessary occasionally. Gas yields and gas production rates per volume digester were in the range known from laboratory experiments but comparably in shorter retention times (5). The system seems to be appropriate for biogas production from crops only. REFERENCES (1) BADGER, D.M., BOGUE, M.J. and STEWART, D.J. (1979) Biogasproduction from crops and organic wastes. New zealand Journal of Science, Vol. 22, po. 11-20. (2) SCHUCHARUT, F. (1981). Untersuchungen zum Gärverhalten von tierischen Exkrementen und Pflanzen (Study of the fermentation process in animal excrements and plants) . Grundlagen der Landtechnik, Vol. 31 pp. 42-47. English: Translation T 478, NIAE, Silsoe, Bedford (UK). (3) BAADER, W. (1981) . Erste Erfahrumgen mit einem vollständig gefüllten, vertikal durchstränten Biogasgenerator (First experiences with a campletely filled vertical flow anaerobic digester). Grundlagen Landtechnik, Vol. 31, pp. 50-55. English:Translation T 476, NIAE Silsoe, Bedford (UK). (4) BAADER, W. et al. (1984) . Die FAI-Versuchsbiogasanlage (The FAL-EXperimental-Biogas plant), Landbauforschung Völkenrode, Special vol. No. 72. (5) MATHISEN, B. and THYSETIUS, L. (1984). Biogasproduction from fresh and ensiled plant material. In proceedings of World conference Bioenergy 84 Göteborg (Sweden). ANAEROBIC DIGESTION OF ORGANIC FRACTION OF MUNICIPAL SOLID WASTE-PRELIMINARY COMUNICAT ION Paoto Cescon, Franco Cecchi, Franco Avezzu and Pietro G.Traverso Dipartimento di Scienze Ambientali - Università di Venezia Calle Larga S.Marta 2137 - 30123 Venezia INTRODUCTION - Anaerobic digestion for energy recovery from organic fraction of municipal solid waste (OFMSW) is one of the recent biological methods developed. In previous studies an evaluation of the potential for processing organic wastes has been made (1-4). In a recent rewiew (5) a clear projection of favorable economics for the OFMSW anaerobic digestion is presented in comparison with other bioconversion technologies. The aim at different total solids content in the feed slurry. The first experiments are carried out in order to evaluate the digester performance by varying the OFMSW/Primary sludge (PS) total solids (TS) ratio. The reactor size ( https://www.w3.org/1998/Math/MathML"> 3 m c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> working volume) is a means of predicting the full scale plant problems. MATERIAL AND METHODS - The pilot plant is schematically shown in Fig. 1 . The source separated OFMSW is shredded and analysed (TS) before mixing in a ho mogenizer with the sludge from a municipal wastewater PS. The ratios (OFMS W/PS) and the TS percentage in the feeding sludge are controlled, hence the feed is pumped into the storage tank. The digester is feed discontinuosly (three times a day). The TS content in the digester is controlled by purging the bottom sludge (when archimedian screw stirring devices is adopted). The liquid level in the reactor is controlled by a hydraulic valve so that the discharge of the effluent is a consequence of the feeding flow. A hydraulic valve in the gas pipe warrants https://www.w3.org/1998/Math/MathML"> 150 - 180   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.c. pressure of the gas in the digester top. The analytical plan and the parameters which are controlled are in tabb. 1-2. EXPERIMENTALS AND RESULTS - The experimental data from a preliminary analy ses of the components of the MSW from a representative quarter in Treviso City are in Fig. 2. The averaged values are consistent with the related ones in N.W. Italy (6). The main characteristics of OFMSW, PS, Feed are in Tabb. 3-5. The operative conditions are in Tabb. https://www.w3.org/1998/Math/MathML"> 6 ; p H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and temperature in the reactor are, respectively: 6.9-7.3 and https://www.w3.org/1998/Math/MathML"> 34 - 36 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The SV percentage in the selected size ranges inside the reactor and in the OFMSW are in Fig. 3. Figg. 4,5 show the comparison between the specific TS-VS, Inert Solids (I) values in each size fraction (TS or VS or I retained by the sieve / TS or vS or I in the sample) and the related values in OFMSW. Figg. 6 and 7 show the TS and VS (respectively) fractions of the sample not retained by the sieves. The SGP vs. OFMSW percentage in the feed is shown in Fig. 8. CONCLUSIONS - a) The OFMSW digestion process can be carried out without the addition of nutrients or baffers; b) The SGP is linearly dependent on the OFMSW percent in the feed, the SGP with https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> OFMSW is about twice the SGP with https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> PS; c) The archimedian screw stirring device is lacking when the feed OFMSW exceeds https://www.w3.org/1998/Math/MathML"> 30 - 35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> an inactive scum layer is produced during digestion; d) The particle size distribution and characteristics (VS, TS) of the selected size ranges inside the reactor are strictly related to the stirring devices. Nevertheless the SGP seems not to depend on the checked stirring devices in the mixed regions. 18. REFERENCES

C.G.Golueke and P.H.Mc. Gadhey "Comprehensive Studies of Solid Waste Ma nagement" 2nd Annua I Report SERL Report https://www.w3.org/1998/Math/MathML"> n . 69.1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , University of California, Berkeley (1969).

J.T.Pfeffer "Reclamation of Energy from Organic Refuse", EPA Report n. PB231176 (1984).

D.L.Klass and S.Ghosh "Fuel Gas from Organic Wastes" Chemtech. Vol.3, pp. 689-698, Nov. (1973).

L.F.Diaz., F.Kurz, G.Trezek "Methane Gas Production as Part of Refuse Recycling System" Compost Science, 15, (3), Summer, (1974).

D.L.Wise and R.G.Kispert "A Review of Bioconversion Systems for Energy Recovery from Municipal Solid Waste Par. II I Economic Evaluation" Resources and Conservation, 6, 137-142 (1981).

C.N.R. Progetto Finalizzato Energetica I "Atti I Seminario Informativo. Utilizzazione Energetica dei Rifiuti Solidi Urbani" Padova 21 aprile (1980).

AKNOWLEDGMENTS - The authors wish to thank ENEA for financial support, Isti tuto Trevigiano di Ricerca Scientifica for the interest, and Drs. E.Vita, S. Badoer, M.Visentin for their hetp in experimental program. S.Badoer, M. Visentin for their help in experimental program. FEED COD, TS, VS, TKN, NH4, NO3, PO4 TA, VFA, PH, 2 https://www.w3.org/1998/Math/MathML"> C , H , N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , ParticTe Size Distribution 1 EFFLUENT https://www.w3.org/1998/Math/MathML"> COD , TS , VS / TKN , NH 4 , N 03 , PO 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 6/2 REACTOR https://www.w3.org/1998/Math/MathML"> COD , TS , VS , TKN , NH 4 , NO 3 , P 04 , TA , VFA , PH https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2 SLUDGE-OUTLET https://www.w3.org/1998/Math/MathML"> COD , TS , VS / TKN , NH 4 , NO 3 , PO 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1 GAS https://www.w3.org/1998/Math/MathML"> C , H , N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Particle Size Distribution 2/ at intervals PS COD, TS, VS, TKN, NH4, NO3, PO4 6/ intervals OFMSW COD, TS, VS, TKN, NH4, NO3, PO4, C, H, N, 1 Tab. 1 - Analyses Plan. PARAMETERS ANALYSES/WEEK FEED Flow Rate, Temperature / OFMSW/PS (TS/TS) https://www.w3.org/1998/Math/MathML"> 7 / at https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> intervals EFFLUENT Flow Rate 7 REACTOR Temperature, Pressure 7 Tab. 2 - Controlled Parameters TS https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VS https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> PO4 https://www.w3.org/1998/Math/MathML"> ( mg / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> PARAMETERS COD https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 200 176 4.5 MEAN VALUE 218 2 7 Tab. 3 - OFMSW Characteristics PARAMETERS COD TS VS TKN NH4 NO3 TA MEAN VALUE 39.0 41.3 30.2 296 114 https://www.w3.org/1998/Math/MathML"> . 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 887 Tab. 4 - Primary Sludge Characteristics OFNSW% https://www.w3.org/1998/Math/MathML"> 0 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 60/ https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C (%TS) 39.93 43.03 44.22 45.79 46.93 H (%TS) 5.42 6.04 6.34 6.37 6.33 N (%TS) 2.29 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.32 3.25 3.00 Tab. 5 - Feed Characteristics OFMSW(TS%) 0 16 35 60 90 https://www.w3.org/1998/Math/MathML"> 60 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 100 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ORGANIC LOAD KgVS/mC, d 1.63 1.28 1.43 1.26 1.88 1.95 1.97 HRT, 14.5 18.0 16.0 20.0 18.0 25.0 27.0 VSRT, d 33.0 32.0 21.0 25.0 18.0 25.0 27.0 REACTOR, TS https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 46.5 50.5 45.2 50.0 56.5 33.0 31.2 REACTOR, VS https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 26.0 27.8 24.0 31.3 34.5 21.0 20.0 Tab. 6 Operative Tab. 6 - Operative conditions. Armed anchor stirring devices Fig.: 1 MSW FRACTIONS Fig. 2 Fig. 3 Fig. 4 Fig. 5 R= REACTOR O = OFMISW  I-INERT Fig. 6 Fig. 7 Fig. 8 19. Summary 20. 1.- INTRODUCTION 21. 2. - PERIOD OF PRODUCTION ACTIVITY AND PLANT LOCATION APPLICATION OF GAS FROM BTOMASS Conditioning of gas or adaptation of gasfired equipment? F.A.J Rietveld VEG-GASINSTITUUT n.v., Apeldoorn, The Netherlands Summary The success of a blogas installation depends largely on the correct application of biogas. Too many of these profects have failed because of an Lmproper use of the gas. VEG-GASINSTITUUT https://www.w3.org/1998/Math/MathML"> n ⋅ V ⋅ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which Is the central techndcal organisation of the gas distribution companies, has the task of fuxthering the safe and efficient use of gas In the Netherlands. During recent years the institute has been increasingly lnvolved In applications of gas from biomass. Gas from biomass, such as from landfills, animal waste or sewage sludge varies in quality. The gas and 1 ts combustion products are often corrosive. This imposes special demands on the gas distribution system and the equipment. A choice has to be made between two Important options 1.e. conditioning of gas or adaptation of gasfired equipment. 22. INTRODUCTION The gaseous fuels which are produced from biomass are an alternative to the application of natural gas. Thls has led to an increasing Interest within the public gas supply industry in the Netherlands for this form of energy. Especially where biogas from landfills and large scale anaerobic digesters https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> distributed to consumers which are located outside the boundaries of these sources. The expected contribution of gas from blomass to the energy supply In the Netherlands by the year 2000 will be approximately 1000 million https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> natural gas equivalent per year. The gas is expected to come from the Eollowing sources. Gas production in million cubic meter Biomass sotrce per year natural gas equivalent An1mal waste 410 Agricultural waste 50 Muntcipal waste (landfill) 180 Wood waste 340 Waste water 1020 Total 40 Related to the domestic gas consumption within the public gas supply, this amount contributes to approximately https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The production of biogas from animal waste, municipal waste (landfil1) and waste water are in the first instance attractive to the public gas supply because these gases are related to natural gas. Thats why this paper deals with the application of these gases and in particular with gas from landfllls and gas from large scale anaerobic digesters. Figure 1. This consideration is purily based on economics. In paragraph 4 the factors are listed which influence the quality of the gas. Conditioning of the gas will raise the quallty to certain, predetermined standards. For the adaptation of the gasfired equipment we have to consider the influence of the gas on the materials of, for instance heaters, piping, valves, storage vessels and in the case of engines on the lubricant. Eve If the gas is non-corrosive the burners and/or the carburettors have to be modified to take the usually low calorific gas. Figure 2.

SELLING PRICE OF ENERGY

Gas from blomass w111 always be converted to another usable form of energy such as heat, power or electricity. In order to get the highest price for these forms of energy, its conversion has to be efficient. For Instance in case of hot water generation, heaters have to be used with h1gh gas-to-water efflciencles, 1.e. heaters with low thermal losses. In case of electricity generation its is recommended to find use for the cogenerated heat. The thermal efficiency of electrlcity generation ls around https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , while the remaining https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ls usually lost as waste heat. It 15 therefore necessary to pay attention to this aspect of the application. The hlgher the revenue of these energy streams, the more profltable a biogas installation will be. 23. Summary It has been shown previously that marine algae Tetraselmis can be transformed into methane by a one step completely-mixed biomethanation process, in a reliable way and with good yields and good methane production rates. This process can be adapted to work equally Well in sea water Based on previous laboratory results (1) (2), a pilot-scale https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester has been installed by the authors at Lamezia-Terme (Calabria, Italy). The digester has been fed for more than one year with Tetraselmis algae produced by https://www.w3.org/1998/Math/MathML"> 400   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of culture ponds built and operated by the group of Professor Florenzano (Firenze, Italy) and K. Wagener (Aachen, Germany). It has been run on a moderate volumetric loading rate https://www.w3.org/1998/Math/MathML"> ( 0.5   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volatile solids per https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester and per day). The same methane yield and same methane production rate have been reached with the https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pilot digester than with the laboratory scale installations. The one year work with this pilot plant has also given the possibility to integrate all the steps of this energy production system and to show its technical feasability. 24. INTRODUCTION The final goal of this research was to install at the pilot scale level an integrated plant for energy production by biomethanation of cuitivated marine algae Tetraselmis in Southern Italy. It has been shown previously (1) (2), that methane production from biomethanation of marine algae Tetraselmis can be obtained with good rate and yield and good reliability in a one step continuous and completelymixed methane digester maintained at https://www.w3.org/1998/Math/MathML"> 35 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> E.g., a maximum biogas production of https://www.w3.org/1998/Math/MathML"> 1.33   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas https://www.w3.org/1998/Math/MathML"> × m - 3 M L × d - 1 * * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be obtained with a volumetric loading rate of https://www.w3.org/1998/Math/MathML"> 4   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VS https://www.w3.org/1998/Math/MathML"> × m - 3 M L × d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a mean retention time of https://www.w3.org/1998/Math/MathML"> 14   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A yield of https://www.w3.org/1998/Math/MathML"> 0.25   m 3 C H 4 × m - 3 M L × d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be obtained with a concentration of sodium in the mixed liquor of https://www.w3.org/1998/Math/MathML"> 10.6   g × 1 - 1 M L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a mean retention time of https://www.w3.org/1998/Math/MathML"> 14   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a volumetric loading rate of https://www.w3.org/1998/Math/MathML"> 3   k g V S 0 × m - 3 M L × d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the same conditions of biomethanation but without sodium in the mixed liquor the same yield has been reached. (*) For abbreviations and symbols see Table I. This report deals with the results obtained with the pilot scale installation. 25. MATERIAI,S AND METHODS 26. 1 . Description of the installation This installation has been set up at Lamezia-rerme (calabria-Italy) at the beginning of April 1982. It has been built on a surface of nonarable land olose to the sea https://www.w3.org/1998/Math/MathML"> ( + 800   m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A olobal soheme of the installation is proposed in Fig. 1. The installation has been set up on a platform of https://www.w3.org/1998/Math/MathML"> 1000   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( https://www.w3.org/1998/Math/MathML"> 20   m × 50   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) made of concrete. On this surface six ponds of https://www.w3.org/1998/Math/MathML"> 40   m 2 ( 2   m × 20   m ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and four ponds of https://www.w3.org/1998/Math/MathML"> 80   m 2 ( 4   m × 20   m ) h a v e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> been built by the team of Professors K. Wagener (University of Aachen, Germany) and G. Florenzano (University of Florence, Italy) and equipped with a mechanical mixing device. Near the ponds, a digester of https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> working volume, loaned by the Region Wallonne of Belgium has been set up by the authors. This digester is described in Fin. Marine algae Tetraselmis are unicellular organisms. A harvesting system based on a two step sedimentation process has been set up. A prea liminary sedimentation is done in a pond in which a given volume of algal suspension is introduced each day, five days a week. The supernatant is taken off or recycled into the culture ponds and the somewhat concentrated algal suspension is introduced in a sedimentation tank. This tank is the second step of the harvesting system and it is described in Fig. 3. The final concentrated algal mixture is taken out of the sedimentation tank and used to load the digester. 2.2. Operation of the installation 2.2.1. Management of the algal cultures: The cultures of Tetraselmis tetrathele in the 40 and https://www.w3.org/1998/Math/MathML"> 80   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ponds were run on a semicontinuous regime - Every day a given volume of culture suspension was drawn and introduced in the sedimentation basin. An equal volume of new seawater, taken up directly from the sea with a submersible punp, was added to the ponds. The amount of culture suspension harvested daily was adjusted in order to keep the biomass concentration within the optimal values. Carbon, nitrogen and phosphorus were suppled daily as sodium bicarbonate, urea and potassium dihydrogen phosphate, respectively, in the amount required by the growing algal population. Assimilation of the majority of the carbon added in the form of bicarbonate was achieved by frequent adjustment of the pH to 8.6 with diluted https://www.w3.org/1998/Math/MathML"> H C l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The yield of the ponds for 355 days amounted to https://www.w3.org/1998/Math/MathML"> 5.1   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dry weight https://www.w3.org/1998/Math/MathML"> m - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Hence the mixing device utilized proved to be effective. 2.?.? Starting up of the dizester: The digester was filled on day 0 with https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of sludge from a stabiIisation tank of plggery wastes situated in a farm at lamezia-Terme. From day 0 to day 11 the digester mixed liquor was let to ferment at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> without laading until the biogas production had stopped. On day 11 the pH of the mixed liquor was 8.1 and the percentage of methane in the biogas was https://www.w3.org/1998/Math/MathML"> 94 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . On day 12 the digester was loaded as described in https://www.w3.org/1998/Math/MathML"> ( 2.2 . 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 2⋅2.3. Running conditions of the digester: The digester was mun at a temperature of https://www.w3.org/1998/Math/MathML"> 35   ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> After a three months starting and trials period and from day 85 to day 220 , an hydraulic retention time of 25 days was used. The amount of concentrated algae to be added to freshwater to reach a volume of 40 liters was estimated so as to reach a volumetric loading rate of https://www.w3.org/1998/Math/MathML"> 0.5   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VS. https://www.w3.org/1998/Math/MathML"> x m - 3 M L x d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The real concentration was measured on a sample (see https://www.w3.org/1998/Math/MathML"> $ 2.3 . ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and used for all further calculations of parameters. From day 280 to day 310 , the same procedure was used with the exception of the mean Fig. 1. Global scheme of the instal-

ponds of https://www.w3.org/1998/Math/MathML"> 40   m 2 ; 2 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ponds of https://www.w3.org/1998/Math/MathML"> 80   m 2 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 3.1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester; 4. sedimentation tank

https://www.w3.org/1998/Math/MathML"> F i g ⋅ 3 . 1 = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Sedimentation tank algal suspension inlet; 4. algal 3. https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digester; 4. sedimentation tank. sedimentation outlet; 5. super3. I mo digester; 4. sedimentation tank. Sedimentation Fig. 2. : Description of the

of atesterester

digester

load inlet

and 5. heating system

outlet of mixed Iiquor

and 8. sampling

OVerflow

pump for mixing

storage of load

pumping of load

sediment from sedimentation tank

effluent storage tank

contro1 of mixing

Fig. 4. Results of biomethanation obtained during the first year work. 27. REFERENCES (1) ASINARI, C.-M., LEGROS, A., PIRON, C., SIRONVAL, C., NYNS, E.-J. and NAVEAU, H.P. (1981) Methane production by anaerobic digestion of algae. In "Energy from Biomass" série E, vol. 1 , Chartier P. and Palz W. eds, Reidel Publ. Co., Dordrecht, Netherland, 113-120. (2) LEGROS, A., TREDICI, M.R., ASINARI, C.-M., COLLARD, F., DUJARDIN, E., SIRONVAL, C., FLORENZANO, G., NYNS, E.-J and NAVEAU, H. (1983). Methane production by anaerobic digestion of algae, I. In "Energy" from Biomass", Series E, vol. 5, Palz W. and Pirrwitz, D., eds, Reidel Publ. Co., Dordrecht, Netherland, 210-217. (3) LEGROS, A., ASINARI DI SAN MARZANO, C.M., NAVEAU, H. and NYNS, E.-J. (1982). Fermentation profiles in bioconversions. Biotechnology Letters, https://www.w3.org/1998/Math/MathML"> 5 3 ( 1 ) , 7 - 12 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . (4) BALLONI, W. , MATERASSI, R., DE ZARLO, S., PELOSI, E., SILI, C. (1982). Outdoor mass culture of algae in southern Italy utilizing sea water enriched with algal digested sludge. In "Energy from biomass" series E, vol. 3. Grassi, G. and Palz, W., eds. Reidel Publ. Co., Dordrecht, Netherland, 107-113. 28. ACKNOWLEDGEMENTS This research has been supported by research contracts https://www.w3.org/1998/Math/MathML"> n ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ESE-R-025-(B) and ESE-P-021-D from the CEC and E3/CE/IV/1 from the Belgian Science Policy Programming Service. JOINT BELGIUM-BURUNDI BIOMETHANATION DEVELOPMENT PROJECT : MAIN RESULTS AFTER TWO YEARS ACTIVITY D. Compagnion, D. Rolot, E.-J. Nyns and H.P. Naveau https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> V. Baratakanwa, D. Nditabiriye, J. Ndayishimiye and P. Niyimbona https://www.w3.org/1998/Math/MathML">   * * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Unit of Bioengineering, University of Louvain,

1/9, Place Croix du Sud, B-1348 Louvain-la-Neuve, Belgium ** Ministère des Travaux Publics, de I'Energie et des Mines, BP 745 , Bujumbura, Burundi 29. Surmary The aim of the project is to make credible the development of bio methanation in tropical rural areas, especially in Burundi (Africa). It includes the setting up of a "biogas cell" and of six biogas plants for demonstration; moreover a large part of the project is devoted to training and vulgarisation. The field-laboratory of the biogas cell at Bujumbura, is equipped for the technical and scientific monitoring of methane digesters. The four first biogas plants https://www.w3.org/1998/Math/MathML"> 5 - 20   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are built, partly near Bujumbura and partly inside the country. The scientific follow-up, through the experimental laboratory, has led to the continuous running (20 months) of these digesters, based each on a reliable process of biomethanation particularly adapted to each residue and each implementation site. The digesters are running in a semicontinuous or discontinuous mode, according to their design and local conditions. The biogas is used for cooking, lighting and heating, in the aim of fuelwood or liquid fuel economy; the digested effluent is used as fertilizer. 30. FRAMEWORK This project, fully identified elsewhere (1), is subsidised through the Belgian Administration for Development Cooperation (BADC). The 4 year-work has begun in January 1983. The project is placed under the supervision of the Burundi General Direction of Energy, from which scientists or technicians are regularly trained. 31. THE BIOGAS CELL AT BUJUMBURA : A STABLE INFRASTRUCTURE The biogas cell at Bujumbura is equipped with laboratory and small scale methane digesters and a field-laboratory for the follow-up of these and full-scale digesters. The digesters installed there includes simple laboratory batch and semi-continuous digesters, working at ambient temperature https://www.w3.org/1998/Math/MathML"> 25 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by means of a thermostatised room connected to solar collectors. Tests at laboratory https://www.w3.org/1998/Math/MathML"> ( 1 - 51 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and pilot https://www.w3.org/1998/Math/MathML"> ( 60 - 10001 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> scales allow to evaluate the methane digestion potentialities of the available biomass-substrates and the possible mechanical problems before scaling up on the field. The different methods regularly used at this rural laboratory are summarized in Table 1. Table 1. Methodologies used at the field-laboratory of the biogas cell A modular semi-continuous biogas plant, adapted to rural tropical areas, is being developped (2). It combines reinforced concrete to insure the liquid tightness of the bottom part, with flexible polymeric material put on light metallic structure, to insure the gas tightness of the upper part of the digester and of the separate biogas holder. The design of this kind of digester, with the shape of a flat parallelepiped, is in the trend of the horizontal tubular processes https://www.w3.org/1998/Math/MathML"> ( 3,4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A unit of one https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has been installed in the garden of the biogas cell; it allows to confirm the results obtained at the laboratory scale with different kinds of animal manure. Moreover, a pilot biogas plant has been set up, with the financial support of the I.F.S. (International Fundation for Science), to valorise domestic refuses in a two phases process. The soluble organic matter extracted in the first step through a percolation system feeds an anaerobic filter where the active biomass is fixed on a support formed of local bamboo-canes pieces. 32. IMPLEMENTATION OF BIOGAS PLANTS Spectacular results have been obtained with the first biogas plant implemented within this project, at the Experimental Farm of the Faculty of Agronomy at Bujumbura. This site was completely devoid of energy source and the needs suited well to a fuel like biogas. In fact, the biogas produced by digestion of goats solid manure, is used at night to warm up chicks during their first three weeks of life. The same kind of heating tests has also been done by the National Research Centre in Cairo (5). The excess biogas is used for the family needs of the caretaker of the methane digester. The lay out of the biogas plant is depicted in Fig. 1. It comprises two units of the modular digester described above, of https://www.w3.org/1998/Math/MathML"> 7   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> working volume each, and two membrane gasholders, of https://www.w3.org/1998/Math/MathML"> 4   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> capacity each. Separate storage of the produced biogas in two gasholders, allows first, its collection at low pressure and, secondly, its independent use at a higher pressure. For this purpose, a simple removable ballast covers the gasholder ready to be emptied. From the productivities mentioned in Table 2 and the results obtained on several lots of 500 chicks each, one concludes that about https://www.w3.org/1998/Math/MathML"> 25   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of biogas are necessary for heating one lot during three weeks. 33. Captions A similar system was set up at the slaughterhouse of Bujumbura. It uses paunch manure as biomass-substrate. The simple mechanical mixing device, manually operated from outside, is not sufficient to avoid the accumulation of straws on the upper part of the liquor: so that, every three months, the digester has to be opened to remove the build-up scum layer. But this operation is quite easy with the fixed dome in supple polymeric material; indeed it takes only a few hours. The produced biogas is burned in boilers to generate hot water used in the process of pigs skining. Two other biogas plants have been implemented in rural areas, inside the country, where the fresh temperature requires heating through a greenhouse effect. The methane digesters are surrounded by a simple-made tent, serving as elementary glass-house for sun-heating the fermenting liquor The large surface to volume ratio as well as the concept of building the digesters partly above ground and their location inside a tent, suffice to maintain the temperature in the range of https://www.w3.org/1998/Math/MathML"> 25 - 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The sites of implementation are chosen to ensure the popularisation of the process (rural cormunity, school, dispensary,...). A biogas plant has been so built in the Research and Diffusior Center of Kisozi, depending of the Burundi Institute of Agriculture (ISABU). It consists of two discontinuous digesters of https://www.w3.org/1998/Math/MathML"> 10   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> each connected to a metallic gasholder of https://www.w3.org/1998/Math/MathML"> 5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The biomass-substrates are crop residues and solid bovine manure. Finally a modular semi-continuous methane digester has been built in the school of Kiremba (Bururi); this unit of https://www.w3.org/1998/Math/MathML"> 7   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is fed with bovine manure. These two last biogas plants are in starting conditions. The characteristis of the four biogas plants are sumarized in Table 2. Table 2. Main characteristics of the four biogas plants built within the project SC= semi-continuous D= discontinuous An important part of the project is devoted to training and vulgarisation. Demonstrations of the use of biogas appliances and digested slurry are regularly organized. Training courses are organized with the aid of UNESCO-ANSTI and AUPELF, and permit african scientists or technicians to receive theoretical and practical instruction and to get acquainted with biomethanation. Moreover, members of the Burundi General Direction of Energy have the opportunity to be trained at Louvain-la-Neuve University.

CONCLUSIONS

The project strives to combine the building of a few demonstration biogas plants with the important aspect of training, so as to ensure a reliable implementation of biomethanation in Burundi. The biogas cell of Bujumbura, equipped of a field-laboratory and of several pilot digesters, allows to follow-up the biogas plants. The enclavement of this country, its energetic dependence and the requirements of the soils in organic matter, emphasized the advantages of this technology. Moreover, the Authorities have expressed their wish to implement, in a second phase, the process at the community or agroindustrial scales, for the rural electrification. A national biogas program is starting. In this perspective, a national infrastructure has been established to provide technical assistance and to coordinate activities of different projects (IARD, BADC, FAO, GTZ, BORDA, IFS, EGL and chinese team) that have built about 20 methane digesters so far. 34. REFERENCES (1) COMPAGNION, D., ROLOT, D., NAVEAU, H.P., NYNS, E.-J., BARATAKANWA, larisation et intégration de la biométhanisation au Burundi. Tropilarisation et intégration de la (2) COMPAGNION, D., ROLOT, D., NAVEAU, H.P., NYNS, E.-J., BARATAKANWA, V., NDITABIRIYE, D., NDAYISHIMIYE, J. and NIYIMBONA, P. (1984). Modular biogas plant particularly adapted to tropical rural areas. Poster presented at the Int. Conf. : State of the Art on Biogas Technology, transfer and diffusion, Cairo, Egypt. (3) CHEN, R.C. (1983). Up-to-date status of anaerobic digestion technology in China. Third Int. Symp. Anaerobic Digestion, Boston, USA, 415-418. (4) STUCKEY, D.C. (1983). Biogas in developing countries : a critical appraisal. Third Int. Symp. Anaerobic Digestion, Boston, USA, 253270. (5) EL-HALWAGI, M.M., DAYEM, A.M. and HAMAD, M.A. (1983). Design and construction of a new type of digester attached to an egyptian poultry farm. Poster presented at the third Int. Symp. Anaerobic Digestion, Boston, USA. M. ARNOUX and J.Y. MOREL Socjété Générale pour les Techniques Nouvelles (SGN) 78184 SAINT QUENTIN EN YVELINES CEDEX - FRANCE and G. COMINETTA and C. OGGIONNI BS - Smogless, via Mascheroni - 20145 MILANO - ITALY Abstract The SGN anaerobic digestion process utilizes immobilized cells on random plastic media. This allows a considerable reduction of the hydraulic residence time (down to 0.3 day). High organic loading rates can be attained (up to https://www.w3.org/1998/Math/MathML"> 20   k g c o d ⁡ / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reactor.day). We present in this paper results obtained in industrial demonstration plants treating effluents from distilleries (wine, sugar cane) or piggeries (manure). Industrial fu11 scale plants operating, or in starting up phases are also presented. Those units treat effluents from sugar plants (wash water), distilleries (spent wash) or piggeries (manures). In each case the economical aspect is summarized. The SGN process can be successfully applied to treat agricultura 1 wastes (slurry), food industry effluents (breweries, yeast plants, starch plants, potato industry...). Petrochemical and paper industry fields are now investigated. 1. INTRODUCTION Today anaerobic digestion gives an extremely advantageous solution to reduce organic pollution, enabling high pollution abatement with concomftant recovery of energy. The anaerobic digestion has been successfully applied for severa 1 decades to biological sludges stabilization, and to the treatment of animal manure. These substrates having a high concentration in solids, one or two stages of completely mixed digesters may be efficiently used but this requires a long residence time (over ten days) which imposes expensive installations. In order to reduce the size of these units, and consequently the investment, a high biomass concentration has to be kept in the digester. Certain improvements have permitted the biomass concentration to be increased by recycling sludges to the digester. Nevertheless, these improvements are not sufficient to reduce to a great extent the residence time, and consequently, the size of the bioreactors. One of the most important progress in anaerobic digestion is based on fixing biomass. 35. SGN FIXED FILM TECHNOLOGY 35.1. Process Development SGN having over ten years experience in the use of biological fixed films in aerobic biofilters decided to take an active interest in applying this technology to anaerobic digestion. SGN patented technology applies a plastic media which has been widely used in trickling filters. This material is characterized by high specific surface https://www.w3.org/1998/Math/MathML"> 230   m 2 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and high void volume https://www.w3.org/1998/Math/MathML"> ( 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> min). This allows to fixe a large amount of biomass and minimize the risk of clogging. In 1979, a pilot experimentation was carried out in cooperation with the French National Institute of Agronomic Research (INRA). Led to build in 1982 an industrial scale demonstration unit, to confirm laboratory results and to define optimal operating conditions, reliability of the process, investment and operating costs. After this first industrial plant, others demonstration units processing effluents from different fields (spent wash from distilleries, pig manures), have been successfully operated. Now, several full scale plants have been built and commissioned or in construction stage. Operating data concerning these plants are presented hereafter. 35.2. SGN fixed film process general description General description of SGN process is presented in figure I. fig. 1: SGN FIXED FILM PROCESS Raw effluent to be treated is fed through a cooling/heating system (30) to adjust, if required, its temperature. In some cases, a buffer tank https://www.w3.org/1998/Math/MathML"> ( 10 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is needed to control the inlet flowrate. Raw effluent is then mixed with the recirculating flow, and fed to the digester https://www.w3.org/1998/Math/MathML"> ( 40 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Temperature is controlled in the range of https://www.w3.org/1998/Math/MathML"> 35 - 37 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 36. DESIGN AND OPERATING DATA ON INDUSTRIAL PLANTS 36.1. Full scale plants 37. Sugar Refineries (BEGHIN-SAY COMPANY - THUMERIES - FRANCE) Figure II presents a block flow diagram of the waste water treatment 10 The existing waste water treatment includes a https://www.w3.org/1998/Math/MathML"> 30000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lagoon with eration basin equiped with six 15 kwh aerators. The BEGHIN-SAY company (one of the leading european sugar groups) decided to replace their conventional aeration plant and to install a SGN fixed film process. The total cod to be treated was 16 tons/day (wash water from 5000 to 8000 tons/day of beets). The plant, commissioned in October 1983, inciudes:

Heat exchanger

https://www.w3.org/1998/Math/MathML"> 1100   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> packed bed reactor

flare

biogas boiler

It was designed for a minimum https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cod reduction with a loading rate of https://www.w3.org/1998/Math/MathML"> 14,5   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DCO/m³ reactor.day. Key design data were 100 m³/h of raw effluent containing 7 ooo mg/1 coD, for an operation campaign of three to five months each year. The energetical context is the following: The energetical context is the following :

methane production of https://www.w3.org/1998/Math/MathML"> 5000 N m 3 / d a y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (used for production of steam)

saving in electrical consumption (by elimination of the aeration facilities)

The total investment (6 MFF - 1983) is provided to be paid out in 7 years on the bases of energy conservation alone and taking into account a short campaign period of 90 days/year. Please notice the plant capacity to treat high flowrates: https://www.w3.org/1998/Math/MathML"> 125 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the design flowrate in 1984 (because of the low load of the influent) with a COD reduction over the provided one. EFFLUENT FROM SUGAR PLANT EFFLUENT FROM OISTILLERYICOCNAC - FRANLEI fig. 2 fig. 3 THE BIO-GAS PROJECT IN EMILIA-ROMAGNA (Italy): FIRST RESULTS OF FIVE FULL SCALE PI.ANTS 38. SUMMARY 39. INTRODUCTION One fourth of the entire national pig population is concentrated in Emilia-Romagna, a Region that represents one twentieth of the Italian Inand surface the average farm size is 600 heads 480 of pige pulation land surface. The average farm size is 600 heads; 48 s of pig population is on farms larger than 1,000 heads. Therefore, on the one hand many farms have large energy needs, while on the other they have the availabi farms have largesenergy needs, while on the other they have the availabil ILty of high energy potential in the waste water. Anaerobic digestion is the technology that recovers energy from such wastes. The Emilia-Romagna Authorities have financed the realization of 4 demonstration full-scale plants in order to monitor: 1) the efficiency of the anaerobic digestion process; 2) the technical reliability of the plants sold by industry; 3) their economic convenience. 4) the farmer's capacity to manace a digen ster The plants have been installed in farms which differ in size, type of animals bred and management; they are of C.S.T.R. type with different mixing and heating systems. They have been in operation since early 1983. An experimental plug-flow plant on a dairy farm has been brought out and used within the programme. The results given below concern:

the efficiency of the digestion process;

energy contribution of the plant towards the energy needs of the farm;

the electric and thermic consumption of the plant;

problems relating to the introduction of the plant on a farm, and soIutions relating to this. 2. MATERIALS AND METHODS

TABLE II - Main characteristics of the plants The content of Total Solids (TS), Volatile Solids (VS), Total Kjeldahl Nitrogen (TKN), Ammonia (NH - N), Chemical Oxygen Demand (COD), Volatile Acids (VFA), pH and Total Alcalinity (TA) in feed; in digestion and in effluent were measured. Analyses for TS, VS, COD, TKN, https://www.w3.org/1998/Math/MathML"> N H - - N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were carried out in accordance to Standard Methods (APHA, 1975); VA were determined by steam distillation and titration, TA by titration at pH 3.8. The biogas methane and CO content were measured by IR and CO absorption. Furthermore the plants are equipped with a computerized sy TABLE IV - VS, TS and COD removal of the plants

PLUG-FLOW EXPERIMENTAL PIANT

Interesting data were obtained about the heat exchange capacities of the two coils immersed in the still manure, that range from 23 to 46 W.m https://www.w3.org/1998/Math/MathML">   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for this experiment. The iron coil showed a lower heat exchan ge capacity in respect to the polyethylene one. This means that in such conditions the exchange material is relatively less important, because the resistance of the manure to heating is very high. The relatively lower coefficient found for the iron pipe can be explained by the fact that the iron coil is in the first part of the reactor where the density of the manure is higher and the bubbling of biogas is lower. The overall efficiency of the heating system is between 80 and https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The biogas con METHANE PRODUCTION FROM GREEN AND ENSILED CROPS - TECHNOLOGICAL AND MICROBIAL PARAMETERS E. ZAUNER and U. KUNTZEL Institute of Grassland and Forage Research, Federal Research Centre of Agriculture (FAL), Braunschweig, Germany 40. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Methane fermentations of green and ensiled crops were performed at laboratory scale analyzing effects of substrate compounds, bacterial Inoculants and varied fermentation conditions on digestion process. Use of enriched bacterial populations precultured and already adapted to plant material was proved to be advantageous for inoculation. Crops consisting of C:N ratios about 16-12:1 were preferable for anaerobic digestion. Methane yields obtained from continuous fer- mentations of plant biomass generally decreased at increasing loading rates and reduced retention times, whereas quantity of anaerobic bacteria was not tnfluenced by changed process conditions. In most cases critical ranges of loading rate were detected about 5 kg total solids/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .day and at retention times below 10 days. 41. INTRODUCTION In view of increased interest in renewable sources for energy supply investigations on anaerobic digestion of plant biomass were carried out to increase basic knowledge necessary for development of suftable con- version technologies. At present little informations about methane pro- duction from plant material are avallable to derive preferable substrates and fermentation conditions (1 - 5). This paper presents the results of batch and continuous fermentations of green and ens lled crops to check out influences of bacterial inoculants, substrate composition, loading rate and retention time on digestion process.

RESULTS

The conversion abllity of enriched bacteria precultured on different substrates was examined in comparison with rumen fluid and cattle manure bacteria. Bateh fermentations of ensiled grass showed highest turnover rates and methane yields when bacteria grown on grass silage were used for 1noculation (Figure 1). A great quantity of crops materials differing in N and N-free extract (NFE) compotnds were digested in batch-tests to select suitable sub- strates. Increasing nitrogen content generally raised methane yield rein- forced in combination with increasing NFE-contents. Progressive load re- duced these effects (Figure 2). Continuous fermentations of green and ensiled plant biomass (Table l) were performend at https://www.w3.org/1998/Math/MathML"> 37 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by tuse of 161 laboratory flow digesters (Figure 3). Substrates were fed once a day slmultaneously with recycling of effluent. ELECTIVE COLONY COUNTS OF ANAEROBIC BACTERLA Disturbance of methane formation was not caused by reduction of cell numbers but by inhibition of metabolic activity. Abstract Methane yields obtained of all substrates used in experiments generally decreased at increasing loading rates and retention times Indicated by raising concentrations of proplonic acid in effluents (Figure 4). Relative methane yields and propionic acid concentrations in effluent dependent on loadingrate and repention time gzea mays, milk staqe, stlage o Lalium vest, green A sugarbeet leaves, silage 2,0 loading ratel kg TS/m³.dj retention time (d) Figure 4 Limiting loads and retention times that provided still high methane yields and productivities are given in Table 3. METHANE YELDS AND PRODUCTIVITES AT LIMITING VALLES OF LOADING RATE AND RETENTION TIME Highest loading rates could be achleved when plant materials of C:N ratio about 16-12:1 were digested. Data reported from continuous fermentations have to be regarded as preliminary values that have to be proved by long run and scale up experiments to check possible activating or inhibitory effects which might influence fermentation process. 1. REFERENCES (1) KUNTZEL, U. (1984). Biogaserzeugung aus Grüngut. I. Mitteilung: Efnfluß der Grïngutbeladung und des Trockenmassegehaltes auf die Methanbildung im Batch-Verfahren. Landbauforschung Volkenrode 34 , 155-162 (2) BADGER, D.M. (1979). BLogas production from crops and organic wastes. 1. Results of batch dlgestion. New Zealand Journal of Science 22,11-20 (3) SCHUCHARDT, F. (1981). Untersuchungen zum Gärverhalten von tierischen Exkrementen und Pflanzen. Grundlagen der Landtechnik 31 , (4) BAADER, W. (1982). Zur Technologie der Erzeugung von Methan uber anaeroben Abbau von Pflanzenstoffen. In: Fischbeck, G. et al. https://www.w3.org/1998/Math/MathML"> ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Eds. ): Nichtnahrungspflanzen, 116-132, agrarspectrum 4, BLVVerlagsgesellschaft, München. (5) STEINER, A. and KANDLER, O. (1984). Anaerobic digestion and methane production of grass and cabbage wastes. Thlrd European Congress on Biotechnology, Vol. III, Verlag Chemie, 3-8. (6) HUNGATE, R.E. (1969). A ro11 tube method for cultivation of strict anaerobes. In: Methods in Microbiology, Vol. 3B, Norris, J.R. and Ribbons, D.W. (Eds.), Academic Press, New York, 117-132. pig manure potato stillage Total solids https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 73 43 volatile solids https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 53 34 https://www.w3.org/1998/Math/MathML"> C O D ⁡ g 0 2 / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 75 52 Total https://www.w3.org/1998/Math/MathML"> N ( gN / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7.3 2.1 https://www.w3.org/1998/Math/MathML"> N H 3 / N H 4 ( gN / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3.9 0.1 protein https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 21 12.5 grease https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 5.1 https://www.w3.org/1998/Math/MathML"> n . d . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volatile organic 162 24 acids https://www.w3.org/1998/Math/MathML"> ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mmol https://www.w3.org/1998/Math/MathML"> / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lactic acid https://www.w3.org/1998/Math/MathML"> ( m m o l / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1 99 pH 7.5 4.8

Potato stillage as substrate

Stable methane fermentations of potato stillage could be Fig. 1. Gas production in pig manure fermentation at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 56 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Table II. Fermentation data with fermented pig manure at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fermentation substrates tot. volat acids acetic acid propion. acid isobut. acid butyr. accld isoval. acid valer. acid lactic acid fresh potato stillage 24 16 1 0.5 4.5 1.5 0.5 99 fermented pot. stillage 55 4 44 3 2 2 0 0 Fig. 2. Kinetics of gas production Fig. 3. Free ammonia fraction of total ammonia (NH3+NH4) as a function of pH and temperature feed addition 3.0 https://www.w3.org/1998/Math/MathML"> 8.5 p H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Were the only methanogenic bacteria detected in the fermented stillage. 2. Final remarks Figure 3 reveals that in a defined https://www.w3.org/1998/Math/MathML"> N H 3 / N H 4 + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - level the concentration of free ammonia rises as the pH-value and the temperature increase. The main reason for the digestion failure at https://www.w3.org/1998/Math/MathML"> 56 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> using pig manure as substrate may be the high concentration of free ammonia https://www.w3.org/1998/Math/MathML"> ( > 450 m g / l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> found in the thermophilic fermenters. Similar toxicity effects of free ammonia have been ANAEROBIC DIGESTION OF MACROALGAE IN THE LAGOON OF VENICE: EXPERIENCES WITH A https://www.w3.org/1998/Math/MathML"> 5 m C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . CAPACITY PILOT REACTOR S.NICOLINI and A.VIGLIA AGIPGIZA S.p.A., Reggio Emilia, Italy 3. Sumary Research was conducted in onder to check the conversion yields of algae biomasses into biogas with increasing organic loads and decreasing HRT's aimed at verifying the limits of the system itself. The treated material consisted of a mixture of three species of macroalgae infesting the lagoon of venice: ulva rigida, Valonia aegrophila and Gracilaria which the lagoon contained in percentages varying according to the season and area of collection. The system was operated in mesophylic conditions https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to identify and/or to optimize the following parameters:

spatial load

HRT

biogas conversion yields

https://www.w3.org/1998/Math/MathML"> - C H 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the biogas. 4. METHODS The investigation was conducted in the field with the aid of a https://www.w3.org/1998/Math/MathML"> 5   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> capacity anaerobic pilot reactor located in the lagoon area. Before digestion, the algae biomass was subject to a series of pretreatments such as washing, homogenization and storage, in order to make the organic substance more available for transformation. The analytical examination of the algae showed the presence of many cations of heavy metals which could negatively influence the microbic flora responsible for the anaerobic process, hindering correct metabolism. Even with very high specific loads, the adopted methods did, however, enable the control of both https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> levels in the biogas and the inhibition phenomena to which the microbic flora themselves could have been subjected. 5. CONCLUSIONS The results obtained in the above mentioned operative conditions show that the anaerobic digestion of the utilized algae biomasses is feasible and that it is possible to reach conversion yields equal to one volume of biogas per daily reaction volume, even with low HRT (ca. 10 days). The inhibition levels related to the presence of cations of heavy metals and to the high salinity of the medium which particularly contained sulphates, can be limited and controlled within paraphysiological values for the flora subject to a progressive acclimatization. CORRELATION BETWEEN H.R.T., SPECIFIC YIELD & V.S. CONCENTRATION CORRELATION BETWEEN SPATIAL LOAD, pH & https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> AND https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> S CONCENTRATION. BIOGAS PRODUCTION 6. Sunmary The research was conducted in order to check the possibility to treat tannery sludges with a high content of organic substances produced by the depuration systems of one of the most important Italian tanneries poles. In this frame, the system is also working on primary sludges and their mixture with biological ones, in order to give operative solutions to industrial problems. Research allowed to identify and/or optimize the following parameters in mesophyl running conditions https://www.w3.org/1998/Math/MathML"> 35 ∘ C : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

spatial load https://www.w3.org/1998/Math/MathML"> C s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ;

HRT;

biogas conversion yields;

https://www.w3.org/1998/Math/MathML"> C H 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the biogas. 7. METHODS The investigation was conducted in two separate phases; the first one incentered on an explorative reseanch in the laboratory with a pilot unit having an operative volume of 3001 , the second one was conducted in the field with a https://www.w3.org/1998/Math/MathML"> 200   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> capacity industrial reactor. In both cases, there was the same starting-up procedure and the consequentiality of the tested sludges in onder to study feasible running situations and to obtain a https://www.w3.org/1998/Math/MathML"> C s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> 3 K g S T / m 3 r . g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with an HRT of 15 days. 8. CONCLUSIONS Research showed how, in certain cases and particularly for primary sludges, the conversion yields of organic carbon into biogas are high and equal about to https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of those obtained with secondary biomasses of animal origin. As of ten observed with biological sludges, metabolic inhibitions related to high percentages of sodium, chromium and other salts present in the examined substrates in high concentrations is, however, a possibility which should not be ignored. This presence, together with the extrene variability of the relative concentrations, might pose certain limits to the application of this practice which can be considered subsidiary but not "alternative" in the global field of tannery sludge elimination. Furthermore and with reasonable investments, this technology cannot currently be recognized as an active part of the general energy balance of depuration unless the tanning industry rationalizes its productive cycles. Δ S.T. YIELD https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas https://www.w3.org/1998/Math/MathML"> / K g T S / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

HRT (d)

A S.V. YIELD https://www.w3.org/1998/Math/MathML"> m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas https://www.w3.org/1998/Math/MathML"> / K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VS/d)

SPATIAL LOAD (Kg TS/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> react./d)

E. RICHTER, K. -D. HENNING, K, KNOBLAUCH, H. JONTGEN Bergbau-Forschung GmbH, Essen, Federal Republic of Germany 9. Summary Biogas can be used for heat and electricity production or, after methane enrichment, as substitute natural gas However, typical impurities fixe hydrogen sulphide, halogenated hydrocarbons need to be removed prior to use of such gas. Adsorption processes using activated carbon or carbon molecular sieves are particularly suited for these purposes. Hydrogen sulphide is separated by cataTytic oxydation producing sulphur. The halogenated hydrocarbons are removed by adsorption to activated carbon. By means of special carbon molecular sieves and a new Iy developed pressure swing process, the methane concentration can be boosted to reach natural gas quality. 10. Biogas Fig.2.: https://www.w3.org/1998/Math/MathML"> H 2 S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -Removal from Biogases 11. REFERENCES 12. Summary When using biogas in on-site system, to produce electri city and/or heat, more than https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of its energy potential is dissipated. Biogas injection into pipelines permits. instead, a better utilization of its energy content. However for such purposes, as well as for on site auto- motive application, biogas needs to be purified from con https://www.w3.org/1998/Math/MathML"> H 2   S , H 2 O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and other components. An economical analysis is presented comparing physical and chemical absorption and reaction processes vi. sele ctive polymeric membrane separation. The latter has been found competitive for systems treating more than 250 Nmc/h of biogar feed. Due to the higher content of co in biogas landfill,mem brane separation is an even more adequate process. 13. INTRODUCTION The biogas has a valuable energy content because of its methane fraction. The best use of biogas is the direct combus tion for heating purposes. But where the production is relevant the thermal utilization point might be missing or too distant. Electricity generation with or without thermal co-generg tion is often used for on-site systems. But, because of the Iag between the time constant energy production and the fluctuating energy utilization, overal dissipation may occur. In addition electricity generation is not so convenient when compared with electricity costs of the large distributors. By injecting the biogas into pipeline,instead,all biogas energetic content is available to the final users. In the locations that give the largest biogas production this system can be the best utilization. Depending upon its usage,biogas has to be purified. In the case of pipeline injection or engine combustion,biogas needs to be cleaned from inert diluents and from other compo 14. TABLE I- ABIOGAS COMPOSITIONS BIOGAS FROM AV. DAILY PRODUCTION AV. COMPOSITION % VOL. https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> H 2 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> SEWAGE DIGESTER 5.000 https://www.w3.org/1998/Math/MathML"> N M C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 60 38,8 1,0 0,1 0,1 LANDILL 12.000 https://www.w3.org/1998/Math/MathML"> N M C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 50 39,5 7,0 0,002 3,5 The energetio content of biogas depends on its methane fraction. Both co and N are inert diluents,lowering the calorific value of the gas. Biogas is potentially explosive and represents a health hazard because of the presence of H s and CO When burned, biogas releases air polluting so by oxidation of H S: other sulphur containg biogas constituents may cause air pollution, too. https://www.w3.org/1998/Math/MathML"> H 2 O , H 2   S , O 2 , C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , are corrosive for equipments or pipes. In table II are shown gas quality requirements as a fun ction of biogas use. TABLE II_= REQUIRED GAS QUALITY

TRADITIONAL METHODS OF GAS CEEAN UP

One of the most common treatment for biogas cleaning is absorption of H S on solid masses. Solid mixture "bog-ore" is used as "laming mixture". During the treatment of the gas sul phur accumulates around solid particles isolating them from gas contact. When the sulphur has reached https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the weight of reactive mas the solid has to be removed. Another purification system is absorption with water; other systems use chemicals, 1 ike amine, but the water system has large diffusion because of its lower costs and easier main tenance.

MEMBRANE SEPARATION PROCESS

The purification sysstem presented herein is the separation by membranes. The process parameters are:feed pressure, selectivity and permeability of the membranes. For maximum ef ficiency the geometry on the feed side is arranged so that there is no mixing of the feed from point to point on the mem brane. Furthermore the feed velocity at every point is kept high enough to minimize the excess concentration of the slower permeating species in the membrane surface boundary layer. Fig. I - MATERIAL_BALANCE_IN_MEMBRANE_SEPARATION Feed pressure ranges between 15-75 ATA(the minimum for sufficient driving force and the maximum to limit mechanical stresses of the membranes and modules). As shown in Fig. 2 the membranes are configured in spiral woud elements. These elements are ef-ther 4 , or 8 in.indiam. 40 or 60 in.in lenght and housedin steel pressure ves-sels. Minimum feed flowis 25 Nmc/h when using2in. modules.Economic analysis ofmembrane separation process for biogass havedemostrated that 40 ATAas optimal feed pressure. Fig. 2 SPIRAL_WOUD_ELEMENT

COSTS ANALYSIS FOR BIOGAS PURIFICATION

Tab. III presents costs data for water and membrane separation processes for purification of biogas originated by sewage digesters(case A) and landfills (case B). Costs are indicated in It. lire; the capital costs are computed on the basis of 20 years pay-back time. Separation by WATER MEMBRANE Biogas from A A COSTS It.Lire Operating 35 40 27 28 Capital 12 12 14 16 Landfill biogas purification is more exspensive then sludge digestion biogas purification irrispective of the treatment process. This is due to the higher content of inerts in the first. By water treatment, operational costs differences between the two feed sources are larger because of the methane los ses in the water streams,while, with membrane treatment, reco veries up to https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the feed methane are achievable. Capital costs are, instead higher in the case of membrane systems and increase with the https://www.w3.org/1998/Math/MathML"> C O / C H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ratio, because of the need of pre-treating the whole feed stream. Still, membrane separation is overall more convenient, the economic advantage becoming really attractive for plant sizes from https://www.w3.org/1998/Math/MathML"> 250 N m c / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of feed stream, and beyond. Fig.3 ENERGY AND ECONOMIC UTILIZZATION SCHEME

Distribution network losses represent the limited efficiency of the pipeline final users.

Fig.3 reports the energy and economical flow diagrams of biogas, relative to domestic sewage sludges. Biogas economic value is considered pro portional to its methane fraction. The costs of the different phases of treatment and utilization have been computed. The comparison has been done between biogas desulphuration only and subsequent on-site usage for cogeneration and membrane treatment for pipeline injection. The latter appears at least https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> more convenient. 15. REFERENCES

Ashare E. 1978 Fuel gas production from biomass;Ed.D.Wise C.R.C.Vol II

B.A.B.A. Digest 1980/83 Proceedings of workshop on biogas scrubbing

Cernuschi S. 1982 Ingegneria Ambientale 11/82

Cioppa 0. 1968 Ingegneria Sanitaria 4/68

Jannelli G. 1981 Ingegneria Ambientale 3/81

Mazur W.H. and Chan M.C. 1982 A.J.Ch.E. Oct.82

Saltonstall C.W. et al. 1982 comunication by courtesy of Envirogenics Co.

Migliaccio N. 1984 Acqua Aria n https://www.w3.org/1998/Math/MathML">   ∘ 3 / 84 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BIOMASS AND COENZYME F https://www.w3.org/1998/Math/MathML">   420 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DISTRIBUTION IN ANAEROBIC FILTERS

N. O'Relly, P.J. Reynolds, A. Wilkie and E. Colleran Department of Microbiology, University College, Galway, Ireland 16. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Laboratory-scale, random-packed anaerobic filters were utilised to investigate media related effects in upflow anaerobic filters. Using fired clay filters, operation in downflow mode was shown to be more stable and to allow hígher COD conversion efficiency at high loading rates than operation in upflow mode. Clay was clearly superior to other support materials tested with respect to ease and quantity of biofilm development. Thís did not appear, however, to result in superior filter performance at higher loading rates. In both upflow and downflow units, the bulk of the COD removal efficiency was located in the sections closest to the feed inlet. Despite the build-up of VSS in the lower sections of downflow operated filters, it appeared to contribute little to the overa11 reactor performance Treatment efficiency could not be correlated with either specific surface area or porosity. 17. INTRODUCTION The anaerobic filter or anaerobic packed-bed reactor belongs to the group of anaerobic digestion reactors known collectively as retained- biomass reactors. The distinguishing feature of anaerobic filters is the presence of an inert packing material which retains the active microbial biomass both as an attached biofilm and in the form of entrapped flocs or granules in the interstitial spaces. Support media used in tests conducted to date have ranged from stone chips to a number of commercially available plastic and ceramic tower packings and have included more tunsual materials such as fired clay, cloth, shells, coral, reeds and bamboo rings (1). The support material is fixed in a vertical bed which may be loose-fill, modular or channel-packed, is in a fully submerged state and is operated either in an upflow or downflow feed mode (2,3). The anaerobic filter has been guccessfully utilised at laboratory, pilot and full-scale for a variety of low to medium to high strength industrial, agricultural and domestic wastewaters, including distillery, food agricultural and domesticurartewaterz, animal slurries, silage effluent, landfill leachate and domestic sewage. It may be expected that support media surface characteristics and media type, shape, porosity, void size, depth and placement geometry will influence both the distribution and activity of the retained microbial population thithin the anaerobic filter. To date. only a imited number of studies have attempted to identify and evaluate media-related effects in the operation of fixed-bed reactors. Waste flow direction is also likely to affect the degree of retention of the suspended population in fixed-bed reactors, yet few comparative studies have been carried out to date on the effect of feed flow direction on the biomass distribution within the fixed bed, The effect of effluent recirculation on the biomass distribution and on reactor performance has likewise received little investigation either at laboratory or pilot-scale. This paper deals with the effect of support matrix type, flow direction and effluent recirculation, on volatile suspended solids and F 420 . distribution in laboratory-scale, random-packed anaerobic filers. 18. MATERIALS Laboratory-scale filters were constructed from wavin sewer pipes and fittings to an external diameter of https://www.w3.org/1998/Math/MathML"> 156   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a height of I. 2 m as previously described (4). Support materials utilised included polypropylene cascade mini-rings of 38.50 mm in diameter, fired clay fragments which passed through a https://www.w3.org/1998/Math/MathML"> 3.8   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and were retained on a 2.5 cm sieve, mussel shells, 'coral" (a multibranched, calcareous alga known commercially as maerl) and PVC rings of 23 mm internal diameter and https://www.w3.org/1998/Math/MathML"> 25   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> depth. The total volume of each filter was 21.31 with a gas and feed distribution volume of 3.31, giving a filter bed volume of 18 l. The filters were seeded with sludge obtained from the effluent from laboratory filters treating pig slurry and silage effluent. The operating temperature was https://www.w3.org/1998/Math/MathML"> 33 ∘ = 2 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Pig slurry supernatant feed was obtained from an above-ground holding tank in a local piggery. The slurry utilised had undergone considerable 1iquefaction in underfloor tanks during the normal 2-3 week holding period and had been separated by gravity settlement prior to collection. The total coD of the slurry supernatant utilised in the different triats varied from 17,000 to 34,000 mg. 1 , depending on the degree of dilution with wash and rain-water at different periods of the year. Silage effluent was obtained from a local farm and diluted to a total COD content of https://www.w3.org/1998/Math/MathML"> 11,000 m g . 1 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> before feeding. Measurement of TS, SS, VSS, COD and TOA was performed according to standard APHA or USEPA methods, as described previously (5). Methane percentage in the biogas was determined by gas liquid chromatography using a Poropak Q column. Individual volatile acids were determined by CTC using a chromosorh w-HP (80-100 mesh) column packing coated with https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FFAP. Coenzyme F420 was determined using a modified version of the Delafontaine procedure (6). 19. RESULTS AND DISCUSSION The performance of four upflow filters containing cascade minirings, fired-clay fragments, coral and mussel-shells in loose-fill packing arrangement was monitored during start-up and operation at a variety of hydraulic retention times using a pig slurry supernatant feed. The trial was designed to evaluate the effect of porosity and specific surface area on start-up and performance at different loading rates, The porosities and specific surface areas of the support media were: clay, https://www.w3.org/1998/Math/MathML"> 69 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 119   m 2 . m - 3 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> coral, https://www.w3.org/1998/Math/MathML"> 71 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 490   m 2 . m - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; mussel shel.1s, https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 161   m 2 . m - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and plastic mini-rings, https://www.w3.org/1998/Math/MathML"> 94 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 179   m 2 . m - 3 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The reactors were operated ab initio at a constant COD loading rate of start-up phase. Start-up was most rapid with the clay filter (c. 20 days) and was slowest with the mussel shell support. Irrespective of the time taken for start-up, the performance of the four filters at steady state at the HRT and loading rate specified above was similar, with coD removal efficiencies of 69-73 being attained. The loading rate was increased stepwise to 27.9 kgCOD.m https://www.w3.org/1998/Math/MathML">   - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .d by progressively decreasing the HRT from 6 to 3,2 and I days. Treatment Fig. 1. Vertical distribution of the attached and suspended VSS and of their specific https://www.w3.org/1998/Math/MathML"> F 420 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> content in upflow and downflow fired clay filters treating pig slurry supernatant. loading rate of 0.5 to https://www.w3.org/1998/Math/MathML"> 5 k g C O D . m - 3 . d - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , with effluent recirculation. The former procedure allowed the most rapid start-up but no difference was noted between the treatment performance of the two reactors at steady state. The level of attached VSS, in general, was almost an order of magnitude lower than that observed in the clay filter. In both the recirculated and non-recirculated reactors, the attached VSS decreased with increasing reactor height. The decrease was even more marked for the suspended VSS which was present in high concentration in the lower sections of both matrix beds. Clearly recirculation did not result in a more uniform distribution of either the attached or suspended vSS throughout the filter bed. Analysis of the Fhan content again indicated a higher specific Fhen content in the guspended VSS at all levels in both Eilters. A peak in specific Fheo levels was noted for both the attached and suspended VSS in the middle section of the recirculated filter bed (Fig.2). It is clear from these studies that the support matrix type may greatly influence the relative distribution of the biomass in the matrix bed of anaerobic filters. Clay appears to provide a superior surface for attachment and this may be attributed to surface roughness and possibly also to the provision of inorganic nutrients, such as iron, which stimulate the growth and activity of the methanogenic population. Fig. 2. Vertical distribution of the attached and suspended vSS and of their specific https://www.w3.org/1998/Math/MathML"> F 420 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> content in upflow PVC ring filters operated with and without effluent recirculation on a pig slurry supernatant feed. During operation in downflow mode, the bulk of the coD conversion takes place in the upper section of the filter and the biomass which settles in the lower sections appeared to contribute little to filter performance at the relatively high loading rates utilised. Effluent recirculation did not appear to alter filter performance nor did it significantly affect the vSS distribution in upflow feed mode. Ongoing studies with soluble substrates, such as silage effluent and sucrose wastewaters, may yield further information on the evidently complex media-related effects in anaerobic filter performance. 20. REFERENCES (1) COLLERAN, E., WILKIE, A. , BARRY, M., FAHERTY, G., O' KELLY, N. and REYNOLDS, P.J. (1983). One and two-stage anaerobic filter digestion of agricultural wastes. In Proceedings of 3 rd International Symposium on Anaerobic Digestion, 285-302. Published by 3rd International Symposium on Anaerobic Digestion, Cambridge, Massachusetts. KINETICS OF LANDFILL LEACHATE TREATMENT BY ANAEROBIC DIGESTION 21. J.M.LEMA (*) and E. IBAÑEZ(**) (*) Departamento de Química Técnica.Facultade de Química. Universidade de Santiago de Compostela.-Galicia.-Spain (**) Departament de Ouf́mica Tècnica. Facultat de Ciències. Universitat Autònoma. Bellaterra.-Catalunya.-Spain 22. Summary The present contribution deals with the use of Anaerobic Digestion for the treatment of the leachates from the Garraf landfill, Barcelona.-Spain, where 500,000-600,000 th of solid wastes are Barcelona.-Spain, where 500,000-600,003, trof solid wastes are deposited by year, producing https://www.w3.org/1998/Math/MathML"> 100 - 125   m / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day of a highly polluted wastewater. The COD, 21000-23000 is mainly attributable to the presence of vas and most of the remaining is from orotein and presence of VFA and most of the remaining is from protein and hydroxyaromatics compounds. Laboratory anaerobic digesters were operated at HRT (equal to SRT) up to 35,29,24,18,15,12.5,8 and 5 days. Substrate samples were routinely analised for pH, oRP, COD, vFA, VSS, phosphate, protein and ammoriacal nitrogen. Gas composition of the produced biogas was determined by GC. In the digegteng operating at HRT 15 on logs addition of phogphate was necoesary to keep the digester stable. The process was modelled using Chen & Hashimoto's kinetic equation. Experimental data were fitted to the equation by means of a non-linear regresion computer program, getting a good correlation (deviation less than https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in all casest. The value of the kinetic parameters were: https://www.w3.org/1998/Math/MathML"> μ = 0.275 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; K= 0.465 and https://www.w3.org/1998/Math/MathML"> R = 0.10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which indicate the presence of e refractory material. The methane production per volume of digester was also modelled using a experimental value of y (l CH / kg COD removed) of 377 . 23. 1.-OBJECTIVES Without any doubt, of the various alternatives for treatment of urban solid wastes, the controlled landfill is the most common, due to its lower operational costs. One of the major problems associated with the landfills are the waters from the rain or from the waste original moisture that flow along the waste. These waters, leachates, generate a serious contamination problem, both of superficial and underground waters. A study to evaluate the perfomance of the anaerobic digestion of the leachates from the Barcelona urban solid waste landfill iss presented in this paper. The landfill, located in Garraf (Barcelona, Spain) with a disposal area of 72 Ha., treats from 500,000 to 600,000 https://www.w3.org/1998/Math/MathML"> t n / y r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of waste. Its ground has been treated with a layer of gunnite, in order to avoid leaking. As an average https://www.w3.org/1998/Math/MathML"> 100 - 125   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of leachates are collected from the landfill, with the characteristics showed in Table I. 24. 3.-RESULTS Table II The organic load removed per digester volume and day, also refered as the rate of substrate consumption, is given by: https://www.w3.org/1998/Math/MathML"> r s = s T O - s T / θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The methane production rate is related to https://www.w3.org/1998/Math/MathML"> r s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by: https://www.w3.org/1998/Math/MathML"> V C H 4 = Y 0 r s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where https://www.w3.org/1998/Math/MathML"> Y O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the stochiometric yield (CH produced/COD removed). The values of https://www.w3.org/1998/Math/MathML"> Y 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> Y C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> produced/COD feeded ) are shown in table IIIfor each HRT considered. A 1inear regression for Y and https://www.w3.org/1998/Math/MathML"> 1 / θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , as suggested by https://www.w3.org/1998/Math/MathML"> ( 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , gives a value for https://www.w3.org/1998/Math/MathML"> Y 0 = 3771 C H 4 / k g C O D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> removed, with a correlation coefficient of 0,991 . H.R.T. https://www.w3.org/1998/Math/MathML"> 1 / θ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> Y O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Y 5.2 0.1923 368 161.2 8.0 0.1250 374 245.3 12.5 0.0800 375 277.5 15.0 0.0666 377 289.5 18.0 0.0555 377 314.4 24.0 0.0417 409 343.6 29.0 0.0345 408 341.9 35.0 0.0286 407 344.7 By combining equations 1 and 3 with 4 the rate of methane production, https://www.w3.org/1998/Math/MathML"> V C H , 1 C H 4 / m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is obtained: https://www.w3.org/1998/Math/MathML"> v C H 4 4 = ( 1 - R ) S T O Y 0 1 - K / μ m θ - 1 + K - 4 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 1 shows the experimental values of V compared with the values to be obtained by means of equation https://www.w3.org/1998/Math/MathML"> 5 , + ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and the experimental values for the percentage COD removal: https://www.w3.org/1998/Math/MathML"> %   COD removal   = 1 - S T / S TO https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> compared with those obtained for equation https://www.w3.org/1998/Math/MathML"> ( 1 ) ( → ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The maximum removal rate (and maximum methane production) can be shown both graphically or analytically to occur for a HRT: https://www.w3.org/1998/Math/MathML"> θ m a x = ( 1 + K ) / μ m = 6.1   days   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the corresponding wash-out HRT would be: https://www.w3.org/1998/Math/MathML"> θ m i n = 1 / μ m = 3.64   days.   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 25. BIOGAS RESEARCH IN AUSTRIA J. SPITZER, Joanneum Research Society Graz P. SCHUTZ, Ministry for Science and Research W. HIMMEL, Technical University of Graz 26. Summary A five year research program has been conducted in Austria with the goal to replace part of the fossile fuel used for domestic heating in rural areas by biogas. The results of the program, which concentrated on biological fundamentals and on operation of demonstration plants, show that the biological process is well understood and that plant economy depends on an economic solution of the problems associated with process energy demand, gas utilization and substrate flow. Possibilities to solve these problems have been demonstrated. With the expected future increase of energy prices, biogas may be a valuable source of energy in rural areas. 27. INTRODUCTION Austria must import 610 PJ (1982) of primary energy per year which amounts to two thirds of its total primary energy needs. Of these imports https://www.w3.org/1998/Math/MathML"> 73 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are crude https://www.w3.org/1998/Math/MathML"> 0 i 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , refined oil products and natural gas. Import reduction in particular and the use of locally available renewable energy sources in general are, therefore, primary goals of the Austrian energy policy. One of the possibilities to achieve these goals is the increased use of biomass in domestic heating where https://www.w3.org/1998/Math/MathML"> 55 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the energy demand is covered by heating oil and natural gas. To promote this possibility through the production and utilization of biogas in rural areas, a number of R & D projects on the biological fundamentals and on design and operation of demonstration plants has been carried out in Austria under public sponsorship since 1980 . Industry participated in this effort with the design and construction of biogas demonstration plants. Three research groups at three locations were involved under the coordination of the Federal Ministry for Science and Research: The Joanneum Research Society in cooperation with the Technical University of Graz, the Agricultural School Edelhof in cooperation with the Agricultural University of Vienna and the Federal Institut for Agriculture at Wieselburg. Most projects will be finished during 1985 so that conclusions regarding the technical and economic feasibility of biogas plant operation in rural areas in Austria may be drawn (1). 28. BIOLOGICAL FUNDAMENTALS At the beginning of the investigations on the biological aspects of biogas production methods for determining the important parameters characterizing the performance of the digestion process had to be made available: In addition to accurate laboratory methods, suchs as gaschromatography for the determination of the volatile fatty acids and the composition of biogas, simple analytical methods for the measurement of the https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -and https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -content of biogas and the dry-matter content of the substrate were developed for the practical application at biogas plants. An anaerobic glove box with an inert gas supply, a roller-agar layers and sedimentation. It was found that the floating of straw is mainly due to small adhering gas bubbles and may be sucessfully controlled either by frequent stirring of the substrate or by milling the bedding straw and keeping the dry matter content above https://www.w3.org/1998/Math/MathML"> 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in which case the separation of the straw was prevented by the high viscosity of the substrate. Problems encountered with sedimentation were mainly caused by lignin remains of (milled) straw and by chicken feed residues (sand). A sedimentation chamber and a downflow digestor with a conical outlet at the bottom are recommended to avoid sedimentation problems. Process energy demand A large effort was placed on the reduction of process energy demand. Possibilities for thermal insulation, substrate heat recovery systems and heating systems were investigated. With respect to heat recovery it could be shown that only simple designs without mechanical equipment can be economically operated. The digestors B and D of Fig. I were equipped with an integrated serpentine heat exchanger (I) and a prechamber heat exchanger (II) respectively. Both heat exchangers operate batchwise. The integrated system has low investment costs and reduces digestor heat losses to the environment https://www.w3.org/1998/Math/MathML"> T 2 < T 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Operation data indicate that a calculated efficiency of https://www.w3.org/1998/Math/MathML"> 48 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for heat recovery might be achieved during operation. This system is recommended for substrates with low dry-matter content. The pre-chamber system is more rigid and applicable to virtually all substrates encountered in agriculture. Care must be taken to keep heat losses low during the long retention times necessary. The calculated efficiency of https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> could be achieved during operation. With respect to heating systems it could be shown that both wall and floor heating, as well as external heating circuits may have very poor efficiency and should not be used. Aerobic pretreatment for heating purposes also does not appear to be economical. A low-cost heating system using exhaust gases from a generating unit was developed, promising a calculated overat1 efficiency of https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This system is currently beeing tested with digestor A. Good results were also obtained with a direct electric resistance heater consisting of two metal plates on both ends of digestor D exposing the substrate to a low voltage current. 29. PLANT ECONOMY The main parameters influencing plant economy are:

capital investment

biogas utilization and the

price of the energy substituted by biogas.

The first two of these parameters may be optimized by means of a detailed and careful overall design of the plant. Regarding the price of energy, it may be assumed that a future increase will be above the general inflation rate since it is mainly heating oil and electricity that is substituted by biogas in rural areas. This increase will ultimately lead to acceptable plant economy. Much effort was put into determining plant designs with minimized capital investment and maximized utilization of the biogas produced. Depending on how much of the existing farm building structure can be uti- lized for the plant and also on how much of the construction can be done by the investor himself, the capital investment for biogas plants in Austria ranges from 10.000 to 20.000 As per m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of digestor volume. No decrease may be expected since a safe and dependable plant operation does not allow further reduction of component costs and since it is not advisable to design and construct the plant completely without professional support. The energy demand in Austrian farms is such that biogas utilization is generally poor. In most cases domestic heating and hot water production represent the only demand so that a large portion of the annual gas production has to be wasted during the summer. Possibilities for supplying additional users with biogas were investigated in some detail. Since storage of biogas is generally not economical (in particular long term storage required to utilize excess gas produced during summers) only additional users with a continuous energy demand are of interest. While biogas as a fuel for tractors is not economical because of the high cost of compressed gas storage on the vehicle, the operation of small motor driven power generators (genera11y without waste heat utilization) seems to be a good possibility to utilize excess biogas throughout the year. A different approach to improve the economy has been investigated in some detail: cooperatively organized biogas production and utilization in rural areas by either transporting waste of several farms to one central biogas plant or connecting the biogas plants with a gas distribution system. Both investment cost and gas utilization may be improved mand can be found. 30. CONCLUSIONS From the results of five years of biogas research in Austria the fol lowing conclusions may be drawn: The biological process is well understood and does not represent any key problem for the operation of agricultural biogas plants. On the other hand, optimization of the biological processes will not contribute very much to overa11 plant economy. More important with respect to plant economy are those problems associated with substrate flow, process energy demand and gas utilization. Experience with demonstration plants has shown that much attention has to be given to the piping and stirring equipment to avoid pipe blockages, scum layers and sedimentation in the fermenter. With regard to process energy demand it was found that with optimum heat transfer equipment and an optimum fermenter insulation together with a heat recovery system, some improvement of plant economy can be achieved. The greatest potential for optimization lies in gas utilization and the reduction of capital investment for the plant. No generell recommendation for the overall optimization of the plant economy can be given since the ideal situation must be determined for each individual plant. Despite the fact that in Austria the total contribution to the primary energy supply probably lies below two percent, biogas may be a valuable source of energy for specific applications particularly in rural areas. 31. REFERENCES (1) BRUNNER, N. et ai. (1984). Erzeugung von Biogas aus landwirtschaftlichen Abfällen. Institut für Umweltforschung und Institut für Biotechnologie Graz. Research report, ifu-B-13-84. (2) SCHEUCHER, P. https://www.w3.org/1998/Math/MathML"> ( 1984 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Isolierung und Untersuchung von Methanbakterien aus landwirtschaftichen Bogasantagen. Thesis, University of Graz. (3) PANHOLZER, M. (1983). Energiegewinnung durch Abfallbeseitigung: Biogas aus landwirtschaftlichen Abfallen. Thesis, Technical University of Graz. (4) HIMMEL, W.; LAFFERTY, R.M (1983). Operating Experience with a Double Chamber Digestor with Cattle Manure Containing Straw as a Substrate. Anaerobic Waste Water Treatment Proceedings 511-525, 23 - 25 Nov. 1983 , Noordwijkerhout, Netherlands. A B C C B F= feed substrateE= effluent substrateG= gas trap https://www.w3.org/1998/Math/MathML"> & = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogas outietActive volume https://www.w3.org/1998/Math/MathML"> m 3 : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> A : 39 B : 28 C : 43 D : 26 E : 85 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> E: 85 Figure I: Schematic views of five biogas demonstration plants for different substrates in agricultural applications: A - cattle (design: BVT Austria) B - cattle (design: MEI Austria) C-cattle (design: Joanneum Research Society) D-cattle (design: P. Schütz) E - pigs and chicken (design: Joanneum Research Society) I,II - heat recovery systems for plants D and B. MATHEMATICAL MODEL OF A REAL SCALE DIGESTER R. CHIUMENTI*,A. DE ANGELIS^, F. DE POLI, A. TILCHE^\star (*) Università di Padova - Istituto di Meccanica Agraria - Via Gradenigo n. 6 - PADOVA (**) ENEA (Ita1ian Commission for Nuclear and Alternative Energy) - Dip. FARE-TER-COM-IBI - CRE Casaccia - C.P. 2400 - ROMA. 32. SUMMARY The analysis of the time series of different variables of anaerobic digesters in real scale shows that a high correlation exists between the output (biogas yield output solids), and input (input solids, digester tem perature, loading rate, etc.) if the cross-correlation is lagged at a calculated time t. ENEA researchers have applied cross-correlation at different times, up to HRT of the digester, to 5 cases of real scale digesters. The first case about the FOCHESATO Brother's plant is shown. Using the more correlated variables at the lag times showing highest correlation, with a multiple regression program, we obtained a model of the form shown below. We found a model with a F value https://www.w3.org/1998/Math/MathML"> > 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which implies a level of significance between 0.01 and 0.025 33. THE FARM AND THE DIGESTER The Fochesato Brother's barn shelters 150 cows in free stalls. Resting and feeding alleys are made in slotted floor, under which mechanical scrapers transfer the liquid manure outside the barn, where another scrabber conveys the product to the storage basin. A screw pump transfer the manure to the digestyer. The digester is a https://www.w3.org/1998/Math/MathML"> 200   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> self-built horizontal concrete tank. The mixing and heating system consists of two centrifugal pumps and a double pipe external exchanger. 34. CROSS-CORRELATION Cross-correlation functions were calculated between different variables at lag times up to 15 days. Occasionally the lag used is not the best correlated one due to the fact that the cross-correlation is between two variables, and the model is calculated on a larger number of variables (three in this case, but up to five in others). This calculation was made on 46 days of continuous monitoring, but the same model was tested for other periods on the same plant, with similar results. The autocorrelation of the yield (number 1) and the output TS (number 10) indicates a high value at lag zero, decresing day by day. 35. RESULTS In the graph 1 and 2 the comparison of the observed and the calculated values can be seen; the curve of calculated values begins after several days according to the highest lag time applied. Biogas yield (BY) depends on loading rate (LR) at a lag of the three days, and on digester temperature (DT) at a lag of eight days. As shown by the graphs, the calculated values are rather similar to the measured ones, also in the presence of a high variability. The F value is 5.009 (44 df), https://www.w3.org/1998/Math/MathML"> 0.025 > P > 0.01 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Output total solids (OS) depend on digester temperature (DT) at a lag of eight days and on input solids (IS) at a lag of nine days; also in this case the model has a highly significative correlation with the experimental data. The F value is https://www.w3.org/1998/Math/MathML"> 5.682 ( 44 d f ) , 0.025 > P > 0.01 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . https://www.w3.org/1998/Math/MathML">   BY ( t ) = K 1 + K 2 L R ( t - 3 ) + K 3 DT ( t - 8 )   ( t ) 0 S = K 1 + K 2 D T ( t - 8 ) + K 3   IS ( t - 9 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 647 36. ANAEROBIC TREATMENT OF HIGH-LOAD INDUSTRIAL WASTE WATER BY MEANS OF FREE-CELLS FERMENTATION PROCESSO, ZUFFI, N. MILANDE, B. RAYMOND Société BERTIN & CieZone Industrielle40220 TARNOS - FRANCE 37. Summary The company BERTIN and Co, which proceeds from the begening of the seventies about energy and chimical products from biomass, is improving in the way of anaerobic waste water treatment, a set of processes about both the production and the use of biogaz on industrial place. 1.1. Présentation du procédé actuellement développé à l'échelle industrielle Le traitement par méthanisation d'effluents liquides fortement chargés en DCO et/ou en matiere en suspension tels que les effluents d'elevage (lisier de porcs ou de bovins), de brasserie (trouble du moat, fonds de tanks, freintes de bières et éventuellement levures en excès), d'abattoir (effluent de l'atelier triperie-boyauderie, jus de pressage des matieres stercoaires, lisier et sang implique l'utilisation de procédés industriels capables de fonctionner avec des charges appliquées élevées sans entraîner pour l'utilisateur de contraintes importantes pour le suivi technique, l'entretien ou la maintenance. Dans ce but, la Société BERTIN a développé, d'abord à l'échelle pilote https://www.w3.org/1998/Math/MathML"> 3   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , puis à l'échelle industrielle, un procédé à cellules mobiles, initialement inspiré du procédé "contact" classique (avec ou sans séparation des phases d'acidogénèse et de méthanogénèse) avec optimation des conditions de fonctionnement hydraulique permettant d'obtenir le meilleur contact possible entre la biomasse (qui s'absorbe le plus souvent sur les M.E.S. du substrat) et l'effluent à traiter Ce procédé fait l'objet de plusieurs réalisations industrielles sur différents substrats. Le tableau ci-dessous donne quelques exemples des résultats obtenus à différentes échelles. RESULTS OBTAINED AT FULL INDUSTRIAL SCALE Origin of the effluent Piggery waste (without pretreament) Brewery (beer waste, wort waste, yeast waste) Slaughter house Dairy (whey) Pharmaceur tical industry Scale industrial plant https://www.w3.org/1998/Math/MathML"> 170   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pilot plant https://www.w3.org/1998/Math/MathML"> 3   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> industrial unit under construction pilot plant https://www.w3.org/1998/Math/MathML"> 3   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> industrial unit under construction pilot plant https://www.w3.org/1998/Math/MathML"> ( 301 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> industrial unit under pilot plant (30 1) construction specific load kg DCO/ https://www.w3.org/1998/Math/MathML"> m 3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day 6-10 12-16 5-8 12 5-6 Biogas production https://www.w3.org/1998/Math/MathML"> m 3 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> digestor/day 2-3 4-6 1.5-2.4 4.5-5.5 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Average https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas content % vol https://www.w3.org/1998/Math/MathML"> 74 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> D C O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> removal https://www.w3.org/1998/Math/MathML"> 74 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1.2. Développement de technologies associées Bureau d'étude et de recherche spécialisée dans les transferts de technologie, la Société BERTIN a d'autre part développé un certain nombre de procédés technologiques associés au traitement de méthanisation, tels que : - procédé d'épuration du biogaz par contacteur gaz-liquide compact avec régénération continue du catalyseur, permettant d'atteindre des teneurs en https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> inférieures à https://www.w3.org/1998/Math/MathML"> 20 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( V/V ) émulsionneur permettant, dans le cas du traitement d'effluents chargés en matière grasse (abattoir, laiterie, conserverie de viande ou de poisson, suiferie, huilerie), I'obtention d'une dispersion de ces matierres en fines particules dans le fermenteur, dans le but d'augmenter leur surface d'attaque et d'obtenir ainsi une hydrolyse et une digestion plus rapides de ces matières grasses

mise au point d'automates programmables permettant le contrôle en continu d'installations industrielles de méthanisation et de leur équipement annexe.

1.3. Travaux de recherche en cours Nos travaux de recherche actuels portent notamment :

sur l'étude, sur installation de laboratoire et sur installation pilote, du traitement anaérobie d'eaux usées urbaines à basse température (15 https://www.w3.org/1998/Math/MathML"> 25 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> )

sur la mise au point, a l'échelle pilote (300 litres) d'un procédé de méthanisation en fermenteur à lit fluidisé liquide-solide entièrement automatisé.

38. REFERENCES

"Traitement anaérobie d'effluents de brasserie. Expérimentation sur pilote en site industriel". N. MILANDE - B. RAYMOND - Séminaire des contractants AFME - Biomasse - Méthanisation - VALBONNE (1982)

"Contribution à l'étude du procédé contact anaérobie avec et sans séparation de phase. Application au traitement d'effluent de brasserie". N.MILANDE - Thèse de Docteur - Ingénieur (1983)

"Epuration du https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> contenu dans le biogaz". B. RAYMOND - N. MILANDE Séminaire contractants AFME - Biomasse - Méthanisation - ST REMY LES CHEVREUSE (1984)

"Méthanisation des effluents agro-industriels". J.Y. DEYSSON - J.M. INDART - N. MILANDE - B. RAYMOND - Journées MEI (1984)

"Méthanisation d'effluent urbain à basse température". O. ZUFFI B. RAYMOND - N.MILANDE - (1985) - En cours de publication

"Méthanisation de l'effluent de l'usine X en fermenteur à lit fluidisé" C. STREICHER - N. MLLANDE - B. RAYMOND - (1985) - En cours de publication. CLONING AND ANALYSIS OF GENES INVOLVED IN

CELLULOSE DEGRADATION BY CLOSTRIDIUM THERMOCELLUM P. BEGUIN, D. PETRE, J. MILLET, R. LONGIN, H. GIRARD, O. RAYNAUD, M. ROCANCOURT, O. GREPINET and https://www.w3.org/1998/Math/MathML"> J 0 - P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . AUBERT Institut Pasteur, Paris, France Summary Various genes of Clostridium thermocellum cod1ng for cellulases were cloned and ldentified by the expression of cellulolytic activity In Escherichla coll. For at least three of these genes, transcription and translation in E. coll appeared to be fnitiated at s1tes located on the cloned C. thermocellum DNA fragment, and two of the expressed cellulases were found to be partially transported to the periplasmic space. The endoglucanases expressed by three of the clones displayed different speciflcitles toward cellodextrins of various degrees of polymerization. Some of the clones produced actlvity hydrolyzfng methy Iumbellifery https://www.w3.org/1998/Math/MathML"> - β - c e l l o b i o s t d e ,   b u t   n o t   c a r b o x y m e t h y l c e 1 l u l o s e   w e   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are presently checking whether they correspond to genes codlng for cellobiohydrolases. One of the endoglucanase genes has been sequenced and the ortgin of the mRNA transcript determined by Sl nuclease mapplng. The sltes governing initlation of transcription and transla- tion, as well as the signal peptide allowing protein secretion appear quite similar to the corresponding structures described ln other gram-positive bacteria.

INTRODUCTION

Cellulose is the most important renewable carbon source avallable from plant blomass. Hence, 1ts conversion into products that could be used Trom p latt 1010 as petroleum substitutes for industrial chemicals or energy production has been the subject of numerous studies. Among organisms that can degrade cellulose, Clostridlum thermocellum displays several interesting features. This thermophtlic and anaerobtc bacterium secretes a highly potent and thermostable cellulase complex (1-4), which https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> able to degrade crystalline cellulose efflclently. The degradation products are subsequently fermented Into ethanol, acetıc acid, lactic acid, hydrogen and carbon dioxide, ethanol belng the component of interest for energy production (5-7). The rate of cellulose fermentation by C, thermocellum fs https://www.w3.org/1998/Math/MathML"> 11 m 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ted by the degradation rate of the insoluble substrate. When grown on cellulose, the organism has a doubling time of 6 hours, as compared to 2 hours when grown on celloblose. Yet it appears that properly englneered strains of G. thermocellum could be 1mproved considerably in this respect. Comparative studles (4) have shown that slmilar levels of cellulolytlc activity are present in culture supernatants of C. thermocel1um and strains of Tricho- derma reesef hyperproducing cellulase. However, C. thermocellum cellulase has a much higher specific activity, since C. thermocellum culture super- natant contains only https://www.w3.org/1998/Math/MathML"> 0.2 m g / m 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> protein, as compared to 9.5 mg/m. in the case of T. reesel. This high spectflc activity of C. thermocellum cellula- se should allow to reach levels of total activity exceeding those achieved by the best cellulolytic fung1, for which further improvements are limited by the sheer amount of total proteln that should be secreted. In the absence of any known mechanism of genetic transfer, classical. genetlcs in https://www.w3.org/1998/Math/MathML">   thermocellum is 1.imited to random mutagenesis. Furthermo-   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> re, it https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> quite difficult to study the various components involved in cellulose degradation individually, since cellulolytic enzymes from C. that reglons controlling cela expression have a remarkably broad speciflcity. However, comparison with the activity of the purifled enzyme https://www.w3.org/1998/Math/MathML"> ( 2,000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> units/mg protein) (1) lndlcates that, even In C. thermocellum, EGA hardly accounts for more than 1 % of the total proteln. Construction of adequate expression plasmids should allow to increase this figure by at least one order of magnitude. 39. PROPERTIES OF CLONED CELLULASES EGB and EGC have been purifled from extracts of E. coll bearlng appropriate plasmtds (11, Pétré et al., manuscript in preparation). Antiserum directed agalnst E. col1- https://www.w3.org/1998/Math/MathML"> 8 yntheslzed   EGB   was   used   to   demonstrate   - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> that the correspondtng protein was Indeed secreted by C. thermocellum Into the culture medfum, where it was Identlfied as a https://www.w3.org/1998/Math/MathML"> 66,00 0 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dalton polypeptlde the culture medfum, where it was Ldentified as a 66,000 dalton polypeptide coll-synthesized EGC is about 38,000, it appears that EGA, EGB and EGC are a11 different from the https://www.w3.org/1998/Math/MathML"> M = 83 - 94,000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> endoglucangee purffled from thermocellum culture supernatant by Ng and Zelkus (2). EGA, EGB and EGC display different enzymatic specificities toward cellodextrins of various degrees of polymerization. While EGC hydrolyzes cellotriose, cellotetraose and cellopentaose, EGB has no activity toward cellotriose, but hydrolyzes cellotetraose and cellopentaose and EGA reacts with cellopentaose, but only poorly with cellotetraose and not at all with cellotriose (Longin et al., manuscript In preparation). Efficient hydrolysis of crystalline cellulose usually requires the synergic action of endogiucanases and celloblohydrolases (14,15). The Iatter enzymes have 11ttle or no activity toward CMC (15, 16 ) and cannot be detected using the Congo red test (17), However, methylumbel1iferyl-Bcellobioside (18) and p-nitrophenyl-\beta-cellobloside (l9) have recentiy been described respectively as fluorogenic and chromogentc substrates for celloblohydrolases, and some of the clones we isolated recently display activlty toward these subtrates, but not toward CMC. We are currently checking whether any of the encoded enzymes benaves like a true cellobiohydrolase by analyzing the products of hydrolysis of varlous cellodextrins by HPLC. In addition, studles are under way to flnd out possible synergistic interactions in the hydrolysis of native cellulose by the enzymes expressed in the varlous clones. 40. SEQUENCE OF THE CELA GENE The findfng that genes from C. thermocellum could be expressed and transported to the periplasmlc space in E. coll suggested that sequences controlling gene expression and protein secretion might be conserved between these organisms. A study of the DNA sequence of the cela gene of C. thermocellum (13) Indicates that the regions controlling proteln secretion and gene expression bear close similarity to the corresponding sequences found in E. coli and B, subtilis. The amino-terminal sequence sequences found 1n https://www.w3.org/1998/Math/MathML">   E.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and and supernatant is preceded by a slgnal peptide. This peptide displays features s1m1lar to those descrtbed for other secretory protetns from grampositlve bacteria https://www.w3.org/1998/Math/MathML"> ( 20 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . It is rather long ( 32 aminoacids) and contalns 4 basic restdues among the first six aminoacids, followed by a stretch of hydrophoblc residues. Translation Ls Initiated at a GUG codon, which is preceded by an AGGAGG sequence closely matching the canonical shineDalgarno sequence complementary to the https://www.w3.org/1998/Math/MathML"> 3 t   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> end of https://www.w3.org/1998/Math/MathML"> 16   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> RNA (21). WIth regard to transcription control sites, analysls of C. thermocellum mRNA by Northern blotting and Sl nuclease mapping indicates that transcription is monocistronic and that promoter and termination sites are closely related NUCLEAR MAGNETIC RESONANCE APPLICATION IN STUDYING THE BIOLOGICAL PRODUCTION OF ETHANOL FROM SUGAR-CONTAINING MEDIA E. TIEZZI, A. LEPRI and S. ULGIATI Department of Chemistry, University of Siena, Italy Summary NMR spectroscopy has shown large application possibility for the study of biological systems. In this paper we present a C-NMR spectroscopy application to study fermentative processes of containing-sugar media in order to maximize ethanol production.

INTRODUCTION

NMR spectroscopy has been extensively used for the study of biological systems, yielding several conformational and structural features as well as the elucidation of interactions between biomacromolecular constituents https://www.w3.org/1998/Math/MathML"> ( 1,2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Morever, the high sensitivity of FT spectrometers has made possible 13 to sțudy 10 n natural abundance and low sensitivity nuclei, such as https://www.w3.org/1998/Math/MathML"> C , N , 170 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In particular the combined use of C and https://www.w3.org/1998/Math/MathML">   31 P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> NMR have allowed the study of metabolic reactions in cellular systems "in vivo", without interfering with their evolution https://www.w3.org/1998/Math/MathML"> ( 3,4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . NMR is in fact a non invasive technique, which allows the observation of metabolic reactions during their occurrence: as a consequence intermediate and final products can be detected and the kinetics of the processes and the ion transport dynamics can be studied (5). A better knowledge of fermentation processes is required for the aim of getting alcohol fuels from ligneo-cellulosic residues and thus of providing for future energetic requirements. Unfortunately 13 C-NMR spectroscopy is limited by the low natural abundance of this nucleus (only 1%): this problem can be solved by using selectively C-enriched substrates. Such a method makes it possible to follow the metabolic pathway of individual carbon atoms, allowing the elucidation of different pathways and the evaluation of intermediate and final products. In the present investigation we fixed our attention to anaerobic metabolism of sugar-containing media by a thermophilic bacterium (Clostridium thermocellum, ATCC 27405) fermenting cellulose, cellobiose and glucose and by a mesophilic yeast (Saccharomyces cerevisiae, KL-144A) fermenting glucose with high yields (6). In the first case, the mode of growing on glucose of Clostridium thermocellum and the influence of pH on the fermentative process were e- valuated; in the second case, the influence of initial glucose concentration was investigated in order to specify the conditions for the hi- ghest yield and fastest kinetics of ethanol production. Only two differences could be considered in the sample at pH=8.O (Fig. 1-b): the intermediate signal intensity decreased in respect of the previously observed values, while another signal appeared at a little higher frequency; moreover, new intense signals were appearing near 62-65 ppm, suggesting that the fermentation stopped at a different stage in that case. The resonance observed at https://www.w3.org/1998/Math/MathML"> 64.71 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> have been assigned to https://www.w3.org/1998/Math/MathML"> C 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fructose-1,6 biphosphate (5). It has been consequently possible to ascertain, in this particular case, the final point of the cathabolic pathway. Work is in progress for an exact assignment of the other resonances and for the understanding of the reasons why the fermentation stopped. b) Saccharomyces cerevisiae, strain KL-144A. The same amount of yeast https://www.w3.org/1998/Math/MathML"> ( 2 m l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has been inoculated into samples con taining https://www.w3.org/1998/Math/MathML"> 20   g / l   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (A), https://www.w3.org/1998/Math/MathML"> 85   g / l   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (B), https://www.w3.org/1998/Math/MathML"> 200   g / l   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (C), https://www.w3.org/1998/Math/MathML"> 250   g / l   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (D) and https://www.w3.org/1998/Math/MathML"> 280   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (E) of glucose in order to check the influence of the glucose concentration upon the kinetics and the final yield of the process as well as to observe the eventual appearance of inhibitory effects. Tab. https://www.w3.org/1998/Math/MathML"> n . 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> shows the evolution of the glucose metabolization process in the different samples. After three hours glucose degradation is nearly completed in the first sample, while in the last one only https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of substrate has been metabolized after 18 hours. The comparison between samples C and E suggests that adding 80 https://www.w3.org/1998/Math/MathML"> g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> results into a degradation time twice longer, suggesting partial inhibition phenomena since the first steps of the fermentation. TAB. 1 time 3 6 9 12 15 18 sample A 96.76 100.0 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> B 38.32 72.45 97.04 100.0 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C 29.01 57.51 80.16 100.0 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> D 15.69 32.66 55.80 72.21 84.63 88.50 E 14.26 31.39 46.73 63.34 76.08 81.26

Degraded substrate after N hours (%)

TAB. 2 Sample Degraded glucose https://www.w3.org/1998/Math/MathML"> ( g ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Required time https://www.w3.org/1998/Math/MathML"> ( hrs ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A 16 2.5 B 68 7 C 160 9 D 200 13.5 E 224 17

Time required for https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> glucose metabolization

Tab. n. 2 shows the situation in the samples when https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> glucose has been metabolized. Analysis of the data yields the metabolization rates of each sample, either in absolute value or in percent of the initial glucose concentration. Samples A and B have the highest metabolization rates, but they degrade a little amount of glucose in absolute value. On the contrary, the sample C degrades https://www.w3.org/1998/Math/MathML"> 17.8   g / h r s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , namely it degrades ten times more glucose than sample A in a time only 3.6 times longer, obtaining an high ethanol/degraded substrate rate. These and other data point out that https://www.w3.org/1998/Math/MathML"> 200   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the most suitable concentration of ethanol with a high degradation rate, a high conversion coefficient and in a short time, suggesting that the enzymatic system of the used strain reached the maximum of its activity. REFERENCES

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https://www.w3.org/1998/Math/MathML"> 6   S 3   J . A . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> den Hollander, T.R, Brown, K. Ugurbil, and R. G. Shulman, " C-NMR studies of anaerobic glycolysis in suspensions of yeast cells", Proc. Natl. Acad. Sci. USA, 76, 6096-6100 (1979);

J. A. den Hollander and R. G. Shulman, "H C-NMR studies of in vivo kinetic rates of metabolic processes", Tetrahedron, vol. https://www.w3.org/1998/Math/MathML"> 39   N . 21 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 3529-3538 (1983), Pergamon Press Ltd. London.

1. BASIC TRIALS TO CO-IMMOBILIZE ALGAE AND YEAST FOR THE PRODUCTION I. MOCKE and W. HARTMEIER Institute of Microbiology, RWTH Aachen, Worringer Weg, 5100 Aachen, Germany 2. SUMMARY Six alga-strains (5 symbiotic and 1 free living) were investigated for excretion of fermentable sugars. Characterization of one strain, seeming worth to be coimmobilized with a yeast to enable ethanol formation from sun light and carbon dioxide, is given. The influence of the yeast on excretion was investigated by an enzyme system (glucoamylase and glucose oxidase). 3. Introduction In the last decade, two depressions in oil supply led to a lasting shock in the world's economy. In these years, strengthened search for alternative energy sources, namely by means of biotechnology, has been started in many laboratories all over the world. Using sun light as energy for heat winning the production of ethanol from cheap raw materials or the cultivation of special energy crops are some major projects in this area. The final goal of our investigation is to enable ethanol formation from sun light and carbon dioxide by means of an immobilized system comprising sugar synthesising algae and yeast cells fermenting the sugar to ethanol. 4. MATERIALS AND METHODS organi sms Besides mesophyll cells of BETA VULGARIS above all symbiotic algae, noted for transporting C-sources to their hosts in symbiosis, were investigated. The strains, which were examined, are isted in table 1. Table i: Algae examined in this investigation. Species Strain Type resp. source of selection CHLORELLA FUSCA https://www.w3.org/1998/Math/MathML"> 219 - 8   b ⋆ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> free living alga CHI.ORELLA SACCHAROPHILA https://www.w3.org/1998/Math/MathML"> 3.80 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> phycobiont from TRAPELIA COARCTATA CHLORELLA SOROKINIANA https://www.w3.org/1998/Math/MathML"> 211 - 40 c * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> endosymbiont from SPONGILLA FLUYIATILIS CHLORELLA SPECIES https://www.w3.org/1998/Math/MathML"> 211 - 6 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> endosymbiont from PARAMECIUM BURSARIA CHL.ORELLA SPECIES https://www.w3.org/1998/Math/MathML"> 241.80 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> endosymbiont from PARAMECIUM BURSARIA CHLORELLA SPECIES PDI https://www.w3.org/1998/Math/MathML">   + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> endosymbiont from PARAMECIUM BURSARIA

obtained from Deutsche Sammlung fur Algenkulturen, D-3400 Göt inger

obtained from Dr. W. Reisser. Unsversity of Marburg. D-3550 Marburg

5. Analytical methods The first tests of fermentable sugars were made by thin-layer chromatography on silica gel or gelchromatography on Bio-Gel P2 (Bio-Rad). Quantitation of produced sugars were carried out by HPLC (Waters ALC 200) on the strong cation exchange resin Aminex HPX-87H (Bio-Rad) with a precolumn Aminex Q-150 S (Bio-Rad). The same column was used to quantitate acids. Photosynthes is Photosynthetic behaviour was followed by measuring the oxygen evolved with a CLARK-type oxygen electrode. Medium was the same as used for the determination of the excretion rates without a https://www.w3.org/1998/Math/MathML"> N - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> source (equimolar https://www.w3.org/1998/Math/MathML"> K C L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> K N O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Further conditions were: https://www.w3.org/1998/Math/MathML"> 25 ∘ C , p H 7,1 × 10 7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cel https://www.w3.org/1998/Math/MathML"> 1   s / m l , 0.015 M N a H C O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 11000 lux ( = https://www.w3.org/1998/Math/MathML"> 10.6 n E / c m 2 ⋅ s ; 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> osram https://www.w3.org/1998/Math/MathML"> L 18   W / 25 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Growth and excretion Growth and excretion measurements were carried out in a kNIESE-apparatus under following conditions: https://www.w3.org/1998/Math/MathML"> 25 ∘ C , 2 % C O 2 , 10000 l u x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( https://www.w3.org/1998/Math/MathML"> = 9.5 n E / c m 2 ⋅ s ; 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0sram L https://www.w3.org/1998/Math/MathML"> 36   W / 25 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 1 Osram Fluora 40W/77), https://www.w3.org/1998/Math/MathML"> 50 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tubes with https://www.w3.org/1998/Math/MathML"> 30 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> medium. Growth medium was as given by KUHL (1962) enriched with https://www.w3.org/1998/Math/MathML"> 1   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> proteose-pepton, https://www.w3.org/1998/Math/MathML"> 500 μ g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vitamin https://www.w3.org/1998/Math/MathML"> B 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 5 μ g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vitamin B12 per litre. Sugar excretion was investigated in the same medium, but https://www.w3.org/1998/Math/MathML"> 0.01 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> citrate buffer was used instead of phosphate buffer. To prevent shifting of the pH-value during photosynthesis, nitrate was substituted by urea as N-source. In the case of the algae-yeast coimmobilizate modelling system using glucoamylase and glucose -oxidase instead of the yeast the trials were carried out in https://www.w3.org/1998/Math/MathML"> 550 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tubes with https://www.w3.org/1998/Math/MathML"> 360 m l K U H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -medium with nitrate as N-source and under pH-control.

RESULTS With the exception of CHLORELLA FUSCA 211-8b, all algae tested were able to excrete measurable amounts of sugar (see table 2). The amount of sugar excreted being highest with the CHLORELLA strains from PARAMECIUM. These three strains were selected for further trials. At last, CHLORELLA SPEC. 241.80 has been chosen for detailed investigation.

Species Strain Sugar excreted CHLORELLA FUSCA https://www.w3.org/1998/Math/MathML"> 211 - 8   b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> none CHLORELLA SACCHAROPHILA 3.80 traces of glucose CHLORELLA SOROKINIANA https://www.w3.org/1998/Math/MathML"> 211 - 40 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> traces of glucose CHLORELLA SPECIES 211-6 glucose, maltose, maltotriose, maltotetraose CHLORELLA SPECIES 241.80 glucose, maltose, maltotriose, maltotetraose CHLORELLA SPECIES PDi glucose, maltose, maltotriose, maltotetraose BETA VULGARIS traces of saccharose organisms tested. growth https://www.w3.org/1998/Math/MathML"> > p H 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Table 3: Properties of strain 241.80 Table 3 shows some properties of the examined symbiotic alga strain 241.80. Excretion of sugars Figure 1 gives an example for sugar excretion by strain 241.80 in long time cultivation at pH 6 in urea containing medium. Fig.1: Excretion of sugars by CHLORELLA SPEC. at PH 6 The sugar excretion proceeded up to a maximal concentration of nearly 2 o in the culture medium. In the early phase, maltose was by far the main product of excretion. Approximating to a maximal value in the culture broth also considerable amounts of glucose and maltotriose appeared. The growth of the alga as well as the excretion of sugars were considerably influenced by the pH-value of the medium, by the type and ionic strength of buffer and by the nitrogen source. Figure 2 shows the pH-dependence of sugar excretion as maximal maltose excretion per day and table 4 gives the influence of thenitrogen source on excretion. https://www.w3.org/1998/Math/MathML"> F i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2: pH-dependence of daily maltose excretion rates of CHLORELLA SPEC. 241.80. Table 4: Relative sugar excretion rates in dependence of the nitrogen source Nitrogen source Relative excretion rates of maltose Ammonia 0.90 Nitrate 1.62 Urea 1.00 The best maltose excretion rates in the beginning of cultivation were https://www.w3.org/1998/Math/MathML"> 2.2   g / 1 ⋅ d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> using nitrogen free medium. With nitrogen containing media only up to https://www.w3.org/1998/Math/MathML"> 1.3   g / 1 ⋅ d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were obtained in the beginning phase. This was due to increased growth of the cells which prevented the sugars assimilated from being excreted. After some days of cultivation the sugar excretion became very similar whether or not a nitrogen source was added. In long term experiments of more than 10 days nitrogen supplementation was necessary. Nitrate was found to be the best nitrogen source with regard to sugar excretion (see table 4). With increasing maltose concentration in the culture broth the excretion of further maltose showed a saturation behaviour (see figure 1). We succeeded in reducing this product inhibition by additional application of glucoamylase and glucose oxidase. Thus, maltose and other oligomers were hydrolized to glucose by the amyloglucosidase and subsequently converted to gluconic acid by the glucose oxidase. The system of algae with additional enzymes (figure 3) can be regarded as a model of the algae/yeast coimmobilizate envisaged for forthcoming investigations. Fig. 3: Product formation with algae 6. CONCLUSIONS The alga strain found excretes fermentable sugars in an amount seeming worth to be coimmobilized with fermenting yeast, so that a system for ethanol formation from sun light and carbon dioxide could be achieved. 7. REFERENCES KUHL, A. (1962) in: Dtsche Bot. Ges. (Hrsg.), Beiträge zur Physiologie und Morphologie der Algen, 157-166; Verlag Fischer, Stuttgart. CERNICHIARI,E., MUSCATINE,L. and SMITH,D.C.(1969): Maltose excretion by the symbiotic alga of HYDRA VIRIDIS. - Proc. Roy. SOC. B 173, 557-576. ZIESENISS, E. (1982): CHLORELLA Symbiose spezif ische Synthese und Exkretion von Maltose durch CHLORELLA spec. aus PARAMECIUM BURSARIA. - Dissertation, Göttingen. ZIESENISS, E., REISSER,W. and WIESSNER,W. (1981): EVIdence of de novo synthesis of maltose by the endosymbiotic CHLORELLA from PARAMECIUM BURSARIA. Planta 153, 481-485. HARTMEIER, W. , MÜCKE, I. and DÖPPNER, T. (1984): New approaches to produce base materials by means of biotechnology. - 3.ECB München 1984, VolII 503-510; Verlag Chemie, Weinheim 1984. 8. ACKNOWLEDGEMENT This research was carried out under Research Contract no. GBI-004-D (D) of the Biomolecular Engineering Program of the Comission of the European Communities. 665USING YEAST CO-IMMOBILIZED WITH NON-YEASI GLYCOSIDASESW. HARTMEIER, U. FÖRSTER AND C. GIANIInstitute of Microbiology, Technische Hochschule Aachen, D-5100 Aachen (Fed. Rep. Germany) 9. Summary A new procedure to bind non-yeast enzymes closely around living yeast cells is described and characteristics of the co-immobilizates thus created are given. Using these biocatalysts in packed bed reactors unconventional substrates (e.g. lactose and cellobiose) could be continuously converted to ethanol. The half life of the co-immobilized biocatalysts was about three weeks. 10. Introduction Recent developments allow to combine living cells with enzymes from other cells by means of co-immobilization (Hahn-Hägerdal, 1983; Hartmeier, 1983 ). Thus, yeast cells can be enabled to ferment substrates being normally not metabolizable for these yeasts. A preferred method of co-immobilization comprises binding non-yeast enzymes to alginate and subsequent entrapping of the yeast cells with the enzyme-coupled alginate (Hägerdal and Mosbach, 1980). Typical beads of such co-immobilizates have a diameter of one to several millimeters. As an alternative to that method, we now evaluated a procedure leading to single yeast cells with additional enzymes bound closely to the cell walls. Coimmobilization of Saccharoinyces cerevisiae with B-galactosidase and Bglucosidase as non-yeast glycosidases are shown in this paper. 11. Method of Coimmobilization Yeast cells were coimmobilized with β-galactosidase from A. oryzae and with B-glucosidase (cellobiase) from A. niger according to the method schematically shown in figure 1. The yeast cells must be cautiously predried. Rehydration of these cells in an enzyme solution leads to sucking up the enzyme protein onto the cell surfaces where it gets fixed and crosslinked by the addition of tannine and glutaraldehyde. Fig. 1: Co-immobilization of yeast cells and additional enzymes. More details of the method to bind B-glucosidase and B-galactosidase to yeast cells are given elsewhere (Hartmeier, 1981; Jankovic and Hartmeier, 1982). Further entrapment of the biocatalysts into alginate matrices has been carried out in certain cases. 12. Results 12.1. Characteristics of the Coimmobilizates The enzyme envelop around the cells can be made visible by using enzyme antibodies coupled with fluorescein. Figure 2 shows a mixture of yeast cells with and witout additionally bound enzymes; on the right side of this figure the bound enzymes are to be seen by their fluorescence. Fig. 2: Native and enzyme-entrapped cells after addition of enzymeantibodies coupled with fluorescein. Table l illustrates that the viability and binding efficiency of the coimmobilized systems are considerably different from biocatalyst to biocatalyst. There is even a major influence of the specific strain of microorganism on these parameters, so that the data given in table 1 are only selected examples. Using six different strain of S. cerevisiae we found that the viability was between 20 and https://www.w3.org/1998/Math/MathML"> 93 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the remaining amyloglucosidase activity ranged between 5 and https://www.w3.org/1998/Math/MathML"> 19 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Table 1. Viability and binding efficiency of different yeast/enzyme co-immobilizates. Yeast species Non-yeast enzyme co-immobilized Enzyme source Cell viability Binding efficiency https://www.w3.org/1998/Math/MathML">   S.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cerevisiae amyloglucosidase https://www.w3.org/1998/Math/MathML">   Rh.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> niveus https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 13 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   S.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cerevisiae B-glucosidase https://www.w3.org/1998/Math/MathML">   A.   _   niqer   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   5.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cerevisiae B-galactosidase https://www.w3.org/1998/Math/MathML">   A.   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> oryzae https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 13. 3.2 Lactose Fermentation Figure 3 shows that the fermentation rate of the enzyme coated cells is considerably higher than the fermentation rate of the same biocatalysts additionally entrapped into alginate beads of 4 mm diameter. Fig. 3: Batch fermentation of lactose in a stirred tank with free and alginate-entrapped co-immobilizate. Fig. 4: Continuous lactose fermentation in a packed bed reactor. https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lactose, pH 5, https://www.w3.org/1998/Math/MathML"> 30   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A disadvantage of repeated batch fermentations using the enzyme-entrapped yeast cells freely suspended in the fermentation broth is a rapid decrease in B-galactosidase activity due to budding and shearing effects (Hartmeier et al., 1984). Apolying the cell/enzyme co-immobilizates in a packed bed equipment this problem has been overcome. Thus, volupetric productivities of up to https://www.w3.org/1998/Math/MathML"> 10   g / l *   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and dilution rates up to D= https://www.w3.org/1998/Math/MathML"> 1   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were obtained under complete use of the glucose set free from the lactose (see figure 4). Galactose remained unused due to catabolite repression. The half life of the system was about three weeks. 14. 3.3 Cellobiose Fermentation Cellulose, a major component of plant material, is available in large and renewable quantities. Therefore, utilization of cellulosic material has gained much interest. However, cellulose being destined to be a durable structure constituent of plants its breakdown to oligosaccharides and glucose is rather difficult. Enzymatic hydrolysis of cellulose is considerably inhibited by its own intermediates and namely by the end product glucose. The main purpose of this investigation was to find out if coimmobilization of the β-qlucosidase with yeast cells could increase the reaction rate of cellobiose hydrolysis as last step of cellulose breakdown. Figure 5 demonstrates that, indeed, a considerable improvement of cellobiose degradation occurs when yeast is applied in addition to the B-glucosidase. Fig. 5: Cellobiose degradation with B-glucosidase alone and with yeast co-immobilized with β-olucosidase. From figure 6 it can be derived that, depending on the amount of coimmobilizate applied, more or less quantitative conversion of the cellobiose to ethanol can be achieved. The hydrolysis of cellobiose to glucose and its conversion to ethanol is only the last step of cellulase breakdown. In order to convert nonsoluble cellulose to ethanol further procedures must be integrated into the process. Such a process could perhaps use the combined action of soluble cellulase in a membrane reactor and subsequent fermentation of the oligo- and disaccharides in a packed bed containing yeast/ β-glucosidase coimmobilizate. Fia. 6: Continuous cellobiose fermentation with co-immobilizate. 15. Conclusions Non-yeast glycosidases can be bound to yeast cells so that the substrate range of the yeast cells is enlarged. A realistic estimation whether or not co-immobilized yeast/enzyme systems are economically feasible is not yet possible. This new group of biocatalysts should be submitted to further investigation, since it sometimes opens new possibilities of synergistic action which cannot be obtained in the same extent by separately immobilized cells and enzymes. 16. References Hägerdal B, Mosbach K (1980) The production of ethanol from cellobiose using baker's yeast co-immobilized with B-glucosidase. In: Linko and Larinkari (eds), Food process engineering vol 2; Applied Science Publishers, London, pp 129-132. Hahn-Hagerdal B (1983) Co-immobilization involving cells, organelles and enzymes. In: Mattiasson (ed), Immobilized cells and organelles val 2; CRC-Press, Boca Raton, pp 79-94. Hartmeier (l98l) Basic trials on the conversion of cellulosic material to ethanol using yeast coimmobilized with cellulolytic enzymes. In: Moo-Young (ed), Advances in biotechnology vol 2; Pergamon Press, Toronto, pp 377-382. Hartmeier w (l983) Preparation, properties and possible apolication of coimmobilized biocatalysts. In: Lafferty (ed), Enzyme technology; Springer-Verlag, Berlin, pp 206-217. Hartmeier d, Jankovic E D, Forster U, Tramm-Werner 5 (1984) Ethanol formation from lactose using yeast and bacterial cells co-immobilized with B-galactosidase. In: Biotech Europe 84; Online Publications, Pinner, pp 415-426. Jankovic E D, Hartmeier W (1982) Lactosevergärende Coimmobilisate aus Hefezellen und Schimmelpilzlactase, deren Herstellung und Charakteristika. In: Dellweg (ed), 5. Symposium Technische Mikrobiologie; Verlag VLSF, Berlin, pp 377-384. 17. Acknowledgement This research was carried out under contract no. GBI-004-D (B) of the Biomolecular Engineering Program of the Commission of the European Communities. ETHANOL FROM PENTOSES AND PENTOSANS BY THERMOPHILIC AND MESOPHILIC MICROORGANISMS I. Wiege https://www.w3.org/1998/Math/MathML"> 1 * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> J , P u l s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ** *University of Georgia, Department of Microbiology, Athens Georgia 30602 USA **Institute of wood Chemistry and Chemical Technology of Wood D-2050 Hamburg 80 , Federal Republic of Germany 18. Summary The conversion of xylans and xylooligomers from wood and annual plants to ethanol by thermophilic and mesophilic anaerobic bacteria is alscussed. Although all of the investigated organisms reveal xylanolytic activity, ethanol production could be accelerated by prehydrolysis of the xylans during sterilization. 19. Introduction Processes have been developed to convert the carbohydrate portion of lignocelluloses into feedstock chemicals like ethanol. Before a microbial conversion the necessary liberation of the carbohydrates is performed by acia or enzymatic hydrolysis. Acid hydrolysis processes suffer from their low yields due to destruction of carbohydrates. Additionally the formation of de gradation products raises severe problems for the following fermentation. Enzymatic hydrolysis needs a pretreatment to make the 1Ignified Cell, wall accessible to enzymatic attack. Pretreatment can be performed by steaming at temperatures bemtween 170 to https://www.w3.org/1998/Math/MathML"> 230 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> This treatment offers the advantage of hemicellulose separation. The steaming-extraction process has been described previously in detail (1, 2). Here we report studies on the bioconversion of the hemicellulose fraction obtainea from wood by water extraction after steaming. The yeasts used in industrial proauction of ethanol canns directiv utilize xylose, xylans or cellulose to a significant degree. Also the mesophilic bacterium, Zymomonas mobilis, cannot ferment these substrates to ethanol: however, 1 t has production rates above https://www.w3.org/1998/Math/MathML"> 250   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol per liter and hour when fermenting glucose (3). During the last years several fungi and yeasts have been described which can utilize pentoses, specialiy xylose after conversion to xylulose. Most yeasts, however, produce high amounts of xylitol or significant amounts of glycerol as byproducts, thus reducing the yield of ethanol. The conversion of xylose to ethanol has been extensively reviewed by Gong (4). Utilization of XYlooligomers obtained after steaming Birchwood at https://www.w3.org/1998/Math/MathML"> 190 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> 10   m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by anaerobic thermophilic Bacteria. Chromatographic separation on Biogel P 4 and Fractogel TSK HW 50 (100 x https://www.w3.org/1998/Math/MathML"> 2,5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> each). Chemical characteristics of the hemicellulose fraction of birchwood after steaming for 10 minutes at different temperatures (expressed as % of extract dry weight) Steaming temp. https://www.w3.org/1998/Math/MathML">   0 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pH Xylose Total carbohydrates 0-Acety 1 4-0-M-\alpha-G1uA 1) 2 ) 1 ) 2 ) 3 ) 3 ) 170 4.3 38.5 0.9 58.4 10.4 6.5 0.6 3.8 0.07 180 3.8 51.3 1.5 60.8 6.5 8.5 0.58 3.3 0,05 190 3.6 53.2 4.0 64.9 10.8 8.7 0.57 1.9 0,03 200 3.6 54.5 5.9 66.4 12.3 7.8 0.5 1.5 0,02 210 3.5 48.0 13.2 58.7 22.5 7.2 0.53 0.7 0.01

after total accid hydrolysis

as monomeric sugars after steaming

per xylose unts

20. Summary 21. Introduction 22. Materials and methods 23. Table 1: Organisms and media used 677 Figure 1: Influence of cell mass on Figure 2: Fermentation curve of Sacch. cer. on molasses Figure 3: Comparison of experimental Figure 4: Computer coupling for direct biomass determination UTILIZATION OF BAMBOO FOR THE PRODUCTION OF ETHANOL T.J.B. de MENEZES; C.L.M. dos SANTOS and A. AZZINI Instituto de Tecnologia de Alimentos - ITAL 24. Summary Bamboo carbohydrates were saccharified with commercial amylolytic enzymes, and a cellulolytic broth obtained by submerged cultivation of a cellulolytic fungi. The reducing sugars released by this hidrolysis were fermented using Saccharomyces cerevisae, obtaining https://www.w3.org/1998/Math/MathML"> 160 m 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of ethanol per kg of bamboo, corresponding to a fermentation efficiency of https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the theoretical value. Although the addition of the fungal broth increased the hydrolysis efficiency, yielding a higher reducing sugar content, the majority of the bamboo components such as cellulose pentosans and lignin, were only partially solubilised. The alcohol efficiency for the fermentation of cooked and noncooked mashes was about https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 25. INTRODUCTION Within the Graminae family a fibrous plant known as bamboo comprises 45 genera and several especies scattered all over the world. The majority 45 Benera and several especies scattered all over the world. Ihe thajority conditions and types of soil in the Continent of Asia. It is also found naturaly in Japan, Thailand, Ching and in some African countries Th South maturaly in Japar, Thailand, China and in some African countries. In South America, in the northern region of Brazil, bamboo also frequently occurs naturally. The utilization of this source of biomass for the production of ethanol could be considered as an interesting alternative to other raw-materials, mainly as a substitute for wood, showing some advantages in relation to the latter such as having a higher croproductivity carbohydrate yield and lower Iignin content. B. vulgaris, harvested at 3-yearly intervals in Trinidad, showed productivity values of https://www.w3.org/1998/Math/MathML"> 20 t / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha/year of dry stems (1). In Brazil, after 4-5 years of cultivation of B.tulda production values of 90 to 120 t/ha on a wet basis have been reported (2). Most bamboo species grow very rapidly longitudinally, reaching maximum development within a few months. A growth of https://www.w3.org/1998/Math/MathML"> 120   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> within https://www.w3.org/1998/Math/MathML"> 24   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . has benn reported for the bamboo species P. bambusoides (3). Furthermore, due to its extensive radicular system, bamboo can be cultivated in lands where the topography is uneven, wich are otherwise unadaptable for technological agriculture, releasing the fertile areas for food crop cultivation. After cutting, there is no need to replant the bamboo, since it produces new shoots very easily, resulting in economy of energy an labor. In order to make the utilization of this plant feasible achieving high alcohol yield, in addition to the high crop yield of the raw-material, it is necessary to maximise the carbohydrate conversion. For this an efficient carbohydrase system must be available, and a process for the complete conversion of these carbohydrates should be developed. 2. MATERIAL AND METHODS The fungal cultures used for the production of the cellulolytic enzymes and xylanase were Basiodiomycete https://www.w3.org/1998/Math/MathML"> 50   F https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (4) and Rhisopus (5). Saccharomyces cerevisae was used to induce the alcoholic fermentation. The enzymes were prepared by submerged cultivation or using a mold bram process described previously (6). The enzymic fractions C, C and B-glucosidase were determined using the methods of Mandels and Weber (7). One Clucosidase were determined usitrg the methods of Mandels and after https://www.w3.org/1998/Math/MathML"> 24   h . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> One https://www.w3.org/1998/Math/MathML"> C x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> unit is defined as that releasing 1.0 umol giucose/min. One salicin B-glucosidase unit is defined as that releasing l umol One salicit Brgiucosidase unit is defined as that releasimg 1 umol solution to https://www.w3.org/1998/Math/MathML"> 2.5 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> larchwood xylan solution and https://www.w3.org/1998/Math/MathML"> 2.5   m 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> acetate buffer https://www.w3.org/1998/Math/MathML"> ( p H 4.0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and incubating at https://www.w3.org/1998/Math/MathML"> 509 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 15 min. One xylanase unit is defined as that amount of enzyme producing lmg of xylose in 15 min. The bamboo used in the experiment had grow for three years, its typical composition being showun in TABLE 1. Starch determinations were performed using the AOAC methods (8), pentosans by the Peter, Thaler and Taufel method (9) and the cellulose, lignin and ash by the trigol activited method (10). TABLE I. Composition of bamboo. Components https://www.w3.org/1998/Math/MathML"> g / 100   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> drymatter Starch 33 Cellulose 35 Pentosans 17 Lignin 12 Ash 3 The bamboo stalks were chopped into small pieces and the dried chips, containing about https://www.w3.org/1998/Math/MathML"> 7 - 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> moisture, were ground in a hammer mill with https://www.w3.org/1998/Math/MathML"> 0.5   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> screen. Water was added to the powder to obtain 15 to https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of solids, and about https://www.w3.org/1998/Math/MathML"> 1,250 g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the resulting slurry cooked for 30 min under a high presure in a 2 - 0 liter PARR Preaure Reaction apparatus the resulting cooked and noncooked slurries were saccharified with commercial a-amylase and glucoamylase and in some trials the cellulolytic broth was also added as Blucommylase https://www.w3.org/1998/Math/MathML"> 2 πd https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in reducing sugar as glucose by the DNS method. The rate of saccharification was estimated by the reducing sugar produced in the course of conversion. The percent saccharification was expressed as the amount of reducing sugar produced from https://www.w3.org/1998/Math/MathML"> 100 g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of carbohydrate. Cooking and gelatinization were also performed in a 301 ter reator with a 16 1iter working volume. The conditions for cooking and gelatinization were the some as before. A three vessel fermenter, each vessel with a capacity of 7.5 1iters and a working volume of 4.5 liters was used for the fermentation of the hydrolysates. Temperature and agitation controls were also provided. The noncooked but gelatinized slurry from the 30 liter fermenter was distribuited between the three vessels after the addition of the glucoamylase. Fungal broth enzymes, yeast inoculum, and nitrogen, potassium and magnesium salts were added to one of the vessels. A second, which received only the fungal broth, served as a control for the evaluation of the sugar released. In the third vessel, sterilized distilled water replaced the fungal broth, and yeast inoculum and served to evaluate the cellulose and pentosans digesting enzymes. Using a 30 iter fermenter, fermentation was also induced in a slurry previously cooked at l218C and subsequently saccharified for 48 hours. During the course of fermentation the ethanol content of the sampl Was determined from the specific gravity of the destillate and the reducing sugar produced, which was determined by the DNS method (11) feducing sugar produced, which was determined by the DNS inethod (11). After fermentation, che contents of the fermenter were removed and filtered. The recovered solids were washed, filtered and dried to constant weight, and then used for starch (8), cellulose (10) and pentosan (9) determinations The loss of weight was calculated from the difference determinations. The loss of weight was calculated from the difference between these values and the initial values, and expresses carbohydrate digestion.

RESULTS AND DISCUSSTON

In spite of the fact the addition of a misture of cellulose and hemicellulose degrading enzymes increased the rate of sugar formation in the noncooked slurry (FTGURE 1) the comversion of carbohydrates was not complete the feasibility of complete. The feasibility of alcohol production from starchy and cellulosic raw-material is dependent on the optimization of the 1iquefaction and saccharification steps. As shown in Figures 2 and 3 higher the cooking temperature, the higher the rate of sures and 3 the the rate being higher when a mixture of cellulolytic and hemicellulolytic enzymes were added. The higher values of reducing sugar at the end of https://www.w3.org/1998/Math/MathML">   s a c c h a r i f i n a t i o n ,   o b t a i n e d   w h e n   l o w e r   o o o l y n g   t h e m p e r a t u r e s   w e r e   u s e d   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> be explained by enzyme impurities in the broth or in the commercial Since the hydrolysis of cellulose is inhibited by its product a better utilization of the carbohydrate would occur if fermentation were induced simultaneous ly with hydrolysis. TABLE 2 shows that the addition of enzyme simultaneously with hydrolysis. TABLE , shows that the addition of enzyme addition of the extract. The higher consumption of starch by the enzyme contributed to the release of starch granules, which are boutnd to the contributed to the release of starch granules, which are bound to the sample which received only amylolytic enzymes (FIGURE 1 and TABLE 2) other componente were algo reduced uhich can be explanajned by the partial other components were also reduced which can be explanained by the partial solubilization of the cellulose and pentosans and the incompleted autohydrolysis on account of the exposure of the lignocellulosic material to saturated steam (12). TABLE 2 shows that the production of ethanol in the noncooked siurry saccharified simultaneously with the fermentation was https://www.w3.org/1998/Math/MathML"> 10.3   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and the fermentation efficiency was https://www.w3.org/1998/Math/MathML"> 66 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the theoretical value after 70 hr. However, after 20 hr. of fermentation the production of ethanol reached 11.8g per liter corresponding to an efficiency of https://www.w3.org/1998/Math/MathML"> 86 % . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The maximum production was achieved after 27 hours with https://www.w3.org/1998/Math/MathML"> 12.6   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of ethanol per 1 iter of wine, wich corresponds to https://www.w3.org/1998/Math/MathML"> 100 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of ethanol per kg of bamboo. Fermentation after hidrolysis produces higher ethanol yields with the cooked slurry than with the noncooked slurry. With the noncooked slurry, https://www.w3.org/1998/Math/MathML"> 100 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol were produced per kg of bamboo, whereas with the cooked slurry https://www.w3.org/1998/Math/MathML"> 160 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of ethanol were produced per kg of raw material. Although the carbohydrate conversion did not reach its maximum potential, the hydrolysis efficiency could be increased by optimization of the cooking conditions, which could favour the action of the amylolitic and cellulolytic enzymes. The yield in ethanol can also be inproved by recycling the residue to the reactor, in other to undergo a second enzymic treatment. Thus there are a number of possibilities that can be investigated in order to optmize the utilization of bamboo carbohydrates, Erom the preparation of the raw-material, to the fermentation step. The high carbohydrate content of bamboo and the other advantages already mentioned, undoubtedly justify further investigation. FIGURES 1,2 and 3 . Effect of cooking temperature and fungal broth on the rate of saccharification of bamboo slurry. Concentration of solids in the slurry between https://www.w3.org/1998/Math/MathML"> 17 - 19 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

noncooked and without fungal broth; - noncooked and with fungal broth; A-4 - noncooked and added broth with twice the activity of the cellulolytic fractions; 0-0- without cooking; https://www.w3.org/1998/Math/MathML"> x - x - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cooking at https://www.w3.org/1998/Math/MathML"> 120 ∘ C ; ◻ - ◻ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cooking at https://www.w3.org/1998/Math/MathML"> 160 ∘ C ; Δ - Δ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - cooking at https://www.w3.org/1998/Math/MathML"> 175 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Carbohydrase concentration (units/g solids): https://www.w3.org/1998/Math/MathML"> C 1 = 1.41 ; C x = 0.59 ; β https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -glucosidase https://www.w3.org/1998/Math/MathML"> = 0.27 ; xylanase = 1.42 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

26. CONTINUOUS CONVERSTON OF LACTOSE TO ETHANOL USING ZYMOMONAS MOBLLIS AND IMMOBILIZED B- GALACIOSIDASE 27. S. TRAMM - WERNER and W. HARTMEIER Institute of Mikrobiology, Technische Hochschule Aachen, Worringer Weg D 5100 Aachen (FR J ) 28. Summary B-galactosidase (lactase, EC 3.2.1.23) from Aspergillus oryzae was crosslinked with alutaraldehyde. The enzyme was used simultanuously with a new flocculent strain of Zymomonas mobilis in a special uptow floc tower reactor for continuous ethanol production from lactose. Different from the parent strain the new flocculating strain, called TW 602, could be easily retained in a specially deviced fermenter, so that a cell dry weight of https://www.w3.org/1998/Math/MathML"> 49,9   g Λ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was preserved. The specific productivity of the mutant was https://www.w3.org/1998/Math/MathML"> 4 , l g ⁡ / g × h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and therewith significantly higher than the productivity of the parent strain https://www.w3.org/1998/Math/MathML"> ( 3,2   g / g × h ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The bacterial flocs had nearly the same physical properties as the immobilized enzyme particles; both were kept back in the reactor up to a dilution rate of https://www.w3.org/1998/Math/MathML"> 5   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Using substrate with https://www.w3.org/1998/Math/MathML"> 18 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lactose, a productivity of https://www.w3.org/1998/Math/MathML"> 7   g / l × h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (based on total reactor volume) resulted. While the glucose component of the lactose was nearly completely fermented, galactose remained unused. Due to the high dilution rates, the system was not susceptible to infections under non sterile conditions. It remained stable for at least 250 hours. Besides for lactose, the system was also practicable for maltodextrin. 29. Introduction Many attempts have been made to work out a process of technical interest for ethanol production with Zymomonas mobilis. In Germany, a plant of https://www.w3.org/1998/Math/MathML"> 80   m 3 - 5 cale https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for the ethanol production from hydrolized B-starch is already in operation. For this process a volumetric productivity of https://www.w3.org/1998/Math/MathML"> 3,6   g / x h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a dilution rate of https://www.w3.org/1998/Math/MathML"> 0,06   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are reported (Bringer and Sahm, 1984). The advantages of flocculating growth characteristics have repeatedly been revealed as a method to optimize the volumetric productivity, since there is no need of filter. membranes or cell recycle to preserve high biomass concentrations (Rodriguez and Danley 1983; Strandberg et al. 1982) For industrial application it would in addition be interesting to broaden the substrate range of the organism, which can only ferment glucose, fructose and sucrose. It has recently been tried to insert the missing hydrolytic capacity by means of genetic engineering, which led only to poor fermentation rates (Goodman et al., 1984). Another possibility to add the missing hydrolizing capacity is the coimmobilization of the organism with an additional enzyme (Hägerdal 1980; Hartmeier 1981). In a preceeding investigation (Hartmeier et al. 1984) we could show that Z. mobilis coentrapped with B-galactosidase from mould origin in alginate beads can be used for the fermentation of the glucose part of lactose. However, the productivity of this system, as calculated per total fermenter volume, was considerably decreased due to the space occupied by the non-productive matrix material. The present study tries to combine the advantages of flocculating organisms and immobilized enzymes by using both for simultanuous hydrolysis and fermentation of non fermentable substrates in a special upfiow floc tower fermenter. The fermentation of lactose was chosen as a first model substrate and compared with the direct con version of glucose. 30. Material and Methods Crganism. The flocculent strain was derived by UN-mutagenesis of Z.mobilis ATCCl0988. The irradiated cells were selected for flocculation in a specially deviced upflow fermenter(fig. 3) by increasing the dilution rate continuousiy to a rate of https://www.w3.org/1998/Math/MathML"> 1   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , where only flocculating cells were kept back in the reactor. Fermentation medium and culture maintainance: see Rodriguez and Callieri (1983); instead of https://www.w3.org/1998/Math/MathML"> 100   g / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sucrose https://www.w3.org/1998/Math/MathML"> 100   g / g l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ucose , https://www.w3.org/1998/Math/MathML"> 180   g / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lactose or https://www.w3.org/1998/Math/MathML"> 100   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mal to dextrin were used. Beet molasses (from Pfeifer & Langen, Euskirchen, FRG) was diluted to a sucrose concentration of https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and supplemented with the same mineral salts as the normal fermentation media. Instead of yeast extract https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> whey powder (from Milchver sorgung Rheinland e. V. , Krefeld, FRG) were added. Continuous fermentations. Trials were started with an inoculum of https://www.w3.org/1998/Math/MathML"> 600 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with a dilution rate of https://www.w3.org/1998/Math/MathML"> 0,14   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 24 hours. The tower fermenter consisted of two parts, a cylindrical glass column with https://www.w3.org/1998/Math/MathML"> 4   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in diameter and https://www.w3.org/1998/Math/MathML"> 35   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lengh, and a settler with variable working volume. The main stream of carbon dio x ide was taken out by the inverted funnel, so that the overflow was located in a region free of turbulences and floccules; by this system a loss of bacterial flocs and enzyme particles along with the effluent was avoided. Medium and immobilized enzyme were introduced at the base, the temperature was regulated at https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by means of a water jacket, and the pH-value was kept at 4,5 by automatic addition of https://www.w3.org/1998/Math/MathML"> 1 M N a O H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The tower fermenter (see fig. 1 ) was constructed based on the experiences of Prince and Barford(1982) and Rodriguez and Callieri (1983). Immobilization of the enzyme. The hydrolases were immobilized by crosslinking with glutaraldehyde according a method of Hartmeier et al. (1984). Analytical methods. Ethanol and glucose were determined enzymatically (test set no 176290 and 716251 from Boehringer, Mannheim, FRG). Cell dry weight was determined after centrifugation, two fold washing of the cell suspension and drying at https://www.w3.org/1998/Math/MathML"> 110 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 20 hours. The B-galactosidase activity was determined on https://www.w3.org/1998/Math/MathML"> 0.5 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lactose in https://www.w3.org/1998/Math/MathML"> 0.1 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> acetate buffer of https://www.w3.org/1998/Math/MathML"> p H 4.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 10 minutes. The amount of glucose set free was determined enzymatically. 31. Results and Discussion Character istics of Z. mobilis TW 602 A compar ison of the growth and ethanol formation characteristics of Z. mobilis ATCC 10988 with those of the mutant strain Z. mobilis TW 602 is given in figures 2 and 3 . It becomes obvious from these batch experiments that the newly isolated mutant is more suitable to the require ments of ethanol production than the parent strain. Although the growth rate of the mutant at https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> glucose was lower than that of Z. mobilis ATCC https://www.w3.org/1998/Math/MathML"> 10988 0.23 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively https://www.w3.org/1998/Math/MathML"> 0.28   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the specific productivitiey of ethanol for mation was https://www.w3.org/1998/Math/MathML"> 4.1   g / g × h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These productivity data are derived from the slope of the curves (fig. 2 and fig. 3) after https://www.w3.org/1998/Math/MathML"> 16   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of batch fer mentation. Ethanol production in the tower fermenter Results of the continuous fermentation carried out with https://www.w3.org/1998/Math/MathML"> 7.5   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the immobilized B-galactosidase of Aspergillus oryzae on https://www.w3.org/1998/Math/MathML"> 18 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lactose are given in figure 4 . All the glucose set free by the enzyme was rapidly fermented by the bacteria. Hydrolysis of the lactose was obviously the rate limiting step of this system, especially because the enzyme is inhibited by the non fermentable galactose. Therefore, lactose is not at all an ideal substrate to be converted by the system presented. Nevertheless the volumetric productivity of https://www.w3.org/1998/Math/MathML"> 7   g / l ⋅ h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , reached when increasing the dilution rate to https://www.w3.org/1998/Math/MathML"> 0.33   h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , can well compete with the data found by other working groups https://www.w3.org/1998/Math/MathML"> ( 3.978   g / 1 ⋅ h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with Kluyveromyces co immobilized with B-galactosidase in alginate beads; Hägerdal, 1980). First trials with the simultanuous saccharification and fermentation (SSF) of dextrins with a system containing immobilized glucoamylase (Miles Kali Chemie, Hannover), show that this system will be even more effective, probably because the inhibiting product glucose does not accumulate (see table 1). For comparison, there are also given results on glucose-and sucrose media. Beet molasses had to be diluted to a sucrose concentration of https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , since Zymomonas did not grow well with more concentrated molasses, probably because of the mineral content (Skotnicki et al. 1984). The addition of https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> whey powder instead of yeast extract led to a https://www.w3.org/1998/Math/MathML"> 16 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> increase of the ethanol yield. It was not possible to avoid a considerable amount of unused sugar in the effluent of sucrose and molasses fermentations. Even with reduced dilution rates the carbohydrate content never fell below https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These difficulties could be caused by an in hibitory effect of ethanol on the enzymes involved in sucrose hydrolysis (Lee et al. 1981). Thus, first trials show that it might be advantageous to add immobilized invertase to improve the fermentation of sucrose. Fig 1: Upflow tower fermenter 688 Table 1: Different fermentations with Zymomonas mobilis TW 602 in the upflow floc tower fermenter. substrate concentration https://www.w3.org/1998/Math/MathML"> [ ν / 3 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dilution rate https://www.w3.org/1998/Math/MathML"> h - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> productivity https://www.w3.org/1998/Math/MathML"> [ g E t O H / 1 × h ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lactose 18 0,19 7 maltodextrin 10 0,29 9,4 molasses 5 1,00 18 sucrose 10 0,88 29,3 glucose 10 1,3 60 32. References Bringer S, Sahm H (1984) Continuous ethanol production from glucose with Zymomonas mobilis. In: 3rd Europ Congr Biotechnol vol 2. Verlag Chemie, Weinheim Deerfield Beach Basel, pp 339-343 Goodman AE, Strzelecki A T, Rogers P L (1984) Formation of ethanol from lactose by Zymomonas mobilis.J Biotechnol 1: 219-228 Högerdal B (1980) Enzymes co-immobilized with microorganisms for the microbial conversion of non metabolizable substrates. Acta Chem Scand 34; 611-613 Hartmeier W (1981) Basic trials on the conversion of cellulosic material to ethanol using yeast coimmobilized with cellulolytic enzymes. In: Moo - Young M (ed) Advances in Biotechnology vol.3. Pergamon, Toronto, pp 377-382 Hartmeier W, Förster U, Tramm Werner S (1984) Co immobilization of fermenting microorganisms and B-galactosidase for lactose fermentation. In: 3rd Europ Congr Biotechnol vol 2. Verlag Chemie, Weinheim Deerfield Beach Basel, pp 361-369 Lee K J, Skotnicki M L, Tribe D E Rogers PL (1981) The kinetics of ethanol production by Zymomonas mobilis on fructose and sucrose media. Biotechnol Lett 3: 207-2 12 Rodriguez E, Callieri D A S (1983) Conversion of sucrose to ethanol by flocculent Zymomonas sp. strain in a continuous upflow floc reactor. Europ J Appl Microbiol Biotechnol 18: 186-188 Skotnicki ML, Warr RG, Goodman A E Lee K J, Rogers P L (1984) High productivity alcohol fermentations using Zymomonas mobilis. Biochem Soc Sympos 48: 53-86 Strandberg https://www.w3.org/1998/Math/MathML"> G   W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Donaldson T L, Arcuri E f (1982) Continuous ethanol production by a flocculent strain of Zymomonas mobilis. Biotechnol Lett 4: 347-352 Acknowledgernent This research was carried out under contract no GBI 004-D (B) of the Biomolecular Engineering Program of the Commission of the European Communities. 33. Summary SGN has developed a continuous ethanol production process without external cell recycling. The work covered syrups with mineral salts, sugar beet juice, and molasses. The results obtained with the syrup and sugar beet juice have proved the feasibility of this process, low residence time and good productivity. On molasses, thanks to an aeration of 2 VVH it has been possible to maintain active cells in a reactor without having to extract them for regeneration. 34. Introduction SGN has developed a continuous sugared juice fermentation process to obtain ethanol. This process is called : "SGN Cell Concentration Process". The reactor enables SACCHAROMYCES CEREVISIAE to concentrate and in certain parts, to reach a concentration higher than 100 g/liters. This containment saves a11 cell recycling and, by giving a rapid ethanol synthesis, entails only a low residence tilie (4 to 5 hours). We have performed three types of experiments:

on syrup with a 50 liter pilot unit on sugar beet juice with a 7000 liter pilot unit on molasses with 25 and 135 liter pilot units.

35. Objectives

To determine the maximal cell concentration in the fermentor.

To determine the minimal residence time needed to consume the sucrose.

To quantify the influence of low aeration on molasses fermentation. To maintain the activity of the cell in the molasses reactor without having to regenerate them.

36. Methodology

Culture medium : sugar beet juice (120 to https://www.w3.org/1998/Math/MathML"> 160   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of sucrose), syrup (160 g/1 sucrose) or molasses (80 to https://www.w3.org/1998/Math/MathML"> 150   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of sucrose)

Strain: distillery strain of SACCHAROMYCES CEREVISIAE Isolated from industrial vessels and two strains of SACCHAROMYCES CEREVISIAE SPE.

Fermentation parameters : pH 3.2 for syrup and 4,5 for beet juice and motasses. Temperature: https://www.w3.org/1998/Math/MathML"> 32 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> For molasses : aeration flow 2 VVH Analysis

Ethanot by gas chromatography. - Sucrose by fehling method.

Biomass by dry matter and by centrifugation (%).

Bacteria by counting on microscop.

37. ResuTts NOTA For each experiment, the whole reactor was not systematicaliy used, the fermentation was of ten completed in only a part of the reactor. 38. Conclusions10 Pilot plant fermentation 50 liters syrup t mineral salts

Obtention of a maximal cell concentration of https://www.w3.org/1998/Math/MathML"> 55 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the reactor.

Determination of a minimal residence time of 3.5 hours to metaboilze the sucrose https://www.w3.org/1998/Math/MathML"> ( 160   g / l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from syrup with mineral salts.

Preservation of 99 of of the living biomass in the reactor. - Maximal reactor productivity reached: https://www.w3.org/1998/Math/MathML"> > 20   g / 1 / h . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Preindustrial (7 000 liters) beet juice

Resjdence time of 7 hours.

Relatively few contamination problems.

No biomass recycling and concentration of https://www.w3.org/1998/Math/MathML"> 40 % ( 90 - 100   g / l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yeasts in reactor.

Obtention of product at https://www.w3.org/1998/Math/MathML"> 9.5 %   V / V . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pilot plant fermentation 25 iiters molasses

An aeration (air + oxygen) of 2 VNH kept the cells confined in the reactor without the need for outside regeneration.

Maintaining active SACCHAROMYCES in the reactor for a minimum period of 10 days : https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sugar was consumed for a residence time of 4 to 5 hours, with a yield of 62 liters ethanol for https://www.w3.org/1998/Math/MathML"> 100   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of consumed sugar.

Obtention of a product at https://www.w3.org/1998/Math/MathML"> 9 %   V / V https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> during 48 hours.

Finally, the process concept enables vinasses and effluents to be processed after distillation, by methanation and/or evaporation, each process scheme being economically optimized. ACETONE BUTANOL FERMENTATION OF HYDROLYSATES OBTAINED BY ENZYMATIC HYDROLYSIS OF AGRICULTURAL LIGNOCELLULOSIC RESIDUES R. MARCHAL, M. REBELLER, F. FAYOLLE, J. POURQUIE and J.P. VANDECASTEELE Institut Français du pétrole 92506 Rueil-Malmaison (France) Summary IFP Is developping a process of conversion of lignocellulosic substrates into butanol and acetone. This process includes steam explosion pretreatment of the substrates, enzymatic hydrolysis and acetone butanol ethanol (ABE) fermentation. Present results obtained for enzymatic hydrolysis and for ABE fermentation are discussed. They show the feasibility of the general process and point out the possibilities of improvement of the overall conversion yields. 39. INTRODUCTION IFP is developping a process for enzymatic hydrolysis and acetone butanol ethanol (ABE) fermentation of cereal straw and corn stover as part of a program for the production of substituted fuels. The general scheme of the process which will be experimented on a preindustrial scale in a plant under construction at soustons in the southwest of France, is shown in Fig. 1. Some recent results regarding the steps of enzymatic hydrolysis and ABE fermentation are presented below.

RESULTS

Pretreatment is a key step for hydrolysis performance and for the economy of the process. The steam explosion pretreatment has been selected after a comparative evaluation of various techniques on the basis of cost and efficiency. The hydrolysis of lignocellulosic materials is carried out in batch conditions with the cellulase complex of T. reesei CL 847. This enzyme is produced by a batch fermentation process from a soluble substrate (lactose) (Warzywoda et al., 1983a, Warzywoda et al., 1983b). Substantial improvement of cellulase production (average enzyme titer: https://www.w3.org/1998/Math/MathML"> 22.5 F P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> units per ml ) has been recently obtained by fed batch addition of lactose (Vandecasteele and Pourquie, 1984 https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A typical hydrolysis kinetics of steam-exploded corn stover with these enzyme preparations is shown in Fig. 2. Fig. 2. Hydrolysis kinetics of steam-exploded corn stover with the Trichoderma reesei cellulase complex. Conditions: Corn stover nas been pretreated by steam explosion (21 hydmolyzed by Trichoderma reesei CL https://www.w3.org/1998/Math/MathML"> 847 c e l l u l a s e s ( 180   g / I https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (d w.) hydrolyzed by Irichoderma reesei CL 847 cellulases https://www.w3.org/1998/Math/MathML"> ( 180   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (d.W.) Of pretreated material, 10 FP units cellulase per g of substrate, so c). The sugars produced (glucose and xylose) are determined by HPLC. The sugars obtained are essentially glucose and xylose with very little cellobiose. The final sugar yield is about 34 % with respect to the initial dry matter and https://www.w3.org/1998/Math/MathML"> 55 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with respect to the potential sugars. Recent modifications in pretreatment conditions resulted in a spectacular increase of sugar yield ( 80-85 % with respect to potential sugars) using the same hydrolysis conditions as above. Hydrolysates obtained from steam-exploded materials contain inhibitory compounds which considerably hinder or block the ABE fermentation. The characterization of these inhibitors is presently studied. Simple and efficient treatments of hydrolyzates which allow their fermentation into ABE have been found. https://www.w3.org/1998/Math/MathML"> Fig . 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> shows an exemple of such a fermentation. Fig. 3. Acetone-butanol fermentation of corn stover hydrolyzates obtained after steam explosion pretreatment. Conditions : The corn stover hydrolyzate https://www.w3.org/1998/Math/MathML"> 155   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of glucose plus xylose) was supplemented with https://www.w3.org/1998/Math/MathML"> 3   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ( https://www.w3.org/1998/Math/MathML"> N H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) 50 and https://www.w3.org/1998/Math/MathML"> 3   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> corn steep liquor and sterilized after pH adjustement. The fermentation was performed at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> using C. acetobutylicum IFP 920 . As illustrated in Fig.3, xylose is commonly utilized more slowly than glucose by https://www.w3.org/1998/Math/MathML">   C. acetobutylicum   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as previously described by Ounine et al. (1983). Selection of better xylose-utilizing strains is under way and is expected to allow a significant improvement of the fermentation performance. Another point of interest is the simultaneous enzymatic hydrolysis and ABE fermentation of pretreated lignocellulosic substrates. Excellent performance for this one-step procedure has already been obtained in the case alkali-pretreated straw (Marchal et al., 1984). REFERENCES ACID HYDROLYSIS FOR THE CONVERSION OF CELLULOSIC BIOMASS TO ETHANOL JOHN PAPADOPOULOS Forest Research Institute, Terma Alkmanos Athens 11528 , GREECE 40. Summary The production of ethanol from lignocellulosic substrates requires the hydrolysis of cellulose to glucose and the fermentatlon of glucose by yeast to ethanol. In any of the lignoceliulosic to ethanol proposed processes, a11 by-products should be considered for exploitation. In order to achlve this objectlve the llgnocelluloslc substrates should be prehydrolysed for optimal recovery of the hemicellulosic components, followed by the maln hydrolysis step aiming at high glucose and lignin yields. B1rch wood was subjected to acidlc treatments with various acids, namely dilute sulfuric acid, concentrated hydrochlorlc acid and anhydrous hydrogen fluoride. For both prehydrolysts and hydrolysis with dilute sulfuric acid, signiflcant loses of xylose and glucose were obser ved as reaction time was prolonged. The optimum ylelds for xylose and glucose were 49 and 61 percent respectively. Hlgher yields of xylose and glucose were recorded, 93 and 87 percent respectively, by treating birch-wood with concentrated hydrochloric acid. Finally, hydrolysis with anhydrous hydrogen fluorlde gave the highest ylelds for xylose and glucose, 91 and 93 percent respectively. The structureal changes occuring in lignin durlng hydrolysls with the various acids were also Investigated. The HCI-11gnin residues appear to be the least condensed and the HF-IIgnin residues the least hydrolysed. 41. INTRODUCTION Renewable resources in the form of forest products and agricultural residues have long been used as raw materials by a wide varlety of industries, such as construction, pulplng, textiles and so on, Because of profected future petroletm shortages renewable reseources have gained considerable attention as an alternative source for the production of energy and chemicals. Wood as the most abundant renewable resource avallable, becomes the prime candidate for the conversion to fuel, solvents polymers, plastics, chemical intermediates and so forth (1,2). Although technologically feasible (3), the development of economically viable processes, was hindered elther by the competition of large-volume, low priced petrochemicals or the non-competative economics focused in the production of a single product. It has been suggested that in any of the lignocellulosic to ethanol proposed schemes all by-products should be considered for exploitation, for the process to be economically successful. In order to achive this objectlve, optimal recovery of all wood components should be attained (4). The purpose of this paper is to glve a systematic and comparative presentatıon of the varlous acld hydrolysis treatments of some economical interest, namely, dilute stifurlc ac1d, concentrated hydrochlorlc acid and anhydrous hydrogen fluorlde, under reaction conditions permitting optimum recovery of Abstract the carbohydratics. The classical two-stages hydrolysis processes, namely the concentrated hydrochlorlc acid and dilute sulfuric acid, are energy consuming and lead to the formation of carbohydrate decomposttion products which may hamper further biotransformations of the saccharide products to ethanol. As hydrolysis with anhydrous hydrogen fluoride takes place at amblent temperatures, the energy requirements of this process seams to be of limited tmportance. However, anhydrous hydrogen fluoride Is a toxic and expensive chemical and It should be recovered quantitatively, for the process to be economically viable. In addition, both xylose and glucose are recovered as a mixture from the hydrolysis liquor and thelr separation 18 assoctated with additional cost. 2. HYprolysis of Carbohydrates During the early stages of the development of wood hydrolysis processes, both hemicelluloses and celluloses were hydrolyzed in a single step. Because of its crystalline organization, celluloge requires more stringent conditions (high temperature or high acid concentration). Under the same conditions hemicelluloses are hydrolyzed much faster to the related momomers, followed by decomposition of the hydrolysis products. To overcome there limitations, the overall hydrolysis processes has been often deslgned as a two-step processes. For dilute sulfuric acid prehydrolysis of birch wood-meal was carried out with https://www.w3.org/1998/Math/MathML"> 0.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sulfuric acid at 1400 C, at various reaction tlmes and hydrolysis with https://www.w3.org/1998/Math/MathML"> 0.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sulfic actd at https://www.w3.org/1998/Math/MathML"> 180 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . From the figures 1 and 2 becomes apparent that under the reaction conditions employed only small. ylelds of xylose and glucose can be obtained (49 and 61 percent respectively). That https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> because at the high temperatures employed, car bohydrates degrate to products of non- saccharide nature. It seems likely that in order to achieve quantitative yields a continous hydrolysis process should be developed (4). As in any chemfcal process, the amount of solvent used, in this case dilute sulfuric acid, is of considerable importance in the overall economic of the process. A continous process wl11 require large amounts of solvent which must be recovered quantitatively. Because the hydrolysis with sulfuric acid employs very small concentrations of acid, therefore large quintities of water, its recovery should be considered as non economical. For concentrated hydrochloric acid prehydrolysls was carried out with https://www.w3.org/1998/Math/MathML"> 30 % H C l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 40 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and hydrolysis with https://www.w3.org/1998/Math/MathML"> 43 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 50 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (5). The highest ylelds for xylose and glucose were 93 and 87 percent respectively (F1gures 3 and 4). The process is characterized from the moderate temperatures used and the high acid concentrations needed. Because of such high concentrations, a recovery above https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> should be achieved for the process to be economically a recore Hydrolysis with anhydrous hydrogen fluoride was carried out in one step at ambient temperature. Quantltative ylelds of xylose and glucose were achieved in relatively short times (Flgure 5) (6). However, the process https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> assoclated with the use of an expensive and toxic solvent, which should be totally recovered and it should be probabiy considered as non economical Furthermore, the reaction products, namely xylose and glucose need to be separated. 42. RESIDUAL LIGNIN The potential from the utllization of https://www.w3.org/1998/Math/MathML"> 11 gnin https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to the overall economics of any wood hydrolysis process was recognlzed only a few year ago and since then a considerable effort has been deyoted towards the deyelopment of integrated wood conversion processes (7.). In its native form, lignin is a three dimensional, highly branched, anorphous macromolecule and appears to be insoluble in any common solvents. Although its detailed structure is not yery well defined a considerable amount of knowledge about its structure has been accumulated over the years through. biosynthetic or degradative invetigations. Since all the obtained lignin residues were Insoluble, the differences in their structural characteristics was studied on the bogls of very well defined depolymertmatton technlques. In the prem sence of acids, hydrolysis of lignin occurs resulting in the formation of lower molecular weight fragments (8). The liberated lignin fractions do not accumulate but react through self condensation to form higher molecular welght adducts. Condensation reaction of https://www.w3.org/1998/Math/MathML"> 11 gnin https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> become of particular importance since they, to a considerable extent govern further utilization of lignin in the degraded or macromoleculax form (9). The extend of 1ignln condensation was estimated by nitrobenzene oxidation whlle the differences in depolymerlzation among the yarious Ifgnin preparations were defined on the basis of the new functional groups generated and in particular, new phenolic hydroxyl groups. The extent of condensation of the l1berated lignin fractlons which as known leads to the formation of new carbon to carbon bonds can be determined indirectly by alkaline nitrobenzene oxidation. Thus the formation of new carbon-to- carbon ilnkages is followed by decrease in the yield of total aldehydes. The reaction conditions for the lsolation of the variots lignin residues were chosen so to enable optimum recovery of carbohydrates. Thus for dilute sulfuric acid, prehydrolysis was carried out with https://www.w3.org/1998/Math/MathML"> 0.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sulfuric acid at https://www.w3.org/1998/Math/MathML"> 140 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 1 hour and hydrolysis with the same acld concentration at https://www.w3.org/1998/Math/MathML"> 180 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for two hours. A two-stages hydrolysls was also employed for the treatment of birch-wood with concentrated HCI. Prehydrolysis was carrled out with https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrochlorlc acid for 90 minutes, followed by hydrolysis with https://www.w3.org/1998/Math/MathML"> 43 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> HCL at https://www.w3.org/1998/Math/MathML"> 50 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for two hours. Finally, hydrolysis with anhydrous hydrogen fluorlde was carried out in one stage at amblent temperatures for 30 minutes. Table 1 shows that HCl-Iignin resldue fs the least condensed while https://www.w3.org/1998/Math/MathML"> H 2 S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and HF https://www.w3.org/1998/Math/MathML"> 118 nin https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> residues appear to condense at about equal rates.Considering that hydrolysis with HCl and https://www.w3.org/1998/Math/MathML"> H 2 S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> results also in the release of small amounts of acid soluble low molecular weight ilgnin in the hydrolyzates (11 and 7 percent respectively,) whlle HF does not, https://www.w3.org/1998/Math/MathML"> 1 t 1   s 11 k e l y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> that HF lignin residues are the most condensed of the three. Table (expressed as molar percentage) In the presence of alkalı and elevated temperatures https://www.w3.org/1998/Math/MathML"> 11 gnin https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> depolynerizes mainly via splitting of alkyl-aryl ether linkages with subsequent formation of new phenolis hydroxyl groups. Phenolic groups can be methyla ted by dlazomethane and thelr Increase can be indirectly determined by me- Birch Wood https://www.w3.org/1998/Math/MathML"> H 2 S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lignin HC1 - lignin asuring the increase In methoxyl group. It becomes apparent from table 2 that HF-lignin shows the smallest methoxyl increase which indlcates that HF-lignin residues contain small amounts of phenolic groups. This observation combined with the lncrease of the Ph-OH groups after alkaline hydrolysis, table 3, can lead to the postulation that aryl-alkyl ether linkages are not cleaved in the presence of anhydrous hydrogen fluoride (6). In contrast, hydrolysis of these 1 inkages proceeds to a larger extent in the case of dilute sulfuric acid hydrolysis. The previous postulation is also suppoted by the molecular weight distribution curves observed, after alkaline degradation of lignin (FIgure 6),where elution profiles showed that HFwlignin residues are the most degraded. Table 2. Increase in phenollc hydroxyl as expressed by the Increase in methoxyl content after methylation. Original Methoxy1 content Methoxy1 content after methylation Methoxy1 content increase https://www.w3.org/1998/Math/MathML"> H 2 S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - lignin 16.8 34.1 18.3 https://www.w3.org/1998/Math/MathML"> H C l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> - lignin 17.3 32.5 15.2 HF - lignin 18.9 28.6 9.7 https://www.w3.org/1998/Math/MathML"> T a b l e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3. Increase in methoxyl content of the HF-1ignin residues. https://www.w3.org/1998/Math/MathML">   Methoxy1 content   28.6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Reaction time (min) 0 38.3 60 40.9 43. REFERENCES (1) COLDSTEIN, I.S. (1975). Potential for Converting Wood into. Plastics. Science 189, 847-852. (2) COLDSTEIN, I.S. (1979). Chemicals from Wood. Unasylva https://www.w3.org/1998/Math/MathML"> 33 ( 125 ) , 2 - 9 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (3) OSHIMA, H. (1965). Wood Chemistry Process Engineering Aspects Process Monograph No 11 , Noyes Development Corporation, New York, 1965. (4) COLDSTEIN, I.S. (1981). Intergrated PIants for Ghemicals from Biomass, in Organic Chemicals from Biomass, I.S. Goldstein, Ed, CRC Press, Boca Raton F.L Chap 12 . (5) PAPADOPOULOS, J. CHEN, C-L, and COLDSTEIN, I.S. (1983). Behavior of Sweetgum Wood Xylan and Lignin During Hydrolysis with Concentrated Hydrochloric Acid at Moderate Temperatures, Journal of Applied Plymer Sience, Applied Polymer Symposlum 37,631-640. (6) DEFAYE, J., GADELLE, A., PAPADOPOULOS, J. and PEDERSEN, C. (1983), Hydrogen Fluoride Saccharification of Cellulose and Lignocellulosic https://www.w3.org/1998/Math/MathML"> M a - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> terials Journal of Applied Polymer Science, Applied Polymer Symposium 37, 653-670. (7) FALKEHAG, I.S. (1975). Lignin in materia1s. Applied Polymer Science, Applied Polymer symposium 28,847-852. (8) LAI, Y.Z. and K.V. SARKANEN (1971). In "LIgnins" (K.V. Sarkanen and C. H. Ludwig, eds) Wiley-Inferscience, N.Y. Chapter 5, 185-186. (9) PAPADOPOULOS, J. (1983). Some strutural characteristics of Acid Hydrolysis tignins, in Biomass Utilization (W. Côte, ed.). Plenum Press, 299307. 701 NMR-ANALYSIS OF FERMENTATION PRODUCTS BY CLOSTRIDIUM ACETOBUTYLICUM C. ROSSI*, P. VALENTI, N. MARCHETTINI* and N. ORSI *Dipartimento di Chimica Università di Siena Istituto di Microbiologia Università di Roma 44. Summary The utilization of glucose during anaerobic fermentation of Clostridium acetobutylicum has been studied by means of carbon-13NMR resonance. When [1-13-C] enriched-glucose is used as carbon source it is possible to investigate the distribution of 13-C labelled atoms among intermediate and final products. In the wild strain we have noticed several compounds of glucose utilization as intermediate and final products in addition to acetone-butanol-ethanol (ABE). On the contrary in butanol tolerant strain PV2 only ABE and their precursors are produced.

INTRODUCTION

Recent studies pointed out that nuclear magnetic resonance (NMR) spectroscopy provides detailed information about kinetics of metabolic reactions, metabolic pathways involved in biosynthetic processes and physical chemical properties of macromolecules present as natural constituents of cell, organs and tissues https://www.w3.org/1998/Math/MathML"> ( 1 - 4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . By using proton, carbon and phosphorus nuclear magnetic resonances many different cellular events can be analyzed by means of a "non invasive technique" (5-7). Intensity, chemical shift and relaxation time NMR parameters measured "in vivo" bacterial and yeast suspensions give information about the cellular behaviour at molecular level (8). By comparing NMR results obtained on different microorganisms it has been possible to have some information about: i-the metabolic rate and the end products yielded; ii-the presence of alternative metabolic pathways of a biosynthetic process; iii-the best condition to obtain higher yield in end products. In the present report we studied by NMR approach the glucose metabolism of a wild strain of Clostridium acetobutylicum 6445 and its mutant PV2. The comparison of both glucose metabolic process and efficiency of acetone, butanol and ethanol (ABE) conversion has been used to study the metabolism of the butanol-tolerant mutant strain. In order to obtain well resolved 13C-NMR spectra, 13C-enriched substrates were used by reason of https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> natural abundance of https://www.w3.org/1998/Math/MathML"> 13 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In this way, by selective 13C-enrichment of glucose molecules, it has been possible to study the total glucose catabolism by following the distribution of the 13C labels among different carbons of intermediate and end product molecules. several metabolites not directly involved in ABE production. B) After https://www.w3.org/1998/Math/MathML"> 48 h r s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of fermentation the number of cells was the same https://www.w3.org/1998/Math/MathML"> 2 × 10 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for both strains and the only difference was in the final pH of the culture with values of https://www.w3.org/1998/Math/MathML"> p H = 3.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> P V 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> p H = 4.8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for the 6445 strain. As to the NMR spectra, the two strains (figure the 6445 strain. As to the NMR spectra, the two strains (figure 2A and 2B) still showed some differences. In fact spectrum 2A obtained from the supernatant of the wild strain still shows butyric acid NMR signal and two unidentified NMR signals at 22.65 and 38.4 ppm respectively, due to ABE alternative metabolic production. The NMR analysis of the supernatant obtained from PV2 shows only ABE NMR signal whereas only one unidentified resonance at https://www.w3.org/1998/Math/MathML"> 38.04 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is evident.

CONCLUSION The fermentation performed in a synthetic medium showed differences in glucose utilization in parent and butanol-tolerant

strains. In particular the mutant strain showed a narrower pattern of fermentation products with a higher production of butyric acid after 24 hours and of ABE products after 48 hours. These data underline the importance of NMR for the study of metabolic characteristics of the mutants and for the understanding of glucose pathway in C. acetobutylicum. Sci. USA 78, 60 (1981);

J. K. Barton, J. A. den Hollander, T. M. Lee, A. Mac Laughlin

and R,G, Shulman; Proc. Natl, Acad, Sci, USA 77, 2470 (1980)

T. Ogino, J. A. den Hollander and R. G. Shulman; Proc. Natl. Acad. Sci. USA https://www.w3.org/1998/Math/MathML"> 80 _ , 5185 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1983);

J. Gillies, K. Ugurbil, J. A. den Hollander and R. G. Shulman;

Proc. Natl. Acad. Sci. USA 78,2125 (1981); L. O. Sillerud and R. G. Shulman; Biochemistry https://www.w3.org/1998/Math/MathML"> 22 _ , 1087 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 1983 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ;

G. Monot, J. R. Martin, H. Petitdemange and R. Gay; Appl.

Environ. Microbiol. 44, 1318 (1982);

P. Valenti, P. Visca and N. Orsi; Proceedings of Third EC Conference Energy from Biomass, Poster https://www.w3.org/1998/Math/MathML"> n . 388 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1985).

Acknowledgements This work was supported by "PROGETTO FINALIZZATO ENERGETICA CNR- ENEA" Grant ENEA N. 32 . We thank Miss Anna Lusini for her technical assistence. ENZYMATIC HYDROLYSIS AND SCP PRODUCTION FROM SOLVENT DELIGNIFIED EUCALYPTUS GLOBULUS L. BIOMASS M. T. A. COLAC, https://www.w3.org/1998/Math/MathML">   ( * ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and H. PEREIRA https://www.w3.org/1998/Math/MathML">   ( * * ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (*) DTIA, LNETI - Laboratorio Nacional de Engenharia e Tecnologia Industrial (**) Centro de Estudos F1orestais, Instituto Superior de Agronomia, Lisboa Summary Eucalyptus wood was solvent delignified with the ethano1:water (1:1) system. Delignification levels of https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> residual lignin could be obtained, correspond- ing to approximately https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> delignification yield. Enzymatic hydrolysis of ethanol pulped wood was fast and presented high yields. After https://www.w3.org/1998/Math/MathML"> 72 h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of hydrolysis, approximately https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> saccharification yield was obtained in relation to total polysaccharides. Growth of Geotrichum candidum and Saccharomyces cerevisiae on the solvent treated wood substrate after enzymatic hydrolysis allowed to obtain a sCP enriched biomass with approximately https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> protein content.

INTRODUCTION

Enzymatic hydrolysis and microorganism growth on most native lignocellulosic materials can only be achieved in acceptable rates after substrate pretreatment to reduce crystallinity of cellulose, disrupt the lignin-carbohydrate complex and enhance microbial access. Different substrate pretreatments previous to enzymatic processes have been proposed and experimented, which included chemical, mechanic- al or physical-chemícal methods [1]. Wood has attracted attention as a cellulosic substrate as a result of the potential biomass availability in both forests and residues from forest opera- tions. However, cell-wall chemical organization, high lignin content and crys- tallinity of cellulose prevent wood to be considered a ready substrate for sugar utilization: wood has poor rates in enzymatic processes and effective pretreat- ments are necessary to allow acceptable conversions. Solvent pulping has recently been evaluated as an alternative to convention- al pulping as well as a substrate delignification pretreatment [2]. One of the solvent systems which has received most attention is the system ethanol:water both in uncatalised and in acidic and alkaline media [3]. Organosolv ptilps show high susceptibility to enzymatic hydrolysis, as shown by experiments with butanol [4], ethanol [3] and methanol [5] delignification. Enhancement of single-cell protein production by solvent delignification of substrate has also been shown for butanol [6]. Eucalyptus globulus L. has been previously investigated as a cellulosic substrate. Enzymatic hydrolysis of eucalypt wood showed a low saccharification rate of https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the substrate but delignification with ethanol significantly in- creased hydrolysis [7]. Also hydrolysis after sodium hydroxide treatments achieved a https://www.w3.org/1998/Math/MathML"> 33 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> saccharification rate and https://www.w3.org/1998/Math/MathML"> S C P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> production on the hydrolysis syrups with Candida spp. corresponded to 50-60% of the reducing sugars [8].

MATERIAL AND METHODS

Experiments used Eucalyptus globulus L. wood with the following chemical composition: ash https://www.w3.org/1998/Math/MathML"> 1.0 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , extractives 1.4%, lignin 23.0%, cellu1ose https://www.w3.org/1998/Math/MathML"> 57.0 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and In ethano1 pulping of eucalypt wood only delignification levels to https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> residual lignin could be attained, which correspond to delignification rates of approximately https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Table I). Delignification is accompanied by polysaccharide hydrolysis which increases with temperature: for 120 minutes pulping time, the ratio of hydrolysed hemicellulose to solubilised 1 ignin was 0.86 at 165 ac and 1.03 at 175 으. These results for the organosolv pulping behaviour of Eucalyptus globulus wood are in accordance with published work on pulping of hardwoods with uncatalyzed ethanol-water systems and without preconditionning [3,9]. TEMPERATURE PULPING TIME, MIN PULP YIELD % OF WOOD RESIDUAL LIGNIN % OF PULP 165 OC 60 79.4 18.3 120 76.0 13.3 150 64.4 11.6 180 61.1 9.8 175 OC 15 96.4 21.7 30 90.4 18.0 60 74.7 16.0 90 66.9 13.3 120 66.9 10.0 Table I - Yields and residual lignin in ethanol pulps of eucalypt wood Enzymatic hydrolysis of ethanol pulped wood was fast and increased with hydrolysis time (Table II and Figure II). After https://www.w3.org/1998/Math/MathML"> 16   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of hydrolysis, more than https://www.w3.org/1998/Math/MathML"> 500 m g / m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reducing sugars (calculated as glucose) could be obtained from all 1ignocellulosic pulps studied; after https://www.w3.org/1998/Math/MathML"> 72   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , approximately https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> saccharification yield was obtained in relation to total polysaccharides. Delignification degree did not appear to affect cellulose hydrolysis and very high yield pulps ( https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) with only https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> delignification compared favorably to pulps of luch lower residual lignin. Considering that untreated eucalypt wood showeda saccharification yield of only https://www.w3.org/1998/Math/MathML"> 10 % [ 7 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , it appears that ethanol greatly enhances enzyme access to cellulose by action on the cell-wall supramolecular structure. Growth of Geotridum candidum and Saccharomyces cerevisiae on the substrate after hydrolysis with different times was achieved in good yields and a protein enriched product could be obtained. Crude protein content of the SCP biomass was approximately https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Table III). HYDROLYSIS TIME, H REDUCING SUGARS, % OF SUBSTRATE 175 QC, 15 MIN 175 OC, 3OMIN 175 OC, 90MIN 165 OC, 120MIN 16 54.5 50.0 55.0 54.0 24 60.5 58.5 59.5 59.5 48 66.5 68.0 69.0 74.0 72 75.5 82.5 Table II - Enzymatic hydrolysis of ethanol delignified eucalypt wood Reducing sugars calculated as glucose, in % of the substrate (o.d. Figure II - Enzymatic hydrolysis of ethanol delignified pulps (Hydrolysis expressed as saccharification yields in relation to polysaccharides in substrate) Table III - Crude protein content of SCP enriched biomass

CONCLUSIONS

Ethanol-water delignification produces pulps which are highly susceptible to enzymatic hydrolysis. Saccharification yields are not related to delignification level and approximately the same polysaccharide hydrolysis could be obtained for pulps with only https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> delignification (21.7% residual 1 ignin) Growth of Geotrichum candidum and saccharomyces cerevisiae could be made on previotsly enzymatically hydrolysed substrates and crude protein content in dried SCP enriched products was approximately https://www.w3.org/1998/Math/MathML"> 40 % . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Solvent treated eticalypt wood shows interesting promises as a substrate for enzymatic hydrolysis and for production of SCP-enriched products. REFERENCES [1] MILLETT, M. A., BAKER, A. J. and SATTER, L. D., (1975), Biotechnol. & Bioeng. Symp. 5, 193-219 [2] SARKANEN, K. V., (1980), EUCEPA Symposium, Helsinki,2-5June1980, 37-5 [3] SARKANEN, K. V. (1980), in:"Progress in Biomass Conversion", Academic Press, NY, 127-145 [4] HUMPHREY, A.E., (1979), Adv. Chem. Ser. 181, 25-29 [5] SHIMIZU, K. and USAMI, K., (1978), J.Japan Wood Res. Soc. 24, 632-637 [6] BELLAMY, W. D., (1976), presented at the 33rd General Meeting of the Society for Industrial Microbiology, August17 [7] PEREIRA, H. and M.T.COLACO, (1985), Biotechn. Lett., submitted for publication [8] COSTA, M. B., (1983), in:"Producão de Novas Proteinas e Utilização de Recursos Inexplorados. 10 Simpósio Nacional", NOPROT 81 , Lisboa, 160-163 [9] GOMIDE, J. L., (1978), Ph.D. Thesis, North Carolina State University AKNOWLEDGEMENTS We aknowledge the help of Märio Filipe oliveira, Isabel Miranda and Maria Rosa Resende in experimental work and of Baptista de Sousa in manuscript preparation. ENHANCED BUTANOL-TOLERANCE IN MUTANTS OF CLOSTRIDIUM ACETOBUTYLICUM P. VALENTI, P. VISCA and N. ORSI Istituto di Microbiologia - Università di Roma "La Sapienza" P.le Aldo Moro 5 - 00185 ROMA (ITALY) 1. Summary A butanol-tolerant mutant capable of growing in the presence of https://www.w3.org/1998/Math/MathML"> 20   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of butanol was obtained from Clostridium acetobutylicum. By comparison with the parent strain this mutant also gave a higher production of solvents in synthetic medium. Its morphological analysis showed a partial block of sporulation which appeared to be completely indipendent from ABE production. 2. INTRODUCTION Clostridium acetobutylicum is an anaerobic microorganism which in fermentation cultures normally produces acids and solvents. In the first step of the fermentation process the acids are synthetized and successively the conversion of acids to neutral solvents takes place (1). The solvents produced are represented by acetone, butanol and ethanol (ABE). As carbohydrate source, C. acetobutylicum can utilize corn mash and molasses but can also produce ABE from a great variety of carbon sources. The ratio of conversion to solvents varies between 20 and https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (2). This low value of conversion is justified by the butanol toxicity and also by end-products. It is known that growth in the presence of alcohols produces a modification of cell structures and membrane associated enzyme activity (3). Fur thermore, it has been noticed that butanol produces on https://www.w3.org/1998/Math/MathML"> C . acetobutylicum   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> degeneration and lysis of swollen cigar shaped clostridial forms (4) which are associated with solvents production (5). The aim of this research was the selection of mutants of C. acetobutylicum NCIB 6445 capable of growing in higher concentrations of butanol. 3. MATERIALS AND METHODS https://www.w3.org/1998/Math/MathML">   Strain and culture condition:   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C. acetobutylicum NCIB 6445 and its butanol-tolerant derivative, PV1, were grown under stringent anaerobic condi tions in an anaerobic glove box (Forma-Scientific, Marietta, Ohio) at https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in a medium described by F. Monot et al. (2). The NCIB 6445 and PV1 strains were maintained at https://www.w3.org/1998/Math/MathML"> 4 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as freeze-dried spore preparations. Spores were activated by heat shocking at https://www.w3.org/1998/Math/MathML"> 75 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for https://www.w3.org/1998/Math/MathML"> 2 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> followed by cooling on ice before inoculation. Selection of butanol-tolerant strains: the butanol-tolerant strain PV1 was derived from wild-type C. acetobutylicum NCIB 6445 by an enrichment pro cedure. Parent str'urn cultures were inoculated under anaerobic conditions in a medium to which were added different concentrations of butanol. After 24 hours the growth was evident only in the control culture without butanol, but after 48 hours a similar optical density was obtained also in the cultu re with https://www.w3.org/1998/Math/MathML"> 10   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of butanol. This culture was transferred sequentially to fresh medium containing increasing amounts of butanol (up to 20 g/ 1 ). After the seventh transfer, a selected strain capable of growing in 20 g/ of butanol was obtained. Growth and morphology control: bacterial growth was measured in the liquid medium by optical density at https://www.w3.org/1998/Math/MathML"> 620   n m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and by dilution plating method in TGY medium (tripticase https://www.w3.org/1998/Math/MathML"> 30   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; yeast extract https://www.w3.org/1998/Math/MathML"> 20   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; glucose https://www.w3.org/1998/Math/MathML"> 5   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; agar https://www.w3.org/1998/Math/MathML"> 15   g / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). During the fermentation process samples were taken at different times and microscopically examined for morphological characterization. Analysis of solvents: acetone, butanol and ethanol were determined by gas chromatography according to Barter et al. https://www.w3.org/1998/Math/MathML"> ( 6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

RESULTS

Selection of butanol-tolerant mutants: butanol-tolerant mutants were obtained by the enrichment procedure described above. One of these mutants, strain PV1, was able to grow at the butanol concentration https://www.w3.org/1998/Math/MathML"> ( 20   g / l ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which was inhibitory to the parent strain. At the same temperature of growth https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the maximum od for PV1, at stationary phase, was higher than that obtained by the parent strain. Responce of C. acetobutylicum to butanol: fig. 1 presents results obtained with PV1 and parent strain in a medium with butanol added at different concentrations. It appears from this that the PV1 strain is more tolerant to the butanol toxicity and is able to grow up to https://www.w3.org/1998/Math/MathML"> 20   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig. 1: Growth of C. acetobutylicum 6445 (0) and PV1 ( ) in presence of dif ferent concentrations of butanol. Production of solvents in synthetic medium: the production of solvents by both strains is shown in Fig. https://www.w3.org/1998/Math/MathML"> 2 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 2   b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A B Fig. 2: Production of solvents by C. acetobutylicum 6445 (A) and PVI (B). Butanol https://www.w3.org/1998/Math/MathML"> ( 0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , aceton https://www.w3.org/1998/Math/MathML"> ( x ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , ethanol https://www.w3.org/1998/Math/MathML"> ( ◻ ) , pH ( Δ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , biomass https://www.w3.org/1998/Math/MathML"> ( 0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . It can be noticed:

the higher biomass produced by PV1 mutant strain

the lower value of pH in the culture of mutant after 18 hours

the higher concentration of solvents produced by PV1

the prolonging of the stationary phase of PV1 before the lysis. Effect of glucose concentration on production of solvents: different concentrations of glucose https://www.w3.org/1998/Math/MathML"> ( 2 % ; 4 % ; 6 % ; 8 % ; 10 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were added to the synthetic medium.

The data obtained are summarized in fig. https://www.w3.org/1998/Math/MathML"> 3 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 3 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and show that the efficiency of conversion of glucose into solvents was the same up to https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of glucose for the parent strain and up to https://www.w3.org/1998/Math/MathML"> 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of glucose for the mutant. Furthermore, the maximal production was obtained with the parent strain between 72 and 96 hours and between 24 and 48 hours for the mutant. Fig. 3: Efficiency of conversion of glucose to solvents by C. acetobutylicum 6445 (A) and by PV1 (B). Morphological characterization: the morphological aspects of both strains were monitored during batch fermentations. Significant differences in clostridial stages were not observed, but clostridial forms of mutant showed a later degradation and lysis. Moreover, the cultivation of both strains in sporulation medium (7), showed differences in the production of spores, PVI beeing partially blocked as shown in fig. https://www.w3.org/1998/Math/MathML"> 4 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 4 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig. 4a:C. acetobutylicum 6445 Fig. 4b: C. acetobutylicum PV1 4. CONCLUSIONS By successive selection in synthetic medium plus butanol it was possible to isolate a PV1 tolerant mutant strain characterized by the following properties:

a higher biomass production

a higher and faster production of solvents

a more rapid decrease of the culture pH

a later degradation and lysis of clostridial forms.

The data obtained with this mutant confirm that solvent production is connected with clostridial forms and suggest that a partial block of sporulation does not affect ABE production. 5. ACKNOWLEGMENTS We thank dr. Vito Pignatelli, dr. Quinta Tardella, Mr. Lino Di Giuseppe and Mr Franco Sturba for chemical analysis and technical assistance. This work was carried out and supported by "Progetto Finalizzato Ener getica" CNR-ENEA GRANT ENEA https://www.w3.org/1998/Math/MathML"> N ∘ 32 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 6. REFERENCES

B. Atkinson and F. Mavituna (1983): Biochemical engineering and biotechnology handbook p. 308-314. The Nature Press (USA and Canada).

F. Monot, J.R. Martin, H. Petitdemange and R. Gay (1982):Acetone and butanol production by Clostridium acetobutylicum in a synthetic medium. Appl. Environ. Microbiol. 44: 1318-1324.

M. Fletcher https://www.w3.org/1998/Math/MathML"> ( 1983 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : The effects of methanol, ethanol, propanol and butanol on bacterial attachment to surface. J. Gen. Microbiol. 129: 633-641.

A. Van der Westhuizen, D.T. Jones and D.R. Woods (1982) Autolytic activity and butanol tolerance of Clostridium acetobutylicum. Appl. Environ. Microbiol. 44: 1277-1281.

D.T. Jones, A. Van der Westhuizen, S. Long, E.R. Allcock, S.J. Reid and D.R. Woods (1982): Solvent production and morphological changes in https://www.w3.org/1998/Math/MathML"> C l o - _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stridium acetobutylicum. Appl. Environ. Microbiol. 43: 1434-1439.

J.M. Barber, F.T. Robb, J.R. Webster and D.R. Woods (1979). Bacteriocin production by Clostridium acetobutylicum in an industrial fermentation process. Appl. Environ. Microbiol. 37: 433-437.

S. Long, D.T. Jones and D.R. Woods (1984): Sporulation of Clostridium acetobutylicum P262 in a defined medium. Appl. Environ. Microbiol. 45 : 1389-1393. INFLUENCE DE LA NUTRITION AZOTEE SUR LA CROISSANCE

ET LA PRODUCTION D'HYDROCARBURES DE L'ALGUE UNICELLULAIRE BOTRYOCOCCUS BRAUNII F. BRENCKMANN, C. LARGEAU, E. CASADEVALL et C. BERKALOFF Laboratoire de Chimie Bioorganique et Organique Physique - UA CNRS 456 E.N.S.C.P, 11 , rue Pierre et Marie Curie - 75231 PARIS CEDEX 05 - FRANCE.

Laboratoire de Botanique-Cytophysiologie Végétale - LA CNRS 311

E.N.S, 24 , rue Lhomond - 75005 PARIS - FRANCE. 7. SUMMARY The influence of nitrogen nutrition on growth and hydrocarbon production of the green unicellular alga Botryococcus braunii was examined. It appears that nitrogen starvation is not an obligatory condition for a high hydrocarbon production; in fact the highest productivities were observed during exponential growth. The initial nitrate concentration allowing a maximal hydrocarbon production, from air-1ift batch cultures, was determined. 8. INTRODUCTION Grâce à un contenu élevé en hydrocarbures (1) l'algue verte unicel1ulaire Botryococcus braunii apparaît, a priori, comme un agent efficace de transformation de l'énergie solaire en énergie chimique (2,3). Dans le but d'optimiser les conditions de culture nous avons examiné, ici, I influence de la nutrition azotée sur la croissance de B. braunii et sur sa production d'hydrocarbures. 9. MATERIELS ET METHODES Une souche axénique (souche A) fournie par I'algothèque d'Austin (University of Texas) a été utilisée. La préparation des inocula ; les cultures standard (batch air-1ift) ; la détermination de la production de biomasse et du temps de doublement en phase exponentielle ; 1 analyse qualitative et quantitative des hydrocarbures ont été effectuées comme décrit précédemment https://www.w3.org/1998/Math/MathML"> ( 3,4 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> L' analyse des nitrates du milieu áté réalisée par HPLC (colonne Ionospher A Chrompack). La qualité de I"inoculum joue un rôle important dans l'évolution de la culture. Des tendances identiques, sur l influence de l'azote, ont été observées à partir de divers inocula: cependant, seules des cultures menées en parallèle à partir d'un même inoculum sont strictement comparables. 10. RESULTATS ET DISCUSSION Les courbes de croissance de B. braunii pour trois concentrations initiales différentes en nitrate et les caractéristiques de la phase exponentielle de croissance (fig. I, Iab. I) suggerent que le nitrate est https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> élément potentiellement limitant des cultures en conditions standard (NO3- https://www.w3.org/1998/Math/MathML"> 200 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). TABLEAU I - Caractéristiques de la phase exponentielle de croissance pour differentes concentrations initiales du milieu en nitrate (a). Concentration initiale https://www.w3.org/1998/Math/MathML"> N O 3 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mg/1 Durée de la phase exponentie1le (j.) Temps de doublement de la biomasse (j.) 200 (b) 6 1.88 1000 9 et https://www.w3.org/1998/Math/MathML"> + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.07 3000 9 et https://www.w3.org/1998/Math/MathML"> + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.06 (a) Moyenne de deux expériences. (b) Concentration en nitrate des cultures standard. On observe en effet que la durée de la phase exponentielle crô̂t avec 1'augmentation de la concentration initiale en nitrate du milieu. La durée de cette phase semble toutefois identique pour les deux concentrations en nitrate les plus élevées. Etant donné que les temps de doublement sont voisins, ceci indique que pour la concentration la plus élevée, le nitrate https://www.w3.org/1998/Math/MathML"> n ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est plus l' élément responsable de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> arr https://www.w3.org/1998/Math/MathML"> e ˆ t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de la phase exponentielle, arrêt qui pourrait être dû à un autre élément devenu à sont tour limitant, à moins qu'il ne https://www.w3.org/1998/Math/MathML"> s ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> agisse https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 'un métabolite rejeté dans le milieu et ayant atteint une concentration toxique. Il est important de noter que de concentrations aussi élevées que https://www.w3.org/1998/Math/MathML"> 3000 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ne sont pas inhibitrices pour la culture. Afin d'apporter la preuve formelle que https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> azote constitue bien https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> élément limitant dans les conditions de culture standard, l'évolution en fonction du temps de la concentration des nitrates du milieu a été suivie pour une durée de culture de 24 jours. Les résultats montrent (fig. II) que l"absorption des nitrates se poursuit régulierement et jusqu' a total épuisement dut milien pour 200 et https://www.w3.org/1998/Math/MathML"> 1000 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de concentration initiale Pour 200 mg/1, https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> arrêt de la phase exponentielle colncide (au temps 8 j.) avec https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> apparition de la carence en nitrate. Bien que ceci soit moins net pour https://www.w3.org/1998/Math/MathML"> 1000 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , car le nombre limité de mesures possibles n'a pas permis de déterminer avec une grande précision ni le temps d'arrêt de la phase exponentielle, ni celui de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> épuisement du milieu, on peut cependant dire aue dans ce cas les deur évènements se produícent dans la même zone de temps. Pour https://www.w3.org/1998/Math/MathML"> 3000 m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , il est bien évident que larrêt de la phase exponentielle ne résulte pas 'une carence en nitrate. A 1'issue de cette étude il est possible de dire que l azote est bien pour les conditions de culture standard le facteur limitant, https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est-a-dire celui dont lépuisement est responsable du ralentissement de la croissance. Cependant, après la disparition des nitrates qui détermine https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> arrêt de la phase exponentielle la biomasse continue encore de croittre ie poids de cette derniere atteint en effet en phase stationnaire tune valeur 2 à 3 fois plus forte qu'à la fin de la phase exponentielle. I1 est connu (5) que si la croissance est contrôeé en premier 1 ieu par la concentration dans le milieu de culture d"un élément limitant, elle subit également le contrôle de la concentration intracellulaire (quota intracellulaire) de cet élément. Le taux de croissance en phase de ralentissetnent pour des cultures limitées en azote, et la durée de cette phase de ralentissement sont fonction du quota intracellulaire en azote. Le tableau II qui rapporte les teneurs en azote de la biomasse respectivement pour la phase exponentielle et pour la phase stationnaire montre que 1 'arrêt total de la croissance intervient lorsque cette teneur s'abaisse à https://www.w3.org/1998/Math/MathML"> 1 % . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> On notera que les teneurs intracellulaires en azote, Si 1 'on considère 1 a production d'hydrocarbures (tableau V) en fonction de la concentration initiale du milieu en nitrate, il apparait que les fortes concentrations conduisent à des productions d'hydrocarbures plus élevées. Ceci provient du fait que dans ces conditions la production de biomasse est plus importante et que meme si la teneur en hydrocarbures est plus faible on obtient néanmoins, globalement, un gain en production TABLEAU V - Production d'hydrocarbures (mg/I) pour différentes concentrations injtiales du milieu en nitrate après un même temps de culture. Concentration initiale en https://www.w3.org/1998/Math/MathML"> K N O 3 ( m g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Expérience I (a) (après https://www.w3.org/1998/Math/MathML"> 34 j . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) Expérience II (a) (après https://www.w3.org/1998/Math/MathML"> 19 j . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) 200 470 234 1000 598 265 3000 592 249 Si 1'on traduit ces résultats en terme de productivité (mg. d'hydrocarbures/g. de biomasse/jour) il apparait que les productivités maximales en hydrocarbures https://www.w3.org/1998/Math/MathML"> s t   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> observent pour la phase exponentielle et sont identiques (62 mg/g/j) pour les concentrations initiales testées (pendant la duree de cette phase, l'azote n'est encore limitant pour aucune des cultures). Cette productivité baisse ensuite progressivement mais plus lentement que la productivité en biomasse. Ces résultats montrent que la synthese d'nydrocarbures est plus importante en phase de croissance active quand les nitrates sont abondants dans le milieu, mais aussi qu une carence en nitrate affecte moins la synthese des hydrocarbures que celle des autres composants de la biomasse. Ceci se traduit au cours de la phase de décélération de croissance par une augmentation de la teneur en hydrocarbures de la biomasse alors que la productivité en hydrocarbures baisse brusquement. (Un tel comportement est vraisemblablement assez général chez les microalgues pour lesquelles des accumulations de lipides en carence d https://www.w3.org/1998/Math/MathML">   ⊤ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> azote sont observées. Voir à titre d https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> exemple les données rapportées récemment (7) qui permettent de tirer les mêmes conclusions). Or, le seul chiffre significatif lorsqu' on a pour objectif la production d hydrocarbures est celui de la productivité. Il est donc important de maintenir le plus Iongtemps possible la culture en phase exponentielle de croissance (productivité maximale) et donc d'utiliser des concentrations initiales en nitrate élevées. Pour les conditions de cultures expérimentées, cette concentration est de 1'ordre de https://www.w3.org/1998/Math/MathML"> 1   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (0.01 mole) de nitrate. MAXWELL, J.R., DOUGLAS, A.G., EGLINTON, G. and Mac CORMICK, A. (1968) Phytochem. 7, 2157.

LARGEAU, C. . CASADEVALL, E, and DIF, D. (1980) Energy from Biomass p.653

CASADEVALL, E. , DIF, D., LARGEAU, C., GUDIN, C., CHAUMONT, D. and DESANTI, O. (1985) Biotechnol. Bioeng. 27 (in the press).

LARGEAU, C., CASADEVALL, E., BERKALOFF, C. and DHAMELINCOURT, P. (1980) Phytochem. 19, 1043.

DROOP, M.R. (1973) J. Phycol. 9, 264.

SHIFRIN, N.S. (1980) Ph. D. Thesis (MIT).

PIORRECK, M., BAASCH, K-M. and POHL, P. (1984) Phytochem. 23, 207. d"hydrocarbures.

11. REFERENCES Remerciements : Ce travail a été financé en partie par le programme Energie Solaire de la C.E.E. (Projet E "Energy from Biomass") contrat https://www.w3.org/1998/Math/MathML"> n ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ESE-R-022 F. INFLUENCE OF LIGHT INTENSITY ON HYDROCARBON AND TOTAL BIOMASS PRODUCTION OF BOTRYOCOCCUS BRAUNII. RELATIONSHIPS WITH PHOTOSYNTHETIC CHARACTERISTICS F. BRENCKMANN, C. LARGRAU, E. CASADEVALL, B. CORRE and C. BERKALOFF https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Laboratoire de Chimie Bioorganique et Organique Physique, UA CNRS 456, ENSCP 11 rue Pierre et Marie Curie, 75231 PARIS, Cedex 05, France Laboratoire de Botanique-Cytophysiologie Végétale, LA CNRS 311, ENS, 24 Rue Lhomond, 75005 PARIS, France Summary "Air lift" batch cultures of the hydrocarbon-rich alga Botryococcus braunii were carried out under different light intensities. The influence of illumination on total biomass, hydrocarbons, cell ultrastructure, pigments and photosynthetic activity was determined. Adjustement in light intensity provides, in this type of cultures, a large improvement in hydrocarbon production. 12. INTRODUCTION The green unicellular alga Botryococcus braunii exhibits unusually high hydrocarbon levels (I) and values as high as 44 % wre observed from laboratory cultures https://www.w3.org/1998/Math/MathML"> ( 2,3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This alga was generally considered (4) as a slow growing species (mean generation time one week); however, "air lift" cultures https://www.w3.org/1998/Math/MathML"> ( 2,3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> afford a large improvement in growth rate (generation time ca 2 days). A systematic examination of the influence of various parameters on hydrocarbon production was therefore undertaken from "air 1 ift batch cultures. In the present work we examined the influence of light intensity on the productivity and the photosynthetic characteristics of B.braunii.

MATERIALS AND METHODS

An axenic strain (strain A) supp1ied by the Austin Cu1ture Collection (University of Texas) was used in this work (It provides fairly large productivities https://www.w3.org/1998/Math/MathML"> ( 5,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under unoptimized "air lift" conditions). Air lift batch cultures were carried out, using a CHU 13 modified medium, as previously described (3). All the reported results correspond to cultures which remained axenic. Variations in biomass; determination of doubling time ; identification and quantitative analysis of hydrocarbons ; pigment analysis; measurement of https://www.w3.org/1998/Math/MathML"> O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> evolution under saturating light and Co2 ; ultrastructural examination using tramission electron microscopy were carried out as previously reported https://www.w3.org/1998/Math/MathML"> ( 3,7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Light intensity within culture vessels was determined using a LI https://www.w3.org/1998/Math/MathML"> 183   B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Quantum Radiometer Photometer, fitted with a LI https://www.w3.org/1998/Math/MathML"> 193 S B https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> spherical sensor. The quality of the inoculum, obtained by unaerated and unshaked cultures (3), is important for the evolution of the batch. Identical trends, regarding the influence of light intensity, were observed from various inocula; however, only parallel cultures started from same inoculum can be strictly compared and afford a high degree of reliability. 3. RESULTS 3.1. Biomass Biomass production strongly depends on light intensity during "air 1ift" batch cultures (continuous illumination) (Pig.I). No exponential growth is observed with I4; in fact a Iinear increase in biomass takes place, after a short lag phase, during all the experiment. An exponential growth occurs in the other cultures but the mean biomass doubling time increases lightly when light intensity is enhanced : I3 (2.1 days), I2 https://www.w3.org/1998/Math/MathML">   t h e s e   t h r e e   c u l t u r e s   a r e   t h e r e f o r e   f a t i v i n g   l o w i n g e t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> they increase considerably, especially from day 15, since il is then characterized by an important lowering in biomass while I2 and I3 are still actively growing. 3.2. Hydrocarbons Light intensity does not affect the structure of the hydrocarbons synthesized by B. braunij (mainly C27, C29 and C31 alkadienes); however large quantitative variations are noticed (Table I). The highest production and the highest hydrocarbon level relative to total biomass are achieved with I3. Under high intensity (I1) a Iarge decrease in the amount of hydrocarbons recovered from the algal biomass occurs at the end of the culture; a. Low hydrocarbon level is also obtained at this stage. With low intensity (I4) a regular but slow hydrocarbon production is observed; I4 cultures are characterized by a low hydrocarbon level. 3.3. Ce11 ultrastructure (Fig.II) I1 cells show a sma11 and disorganized chloroplast (C) with very few starch grains ; the cytoplasm contains numerous vacuoles (v) and hydrocarbon inclusions (IH); lysis or complete disorganization is observed in many cells. I2 and I3 cells exhibit a larger and more organized chloroplast containing starch grains (S); vacuoles and cytoplasmíc inclusions are still important; a large amount of external hydrocarbons (EH) is noticed in outer walls (TLS) of I3. I4 cells contain a well developed chloroplast with a high degree of organization and few starch grains: vacuoles, hydrocarbon inclusions and external hydrocarbons are less important. 3.4. Pigments I1 cultures become rapidly yellowish and a nearly complete bleaching occurs at the end of the batch, while I4 cultures are still deep green. Quantitative extraction of B. braunij pigments is difficult because of the presence of outer walls; pigment content was therefore estimated from in vivo OD meastrement at https://www.w3.org/1998/Math/MathML"> 678   n m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (ch1 a) and https://www.w3.org/1998/Math/MathML"> 655   n m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (ch1 b). With high light intensities (I1 and I2) the total amount of chl a tends to decrease during the last stages of the culture (Fig.III), especially in I1. On the contrary a continuous rise is noticed in I3 and i4. When chl a level relative to biomass is considered (Fig. IV) a maximum appears, for I1, I2 and I3, during the exponential stage ; afterwards a sharp decrease, lightly more important in I1, takes place. With I4 a high level is maintained during all the experiment. The same general features are obtained from ch1 b. In fact, for a given culture the chl a/ch1 b ratio does not significantly varies during the batch. When chl relative abundances are compared in the different cultures it appears that reduction in light intensity is associated with decrease in https://www.w3.org/1998/Math/MathML"> c h ⁡ 1 a / c h 1   b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ratio revealed by lowering in the on https://www.w3.org/1998/Math/MathML"> 678 / O D 655 r a t i o https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : I1 https://www.w3.org/1998/Math/MathML"> ( 1.32 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , I2 https://www.w3.org/1998/Math/MathML"> ( 1.22 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , I3 https://www.w3.org/1998/Math/MathML"> ( 1.13 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , I4 https://www.w3.org/1998/Math/MathML"> ( 1.08 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . On the other hand low intensity cultures (I4) are characterized by considerably higher pigment levels at any stage of the batch (Fig.IV) while only small differences are noticed between I1, I2 and I3. 12.1. Photosynthetic activity Ch1 photosynthetic capacity (O2 evolved.min https://www.w3.org/1998/Math/MathML">   - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> amount https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Chl) was determined, under saturating light (see Methods), at various stages of the batch. With I1, I2 and I3 this activity markedly decreases after day 6 (table II); on the contrary high values are always maintained in I4. For a given culture time the capacity is enhanced when light intensity is reduced. 13. DISCUSSION Light intensity plays a major role on total growth of B.braunii ; the orientation of the agal metabolism (hydrocarbon and chl levels relative to biomass) is also strongly affected. Light is limiting in I4, as shown by the lack of exponential phase and by prolonged 1inear growth. However, adaptation of B.braunil to light limitation occurs: total biomass and hydrocarbon productions after 21 days are only about three times and four times smaller, relative to I3, while energy supply was divided by five. This adaptation is more efficient for total biomass than for hydrocarbons. Adaptation to light limitation is associated with increase in chloroplast size and organization. The amount and the photosynthetic capacity of chl are also enhanced relative to Il, I2 and I3, especially during the last stages of the batch. (The former feature was generally observed https://www.w3.org/1998/Math/MathML"> ( 8,9 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> while the latter was only noticed (9) in few species). Owing to these two increases, the photosynthetic capacity of the cultures (O_{ evolved.min-11-1 of culture under saturating light) shows a } considerable enhancement in I4. Stich a property is important in view of growth under natural light : during low intensity periods the algae will build a highly efficient photosynthetic apparatus, so that a very important photosynthesis will take place as soon as the cells will be submitted to high light (photoinhibition will be then observed only if prolonged illumiration https://www.w3.org/1998/Math/MathML"> ⩾ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> I 1 occurs). A large photoinhibition takes place with Il after few days of culture; the detrimental effect of this high intensity is still more pronounced for hydrocarbon production than for total biomass. Moreover, important decream ses in biomass and hydrocarbon are observed at the end of the cultures, associated with cell lysis. Many cells exhibit also small and disorganized chloroplasts. Due to degradation by photooxidation, chl total amount and 1evel relative to biomass sharply decrease at the end of the culture; in addition low chl photosynthetic activities are achieved. Photoinhibition, however less marked, also occurs with I2. I3 is optimum both for total biomass and hydrocarbon production. In spite of the thick colony matrix surrounding B.braunii cells, this optimal value is close of the one recently reported for various unicellular algae (9). I3 affords the largest amount of hydrocarbon-rich biomass; adjustement of light intensity provides therefore an important improvement (ca x. 3) in hydrocarbon production relative to I2 (intensity generally used in previous unoptimized "air lift" batch cultures). ACKNOWLEDGMENTS. Thís work was supported by the EC solar Energy Program, Project https://www.w3.org/1998/Math/MathML"> E   ' ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Energy from biomass, contract number https://www.w3.org/1998/Math/MathML"> E S E - R - O 22   F . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure II: Transmission electron midays of culture under I1 and I4. References MAXWELL, J.R., DOUGLAS,A.C., EGLINTON, G. and MAC CORMIKC,A. (1968). Phytochem, 7, 2157. LARGEAU,C., CASADEVALL,E. and DIF,D. (1980). In Energy from Biomass (PALZ.Wh. , CHARTIER, P. and HALL,D.O. Ed), 653.

CASADEVALL, E., DIF, D., LARGEAU, C. , GUDIN,C., CHAUMONT, D. and DESANTI, 0 . (1985). Biotechnol. Bioeng. 27 (in the press).

BELCHER, J.H. (1968). Arkiv. Mikrobiol. 61, 335 .

CHIRAC, C., CASADEVALL, E. , LARGEAU, C. and METZGER,P. (1982) . C.R. ACAd. Sci. Paris, 295 III, 671.

CHIRAC, C., CASADEVALL, E. , LARGEAU, C. and METZGER,P. (1985) . J. Phycol. (in the press).

LARGEAU, C., CASADEVALL,E., BERKALOFF,C. and DHAMELINCOURT, P. (1980). Phytochem. 19, 1043. FALKOWSKI,P.G. and OWENS,T.G. (1980). Plant Physiol 66,592.

RICHARDSON,K. and BEARDALL RAVEN,J,A. (1983). New Phyto1. 93,157. SCREENING OF WILD STRAINS OF THE HYDROCARBON-RICH ALGA BOTRYOCOCCUS BRAUNII. PRODUCTIVITY AND HYDROCARBON NATURE

P. METZGER https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , E. CASADEVALL https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , A. COUTE https://www.w3.org/1998/Math/MathML">   * * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and Y. POUET https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Laboratoire de Chimie Bioorganique et Organique Physique - UA CNRS 456 E.N.S.C.P. 11, rue P. et M. Curie - 75231 PARIS CEDEX 05 - FRANCE.

Laboratoire de Cryptogamie - LA CNRS 257

Muséum Nationa1 d'Histoire Naturelle 12, rue Buffon - 75005 PARIS 14. Summary New strains of the hydrocarbon-rich microalga, Botryococcus braunii were isolated from various samples collected in Australia, France, Ivory-Coast, Morocco and West Indies. On the basis of the nature of the hydrocarbons produced, this screening establishes the existence of two races in B. braunii. Each race produces a well-defined hydrocarbon class all along the growth : straight-chain alkadienes and trienes, odd numbered from C https://www.w3.org/1998/Math/MathML">   23 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to Con (the A race) or triterpenic hydrocarbons of general formula https://www.w3.org/1998/Math/MathML"> C H 2 - 10,30 ⩽ n ⩽ 37 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , termed botryococcenes (the B race). For a same race and depending on the strain origin, variability occurs for the composition of the hydrocarbon mixture: cis-trans isomerísm and presence of trienes for the A race, various botryococcene compositions for the B race. The hy drocarbon content of these new strains (A and B races) is very high, from 20 to https://www.w3.org/1998/Math/MathML"> 52 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dry wt. With the adjustement of some factors (nitrate supply, size of the inoculum) an hydrocarbon content of https://www.w3.org/1998/Math/MathML"> 1.35   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for a 120 1. culture was obtained with a B strain cultivated under semi-protected conditions. 15. INTRODUCTION On the basis of observations carried out on samples collected in nature, some authors suggested that the colonial alga B. braunii could produce two different types of hydrocarbons at different stages of the growth (1). Unbranched 1inear alkadienes and trienes, odd-numbered from https://www.w3.org/1998/Math/MathML"> C 25 t o C 31 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> would be produced by green cells during active growth, when triterpenic hydrocarbons of general formula https://www.w3.org/1998/Math/MathML"> C n H 2 n - 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , with https://www.w3.org/1998/Math/MathML"> 30 ⩽ n ⩽ 37 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , termed botryococcenes would originate from orange resting state cells. Up to now the strains available from culture collections derive from a same sampling (Scotland); whatever growth state, they produce only alkadíenes. The present screening was undertaken from wild samples so as to isolate botryococcene-producing strains and to test the productivity of new strains grown in laboratory. MATERIAL AND METHODS The origins of the samples are given in tables I, II and III. When sampling was performed during blooms, enough biomass was obtained to analyze directly hydrocarbon content (Australia, West Indies and France - Sanguinet; B.braunii colonies accounted for more 90 % of the biomass). When colonies were in too Iow number relatively to the whole phytoplankton of the sampling, only isolation (on agarized cHU 13 medium and culture were carried out (2) (Ivory-Coast, France-Morvan and Morocco strains) . Isolation of unialgal and fungus free b. braunii colonies fell with the Australian and Sanguinet samples. The composition of the culture medium, the batch air-lift conditions, the determination of biomass concentration, the extraction and the purification of hydrocarbons and their GC/MS analyses have been previously des- For the 1201 cultures, an aquarium of the following dimensions was employed: width https://www.w3.org/1998/Math/MathML"> 0.2   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , length https://www.w3.org/1998/Math/MathML"> 1.3   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , height https://www.w3.org/1998/Math/MathML"> 0.6   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Aeration vas performed with air-1 % https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Elltered on Millipore prefilter, at a rate of 10 I.h per liter of medium; temperature https://www.w3.org/1998/Math/MathML"> 27 ∘ ± 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; continuous illumination 16. RESULTS AND DISCUSSION 1 - Considering the type of compounds up to now produced in laboratory cultures, the algae were separated into two categories : those yielding botryococcenes (table II) and those yielding unbranched alkadienes (table III). No variation of the hydrocarbon type was observed neither along the growth, nor in resting state. Moreover, West Indies strains continue to produce botryococcenes, as in nature (table I). So it must be concluded that two races of B. brauni1 exist, each synthesizing a well-defined type 2 - For a same race, some variabilities in hydrocarbon composition were observed, depending on the strain origin, both in nature (table I) and in laboratory culture (tables II and III). For the A race, table III, the Grosbois strain showed the particularity to synthesize, beside cis alkadienes, trans isomers never detected up to day in B. braunii extracts (isomerism occurs on the double bond located into the chain), when the other strains produced only cis hydrocarbons: number and amount of trienes depended also on the strain origin. For the B race a very large variability was observed. So the West Indies strains produced https://www.w3.org/1998/Math/MathML"> C 33 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C 34 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrocarbons in nature (table I) when they yielded essential1y C https://www.w3.org/1998/Math/MathML">   34 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrocarbons in laboratory cultures (table II); the Ivory-Coast strain exhibited a predominance of https://www.w3.org/1998/Math/MathML"> C 3 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C 33 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrocarbons in laboratory culture. Then, it appears that for a same race, different genetical populations exist and at the least for the B race, that physicochemical factors are also at the origin of chemical variations. 3 - After three weeks of growth and with the same culture conditions, the Ivory-Coast and Morocco strains gave the highest biomass production. Nevertheless, the Martinique strain was the most productive (1.O5 g of hydrocarbons/1), with a level near https://www.w3.org/1998/Math/MathML"> 38 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dry wt. value similar to those noticed for collected samples in this study and by most of the authors (3). 4 - The relative slow growth of B. braunii (mean doubling time of 2. 3 days for the two races (2), during the exponential phase), and thereafter an unfavoumble concurrence in open air of fast growing microorganisms drocarbon producer (4). of hydrocarbons. https://www.w3.org/1998/Math/MathML">   * n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .i. : compounds not identified owing to a poor resolution of the GC peaks ; nevertheless their retention times are different from those of alkadienes and trienes. TABLE IV - Growth of a botryococcene-producing strain for a 1201 culture in a batch air-lift system (semi-protected conditions). Hydrocarbon production and content. Cu1ture duration (days) Extra https://www.w3.org/1998/Math/MathML"> K N O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> supply https://www.w3.org/1998/Math/MathML"> m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Dry biomass https://www.w3.org/1998/Math/MathML"> m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Botryococcenes https://www.w3.org/1998/Math/MathML"> m g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> % of dry wt. 0 * 343 1 428 116 27 3 782 282 36 6 100 1347 443 33 8 1740 660 38 10 200 2155 812 38 13 200 2800 1110 40 15 3000 1350 45 * % of dry wt. 0 * 343 1 428 116 27 3 782 282 36 6 100 1347 443 33 8 1740 660 38 10 200 2155 812 38 13 200 2800 1110 40 15 3000 1350 45 * Initial concentration https://www.w3.org/1998/Math/MathML"> 200 m g / 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> \begin{abstract}In sharp contrast, data concerning the culture of the most productive strain (La Manzo) in a 1201 system are very promising for its culture in semi-protected conditions. In a first experiment, the culture was conducted from a low initial biomass concentration (50 mg/1), and without extra nitrate supply. In these conditions, contamination of the culture medium by blue-green algae and Chlorella appeared detrimental after a six week period (hydrocarbon production: https://www.w3.org/1998/Math/MathML"> 0.5   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The second experiment (table IV) was initiated with an high biomass concentration in the inoculum (initial biomass of the culture: https://www.w3.org/1998/Math/MathML"> 0.34   g / 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and nitrate was added when the medium was depleted. So, contaminations were negligible and a content of https://www.w3.org/1998/Math/MathML"> 1.35   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of botryococcenes per liter of culture could be achieved after 15 days (biomass concentration https://www.w3.org/1998/Math/MathML"> 3.0   g / 1 ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrocarbon level https://www.w3.org/1998/Math/MathML"> 45 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). An exponential phase was observed up to 4 days with a mean doubling time in biomass of c.a 2.5 days; then the growth was linear up to 13 days. The screening of B. braunii wild samples has demonstrated that this alga consists of two physiological races, each producing either alkadienes or botryococcenes. The two races exhibit a very large chemical variability, depending on the geographical origin of the samples. Moreover recent developments show that other new strains can produce compounds as different as long chain fatty alcohols or polyterpene derivatives. This variability could broaden the use of the algae as new material and oil producers. Concerning the possibility of growing B. braunii in view Lo economical prospects, the results obtained in laboratory with a 120 batch air-lift system show that B. braunii culture in open air is not

BROWN A, C , KNIGHTS B.A, and CONWAY E, Hydrocarbon content and its relationship to physiological state in the green alga B. braunii (1969) Phytochem. 8,543-547.

METZGER P., BERKALOFF C., CASADEVALL E. and COUTE A, accepted for publication in Phytochemistry (1985).

WAKE L.V. and HILLEN L.W, Nature and hydrocarbon content of bIooms of the alga B. braunii occuring in Australian freshwater lakes, (1981) Aust. J. Mar. Freshwater Res. 32, 353-367.

WOLF F.R., B. braunii an unusual hydrocarbon-producing alga (1983) App1. Biochem and Biotechn. https://www.w3.org/1998/Math/MathML"> 8 _ , 249 - 260 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> \end{abstract}

CONCLUSION

17. REFERENCES CHROMATOGRAPHIC STUDIES OF CRUDE OILS FROM WOOD D. MEIER, R. DORRING and O. FAIX Federal Research Center for Forestry and Forest Products, Institute of Wood Chemistry and Chemi cal Technology of Wood Abstract Summary Product oils derived from the direct thermochemical conversion of wood have been analyzed and tharacterized using one liquid and two gas chromatographic methods. High Performance Gel Permeation Chromatography (HPGPC) was applied to achieve a separation according to molecular size. Capillary gas chromatography was used for the separation and quantification of single components in the crude oil. A packed column was used to determine the boiling point distribution. All methods applied turned out to be suitable for the chemi cal comparison of oils fror. different feedstocks and processes. \begin{abstract}1. INTRODUCTIONWood can be converted to an oil using reducing gases (carbon monoxide, hydrogen), high temperatures and pressures as well as suitable catalysts. The product oil is always a complex mixture of degradation products of the different wood components: cellulose, hemicelluloses and lignin. The most common methods used to characterize biomass or fractions of them have been GC/FID or GC/MS (1-3). SESC-fractionation and gel permeation chromatography have only been used to a less extent (4). No standard methods are available for the characterization of the biomass oils. Hence, the results of different working groups are difficult to compare. Therefore, in this study three chromatographic methods, from which one works in the liquid phase and two in the gas phase, were studied to improve the chemical characterization of product oils from biomass feedstocks.\end{abstract} 2. LIQUID CHROMATOGRAPHY The effectivity of the thermochemi cal treatment of biomass can be measured by the determination of the molecular weight (MWt) distribution of the oil produced. The lower the molecular weight the better the degree of degradation which is an important parameter for the further processing of the oil. Figure I shows the MWT's of different biomass oils which were produced under the same conditions and demonstrates the influence of the starting material. 18. GAS CHROMATOGRAPHY High resolution capillary gas chromatograph (HRGC) is a very suitable method to separate and quantify single components of oil fractions. Figure II demonstrates the separation of the phenolic fraction of two biomass oils. The chromatographic data of the reference phenols can be used to calculate the amounts of each component. A packed GC column was used to detemine the boiling point distribution according to ASTM-method D 2887-73. This method, primary developed for the analysis of petroleurr products, has been proven in this study to be also practicable for oils from biomass. An example is shown in Figure III, where the influence of different catalysts on the boiling point distribution curve is demonstrated. 19. ACKNOWLEDGEMENT This work was financially supported by the Federal Ministry of Food, Agriculture and Forestry, project number 81 NR 006. 20. REFERENCES (1) RUSSELL, J.A., MOLTON, P.M. and LANDSMAN, S.D. (1983). Chemi cal comparisons of liquid fuel produced by thermochemi cal liquefaction of various biomass materials. Alternat. Energy Sources 1980,3,307. (2) SCHIRMER, R.E., PAHL, T.R. and ELLIOTT, D.C. (1984). Analysis of thermochemi cally-derived wood oil. Fuel ,63,368. (3) BOOCOCK, D.G.B., KALLURY, R.K.M.R. and TIDWELL, T.T.(1983). Analysis of oil fractions derived from hydrogenation of aspen wood. Anal. Chem. , 55, 1689. (4) DAVIS, H.G. (1983). Direct liquefaction of biomass, final report and summary of effort 1977 - 1983. Lawrence Berkely Laboratory, LBL16243. Figure I Standardized MWt-distribution curves of oils from different lignocellulosic feedstocks Figure II Capillary gas chromatograms of phenolic reference substances and phenols of the oils from straw and lignin Figure III Influence of catalysts on the boiling point distribution curves of oils from beech wood which were produced under similar reaction conditions METHYL ESTERS OF TALLON AS A DIESEL COMPONENT D.W. RICFIARDSON, R.J. JOYCE, T.A. LISTER and D.F.S. NATUSCH Liquid Fuels Trust Board, hellington, New Zealand Sumary A series of investigations has been undertaken to assess the viability of including the methyl esters of tallow as a camponent of New Zealand's diesel fuel. The investigations show that there is a surplus of tallow available for this use; that the monoglyceride content of the resulting ester must be Iimited to very low concentrations; and that the fuel properties of a 10 q v/v blend are essentially the same as those of the diesel component of the blend. The costs of producing tallow methyl esters as a blendstock are considered to be comparable to those for the production of conventional diesel fuel. provided that a large scale esterifica- tion plant is established and that a good return is received for the co-produced glycerol Preliminary engine test results indicate that https://www.w3.org/1998/Math/MathML"> 10 o f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 20 o g v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blends will perform as well as neat diesel fuel, but endurance testing and lubricant quality aspects are yet to be determined. The ignition quality of blends is significantly better than that of diesel. overall it would appear that the use of tallow methyl esters as a diesel extender, at https://www.w3.org/1998/Math/MathML"> 108 v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the diesel, could be attractive in countries where large amounts of tallow are produced and where cold temperatures (less than - 10 degrees C) are not encountered.

INTRODUCTION

The production and use of alternative diesel fuels is particularly pertinent to New zealand since, to date, all the alternative fuels which have been intraduced (CNG, LPG ana Mobil synthetic petrol) are essenti- ally petrol alternatives. Thus there is a potential imbalance between the supply of fuels for refined petrol and diesel. A great deal of attention has been given, worldwide, to the possi- bility of using plant oils and animal fats as diesel fuel replacements or extenders. Such usage is seen to be attractive in many countries because these materials are locally available and are an essentially renewable resource. Because New Zealand's agriculture is largely based on animal production (meat and wool) rather than on crop production, animal fats are the only significant triglyceride resource available for potential use as a diesel substitute or extender. In order to establish the feasibility of utilising tallow to extend diesel supplies, the Liquid Fuels Trust Board has implemented a pro- gramne designed to:

Establish the availability of tallow.

Identify an appropriate technology for the esterification of 2. Identify an appropriate technology for the esterification oftallow. 3. Define the performance characteristics of diesel engines fuelled with tallow ester/diesel blends.

Identify strategies for the introduction of tallow esters into the nation's diesel supply.

The results of this programme, which is due for completion in 1986 , are discussed in the following sections. New Zealand currently exports about 85,000 tonnes of inedible tallow per annum. This is equivalent to about 7 of of the current national automotive gas oil demand. Improvements in tallow recovery methods and an increase in the proportion of trimed meat produced by the meat processing industry, is expected to increase the available inedible tallow to about https://www.w3.org/1998/Math/MathML"> 12 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the equivalent diesel demand by the end There are eight identifiable grades of tallow produced in New Zealana. These are: edible tallow margarine grade tallow, three bleachable inedible tallows, and three unbleachable inedible tallows (1). The bulk of the inedible tallows, which are the tallows most likely to be utilised for tallow ester production, are produced in three grades (two bleachable and one unbleachable), amounting to about 80 웡 of These inedible tallows, in aggregate, have weighted averages of 3.3% Free Fatty Acids; 0.98 unsaponifiables; and an Iodine value of 47. These are suitable qualities for esterification. 21. PRODUCTION OF TALLOW ESTERS The process chosen for the production of tallow methyl esters can be divided into a number of steps. The raw tallow is first treated with sodium hydroxide solution to neutralise the free fatty acids which are then removed by centrifuging. A two stage base catalysed esterification process, with glycerol removal at the end of each stage, is then carried out. Dry ingredients are used and the reaction is carried out at methanol reflux temperature. Ax excess of methanol is used. The crude ester product is heated under vacuum to remove the excess methanol, which is then recycled. The product is then washed three times to remove water soluble contaminants (glycerol, catalyst residues, soaps, and methanol). It is then bleached, with an acid activated Fuller's earth to remove mono and diglycerides, colouring matter, and some of the unsaponifiables. The product is finally filtered and sent to store. The mono and diglyceride content of the finished ester is The resulting crude glycerol by-product is then processed to remove water, methanol and other contaminants. Production cost estimates (2) have been developed for two plant sizes; a 1,000 litre/hour plant annexed to an existing meat works, and a 10,000 litre/hour centralised plant in a stand alone configuration. 22. THE TAILLOW RESOURCE

1 TALICO PRODUCTION of this decade (1).

23. 2.2 TALLON QUALITY 24. 3.2 PRODUCTION COSTS Capital costs are estimated to be NZ$4.7 and NZ$17.4 million respectively * The capital and operating costs of production fram these plants, including a glycerol by-product creait, are shown in Table I. To be competitive with diesel fuel costs (NZS510/te) the delivered cost of tallow must be less than NZS325 ana NZS525/tonne respectively. All the above costs are in 1983 dollars. It is apparent from these figures that only the larger plant could produce tallow methyl esters at a cost competitive with that of diesel. Furthermore it is clear that the economic viability of tallow ester manufacture depends critically on the value of the by-product glycerol. Tallow prices are however not stable and long term averages will probably need to be used to measure the viability of the use of esters as diesel extenders. 25. PROPERTIES OF TALLOW ESTER/DIESEL BLENDS

1 PROPERTIES OF TATIOM ESTERS

Table I lists typical inspection data from six batches of tallow ester. The concentrations of water, methanol, alkali metals and monoglyceride content were specified at maxima of https://www.w3.org/1998/Math/MathML"> 0.1 % , 0.18,1.0 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and https://www.w3.org/1998/Math/MathML"> 0.05 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively. 25.1. PROPERTIES OF TALION ESTER/DIESEL BLENDS Table I also lists the inspection data of the esters with a typical winter grade diesel fuel and with 10 of and 20 of v/v blend of ester in diesel fuel (3). Blend volatility, low temperature properties and stability are discussed below. 4.2.1 volatility The distillation data (3) of the ester/diesel blend demonstrates the bulking effect that the ester has on the diesel. Thermogravimetric analysis (4) of both the ester and the blend demonstrates that there is a gradual but continuous loss of residue, to approximately zero, with rising temperature (to 300 degrees C ). These analyses suggest that long term crankcase lubricating oil dilution and general engine fouling coula occur (4). 4.2.2 Low temperature properties. The low temperature properties of the blends (3), as indicated by Cloud Point and Cold Filter Plugging Point, are concentration dependant. These inspection data are given in Table III. 4.2.3 Blend clarity. The initial samples of ester used in blending tests were not limited in monoglyceride content. Since monoglycerides are only sparingly soluble in diesel fuel they precipitate if present at concentrations greater than about 0.0058 monoglyceride in the ester/ diesel blend (5). [Bleaching the ester with acid activated Fuller's earth reduces the monoglyceride content of the ester to less than https://www.w3.org/1998/Math/MathML"> 0.05 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> w / w ( 6 ) ⋅ ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4.2.4 Blend stability. Tests are currently under way to determine appropriate concentrations of anti-oxidant, biocide and low temperature flow improvers which will enable stored blends to achieve similar storage properties to those of conventional diesel fuel. 5. ENGINE TESTING

I COMBUSTION PERFOKMANCE OF BLENDS

5.1.1 Cetane number. The cetane number (ignition delay) of the neat tallow esters and of https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 20 % v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blends of ester in diesel fuel have been measured using a single cylinder version of the Perkins 4.236 engine (4). The results are shown in Table IV. An improvement in ignition delay is apparent. 5.1.2 Cylinder pressure analysis. The improved ignition delay associated with ester/diesel blends results in a reduction in the rate of pressure rise within the cylinder. This leads to a corresponding decrease in combustion noise. A reduction in peak cylinder pressure is also noted. The differences between engine performance with diesel fuel and with the blends are not great, and lie within the accuracy limits of the measurement procedures. These test bench results indicate that the tallow ester/diesel blends give an improvement in cambustion performance compared with diesel. However the differences may not be large enough to be distinguishable under normal operating conditions. 5.2 ENGINF PRRFORMANCE 5.2.1 General. Power output, fuel consumption and emissions were measured over a wide range of loads, speeds and injection timinas. The results showed that power output and fuel consumption figures are similar for the blends and for diesel fuel. only in the case of the neat ester is there a clear trend towards higher fuel consumption. The neat ester has a net calorific value about https://www.w3.org/1998/Math/MathML"> 10 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lower than that of diesel fuel, but for the 10 of and 20 o v/v blends the calorific value is only 18 and 28 lower respectively, and is unlikely to be noticeable under normal operating conditions The sensitivity of the engine to injection timing changes was not noticeably altered by the use of the blends. A general trend towards a reduction of https://www.w3.org/1998/Math/MathML"> H C , C O , N O x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and smoke emissions with increasing ester content of the test fuel was observed. However only in the case of neat ester fuelling are such differences significant. Emissions under idling conditions are not noticeably different for the blends and diesel. 5.2.2 Cold start performances. A vehicle application version of the Perkins 4.236 engine was used to compare the cold start performance of 108 and https://www.w3.org/1998/Math/MathML"> 208 v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blends of ester with diesel. Difficulties were experienced during the cold start tests and no firm conclusions on cold start behaviour can be reached. It is concluded that further work should be undertaken. 5.3 CKANKCASE OIL DILUTION Dilution rates and the effects of dilution in the crankcase oil when using the 10 & and 20 ₹ v/v blends, have been compared with diesel fuel, using the single cylinder Perkins 4.236 engine. A range of engine operating conditions was investigated and the worst case conditions for dilution with the blends have been identified. These conditions are high speed, light load, steady state operation with low oil and coolant temperatures. Under these conditions the https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> v/v blend caused the viscosity of crankcase oil to reduce faster than it would have done with diesel fuelling, but this is not expected to cause lubrication problems within normal oil change periods. 5.4 ENDURANCE TESTIMG Two 300 hour endurance test runs are currently being conducted using a https://www.w3.org/1998/Math/MathML"> 20 % v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blend. Engine stripdown and camponent inspection will take place at the end of each run. The https://www.w3.org/1998/Math/MathML"> 20 % v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blend has been chosen so as to accentuate the emergence of any detrimental effects which might arise from the use of a https://www.w3.org/1998/Math/MathML"> 10 z v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blend.

5 FIEID TRIALS

Plans are well advanced for approximately 30 vehicles, which include annibuses, town carriers, long haul freighters and farm vehicles, to operate in New Zealand using a https://www.w3.org/1998/Math/MathML"> 10   g v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blend of tallow esters with diesel. It is anticipated that a total operating time of 10,000 hours, or approximately https://www.w3.org/1998/Math/MathML"> 500,000   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , will be achieved.

DISCUSSION

It is apparent from the foregoing remarks that New Zealand produces sufficient tallow to substitute for a significant portion of the national diesel demand in the form of methyl esters of tallow. The economics of such production are, however, vitally dependent upon the value of the by-product glycerol produced. Also it is recognised that tallow esters may have a greater value as oleo chemical feedstocks than as a diesel extender. However the properties of tallow esters are such that their inclusion in diesel does not require any modification of engine operating parameters or fuel distribution systems. Consequently it would be possible to market tallow esters in such a way as to achieve their greatest value while still enabling their periodic use as a diesel extender to provide a base market. The properties of tallow ester blends with diesel fall outside the normal diesel specifications used in new Zealand for blends greater than https://www.w3.org/1998/Math/MathML"> 10 % v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . However combustion performance improves as the concentration of tallow ester increases up to https://www.w3.org/1998/Math/MathML"> 208 v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (and probably beyond this). In particular the cetane numbers of blended fuels are significantly greater than those of pure diesel which leads to reduced engine noise and offers the prospect of being able to blend with a lower quality diesel fuel and still maintain an acceptable cetane number. Overall tallow ester blends with diesel up to https://www.w3.org/1998/Math/MathML"> 10 % v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> result in a marginal improvement in engine performance over that for pure diesel. There is, however, a possibility that lubricant degradation and engine fouling resulting fram the use of tallow ester blends may be greater than for the case of pure diesel fuel. Preliminary indications are, however, that neither of these problems is likely to be so great as to limit the use of the tallow ester blends. 26. CONCIUSIONS

The economic viability of extending diesel with tallow esters depends upon the long tenn cost of the tallow being less than about NZ$525/ tonne, the glycerol by-product value remaining above about NZ$1800/ tonne and the operating economies of a large scale processing plant.

Processing tallow to tallow ester requires good post-esterification processing to reduce the monoglyceride content of the ester to below https://www.w3.org/1998/Math/MathML"> 0.05 % w / w https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

The Iow temperature properties of tallow ester diesel blends are concentration dependent. A https://www.w3.org/1998/Math/MathML"> 108 v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> conforms with standard New Zealand diesel specifications. 4. The engine performance using tallow ester/diesel blends is similar to that for diesel fuel, however the presence of esters improves the diesel fuel ignition properties.

The use of blended fuels appears to offer exciting prospects for use within New Zealand.

27. REFERENCES (1) "Availability, quality, location and prices of tallow for the production of a diesel fuel substitute"; Liquid Fuels Trust Boara Report No. 2032; Wellington, New Zealand. 1983. (2) "Manufacture of tallow esters - cost estimates"; Liquid Fuels Trust Board Report No. 2033; well ington, New Zealand. 1983. (3) "The Properties of tallow ester/diesel blends"; BP Oil New Zealand Limited; (Report to the Liquid Fuels Trust Board 1983) (4) "Engine validation tests in tallow ester/diesel blends"; Perkins Engines Limited; (Interim report to the Liquid Fuels Trust Board 1985). (5) "Research on tallow ester manufacturing techniques"; G A Strange; Department of Scientific and Industrial Research, Lower hutt, New Zealand; (Report to the Liquid Fuels Trust Board 1984). (6) "The removal of monoacyl glycerides fram tallow esters"; ICI New Zealand Limited; (Report to the Liquid Fuels Trust Board 1985). TABLE I: PROPERTIES OF ESTERS, DIESEL FUEL AND BLENDS (1) Carbon residue on neat ester (2) Calculated TABLE II:COSTS FOR TALLOW ESTER MANURACTURENZ $ (1983) per tonne of ester https://www.w3.org/1998/Math/MathML"> 1,0001 / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> plant https://www.w3.org/1998/Math/MathML"> 10,0001 / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> plant Capital and operating costs Glycerol credit 336.60 149.70 Net production cost https://www.w3.org/1998/Math/MathML"> - 161.50 175.10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 175.30 25.60 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Diesel price Needed Tallow Price https://www.w3.org/1998/Math/MathML"> 510.00 334.90 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 510.00 535.60 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> = = = = = = = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TABLE III: LON TEMPERATURE PROPERTIES OF ESTER/DIESEL BLENDS Vol o Ester in Diesel Fuel Cloud Point Cold Filter Plugging Point https://www.w3.org/1998/Math/MathML"> 0 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0 https://www.w3.org/1998/Math/MathML"> ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 5 https://www.w3.org/1998/Math/MathML"> - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 10 https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 15 0 https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 20 https://www.w3.org/1998/Math/MathML"> + 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> + 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> oC https://www.w3.org/1998/Math/MathML"> ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> oC TABLE IV: CETTANE NUMBERS OF TALLOW ESTERS AND BLENDS Fuel Cetane Number * BS2869 Class A https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas oil 47 NZ automotive gas oil 47 https://www.w3.org/1998/Math/MathML"> 10 8 v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ester in A https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas oil 50 https://www.w3.org/1998/Math/MathML"> 208 v / v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ester in A https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas oil 54 Tallow ester (neat) 70

By IP41/60

28. PRODUCTION OF HYDROCARBONS FROM BIOMASS W. Research Division, 3180 Wolfsburg, FRG C. Buhs and H. H. Oelert Inst. Of Petroletum Res. 3392 Clausthal-Zellerfeld, FRG G. Relfenstahl and F. Wagner Inst. of Biochem. and Biotechnol., Techn. Univ., 3300 Braunschweig, FRG 29. Summary The mafn object of the research project was to convert biomass and organic waste materials to an energy rich liquid which may be suitable as dlesel fuel. Several procedures were tested, such as fermentation of yeast and bacteria for lipid production, cultivation of the algae Botryococccus braunit, extraction of hydrocarbon producing plants (Euphorbia lathyris) and liquefaction of 11pid containing yeast, Euphorbia, algae, sewage sludge, bagasse, and black Ilquor. Liquefaction experiments were run In aqueoug phase at high co pressure in a batch stirred reactor. The analysis of products of extraction and Ifouefaction processes shows, that hydrocarbons are produced. This route of biomass conversion, however, https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> not yet economical. 30. Introduction High priced crude oll and shortage of of1 In1tiated research on use of renewable energy resources. Volkswagen research is mainly lnterested In fuels for transportation or stationary engines. Ethanol from starch or sugar and blogas from manure are suitable for use In passenger car engines, as demonstrated in different countries especially in BraziJ. However, a substantial decrease of crude ofl consumption 1n those countries w111 only occur after subetituting diegel fuel, too. Therefore investigations were made to flnd out to what extent different feedstocks are can-didates for the production of liotid hydrocarbons sultable as diesel substitute.

Objective of the project

Many proposals were made for producing hydrocarbons from biomass. Main routes are

tise of hydrocarbon-rfch blomass

lquefaction and/or hydrogenation of blomass Hydrocarbon-rich blomass in this project means all plants and microorganisms containing hydrocarbons, Iiplds or fatty acids. After extracting these components the residues as well as other organic waste material is liquefied by thermal processes. Blomass shows s H/C ratio which is similar to that of hydrocarbons. FIGURE 1: RoUTES FOR BIOMASS CONVERSION Figure 2: Processing of BIOMASS FIGURE 3: HYDROCARBONS EXTRACTED FROM EUPHORBIA LATHYRIS F1GURE 4: HYDROCARBONS FROM LIQUEFIED EUPHORBIA LATHYRIS FIGURE 5: HYDROCARBONS FROM HYDPOGENATED SEWAGE SLUDGE RENEWABLE HYDROCARBONS AND INDUSTRIAL CHEMICALS FROM RENYAN PLANTS A. Ng'eny-Mengech and S.N. Kihumba Department of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi, Kenya. Summary Indigenous Kenyan plants of the families Euphorbiaceae Moraceae and Ascleoiadaceae have been screened for their hydrocarbon, o11, phenolic, sugar, protein and Eibre content. Each species is then evaluated as a potenttal multimuroose crop for fuel, chemical feedstock and fodder production. The method has been applied to whole plant material, dried stem latex and to the new terminal leafy growth of fast-growing trees. The species selected for analysis are primarily from the semi-arid regions of Kenya, but also include potential fuel/fodder trees from the high-potential zone. Heats of combustion and spectroscopy of all plant fractions has been undertaken. I. INTRODUCTION Considering the fact that many developing countries are presently spending up to https://www.w3.org/1998/Math/MathML"> 40 - 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of their foreign exchange earnings on the importation of crude petroleum and individual families as much as a quarter of their income for domestic fuel, it is wise to re-examine the role that agriculture can olay in meeting the energy requirements of the Third World. The expertise required to produce potential energy crops is already extant in the indigenous peasant population of most of these largely agrarian societies. Biomass-derived energy is appropriate for both domestic and industrial applications, and at the same time biomass can provide many of the feedstocks Eor emergent chemical industries. In order to discover previously unexploited sources of energy and raw materials, our group at the University of Nairobi have undertaken a screening programme of plants growing in Kenya. Using a combined solvent extraction/ partitioning scheme developed by Buchanan and co-workers at the U.S. Department of Agriculture (1), the dried plant material is divided into four major fractions each of potential industrial importance. Each fraction has been evaluated for its heat values and detailed chemical TABLE I: YIELDS OF EXTRACTABLES FROM 10 KENYAN. PLANTS (calculated as i Dry Weight) As of metl after methanol extraction TABLE II. HEATS OF COMBUSTION OF PLANT FRACTIONS IN MJ/KG PLANT Whole P1ant Oi1 Hydrocarbon PolyFraction phenol Methanol Fraction Euphorbia nykai 42.5 https://www.w3.org/1998/Math/MathML"> 41.1   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 35.5 Calotropis procera leaves 41.5 39.3 31.0 Ficus benjamina 41.5 48.1 36.1 20.3 F. glumosa 41.5 46.6 36.4 19.0 F. volgelii 41.6 44.6 27.5 26.0 F. capensis 43.3 46.8 36.1 21.0 TABLE III. WHOLE PLANT OJL AVALYSIS FROM SOME KENYAN PLANTS PLANT Saponification number Unsaponifiable matter Iodine number Eurphorbia nykai 48 68.0 Calotropis procera 1eaves 75 85.0 110 Ficus benjamina 190 37.5 F. glumosa 233 25.0 106 F. volgelii 229 30.0 90 F. capensis 161 28.6 10 Coconut oil 254 192 130 Sunflower oil Reference fuels - Heat of Combustion in https://www.w3.org/1998/Math/MathML"> M J / K G https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Anthracite coll 30.1 Crude oil 44.1 Fuel oil https://www.w3.org/1998/Math/MathML">   45.2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Gasoline https://www.w3.org/1998/Math/MathML">   48.2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 31. INTRODUCTION then up to 1982 , the drylng cost https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> co-operatlves increased by 20 % each year This was due essentlally to the fuel ofl and gas riging cost. Energy represented till https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total drylng cost. In such a context, researches have been engaged as far as biomass use is concerned. For 6 years, about 30 corn dryers have been using cereal straw as an energy source and more than 10 plants have been using corn cobs. These drying systems require obviously more labour. For 2 years, the rlse of corn drylng cost has been limited from 5 to 6 % per year that minimizes the interest for biomass use. That is the reason why A.G.P.M. goes on studylng these systems with a vlew to lmprove them. Researches engaged Intend to prepare the application of this technology as soon as possible and according to better social and economical factors. As a result, today in France, biomass uses for corn drying represent 1000 tuns of ofl that is to say https://www.w3.org/1998/Math/MathML"> 0.3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of national energy consumption for drying. grates. WOODSTOVES IN THE NETHERLANDS, ENVIRONMENTAL AND SOCIAL IMPACTS P.A.OKKEN Centre for Energy and Environmental Studies (IVEM) State University, PO Box 72 , Groningen, the Netherlands 1. Summary In the Netherlands natural gas is the dominant fuel for space heating. In recent years however, the use of woodstoves has become popular again. This might save energy and increase airpollution. In order to asses the energy and environmental impacts of this sudden revival and to determine the possibilities for public information programs, a questionaire was sent to 1300 woodstove users. Clean dry seasoned wood appears to be the most important fuel. Yet, painted or impregnated wood is also used, wich increases airpollution. Lignite, coal, waste paper and packages are also used to some extent. In general the stoves have too much heating capacity, and conseqeuntly they must be operated with little air-supply, wich gives airpollution. Stove-operation and fuel supply were analysed in relation to users- attitude, by means of several statistical techniques. Three different patterns of usage were detected. Important is the itloot pattern in Wich frequent use of waste fuels is correlated with a natural lifestyle friendly to energy and environment, without recognition of adverse impacts on nature or landscape. The detected patterns of usage might play an important role in public information programs.

INTRODUCTION, WOODSTOVES IN THE DUTCH ENERGY CONTEXT

In the Netherlands woodstove sellings have made a recent progress. However, woodstoves can have unfavourable environmental impacts. At State University Groningen, faculty of IVEM, environmental effects of woodstoves are investigated and the actual tsage of woodstoves is surveyed by means of questionaires and interviews. This interdisciplinary research is done by Planning and Environmental Control (VROM). In former days wood was an important fuel in the Netherlands. After periods are connected to the nationwide natural gas network. Gas heating appliances are stoves, boilers and furnaces lands, equivalent to https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the Dutch houses. This is a remarkable comeback In 1983 IVEM sent a questionaire to two independant groups of woodstove Woodstoves are usually https://www.w3.org/1998/Math/MathML"> ( 90 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> found in houses wich also have gas heating. The stoves are traded in the Netherlands as woodstoves, multi-fuel stoves or solid-fuel stoves. Different types are illustrated in figure l. Most common is the modern Danish stove. This is a typical multi-fuel stove. an original woodstove. Less common types are the traditional Dutch potbelly Figure 1:Woodstoves in the Netherlands. Percentage share in recent sellings FRONTLOADER https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> DANISH DESIGN STOVE https://www.w3.org/1998/Math/MathML"> 5 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . POTBELEY https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FIREPLACE INSERT https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FRAHKLIN STOVE https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CERAMIC STOVE 1 2. FUELS AND WOOD SUPPLY The fuel usage as questionaired is summarized in table 1. cast-off wood from house breaking. Fuels used to some extent are lignite, packages/wrappings, coal and waste papers. Lignite, coal and a part of the fuelwood are bought in shops or at forestries. The other fuels are collected from waste or at work by the woodstove tiser. The Netherlands is densily populated. There is few inland wood available. Only 8 % of the country's surface is covered with forests and trees. As a consequence https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the nation https://www.w3.org/1998/Math/MathML">   ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> s wood demand has to be imported. Woodpulp for paper is imported from Sweden, hard woods for building materials are imported from tropical countries. The amount of woodwaste in the Netherlands potentially available for stoves and masonry fires, is lloo thousand tons a year. More than half of this is cut-off wood from building and furniture industries. The rest is wood left behind in inland tree and forest cutting. The precarious woodbalance is reflected in wastepaper recycling. More than https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of all wastepaper is collected and re-used in paper industries, up to 1050 thousand tons a year. In the Netheriands recycling of woodwaste or wastepaper is energetically preferable to burning in a woodstove. For instance: when wastepaper is recycled it costs 24 GJ fossil energy/ton. When wastepaper is burned in an efficient woodstove it saves 16 GJ fossil energy /ton (otherwise needed to heat the house) on the one hand, but on the other hand it costs 36 GJ fossil energy and 18 GJ wood energy to make a ton of new paper. Hence, when recycling is the alternative, burning wastepaper in a woodstove costs 38 G.jton https://www.w3.org/1998/Math/MathML"> ( = 36 + 18 - 16 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , while recycling costs 24 GJ/ton. If woodstoves compete with existing recycling streams (woodwaste and wastepaper recycling), a further expansion of woodstoves is undesired. Wood appears to be the most important fuel. Some wood was characterized as Table 1 : Fuel usage in woodstoves in the Netherlands (1983)

ENVIRONMENTAL IMPACT

Risk is a negative environmental impact. Woodstoves hold fire-risks and can cause indoor airpollution and give risks in woodcutting Wood ig a renewable energy sotrroe, thág io a positive impact. Particular attention has been given to airpollution. In the Netherlands the potential airpollution is quite clear because natural gas, the dominant fuel, gives only minor airpollution. The gaseous emissions are dependant of fuel, stovetype and operation. Some of the woodfuel is characterized as cut-off wood or treated wood. This wood can be painted or impregnated. By burning steh wood, special compounds can be emitted into the atmosphere, for example lead (from paint) and arsenic or dioxins (from impregnates). This increases airpollution. Most woodstoves are fitted with an adjustable air supply. We have found that https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the woodstoves are operated with the air supply closed as much as possible. This is felt necessary, because most woodstoves are too great for Dutch houses. Mean woodstove capacity found was 12 kilowatt, while a maximum of https://www.w3.org/1998/Math/MathML"> 5   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> should be enough. In consequence stoves are operated with little air supply in order to temper the heat output. The wood is burned at starved- air conditions in a smoldering fire. This incomplete combustion increases airpollution Carbon monoxide, particulates, polycyclic aromatic hydrocarbons, aldehydes, ketones, et are emitted, wich can give health problems Carbon monoxide emission figures, as compiled from hundreds of published measurements from normal woodstoves burning seasoned wood, in dependence of air supply, are summarized next 3. FLUIDISED BED COMBUSTION OF BOTH LIGHT AND WET BIOMASS B. WILTON, University of Nottingham J.F. WASHBOURNE, Energy Equipment Co. Ltd. 4. Summary Al though combustion of coals in a fluidised bed of sand is recognised as being a particularly efficient way of using poor quality fuel there has been iittle work on the fluidised bed combustion of biomass. Problems of elutriation of fuel and sand may be encountered in fluidised bed units so to minimise these effects intermittant fluidisation and under-bed feeding is being used, together with a large expansion chamber in which some centrifugal treatment of the flue gases will be possible. It is expected that moist biomass will be able to be used and this should be an attractive feature as it will reduce the need to store and/or dry bjomass before use. Fluidised bed combustion should also produce fiue gases that are less polluting than those given off by other methods of combusting biomass. When compared with most other fuels biomass is at best less convenient, while at worst it can be almost impossible to use. It is less energy-dense than oil, coal or fuel gases, it will not flow through narrow pipes (although it can be conveyed in fluids through large ones) and biomass harvesting, handling and storage can all present problems. Despite all these drawbacks it undoubtedly has a part to play in helping to meet the world's energy demands. Two further major problems with biomass are that it can be extremely variable and in some cases it can be very wet. In general dry biomass fuels are utilised by combustion or gasification, whereas the only sensible way of using some of the wettest ones is by fermentation: as so often happens it is the in-between moisture content materials which cause problems. Another feature of biomass that has to be considered is that the period of availability can vary considerably. Some materials are produced more-or-less continuous?y: if they happen to be wet, like waste animal slurries, then fermentation is obviously the most promising pathway to follow. If they are produced annually it is ikety that there will be an optimum season for collection and this will almost invariably be followed by storage to even out the supply. It may also be found necessary to dry the material to some extent to prevent deterioration in store. Perennial crops or their by-products are different: they can often be taken at more-or-less any season, however once again they will normally need to be dried ejther before or during storage It would be useful to have available methods of rapidly extracting energy from moist biomass materials without the need to dry and store or ferment them. This would allow collection (harvesting) and utilisation to be consecutive operations, thus tending to minimise cost. Moist fuels can be used in gasification plants and in very large furnaces, however the cost of these appliances is high, so in the current work at Nottingham the aim is to develop a fair ly small, and reasonably cheap unit capable of using these intermediate moisture content fuels. The method selected - to use a fluidised bed combustion unit - 15 also expected to minimise the risk of producing polycyclic aromatic hydrocarbons in the flue gases. This is an important factor in biomass combustion because of the carcinogenic properties of these compounds. The addition of limestone or dolomite to the bed will also retain much of the sulphur present in the fue?. With the exception of pulverised fuel combustion systems, it is usual in conventional combustion equipment for the fuel to be fairly static in the combustion zone; in such conditions moist fuel will dry out only slowly. In flujdised bed units, however, the rate of heat transfer between particles is high; moist fuels should dry out quickly, their volatile components should be given off rapidly and combustion of the non-volatiles should be achieved in a short time. One of the chracteristics of the fluidised combustion of coal is that of carryover of ash and, in some designs of plant, of the elutriation of the bed material. Some biomass materials have relatively finely divided components, for example leaves and pieces of fibre, so elutriation of these fractions could cause a problem. The longer that such materials can be retained in the bed the better, so it was decided to feed the fue? into the bed below the surface rather than adopt the simpler approach of dropping it onto the bed (see figure 1 ). Several other design features should minimise the problems of elutriation and moist fuel; these include (i) having a slotted fuel feed tube which runs through the bed (ii) using a fluctuating velocity air supply to the bed so that for several periods of a few seconds duration each minute the bed is not quite fluidised, and (iii) having a large expansion chamber above the bed, with secondary air being introduced tangentially to encourage centrifugal separation of particles entrained in the flue gases. There is very little published work in this area and a large number of materials and design features need to be studied. Among the materials that will be used first are chopped cereal straw, freshly produced wood chips and bagasse pith: once the preliminary work on these three widely differing potential fuels has been started, work on mixtures of biomass fuels may well be undertaken. 0 Figure 1 DEVELOPMENT OF A DOMESTIC FIRENOOD BURNER FOR COOKING https://www.w3.org/1998/Math/MathML">   S. G. MUKHER.JEE     Professor of Thermal Engineering     Indtan Institute of Technology, Kharagpur   721302   INDIA.   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Summary 5. INTRODUCTION 2.3 Analytical methods : Samples of flue ges were analysed using gas criromatom graphy for carbon monoxide, carbon dioxide, and oxygen and using e chemllumiriscent anelyser for nitrogen oxides. The smoke density wes calculated using a smoke indicator whicri measured the transmitted light passing across tre flue. Phe Indicator consisted of a lagt beam projector and a photocell receiver. The light beem from the projector was allgned across the flue and atteruation upto & maximum of 100 coul d be measured. Smoke wes collected from wood bumer for examiratior https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a transmission electron inicroscope. a copper electror microscoge grid with a farmver (polyvinyl formal) support I1lm was inserted carefully lnto a metal probe. lhe probe was placed in the wooa burner above ior about twenty seconds. After removal of the probe, the grid was examinea In the electron microscope to analyse the particle size and sliape (4).

EXPERIMENTAL KESULTS

1 Analysis of wood :

The soft wood was anelysed and the following results were obtained: calorific value https://www.w3.org/1998/Math/MathML"> 2.26 × 10 4   k J / k g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mo1sture content 7.4. ash content https://www.w3.org/1998/Math/MathML">   0.15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volatile matter https://www.w3.org/1998/Math/MathML"> - H 2 O 80.9 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3.? General behaviour of wood combustion and gas anslyses: In the fixst experimente known amount of soft wood Wes burnt flrstly witi the elr door fully open and secondly WItri the elr door half: open. Its betaviour during combustIon wets observed. In tre second experiment tre soft wood was added at three intervals of time during combustion and another experiment was performea on betch orocecs. The mean observed concentratıon of smoke was 1.7 mg 1 I of flue gas. 3.3 Calorimeter experiment : By using cooking vessel as a calorimeter and thermopile, heat used was computed and 1t was found that out of the total calorific value, only 30 , was utilised for cooking purposes.

DISCUSSIONS

I General nature of wood combustion : Wood is normally burnt either in the open, in open fire places or in slingle stage-closed combustion unfts as used here. It could also be used In two-stage combustion units in which any carboneceous material is burmt out in the second stage. Although the latter is preferable but

6. REFERENCES JOINT ENTERPRISE AND UTILIZATION OF A BRIQUETTING PLANT FOR STRAW M. BRENNDORFER Kuratorium für Technik und Bauwesen in der Landwirtschaft e.V. 6100 Darmstadt, Federa 1 Republic of Germany Summary Combustion of cereal straw as bales or loosened material brings along some serious disadvantages: low bulk density, handling difficulties while charging the furnaces, technical problems with combustion and high emissions. By using high compression to make briquettes, cobs or pellets out of straw it was expected to solve these difficulties. Briquetting plants are expensive however. This is why nine agricultural and one non agricultural partners formed a cooperation for the joint operation and use of a briquetting plant. Its purpose is to cover their own energy demand and to sell briquettes to external customers, also to the non agricultural users. According to present operation experience the operating reliability can be considered as good. Cost for producing briquettes depend on the rate of utilization, organization and preparation. At an optima 1 utilization rate of about 1000 hours/year the production cost amounts to about 145 DM/ton of briquettes with https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> subside and https://www.w3.org/1998/Math/MathML"> 180 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton without subside. Combustion of these briquettes resulted in very low emissions (dust content), which are fully in accordance with the emission standards of the Federal Republic of Germany.

Introduction

In 1982 a cooperation for the joint operation and use of a briquetting plant was founded by nine farmers and a non agricultural partner in Aarbergen-Panrod near Wiesbaden, Germany. The objective for this joint enterprise was:

the common purchase at equal shares

the common installation and

the common use

of a straw-briquetting plant. This plant was subsidized by the Hessian State with 40 percent. The straw briquettes are used for the individual house heating. By using high compression to make straw briquettes it was expected to solve the difficulties which exist in combustion, air pollution and handling. Briquettes are one particular type of stampings. Their characteristics are shown in table 1. In comparison to other types of fuel briquettes have advantages as well as disadvantages: Table 1: Characteristics of stampings stampings diameter mm lenght mm bu7k density https://www.w3.org/1998/Math/MathML"> k g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Briquette 40-100 50-2501) 300-450 Cobs 15-30 https://www.w3.org/1998/Math/MathML"> ≤ 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 400-600 Pellets 6-12 https://www.w3.org/1998/Math/MathML"> ≤ 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 450-600

Length differs according to cooling track and purpose

Table 2 presents important characteristics of straw briquettes in comparision to other briquettes. Tab. 2: Physical criteria of different fuel briquettes in comparision Form of briquette Heat/value https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> k W h / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Density https://www.w3.org/1998/Math/MathML"> k g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Bulk density https://www.w3.org/1998/Math/MathML"> k g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Storage requirement https://www.w3.org/1998/Math/MathML"> m 3 / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Energy concentration MWh https://www.w3.org/1998/Math/MathML"> / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Straw 3,32) 800-1400 300-450 2,2-3,3 0,99-1,48 2,53) 800-1400 300-450 2,2-3,3 0,75-1,13 2,04) 800-1400 300-450 2,2-3,3 0,6-0,9 Wood 4,0-4,6 1000-1350 600-800 1,3-1,6 2,58-3,44 Peat 3,5-4,5 https://www.w3.org/1998/Math/MathML"> ∼ 1000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 650-750 1,3-1,5 2,6-3,0 Coat 5,4-9,2 1000-1700 700-820 1,2-1,4 5,11-5,98

air-dried fuet

https://www.w3.org/1998/Math/MathML"> 0 i 1 / s t r a w https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ration 1 : 3 (theoretical) https://www.w3.org/1998/Math/MathML"> 0 i 1 / straw https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ration 1:4 https://www.w3.org/1998/Math/MathML"> 0 i 1 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> straw ration 1:5 Tab. 3: Drive power of a briquetting plant For the 129,5 tons of briquettes 404 operating hours were needed or https://www.w3.org/1998/Math/MathML"> 320   k g / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hour. The average energy or electricity cost amounts to https://www.w3.org/1998/Math/MathML"> 0,42 D M / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and thus are relatively high. Only by means of a monthly maximum rate of utilization a minimization of electricity cost can be achieved. Measurements of emission at working condition showed a dust content of 76 to https://www.w3.org/1998/Math/MathML"> 294 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> flue gas. Thus a 11 emission results are in accordance with the emission standards of the Federal Republic of Germany. From the technical and funtional point of view the briquetting plant can be considered satisfactorily. The same applies to emission quality which results from burning of straw briquettes though existing and non specialized furnaces were used. So far the high investment cost (up to https://www.w3.org/1998/Math/MathML"> 200000 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton of capacity per hour) and the economy of operation are still a problem. An input-output calculation of the first year of operation gives the following results: Table 5: Calculation of cost At cost of about https://www.w3.org/1998/Math/MathML"> 200 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton straw briquettes are in general compatible with brown-coal briquettes (260 DM/ton) but there exist handling disadvantages. By increasing the rate of utilization cost can be reduced further. This can be achieved most effectively when a non agricultural customer with a high and continuous demand of briquettes can be found.

Literature

(1) BOSSEL, U. (Hrsg.); Brikettieren und Pelletieren von Biomasse. SOLENTEC Fachbuchverlag, Adelebsen, 1983 (2) BEWER, E.; Technische Daten und Betriebserfahrungen zur Herstellung von Strohbriketts. Agrartechnische Berichte https://www.w3.org/1998/Math/MathML"> N r . 17 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Hohenheim, 1983 (3) BEWER, E., K. KAMM, K.-H. RøHM; Verfeuerung von Strohbriketts in Kleinanlagen. Landtechnik 40(1985), H. 1, S. 38 (4) BRENNDORFER, M.; Hat die Strohbrikettierung Zukunft? Lohnunternehmen 39 https://www.w3.org/1998/Math/MathML"> ( 1984 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , H. 3, S. 171-176 (5) Verschiedene Autoren; Brikettierung von Stroh zur Wärmeerzeugung. KTBLArbeitspapier 88, KTBL, Darmstadt, 1984 (6) KAMMK., K.-H. ROHM; Ermittlung von Emissionsfaktoren bei der Verbrennung von Strohbriketts in Zentralheizungsanlagen. Bericht der Landesanstalt für Umweltschutz Baden-Würtemberg, Karlsruhe, 1985 7. PELLETIZATION OF STRAW C. WILEN & K. SIPILÄ Technical Research Centre of Finland Laboratory of Fuel Processing and Lubrication Technology SF-02150 Espoo. Finland P. STAHLBERG & J. AHOKAS State Research Institute of Engineering in Agricu\rceilture and Forestry SF-03450 01kkala, Finland 8. Summary In Fintand, heating with straw has been fimpeded by the lack of cheap and well-operating heating equipment suitable for straw combustion, in addition to abundant firewood and peat resources. Heating costs can be reduced by processing the straw to compressed products. The ratio of cost cut-down to the cost of compression is a decisive factor with regard to competitiveness. In Finland, the use of straw pellets as fuel has been the main object of research on compressed straw products. The present techno-economic study based on production experiments in practice concerns the production of straw pellets with a portable pelletizing unit. Studies of heating equipment have been focused on the operation of screw-fed solid fuel burners. Combustion of straw pellets with the solid fuel burners is hampered by the high ash content of straw and by the low melting temperature of ash. To guarantee a smooth operation, the burners must be equipped with ash handling equipment. The best results have been obtained for a burner with a moving sten arate. In the size class of one-family houses and farms, heating with straw pellets is competitive with oil heating at the price of 330 - 580 FIM/t. The production costs of straw pellets are https://www.w3.org/1998/Math/MathML"> 250 - 350 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , if the raw material is delivered from the consumer's own farm. If the raw material must be bought, the production costs are 350 - https://www.w3.org/1998/Math/MathML"> 430 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 9. INTRODUCTION With regard to increasing the use of straw, the use for energy is the most potential alternative. The energy use of baled straw is restricted by the lack of cheap smati boilers suitable for straw combustion. The straw burns poorly in boilers designed for other indigenous fuels. This is due to a considerably lower energy density, a high proportion of ash and melting properties of ash. Baled straw can be effectively used for energy production only in boilers designed especially for this purpose. The price of these boilers is so high that their use is not economic unless the heat consumption exceeds 60 MWh/a. A more effective use of straw for energy production requires processing to compressed products. When using compressed straw products, the costs of combustion equipment, boiler room, fuel storage and heating work are lower. Hence, the costs of the actual compression compared to the benefit obtained are the decisive factor in the production of compressed straw products and in the costs of heating.

THE ENERGY CONTENT OF STRAW

In Finland, the annual straw harvest is https://www.w3.org/1998/Math/MathML"> 1600 - 3000   k g / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with the present harvesting methods, the moisture content being https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The energy content is https://www.w3.org/1998/Math/MathML"> 5.5 - 10 M W h / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Finland's total annual utilizable straw harvest is about https://www.w3.org/1998/Math/MathML"> 2.2 m i 11 . t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 15 - https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of this is used mainly as litter and fodder. Only about https://www.w3.org/1998/Math/MathML"> 0.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is used as fuel. The rest, about https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , is either ploughed in the soil or burnt in the field. The energy content of this disposed amount is about 0.7 Mtoe, which is calculatory sufficient to substitute totally for the light fuel oil used for heating houses and other bulldings on Finland's farms. About 70 . https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of straw is produced in Southern and Western Finland. In these regions, the straw may locally be a very significant energy reserve, as there are no significant amounts of other indigenous fuels available. The low energy density of straw results in higher storage and heating costs and in part also in higher capital costs of the boiler and the boiler room. These costs can be reduced by processing the straw to fuel briquettes or pellets. The production costs of these products are the decisive factor with regard to the total costs.

PRODUCTION OF COMPRESSED STRAW PRODUCTS

Two different compression techniques can be used: pelletization or briquetting. In pelletization, ring or flat die presses are used. The material is extruded through a perforated breaker plate, and the products are small cylinders https://www.w3.org/1998/Math/MathML"> 6 - 20   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in diameter. Screw or piston presses are used in their manufacture. The processing of straw to pellets represents a more modern technique, which is fairly well developed for wood and peat. pelletization and briquet ting methods are compared with each other in Table 1. When the straw is compressed to briquettes or pellets, the bulk density of straw increases to 5 - 10-fold compared to that of baled straw. The moisture content of these products is https://www.w3.org/1998/Math/MathML"> 10 - 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , density https://www.w3.org/1998/Math/MathML"> 450 - 650   k g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and heat value https://www.w3.org/1998/Math/MathML"> 4 - 4.3 k W h / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , i.e. https://www.w3.org/1998/Math/MathML"> 1.8 - 2.8 M W h / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Table 1. Comparison of pelletization and briquetting methods. Pelletization Briquetting Moisture content https://www.w3.org/1998/Math/MathML"> 10 - 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Maximum output of press 4 - 6 t/h Maximum output of press 1-1.5 t/h Energy consumption (chopping, Energy consumption (chopping, pressing) 80 - 90 kWh/t pressing) 40 - 50 kh/t Straw must be chopped fine. The same combustion systems as for The size of the product is small, sod peat and wood can be used.

EXPERIMENTS ON THE PRODUCTION OF STRAW PELLETS

EXPERIMENTS ON THE PRODUCIION OF STRAN PELLEIS tory of Fuel Processing and Lubrication Technology of the Technical Research Centre of Finland and by the State Research Institute of Engineering in Agriculture and Forestry. The experiments were made with a portable pelletization unit constructed especially for this purpose. The intention was to study pelletization properties of straws of different cereals and to produce pellets from different straws for combustion experiments. The straws were pelletized without thermal drying. The portable pelletization unit consisted of a straw chopper, to which small bales could be fed, feeding equipment for chopped straw, and a flat die press. After the pelletization the pellets were cooled on a belt cooler. The portable pelletization unit is shown in Figure 1. It can also be used for pelletizing other raw materials. The output of the unit is https://www.w3.org/1998/Math/MathML"> 0.5 - 1 t / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> depending on the raw material used. The test equipment does not include a power source of its own. Figure 1. Portable pelletization unit.

STRAW ASH

In addition to the low energy density, other factors impeding combustion are the high ash content of straw and the melting behaviour of ash. The ash content of barley, rye and oat is about https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and that of wheat https://www.w3.org/1998/Math/MathML"> 6 - 7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The melting temperature of wheat ash deviates fairly clearly from those of the other cereals. In addition, the melting temperature of straw ash is affected by the soit and by fertilization. The ash melting temperatures of different cereals are presented in Table 3. The melting of ash at low temperatures results in difficulties in the operation of grates and ash handling equipment. The compression does not change melting properties of ash, and hence, the metting behaviour of straw ash should be considered in the design of boilers and stokers fired with compressed straw products. Table 3. Melting temperatures of straw ash. Stage of melting Temperature range, https://www.w3.org/1998/Math/MathML">   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Wheat Rye 0at Barley Initial deformation Hemi sphere 900-1050 1300-1400 Flow temperature 800-850 1400-1500 750-1150 1300-1400 850 1000-1100 1150-1250 730-800 1050-1050 1200

COMBUSTION OF COMPRESSED STRAW PRODUCTS Compressed straw products can be burnt by stoker burners, the burner head of which is equipped with ash handTing equipment. In the size class of https://www.w3.org/1998/Math/MathML"> < 50   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the best results with straw pellets were obtained with a screw stoker, where the ash is removed with the aid of a moving step grate. The stoker, where the ash is removed with the aid of a moving step grate. The grates are powered by the fuel feed screw. The cost of a combustion equipment of this kind is about 500 FIM higher than that of a wood chips burner ment of this kind is about soo FIM higher than that of a wood chips burner with the same output. It is of significance to the operation of the burner head that the ratio of the length and frequence of grate movements to the rate of fuel feed is suitable. In the combustion experiments in the laboratory, a IP 30 burner was connected to a TULI 30 boiler, which is designed especially for stoker use

The results of efficiency tests carried out with barley straw pellets are given in Figure 2 . The moisture content of the pellets was https://www.w3.org/1998/Math/MathML"> 13 - 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . All the tests presented in the table were carried out at the same values of All the tests presented in the table were carried out at the same values of very good. An efficiency of https://www.w3.org/1998/Math/MathML"> > 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is achieved at the boiler load of https://www.w3.org/1998/Math/MathML"> > 1.8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> kW and that of https://www.w3.org/1998/Math/MathML"> > 70   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at the https://www.w3.org/1998/Math/MathML"> 10 a d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> > 2.8   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This indicates that it is possible to achieve an annual efficiency of https://www.w3.org/1998/Math/MathML"> > 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in practice too. The moving step grate can also be used in burners with a higher efficiency, but it is difficult to estimate the upper limit of efficiency at this stage of research.

PRODUCTION COSTS OF STRAW PELLETS

The production costs of straw pellets vary within a wide range in respect to both the production of raw material and the actual compression. As regards the raw material, it is of significance how the capital costs of the harvesting equipment are regarded in the price of the compressed product. When the consumer of the compressed straw product delivers the raw material and pays only for the compression, the costs of raw material are 100-200 FIM/t if the harvesting equipment is used in a reasonable way. The purchase price of straw is https://www.w3.org/1998/Math/MathML"> 200 - 280 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The production costs of straw pellets with the portable pelletization unit were evaluated. The pellets would be produces in a pelletization unit of https://www.w3.org/1998/Math/MathML"> 3 t / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The unit would be in operation 9 months per year and it would be used in two shifts, i.e. the operation time would be https://www.w3.org/1998/Math/MathML"> 3200   h / a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . As the effective operation time is https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and about https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the time is used for Figure 2. Efficiencies of the TP 30 burner and the TULI 30 boiler with straw pellets and at different boiler loads. transports, starts, etc., the annual production of pellets is about https://www.w3.org/1998/Math/MathML"> 7000 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . On this basis, the compression costs of straw pellets are about https://www.w3.org/1998/Math/MathML"> 150 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The production of pellets can be organized so that the pelletization unit stays 1-2 weeks in each village and the local farmers bring their straw for pelletization. If the unit can be connected to the electricity network of the village, the price of electricity is essentially lower and the compression costs of pellets are about https://www.w3.org/1998/Math/MathML"> 120 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . ATternatively, the unit can be moved from one large farm to another, but in this case the amount of pellets should be about 100 t/farm. The production costs of straw pellets are https://www.w3.org/1998/Math/MathML"> 250 - 350 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> when the consumer delivers the raw material. If the raw material must be bought, the production costs amount to 350 - https://www.w3.org/1998/Math/MathML"> 430 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The costs of straw pellets produced with the portable unit are about https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lower than those of pellets made in a stationary unit. In the size class of https://www.w3.org/1998/Math/MathML"> < 50   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , heating with straw pellets is competitive with oil heating at the price level of https://www.w3.org/1998/Math/MathML"> 330 - 580 F I M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The situation is most unfavourable to the straw pellets, if new facilities must be built for the heating unit, a short period of repayment and a high rate of interest are used. The straw pellets are competitive with oil in such a situation when the heating unit is placed in an existing building and the use of indigenous fuel is supported by subventions and by loans at a low rate of interest. 10. CONCLUSIONS When straw is processed to a compressed product, considerable savings are obtained in the costs. At farms, compressed products can be burnt with solid fuel burners equipped with ash handling equipment. The equipment and heating costs are of the same magnitude as for the other solid fuels. The storage costs are lower due to the high density, although a better storeroom is required for the straw pellets due to their poor weather resistance. On the basis of production costs the straw pellets are in certain cases a competitive fuel compared to oil. CHARCOAL AS FUEL : NEW TECHNOLOGICAL APPRQACHES Summary

INTRODUCTION

Charcoal is a fuel widely utilized worldwide, especially in developing countries to meet household needs such as cooking (in towns mainly) and tools... Charcoal is a low-cost fuel with the following advantages :

long proven manufacturing techniques,

high heating value,

-ease of storage and transport, -clean combustion. Moreover, it is known to gasify readily and produce a gas that can be used in engines without requiring sophisticated nor costly systems. Developing countries nowadays urgently need decentralized mechanical energy for electrification, pumping irrigation and traneport purposes we wish to illustrate that plant charcoal derived from biomass can be of interest for stach countries. We will elaborate later on the conditions needed for this process and the solutions proposed by CEMAGREF. leading to biomass conversion into mechanical energy through gasification, especially for small gas producer-engine systems. Research has only borne on antiquated, complex and unreliable processes, unable to make the most of the more widespread feedstocks. Upgraded and increased by the development of new techniques, charcoal production will no doubt enable major breakthroughs to be made. Let's underscore that the basic feedstock is agricultural. Agriculture in developing countries could make use of untapped potentials provided that it has energy, at least for irrigation. Hence, its energy production will greatly exceed its own needs. Conversely, under prevaiting economic conditions, developing countries cannot bet come major food producers unless agriculture helps them generate their own energy. But feedstock conversion remains a problem area.

NATURE OF THE FEEDSTOCKS

Apart from wood which will still be plentiful in some countries, feedstocks include straw, rice hulls, coffee husks and grass. In the near future, energy crops such as giant reeds will join them. We are not in a position to process these materials efficiently because they must be aggrem gated into briquettes. This is expensive and the performance of gasifiers are uneven. How about producing charcoal ? The resulting material would be small coals and coal dust whose pelletization with a "ball-making machine" or an extruding press is easy and inexpensive. The peliets would then be used in a simple, reliable and light gasifier. We have a lready tested it. Charcoal must now be produced. To this end, we are aiming at two objectives:

mobile carbonization using agricultural raw materials such as straw (rice straw mainly), grass.

We built a mobile unit to carbonize bundles of straw and stalks, capable of producing about https://www.w3.org/1998/Math/MathML"> 300   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of charcoal per hour.

stationary carbonization using factory by products like rice hulls, husks (coffee, groundnuts...)

Ne are now working on the total supsension process for this type of feedstock. Moreover, we developed a gas/coal production process with a fixed-bed gasifier with gas recycling. It allows stationary plants to produce gas and charcoal, charcoal to be used in small decentralized plant. Therefore, we could soon offer a whole range of equipment capable of using most of the more widespead feedstocks. Yet, current pelletization techniques can greatly increase the efficiency of conventional wood carbonization in the forest by making use of small coals. About https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the coal is wasted, mainly on the spot and partly during transport. It has been shown in Sudan that the cost of a pelletization plant installed at the retailer's can be recotped in less than one year. There are also gas generation plants. The engines must then work properly. Their performance must be satisfactory and they should not require a permanent operator. In short, performance must match that of Diesel units MOBILE PYROLYSER FOR STEM SIZE PRODUCTS RESULTS FROM RESEARCH WORK IN HEAT GENERATION Dr. A. Strehler TU - München Bayer. Landesanstalt für Landtechnik D-8050 Freising Summary Research work on energy from biomass in weihenstephan began 1974. First the fuel straw was characterised by determining its calorific value, taking into consideration moisture content, storage conditions, species, varieties, growth conditions and fertilization. Other characteristics of the straw such as percentage of volatiles and chemical elements, demand for combus tion air and specific fuel gas volume - were determined. Measurements were made with commercial furnaces; through-burning types, under-burning types and furnaces with automatic charging systems. Test runs were also carried out on prototype furnaces of different systems. A special heat generation system has been developed together with the industry. Diffe rent types of furnaces were constructed, using pressure bales, roto bales, wood pieces and wood chips. Economic calculations show that straw and wood waste are cheap fuels under certain conditions. The main problems in straw and wood combustion are: Combustion quality has to be improved in all types of furnaces, mainly in case of straw. 11. INTRODUCTION Large quantities of surplus straw and wood waste are available as an energy resource in the Federal Republic of Germany and other countries. The heat demand of most farms could be meet completely with these biomass fuels in some regions. In certain wood or cereal producing regions, biomass is generally produced in surplus. In this case, the transport of biomass is necessary to supply consumers in other regions. In FRG 5 Mio t of straw could be available for heat generation. Resources of wood are much higher. but the present non-utilized quantity of fue 1 wood is in a range of 2-3 Mio t/a. Additionally there will be a tremendous quantity of fuel wood as a result of the wood dying in the next years. Another resource can be seen in energy plantations, which might be available in future years in order to reduce the problems of financing the EEC agricultural market. Rape, other oil plants and short-rotation forests are good options. Rape for example could deliver https://www.w3.org/1998/Math/MathML"> O i l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , fodder (pressing residue) and straw (bales and briquettes). On the basis of the available and future resources, research work has been carried out in Weihenstephan since 1974 on the production of energy from cereal straw and, since 1978 , also from wood waste. Sponsors are the Commis- sion of European Communities, Research Ministery, Bonn and the Agricultura Ministeries in Bonn and Munich. Measurements were made at the testing facilities in Weihenstephan (Figure 1) and during practical application in farm dwellings. Figure 1: Boiler test unit in Weihenstephan 12. SELECTED RESULTS 12.1. STRAW BRIQUETTES IN STOVES In hot stoves the combustion quality was better than in cool boilers. Slag was observed when boilers or stoves had temperatures of more than https://www.w3.org/1998/Math/MathML"> 900 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> c in the fuel itself. Single stoves had https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> contents mainly between 8 and https://www.w3.org/1998/Math/MathML"> 12 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with extremes of 2 - https://www.w3.org/1998/Math/MathML"> 16 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Gas temperatares in the stove were from https://www.w3.org/1998/Math/MathML"> 700 - 800 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , flue gas temperatures https://www.w3.org/1998/Math/MathML"> 300 - 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , fuel temperatures https://www.w3.org/1998/Math/MathML"> 300 - 700 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Table I shows individual results for two types of stoves Table I: Test results of straw briquette combustion in different stoves Conclusion: Efficiency too low; combustion quality has to be improved with emissions below https://www.w3.org/1998/Math/MathML"> 150 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 2.2 STRAW BRIQUETTES IN SMALL BOILERS Test results are shown in Table II. Table II: Test results of straw briquette combustion in bottom-burning furnaces (density https://www.w3.org/1998/Math/MathML"> 0.935   k g / d m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , diameter https://www.w3.org/1998/Math/MathML"> 50   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) Conclusion: Flue gas temperatures are slightly high; too much emission. Design has to be improved. 2.3 STRAW AND WOOD IN LARGE BOILERS Tests with different fuels in a large bottom-burning boiler with wood, bales and straw briquettes show better results than small furnaces (Table III). Table III: Test results of wood and straw combustion (bottom burning furnace) Conclusion: The combustion quality is better than the furnaces shown in Table I and I but not good enough. It is necessary to change the furnaces to attain less emission. The improvement of furnaces is done together with manufacturers. 2.4 WOOD COMBUSTION IN LARGE BOILERS In special boilers, dry wood is utilized meanwile with good success; the efficiency is high enough, the combustion quality good enough to meet strict regulations. Figure 2 shows a furnace for big wood logs, developed together with a manufacturer. The bottom-burning system with well-adapted secondary combustion chambers and a large heat exchanger, guarantee a high efficiency with low emission and small work load, when the boiler is connected to a large heat store (water tank). Figure 2: Boiler with bottom-burning system 13. 2.5 COMBUSTION OF WOOD CHIPS Wood chip combustion is well developed with many systems. The new1y constructed pre-furnace with a movable grate also allows a high efficiency and low emission with chopped straw, even without slag problems (Figure 3). 14. Bioflamm-Prefurnace with Moveable Grate https://www.w3.org/1998/Math/MathML"> 100 - 500   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 3: Prefurnace with movable grate 15. 2.6 LABOUR COSTS Figure 4 demonstrates the dependence of combustion system, power, specific price, saving of fuel oil, quantity and labour costs. Figure 4: Labour costs in combustion of straw and wood BASIC OF THE COMBUSTION OF WOOD AND STRAW https://www.w3.org/1998/Math/MathML">   M. Hellwig   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   TU - Munich     Bayer. Landesanstalt fur Landtechnik     D-   8050   Freising   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 16. Summary The fuels wood and straw are characterised by a low carbon content ( https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), a high oxygen content (up to https://www.w3.org/1998/Math/MathML"> 44 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and a large percentage of volatiles (up to https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). More than 2/3 of the heat content of these fuels can be stored in the volatiles. These products burn in the gaseous phase and produce large flames. The reaction products must be completely combusted before leaving the chamber. This requirement is not met in many practical cases, and thus the emissions with wood and straw are much higher than with fossit fuels. 17. FUEL CHARACTERISTICS The chemical and physical properties of wood and straw are important and influence the design of combustion systems. The elementary chemical composition and calorific value of the dry matter is essentially the same for all types of wood and straw, regardless of whether its conifers or deciduous trees or what type of cereal straw. From Table I, it can be seen that in comparison, wood and straw have relatively little carbon and very much oxygen. The biomass fuels contain hardly any nitrogen and sulfer. The high oxygen content leads to a high reactivity at normal combustion temperatures and thus a rather rapid combustion. Table I: Ultimate analysis and heating value of solid fuels The immediate analysis gives concrete results on the behavior of the fuel within the combustion chamber. Information is obtained on the moisture content, ash content, volatiles and the solid carbon content. From Table II it can be seen that wood and straw are the richest in volatiles. The moisture content is one of the most important combustion parameters, which greatly influences the calorific value as well as the quality of combustion. A high moisture content reduces the combustion temperature which in turn hinders a total combustion of the reaction products. Table II: Proximate analysis of solid fuels (wet basis) Moisture + Ash + Volatile Matter and Fixed Carbon https://www.w3.org/1998/Math/MathML"> = 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The volatiles are those products which are set free when the fuel is brought to the combustion temperature. These gas products influence the combustion process and the design of the combustion chamber. 18. COMBUSTION OF BIOMASS The burning process of a fuel rich in volatiles, e.g. wood and straw, is illustrated schematically in Figure 1. When heat is applied, the fuel is initially dryed and the moisture completely driven off. Above https://www.w3.org/1998/Math/MathML"> 150 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the thermal reaction begins and proceeds slowly up to https://www.w3.org/1998/Math/MathML"> 200 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . At https://www.w3.org/1998/Math/MathML"> 275 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the reaction acceferates rapidiy and an exothermal process starts which suddenly sets the volatiles free. The volatiles consists largely of hydrocarbons https://www.w3.org/1998/Math/MathML"> C n H m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , carbon dioxide https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , carbon monoxide https://www.w3.org/1998/Math/MathML"> ( C O ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and hydrogen https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> along with tar residues and water vapor, which burn as gas products in the flame. Solid carbon remains which burns slowly and without flame in the embers. Figure 1: Stages in woodburning Figure 2 shows how the released heat is distributed in the two-phase combustion of wood and straw. With these fuels, over 2/3 of the calorific value is released through the combustion of volatiles. Thus it is necessary to supply combustion air at two points; primary air for the solid carbon and secondary air for the gas products. Calculations show that https://www.w3.org/1998/Math/MathML"> 66 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the stoichiometric air supply is needed as secondary air. Theoretically the solid carbon can first be converted to CO and then out-side the bed, burnt to form https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Here, the secondary air can be increased to https://www.w3.org/1998/Math/MathML"> 83 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These results are shown in Figure 3 . (1) heating to https://www.w3.org/1998/Math/MathML"> 900 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and heid for https://www.w3.org/1998/Math/MathML"> 10   m i n ( D 1   N 51720 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (2) heating to https://www.w3.org/1998/Math/MathML"> 370 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and held for https://www.w3.org/1998/Math/MathML"> 30   m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> thof stetter 1978 https://www.w3.org/1998/Math/MathML">   Figure 2:     Distribution of the heat     of the combustion of wood     and straw fuels   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> air distribution stoichiometic combustion air https://www.w3.org/1998/Math/MathML"> m n 3 / k g c O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 3: Relationship between primary and secondary combustion air for wood fue? 19. COMBUSTION PRODUCTS When the combustion of biomass is complete, the flue gas contains on https://www.w3.org/1998/Math/MathML"> 1 y C O 2 , H 2 O , N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The relation between combustion products and combustion air supply (air excess) can be shown in a simple way graphically. Figure 4 illustrates the combustion triangle for wood. From this the quality (completeness) of the combustion can be determined easily and clearly. Figure 4: OSWALD-combustion-triangle for wood fuel During biomass combustion, however, a number of intermediate arise, especially in the combustion of the volatiles. The by-products https://www.w3.org/1998/Math/MathML"> C n H m , C O , t a r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and soot can occur. When not completely combusted, they cause harmful and noxious components in the flue gas. Incomplete combustion occurs under the following conditions:

General or local combustion air deficiency.

Sudden cooling of the fire gases or flame, e.g. on water-cooled surfaces or through the supply of cold secondary air.

Poor mixing of the combustible products with air.

Delay time of the combustible gases in the chamber is too short.

Temperature in the reaction zone is too low.

Harmful emissions such as https://www.w3.org/1998/Math/MathML"> S O 2 , N O x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and fly-ash can also arise. Due to the low sulfer content and low combustion temperature, only very small concentrations of https://www.w3.org/1998/Math/MathML"> S O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> N O x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> occur. The fly-ash concentration however can be appreciable, especially with straw which has a high ash content. Figure 5 shows the intermediate and gasification products of wood by incomplete combustion. The amounts depend on how the fuel is prepared, the combustion chamber and the combustion characteristics. Figure 5: The combustion products of wood and straw fuel A comparison of emissions can be made after analysis the flue gas of furnaces with various biomass and fossil fuels. Average values for the emissions are given in Table III. It can be seen that in comparison, wood and straw have a higher solids content and higher CO and https://www.w3.org/1998/Math/MathML"> C n H m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentrations. Table III: Typical average concentration of pollutants released during combustion of various fuels in home heatina units 20. CONCLUSIONS An improvement of the combustion quality and thus the reduction of emissions can be achieved with combustion systems optimised for the given fuel. The following three rules are to be observed:

The fuel should be fed continually into the reaction zone (continuous feeder or under-burner systems). 2. The combustion air should be well mixed with the fuel and gas products.

The combustion products should remain in the combustion chamber for a long time at a high temperature.

REFERENCES: (1) GUMZ, W.: Kurzes Handbuch der Brennstoff- und Feuerungstechnik, 3. Auflage. - Berlin: Springer 1962, 749 S. (2) HOFSTETTER, E. M.: Feuerungstechnische KenngröBen von Getreidestroh, Dissertation, Technische Universität München. - Freising-Weihenstephan, 1978. (3) DAVIDS, P., GLIWA, H.: Emissionsfaktoren für Feuerungsanlagen für feste Brennstoffe, https://www.w3.org/1998/Math/MathML"> N r . 98 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Heft 3, 1977, S. 58-68. (4) COOPER, J. A.: Environmental impact of residential wood combustion emissions and its implications. - In: Journal of the Air Pollution Control Association, Vol. 8, No. 8,1980, S. 855-861. (5) WAGNER, W.: Berechnung von Holzfeuerungen fur Wärmeträgeranlagen. In: Wärme Band 85 , Heft 4/5,1978, S. 77-82. TEST RESULTS FROM PILOT PLANTS FOR FIRING WOOD AND STRAW IN THE FEDERAL REPUBLIC OF GERMANY

Kraus

TU - Múnchen Bayer. Landesanstalt für Landtechnik D - 8050 Freising 21. Summary Pilot plants for wood and straw combustion in the Federal Republic of Ger- many are intended to provide valuable knowledge on the function, energy efficiency, environmental hazards, operations and the economy of such sys- tems. Financial support for the construction of the plants and the scienti- fic supervision is provided by Federal and state Ministeries. Woodchips fur- naces are technically well developed; the combustion quality is qood, the emissions are far below the legal regulations for environmental protection. Depending on the particular design and capacity, the costs 1 e between 200 and https://www.w3.org/1998/Math/MathML"> 580 D M / k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of treat generated. The costs per kWh are 9.7-12.1 Pfennig depending on the operation. Plants for firing straw show partially good combustion qualities, however the efficiency needs to be improved and the emissions further reduced. The investment costs run up to https://www.w3.org/1998/Math/MathML"> 200 D M / k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of heat generated for hand-fed plants and up to https://www.w3.org/1998/Math/MathML"> 440 D M / k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for systems with automatic feeders. 22. INTRODUCTION The Bay. Landesanstalt für Landtechnik supervises wood and straw pilot plants, whose construction and scientific personnel is supported by various Federal and State Ministeries. In particular, the granting agencies were the Federal Ministery for Nutrition, Agriculture and Forests, the Federal Ministry for Research and Technology as well as the Bavarian state Ministry for Nutrition, Agriculture and Forests. With the help of the pilot plants, the goal is to gain practical experience with new technologies for firing wood and straw and to communicate the results to manufacturers and potential users. The Scientific supervision includes the planning of the plant and usually an extensive program of measurements. Data is collected on the flue-gas composition https://www.w3.org/1998/Math/MathML"> C O , C O 2 , 0 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , flue-gas and combustion temperatures, solids emission, heat input and output, the necessary auxiliary energy for plant, operation and fuel preparation as well as the labour required for fuel collection and combustion.

MAIN RESULTS FROM THE WOODCHIP PLANTS

The 16 woodchip plants with capacities from 30 to https://www.w3.org/1998/Math/MathML"> 500   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are used to heat farm dwellings and public buildings. These consist of 9 pre-furnace plants (see Fig. 1), 3 Stoker systems, 1 underfeed unit for fine woodchips and 3 bottom-burn boilers (see Fig. 2) for larqer chips from forest wastes. Figure 1: Pre-furnace for fine woodchips (system Hansen) with boiler The measurements for a11 plants show a good combustion quality (Tab. I). At high combustion temperatures around https://www.w3.org/1998/Math/MathML"> 1000 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> content in the flue gas is https://www.w3.org/1998/Math/MathML"> 12 - 13 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (combustion air excess https://www.w3.org/1998/Math/MathML"> = 1.7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and the co content 0.07- https://www.w3.org/1998/Math/MathML"> 0.38 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Thus a firing efficiency of over https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was reached and with the stoker system, a boiler efficiency of https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Pre-furnaces result in a partial radiation loss, which accounts for large differences between the firing and the boiler efficiency. The solids emission in the flue-gas was in the range 43 - https://www.w3.org/1998/Math/MathML"> 167 m g / m H 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (at https://www.w3.org/1998/Math/MathML"> 12 % C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), which is far below the allowed value of 300 https://www.w3.org/1998/Math/MathML"> m g / m n 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the Federal Republic of Germany. The energy consumption in producing woodchips corresponded to about https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the wood's heating value in two tests for both fine and large chip sizes. Depending on the method, the labour for producing chips can be given as 3 to https://www.w3.org/1998/Math/MathML"> 6   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per hour per man. Abstract The purchase price of the firing unit was between 27 and https://www.w3.org/1998/Math/MathML"> 74 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total investment costs. Extensive insta11ations (up to https://www.w3.org/1998/Math/MathML"> 57 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of total costs) or construction measures (up to https://www.w3.org/1998/Math/MathML"> 37 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of total costs) are of ten necessary. The price for the firing unit and fue 1 bunkers with feeders 1 ie between 585 and 235 DM/kW and are independent of the various firing systems. The price is mainly determined by the heat performance of the plant and the size of the bunker. The costs for the heat generated lie between 9.7 and 11.7 Pfennig per kWh and are influenced largely by the cost of the plant, woodchip consumption and the cost of woodchip production. In comparison to a heating oil system, the woodchip combustion systems are economical when the oil price is more than 0.68 to 0.82 DM per liter (Tab. II). Table II: Investment costs and the economics of woodchip burners for selected examples 23. MAIN RESULTS FROM THE STRAW FIRING PLANTS The 11 plants for firing straw with capacities between 70 and https://www.w3.org/1998/Math/MathML"> 1000   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> include 2 hand-fed bottom -burning boilers for high pressure bales (Fig.3) 1 bottom-burning boiler for big bales (see Fig. 4) as well as 8 mechanicalTy fed plants with de-balers for high-pressure and big bales. Bottom ourning solle [Fe Leibl ] 24. Figure 3: Bottom-burningboiler forstraw (systemLoibl) https://www.w3.org/1998/Math/MathML"> 1160   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (system PSW) Through-burning boilers display a relatively low con content; at the same time, high CO emissions arise due to unburnt gasiffication products and high solids emission, which can be up to https://www.w3.org/1998/Math/MathML"> 1640 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at 12 of con (see Tab. III). Table III: Essential results of measurements on straw firing plants (fu71 https://www.w3.org/1998/Math/MathML"> 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> firing plants (fu71 https://www.w3.org/1998/Math/MathML">   load operation) - Preliminary results   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Bottom-burning boilers for high pressure and big bales as we 11 as mechanically fed systems show very reasonable values, although the solids release is of ten above the legally a11owed https://www.w3.org/1998/Math/MathML"> 300 m g / m n 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and requires the use of filters. At high temperatures in the ember bed https://www.w3.org/1998/Math/MathML"> 800 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , slag was observed in the ash. This can cause the grate to become clogged, less combustion air is available to the fuel and the combustion performance is reduced. With the use of movable grates and an automatic ash removal system, these problems can be a 1leviated.An uniform fuel input is important with automatic feeders to obtain a continuous high-quality combustion. Further, the straw should be collected and stored in a dry condition, since moisture contents above https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can cause break-downs of the de-baling and feeder systems and negatively effect the combustion quality. The required energy for de-baling and the systems operations is between 1.3 and https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the generated thermal energy and depends on the efficiency of the plant and the degree to which the straw is chopped. The cost of the plant range between 100 and https://www.w3.org/1998/Math/MathML"> 430 D M / k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , whereas hand-fed units and large capacity systems have a better price-performance ratio. The costs for heat generation can be given as 10.4 to 22 Pfennig per kWh and depend on utilization load of the plant, the efficiency of the boiler and the fuel price. Thus for the implementation on individual farms, straw firing plants become economical at heating oil prices above 0.54-1.15 DM per liter (Tab. IV). Table IV: Investment costs and the economics of straw firing plants for selected examples ATl costs without VAT and without governental subsidies

For the annual heating denand of the farm operation. Conparison costs for ofl heating: 12 to 16 pf/klat

For actual operating conditions considering replacement investments. https://www.w3.org/1998/Math/MathML"> 80   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> efficiency assumed for oil heating.

25. BIOMASS-FUELED FURNACE COUPLED TO GREENHOUSE R.M. Sachs, D. Roberts, K.M. Sachs, B. Jenkins, G. Forister, J. Ebeling, D.W. Fujino. Departments of Environmental Horticulture and Agricultural Engineering, University of Cal ifornia and Woodland Power Company, Davis, CA 95616 26. Summary The furnace, heating a https://www.w3.org/1998/Math/MathML"> 167   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> glasshouse, operated according to specifications when clean, dry wood particles (pits, shells, pelletized residues, shavings or chips) of https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> moisture or less were used; greenhouse air quality met the health standards required for a work environment and the even more stringent standards for flower crop production, but the aromatic materials were objectionable to all personnel polled. When moisture content exceeded about https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wet basis) furnace temperatures fell below that required to direct furnace air into the greenhouse and bridging of fuel also became a serious problem. At these times the furnace air was directed to the bin dryer. Densified fuels flowed without bridging but their current prices, near 1 y https://www.w3.org/1998/Math/MathML"> $ 100.00 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonne, eliminated the economic advantage to using the furnace. The furnace can save ca, https://www.w3.org/1998/Math/MathML"> $ 1.00 / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of operation at peak load conditions when replacing a natural gas fueled system with wood fuels at https://www.w3.org/1998/Math/MathML"> $ 33 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonne. The furnace tested is available at https://www.w3.org/1998/Math/MathML"> $ 7,500 - 8,000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> suggesting a payback in three years assuming interest rates of https://www.w3.org/1998/Math/MathML"> 10 - 14 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Costs associated with fuel storage and drying operations, or a heat exchanger if that were required to eliminate aromatics released to the greenhouse, are not included. 27. Introduction Natural gas, one of the preferred fuets for crop drying and greenhouse heating in california, may cost in excess of https://www.w3.org/1998/Math/MathML"> $ 6.00 / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for commercial enterprises (1). With over https://www.w3.org/1998/Math/MathML"> 13   k m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of greenhouse space, and an average annual consumption of approximate 1 y https://www.w3.org/1998/Math/MathML"> 1.6 × 10 3 M J / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vegetable, flower and foliage plant growers are among the largest agricultural consumers of natural gas in California (2); they are very dependent upon uninterrupted supply for commercial survival. In addition, crop drying operations consume almost https://www.w3.org/1998/Math/MathML"> 4.6 × 10 9 M J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> annually. Wood chips and related biomass fuels are available at approximate https://www.w3.org/1998/Math/MathML"> 1 y $ 33.00 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per dry tonne, or about https://www.w3.org/1998/Math/MathML"> $ 1.80 / GJ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> assuming https://www.w3.org/1998/Math/MathML"> 19 M J / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of wood. The development of alternate fuels and heating systems for greenhouses and crop drying represents protection against interrupted supp 1 ies of fossil fuels and has now become an economically attractive prospect. Results of studies on a prototype wood-fueled furnace retrofitted to a greenhouse and bin-type dryer on the UCDavis campus are reported in this paper. Furnace Specifications and Controls. Actual fuel consumption was https://www.w3.org/1998/Math/MathML"> 6.8   k g / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of wood (design capability is https://www.w3.org/1998/Math/MathML"> 11.3   k g / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), providing https://www.w3.org/1998/Math/MathML"> 130 × 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> J / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to the greenhouse or crop dryer. Greenhouse heating requirements for an entire heating season were not determined in this study but we believe this output is adequate to heat the https://www.w3.org/1998/Math/MathML"> 167   m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> single-paned, glass greenhouse used, maintaining a https://www.w3.org/1998/Math/MathML"> 15 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> differential between ambient and greenhouse environment (3). A https://www.w3.org/1998/Math/MathML"> 77   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fuel hopper was located above the furnace auger feed system with a motor-driven agitator to reduce. Fue bridging is a problem for this and other wood-fueled systems when relatively moist, irregularly sized particle fuels are used (4). Since the furnace is not equipped with an automatic slag removal system, high ash fuels lead to rapid accumulation of slag in the refractory with consemuent decline in furnace operating temperature and diversion of afr away from the greenhouse. Dirt-free, low ash fuels are essential for this type of combustor The furnace is ignited by an electric glow plug inserted through the refractory and into the fuel bed. An air blower is turned on 2 minutes Defore the auger feed motor. Electrical consumption for operation of auger and agitator motors, ignitor, air blowers and electrostatic air precipitator is about 500 watts. Furnace air is directed through a gated box directing air either to the greenhouse or bin dryer. Air can not pass into the greenhouse until the furnace is at or above https://www.w3.org/1998/Math/MathML"> 900 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the greenhouse thermostat calls for heat. Prior to entering the greennouse, stack gas from the furnace is mixed with air recirculated from the greenhouse. The mixture passes through a fiber filter and electrostatic precipitator (Model o902, Emerson Electric Co., St. Louis, MO) and then into a sealed plastic duct held https://www.w3.org/1998/Math/MathML"> 2.4   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> above the greenhouse floor, vented bilateral ly at o. https://www.w3.org/1998/Math/MathML"> 3   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> intervals. The thermostat controlling the furnace is placed l.2m off the floor near the center of the greenhouse. Analysis of Furnace Combustion Gases and Determination of Excess Air. Combustion gases were andlyzed to determine furnace performance and concentrations of major and minor constituents. Results are listed in Table 1. The results of the gas analyses indicate that the furnace was operating with approximately 200% excess air. Excess air was determined by batancing the combustion reaction for an empirical mole of wood using the elemental composition of pine and fir (7). At https://www.w3.org/1998/Math/MathML"> 200 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> excess air theoretical combustion gas concentrations major constituents (Fig 1 ) agree closely with the measured concentrations. The predicted flame temperature at https://www.w3.org/1998/Math/MathML"> 200 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> excess air is close to the average flame temperature of https://www.w3.org/1998/Math/MathML"> 1370   K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> measured by thermocouples inserted in the furnace combustion chamber. Air Dilution in the Greenhouse. Before entering the greenhouse the combustion gases are mixed with air. The amount of dilution was determined from the measured content of the combustion gas https://www.w3.org/1998/Math/MathML"> ( 6.51 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and air mixture https://www.w3.org/1998/Math/MathML"> ( 0.52 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Assuming a background level of https://www.w3.org/1998/Math/MathML"> 300 p p m C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the dilution ratio is 12.2 volumes of air per volume of combustion gas. During recyccling of air from the greenhouse, additional fresh air is as a result of uncontrolled leaks surrounding the main blowers, leading to a further dilution of combustion gases. Concentrations of https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the greenhouse after 5 hours of furnace operation have been measured at https://www.w3.org/1998/Math/MathML"> 0.35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which suggests that the air added on recycling is somewhat in excess of https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total circulated. Toxic Gas Ana 1 yses. The expected levels of the trace constituents, https://www.w3.org/1998/Math/MathML"> C O , N O x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , in the combustion gas were determined by direct GC ana 1 ysis and by an equitibrium ana 1 ys is for combustion of wood using the IBM-PC disk version of the STANJAN equilibrium composition model developed by Reynolds (8). This mode? was run for combustion at the stoichiometric air-fuel ratio (no excess air) and at https://www.w3.org/1998/Math/MathML"> 200 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> excess air. Results of both analyses for product water not condensed (Table 2) indicate that at high levels of excess air the reaction is virtually complete. Low levels of co are expected at https://www.w3.org/1998/Math/MathML"> 200 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> excess air, particular https://www.w3.org/1998/Math/MathML"> 1 y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after dilution of the combustion gases. NOx emissions may be fairly high in the combustion gas (240 ppm) and after dilution be about https://www.w3.org/1998/Math/MathML"> 20 p p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the Flg. 1. Combustion Gas Concentrations air mixture entering the greenhouse. Virtually all NOx should be NO which by itself is not highly toxic to plants, when NO is reacted with ozone in the presence of ultraviolet radiation, peroxyacetyl nitrate, a highly phytotoxic compound, is formed (9). NO2 at 6 ppin wOuld damage some hrighly phytotoxic compound, is formed fye https://www.w3.org/1998/Math/MathML"> 1102 m t   p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ozone, UV radiation and hydrocarbons in the greenhouse environment. At https://www.w3.org/1998/Math/MathML"> 200 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> excess air hydrocarbon levels in the combustion gases should be low and were not detected. Sulfur oxides were not detectable. Ethylene analyses in the less than 100 ppb range were performed on a gas chromatograph equipped with a photoionization detector and alumina column. Greenhouse air samples were taken in a https://www.w3.org/1998/Math/MathML"> 250 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vacuum tube with septum-ports for syringe sampling. spot andlyses for ethylene in the greenhouse, during 4 hr furnace heating runs, detected an average of approximately 40 ppb, with fluctuations up to 800 and down to 17 ppb. Carnation flowers placed in the greenhouse showed no "sleepiness" (petal reflexing) symptoms. Owing to the extreme sensitivity of carnation flowers to ethylene (5) it is probable that ethylene levels remain below 40 ppb for the major portion of the greenhouse heating periods. Tomato seed Iings showed no epinasty, the primary response to ethylene (5). during 5 consecutive trials of one week each. Aroma. Although toxic gases were below the levels permissible for human safety, greenhouse personnel objected to the aroma in the areenhouse during combustion. Levels of aromatic gases were below the limits of detection of the gas chromatographic equipment used but most personnel on the oroject readily detected their presence. Particulates were https://www.w3.org/1998/Math/MathML"> 0.031 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for carbon in a total of https://www.w3.org/1998/Math/MathML"> 0.270 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fine matter, and https://www.w3.org/1998/Math/MathML"> 1.087 m g /   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for coarse matter, this is above the levels for radiant heated greenhouses but below the 2 to https://www.w3.org/1998/Math/MathML"> 10 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> levels permitted for industrial safety https://www.w3.org/1998/Math/MathML"> ( 6 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Particulates in the greenhouse due only to fly ash passing through the cyclone/filter bag/electrostatic precipitator system can be reduced without increasing air flow resistance by adding to the electrostatic precipitator plate area. The precipitator tested reduced particulates passing through the fiber filter by https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fuel Combustion Efficiency. Indirect calculations from char collected in the ash bin as well as direct weighing of fuel inputs and ash residues agree quite closely. The higher heating value of the char measured 30.3 https://www.w3.org/1998/Math/MathML"> M J / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , indicating a large fraction of unreacted fixed carbon. The ash content of the wood fuel was 0.11% and that of the char was https://www.w3.org/1998/Math/MathML"> 9.1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> If we assume that the char collected in the ash bin at the base of the cyclone provides an adequate sample of the total products of combustion, then the enrichment of ash in this residue is a good measure of combustion. Since the char contained https://www.w3.org/1998/Math/MathML"> 9.1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ash, we can assume that https://www.w3.org/1998/Math/MathML"> 0.11 / . 091 × 100 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> roughly https://www.w3.org/1998/Math/MathML"> 99 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , of the fuel was combusted. Five mass balance determinations on https://www.w3.org/1998/Math/MathML"> 77   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fuel loads confirmed that https://www.w3.org/1998/Math/MathML"> 99 + % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the fuel was combusted. A direct heating system such as the one used can exploit the higher heating value of the fuel supplied since the heat required for vaporization of the water formed during combustion can be recovered by condensation of this water on the cool surfaces of the greenhouse. P1 ant Growth Studies. Tomato seed 1 ing growth in the furnace-heated greenhouse was equal to or greater than that in companion greenhouses using standard radiant heating. We expected some increased dry weight gains for plants in the furnace-heated greenhouse due to the augmented carbon dioxide levels during the first daylight hour; however, the increases measured were not statistically significant. A hot water heat exchanger will be fitted to a similar furnace and a hot water storage system utilized for greenhouse heating; cool furnace exhaust gases can be injected into the greenhouse in the daylight hours and hot water can be circulated when greenhouse heating is required (rarely in the daytime in California except on overcast days). If the objectionable aroma of the stack gases is eliminated in the cooling process, this latter system may provide sufficient increased daytime https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to increase productivity of most crops (depending on the ventilation requirements for the greenhouse). https://www.w3.org/1998/Math/MathML">   References     (1) Price quotations from Pacific Gas and Electric Co., San Francisco,   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Calif for January 1985. (2) CERVINKA, V., W.J. CHANCELLOR, R.J. COFFELT, R.G. CURLEY, and J.B. DOBIE (1974). Energy requirements for agriculture in California. Published by California Dept. of Food and Agriculture. Sacramento, CA (3) JENKINS, B.M. (1985). Greenhouse model for evaluating alternative heating systems. Proceedings of the 57 th Annual Rural Energy Conference, University of California, Davis, Calif. 95616. (4) WILLIAMS, R.O, J.R, GOSS, J.J. MELSCHAU, B.M. JENKINS, and J. RAMMING (1978). Development of pilot plant gas if ication systems for the conversion of crop residues to thermal and electrical energy. pp. 142-162. In:ACS Symposium Series, No. 76 "Solid Wastes and Residues" American Chemical Society, Washington, D.C. (5) MASTALERZ, J.W. (1977). The greenhouse environment. John Wiley and Sons, New York, NY. (6) CAL-OSHA (Aug. 1983). Airborne contaminants. General Industry Safety Order 5155. Publication S-100. CAL-OSHA Communications, 525 Golden Gate Ave. San Francisco, CA 94102. (7) JENKINS, B.M. and J.M. EBELING (1985). Correlation of physical and thermochemical properties of terrestial biomass with conversion. In: Proceedings of "Energy from Biomass and Wastes, IX." Inst. Gas Tech., Chicago, IL 60616. (8) REYNOLDS, W.R. (1984). STANJAN Program. Dept. Mechanical Engineering. Stanford University, Stanford, CA. (9) Air Pollution Injury to Vegetation (1970). Publication AP-71. Superintendent of Documents. U.S. Govt. Printing Office, Wash. DC 20402. (10) California Air Resources Board. Evaluation Report. No. C-83-086. Evaluation Test of a Wood Chip Fired Furnace Used for Greenhouse Heating, Filed 18 July 1984. Air Resources Board. 1102 Q St. PO Box 2815 , Sacramento, CA 95812. 1. Acknowledgments Partial funding provided by Universitywide Energy Research Group (UERG), University of California, Berkeley, California, U.S.A. 2. QUALITY OF DENSIFIED BIOMASS PRODUCTS J. CARRE, J. HEBERT, L. LACROSSE Centre de Recherche Agronomique de Gembloux (Belgique) (1) Pierre LEQUEUX Directorate-General for Development Commission of the European Communities (2) 3. Summary Six different kinds of biomass have been densified by six industrial processes, including three basic systems (piston. pellets and conical screw presses). Specific qualification tests were carried on the densified products : density, friability, moisture content under different atmospheric conditions, dimensional stability in water and in wet air. In addition, tests were applied to assess the behaviour of the products to be used in Low-power gas producers ( https://www.w3.org/1998/Math/MathML"> 100   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The results mainly show that the properties of the densified products depend on the system of densification, the specific process, and the raw material. The variations in quality are very large and cannot be determined by only one property. The main properties are the mineral content. the cohesion during gasification and moisture resistance. Many results are need to determine with precision the limits to the use of the densified products. 4. FOREWORD In 1983 the Community sponsored an R & D programme entailing a critical analysis of dry processes for using ligneous matter as a source of energy in south-East Asia. The results pinpointed technologies and processes for converting ligneous matter into alternative solid fuels (e.g.briquettes, peltets and plant charcoat) and potential applications for fuels of this type as a source of energy in the home in craftments workshops and in industry (e.g. improved burners, gasifiers and carboni- zations furnaces). The programme faced complex problems due to the: wide variety of: (a) resources (wood, by-products of agriculture and of the associated industries, animal dung, energy crops, etc.); (b) technologies (ranging from traditional direct uses to sophis- ticated processes for manufacturing synthetic motor fuels): (c) application (from rural areas to modem sectors): (ii) competition with respect to land and resources (i.e. whether they should be used for energy or non-energy purposes) and related products (e.g. gas from coal or digester gas): (iji) the lack of an adequate technical and, above all, economic basis for selecting technotogies and applications for appropriate programmes. 5. ANALYSIS OF THE RESULTS (1) P= pelletizing press: RP= ram pelleting press; CS= conical screw press (2) D= density (3) E= equilibrium moisture (% dry matter by mass) 6. PHYSICAL PROPERTIES 7. USABILITY TEST 8. CONCLUSIONS Firms Processes Fiqure 2: Stretching of densified industrial products in humid air (20 C and https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> relative humidity), as a function of expostre time, of the densification process and of the raw material. The stretching is expressed as a percentage of the initial length, as measured after conditioning at https://www.w3.org/1998/Math/MathML"> 20 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> retative humidity. REFERENCES (1) Centre de Recherche Agronomique (CRA) 23, avenue Maréchal Juin - 5800 GEMBLOUX (Belgium) (2) Commission of the European Communities - DG VIII 200, rue de La Loi - 1049 BRUSSELS (BeLgium) (3) The full study can be obtained on request from Mr P. LEQUEUX 9. ON THE TESTING OF WOODBURNING COOKSTOVES P. Bussmann*, K. Krishna Prasad* and F. Sulilatu**

Department of Applied Physics, Eindhover

University of Technology, Eindhoven, The Netherlands ** Division of Technology for Society, TNO, Apeldoorn, The Netherlands 10. SUMMARY This paper is a contribution to the ongoing debate on the testing of stoves. A practical test procedure needs to be simple, reliable and useful. It is shown that these three requirements place conflicting demands on the test procedure. Thus a hierarchy of testing is necessary. The Ariington procedure prescribes such a hierarchy. A critique of this procedure is given whereafter an ideal procedure is postulated. The outcome of the exercise is that compromises among competing demands are essential for designing an effective test procedure. 11. INTRODUCTION Testing a device is invariably carried out to assess its performance in relation to the task it is expected to carry out. Additional restrictions are placed on the equipment since it has to be operated by a human being. These restrictions come in the form of safety to the operator. Tt is customary to demand stringent safety requirements from household appliances since these are operated by a large and diverse population. The equipment therefore must be regularly tested by independent institutes. The present paper considers woodburning cookstoves for domestic applications. Woodburning cookstoves are usually made by many manufacturers and in a competitive environment. Until recently these devices were never tested. With the growing interest in improved stoves the call for a test methodology becomes louder. The main reason being public funds are spent on stoves in order to alleviate the distress caused by the fuelwood scarcity. Attention primarily Was given to the reduction of the wood use. This is also reflected in the test methodologies designed so far. 12. THE ARLINGTON TEST PROCEDURE A typical example of the methodologies mentioned is the Arlington test procedure (1). The procedure has three levels of testing. The first level. is a water boiling test, a simple simulation of a standard cooking procedure. The results are expressed in the standard specific consumption, ssc, which is the ratio between the water vaporized and the wood used. The second level is the controlled cooking test which involves the cooking of a selected meal. The results are expressed in the specific consumption, sc, defined as the ratio between the wood used and the food cooked. The third level is the kitchen performance test which measures the relative rate of fuel consumed by two stoves as they are used in the normal household environment. The results are expressed in the specific daily consumption, SDC, which is the ratio between the wood use per day and the family size. The problems with the test procedure are:

The definitions of the SSC, the SC and the SDC do not relate with each other. Without additional information it is impossible to use the restlts from one test level at other levels.

The procedure specifies only how to perform a test but does not specify how to evaluate the results. No standards are given against which the performance of the stoves can be assessed.

Safety aspects are completely ignored.

The procedure is not sufficiently clear to enable an experimenter to

Tigure 1. Standard deviation in measured boiling times. be measured and fourtly it must be safety requirements. Fig. 2. Pan diameter and content versus power output (5). obtain remroducible resulto. This can be illustrated in figure 1 in which the standard deviation in the boiling times is plotted. The IVE data (2) covers 130 boiling tests, 10 tests With each stove. Wouters (3) tested 4 stoves and Strasfoge. (4) 2, covering in total 20 and 28 experiments respectively.

THE IDEAT TEST PROCEDURE

The ideal test methodology for Woodburning cookstoves presented in this paper is based on the test methodology for gas ranges (5). This means first of all that water boiling tests have to be performed, in order to measure the efficiency (n) of the stove at power level (P). Secondly it means that the maximum power https://www.w3.org/1998/Math/MathML"> P max   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the stove must be determined. Thirdly the turn down ratio (rmp max/P min) must the turn down ratio (rmp max https://www.w3.org/1998/Math/MathML"> / P min   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mined whether the stove meets the part of the simering process thus one must start with a quantity of Water larger than the final quantity, Mo In addition there is sufficient evidence available to suggest that the efficiency of a stove is not a strong function of the power and the mass of food cooked. Moreover https://www.w3.org/1998/Math/MathML"> d T = 75   K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C p = 4.2   k J / k g K https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The formulas for the SC and the boiling time then become: P.t https://www.w3.org/1998/Math/MathML"> * 2 2 S C = 1   B * 315 n + 1.14 s M ⋅ r k g   of wood   k g   of wood   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> t b = M P * 315 n + 0.14 P ⋅ t s M w ⋅ r s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The equations show that a reduction in SC can be achieved by: increasing the heating value B; increasing the efficiency n: decreasing the power rating of the stove P; increasing the The size of the pan tsed in the tests is chosen according to the power rating. The thumb rule for gas ranges is to have a power density at the pan bottom equal to https://www.w3.org/1998/Math/MathML"> 7 W l n m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (figure 2) This unlue seems too low for woodstoves bottom equal to 7 Whcill (figure 2). This value seems boo low for woodstoves because of their lower efficiency. That is why the x-axis in the figure has three different scales, representing power densities of https://www.w3.org/1998/Math/MathML"> 7   W , 10   W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 17.5   W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per https://www.w3.org/1998/Math/MathML"> c m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bottom area at efficiency standards of https://www.w3.org/1998/Math/MathML"> 50 % , 35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively. The data gathered with the ideal test procedure make it possible to calculate the time to cook and the specific consumption (SC) for any given meal (6). For this the cooking task must be modelled which is done through the water equivalent of the food to be cooked, Mo and the simer time, ts, twren down factor r

Proposed standards

Figure https://www.w3.org/1998/Math/MathML"> 3 . C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration versus time. https://www.w3.org/1998/Math/MathML"> 3 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : charge weight varied; 3b: charge time varied. simmering time https://www.w3.org/1998/Math/MathML"> t s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and increasing the is specified too. No data whatsoever has been reported on other safety aspects like the stability, wall temperature and combustion gas leakage. The authors believe that these aspects will become much more importantin the near Euture.

WATER BOILING TESTS

Water boiling tests are performed to measure the efficiency at different power levels. In case the pan choice and cooking task is not restricted by the stove design, they are chosen according to figure 2 . Therefore Pmax needs to be determined first. Each test lasts for about 1 hour. Evapora- tion is not considered to be a loss, which has led to some confusion. Bringing to boil successive pans might overcome this problem (8). During the boiling test the CO-CO2 ratio is measured. The results are averaged over the whole experiment.

THE POWER OUTPUT

In using the stipulated theory it is necessary to have a steadily burning fire. One way of obtaining such a Fire is by adding small quantities of Wood at shoxt time intervals. Neediess to say this is a cumbersome procedure.However, the stove can be considered to burn in a steady periodic way when wood is added in bigger charges at Iarger time intervals. The power in that case is defined as: https://www.w3.org/1998/Math/MathML"> P = ( d M f *B ) / d t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . where dMf is the charge weight, B the combustion value of wood and dt the the charge interval time. A big advantage of adding the fuel in charges is that it leads to experimental results which are highly reproducible. This is shown in figure 1. The standard devia tion in the boiling times measured by THE/TNO is small, However, adding the The methodology for testing gas ranges gives clear standards for the CO content in the flue gases. In testing woodburning cookstoves this problem has nearly completely been neglected although Smith (1983) clearly showed the seriousness of the problem. As an indicator of the toxicity of the com- bustion gases, the CO-CO2 ratio is used. In the table the norms applied in the Netherlands for different burners are given. Essential is that the power are needed.Criteria also have to be evolvedthe turn-down factor. The question topower is controlled by the stove or bbalance the convection, radiation andwhen simmering. Assuming that the panthe convection heat losses from the pusing the Nusselt number relations forRadiation losses from the pan dependsurface. The losses vary from nearlyface) to 680 W/m https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (black sooted pan).point from a cylindrical, 28 cm diametenvironment is approximately 900 Whingereand radiation 10 wses. The importancetion is prevented, only about https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ofA turn-down factor of 10 is requireddesigns show? Thus the minimum power https://www.w3.org/1998/Math/MathML">   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are needed.Criteria also have to be evolvedthe turn-down factor. The question topower is controlled by the stove or bbalance the convection, radiation andwhen simmering. Assuming that the panthe convection heat losses from the pusing the Nusselt number relations forRadiation losses from the pan dependsurface. The losses vary from nearlyface) to 680 W/m https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (black sooted pan).point from a cylindrical, 28 cm diametenvironment is approximately 900 Whingereand radiation 10 wses. The importancetion is prevented, only about https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ofA turn-down factor of 10 is requireddesigns show? Thus the minimum power https://www.w3.org/1998/Math/MathML">   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reeded. concentration do not change. A problem of a different nature arises due to the build-up of charcoal on the fuelbed. The weight of the fuelbed is important as it determines the time the water keeps on boiling after the last charge has been added. Since the end of the experiment is defined to be the moment of time the water stops boiling, it raises the question whether itis not better to use a power definition based on this time. The discussion so far showed the problems in defining the power output. On top of this, criteria have to be found which make it possible to rate the power of a stove. The criterion used so far is the excessive build-up of the fuelbed Only recently the criterion of the excessively high co-con ratio https://www.w3.org/1998/Math/MathML">   is not enveloped in hot flue gases,     an wall and lid can be calculated     can be calculated     convetion (9)   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> test methodology. CONCLUSIONS The problems in using the Arlington test procedure lie in the fact that results obtained at different test levele do not relate with ench other; that no standards are given; that safety aspects are ignored and that the procedure gives an impression to be very accurate while in fact the reproducibility of results is poor. The ideal test method suggests that the fuel consumption can be calculated once the power-efficiency curve is measured. However, laboratory results from the THE/TNO showed that the understanding of processes in woodburning cookstoves is still at stich a level that clear definitions cannot be given of the power output, the maximum/minimum porer in particular. Testing at different levels is therefore needed which includes controlled cooking tests. Moreover, at the time being only approximate standards can be given. REFERENCES (1) VITA, (1982), Testing the efficiency of woodburning cookstoves, VITA, Arlington. (2) I.V.E., (1983), Etat de développement technique des foyers améliorés en Haute-Volta, I.V.E., Ouagadougou. (3) Wouters, F., (1984), Personal communications. (4) Strasfoge1, S., (1984), Programme régional foyers améliorés, C.I.L.S.S. Ouagadougou (5) V.E.G., (1968), Standards for domestic gas appliances, V.E.G.-Gasinstituut, Apeldoorn. (6) K. Krishna Prasad et al., (1933), Test results on kerosene and other stoves, prepared for the Energy Assessment Division, Energy Department, World Bank, Washington D.C. (7) Verhaart, P., (1983), On designing woodstoves, in Wood Heat for cooking, Indian Academy of Sciences, Bangalore. (8) Micuta, W., (1982), Paper prepared for the Arlington meeting on testing procedures, VITA, Arlington. (9) Kreith, F. and Black, W., (1980), Basic heat transfer, Harper and Row, New York. 13. Summary 14. INTRODUCTION PAH and mutagenicity in emission samples form combustion of wood, wood- and bark pellets, municipal waste and oil Wood https://www.w3.org/1998/Math/MathML"> ( 20 - 75   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Wood pellets https://www.w3.org/1998/Math/MathML"> ( 20 - 100   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Waste https://www.w3.org/1998/Math/MathML"> ( 900 - 2400   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0 il https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( 20 - 5200   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> PAH https://www.w3.org/1998/Math/MathML"> μ g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 900-185000 20-90 10-1960 https://www.w3.org/1998/Math/MathML"> < 0.01 - 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> PAH https://www.w3.org/1998/Math/MathML"> ( m g / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fuel https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 10-1500 0.7-2 0.2-1.5 https://www.w3.org/1998/Math/MathML"> < 0.002 - 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Mutagenicity (rev/kg fuel, TA98 https://www.w3.org/1998/Math/MathML"> + 59 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Mutagenicity (rev/kg fuel, JA98 https://www.w3.org/1998/Math/MathML"> - 59 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Particles (mg/m CO (ppm) https://www.w3.org/1998/Math/MathML"> 0.6 - 6 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0.8 - 1 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0.02 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0.004 - 2 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0.3 - 35 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1 - 2 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0.01 - 0.2 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 0.003 - 3 ⋅ 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 60-310 15-70 70-800 2-150 200-15000 https://www.w3.org/1998/Math/MathML"> 70 - > 1000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 100-1400 10-220 The results show a great variation in the amount of PAH and mutagenicity emitted from combustion of various types of biomass and oil combustion. Regarding these two emission parameters wood combustion is the less favourable of them all. boilers very much depend on the combustion conditions such as the time spent of the stack gas in the combustion zone, secondary air supply and humidity of the fuel. However, the PAM amount emitted from wood heated boilers is high and further improvement of these types of incinerators is needed. The PAH content in stack gas from combustion of wood-and bark pellets is considerable Lower than that from wood combustion. However. the mutagenicity is somewhat higher than the mutagenicity in the stack gas from a efficient wood combustion. The analyses of the stack gas samples from the waste incinerators indicate that paH emission is not the main problem even if considerable amounts (approx. https://www.w3.org/1998/Math/MathML"> 1000 μ g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) can be emitted during the starting period of the incineration. However, the emission of heavy metals, hydrochloric acid and chlorinated organic compounds may give cause to more concern. Small amounts of PAH and a low content of mutagenicity is found in emission samples from oil combustion in big plants of MW-size. However. preliminary results of analysis of stack gas from a small (m 20 kW), older residential oll heater indicate pah emission in the same order as that of a efficient wooconsiderable. REFERENCES 15. KINETICS OF WOOD TAR PYROLYSIS P.MAGNE, A.DONNOT and X. DEGLISE Université de Nancy I, BP 239, 54506 VANDOEUVRE Les Nancy Cedex - FRANCE 16. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The production of tar in all types of biomass gasifier being hindering for a good working, it is advisable to remove it, and the best way is to use flash pyrolysis. Using a two reactor apparatus, we tried to determine some kinetics daca on the flash pyrolysis of tar from pine bark pyrolysis. Assuming that tar pyrolysis is a first order reaction, a curve was constructed of the time necessary for complete pyrolysis of tar versus temperature for the homogeneous reaction and for the reaction catalysed with sand and with dolomite. The activation energies of these reactions, the catalytical efficiencies of sand and dolomite and the heating values of the gases produced were determined. The use of dolomite as catalyst of tar pyrolysis can increase the heating value of the gases to a significant extent.

INTRODUCTION

We have collaborated with the TNEE Company (a subsidiary of st Gobain) in the development of new process fon pine bark pyrolysis (oimoulating in the development of a new process for pine bark pyrolysis (circulating fluidized bed) (1), in order to obtain a gas of medium heating value. All the processes involving thermochemical transformations of biomass fn onden to obtain altemnatives to forsil fuela produce gas chan and tan in order to obtain alternatives to fossil fuels produce gas chez and tar. Tar carried along by gas, condenses as soon as the wall temperatures deoreases. It is therefore advisable to remove it, and the best way is to use flagh pyrolysis consequently we ane intemested in determining oent use flash pyrolysis. Consequently, we are interested in determining certain kinetic data relating to the pyrolysis of tar from biomass pyrolysis in particular. As the results obtained by previous workers (2,3) are inadequate for the design of a gasifier, we tried to obtain some accurate data with and without catalysts in order to facilitate such a design. These data are the residence time (the time necessary for tar to be completly decomposed or, in kinetics terms, the reaction time of tar pyrolysis) and the activation energy. The changes in gas composition and heating values were also studied. 17. EXPERIMENTAL Apparatus (fig.I) shows the laboratory apparatus used for the experiments. It has already been described in details (4). Procedure: Tar vapours were always formed in the same way. Pine bark particles https://www.w3.org/1998/Math/MathML"> ( 1 - 1.25   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in diameter) dropped at a constant flow-rate (o.35 g/min) freely into the pine bark pyrolysis reactor - 2 - maintained at https://www.w3.org/1998/Math/MathML"> 650 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Part of the gas and tar vapours, the whole volume of gas on tar vapours diluted with helium could be directed to the tar pyrolysis reactor. In the reaction cell of this reactor, three types of experiments were carried out under the following conditions: (1) empty reaction cell; (2) reaction cell filled with the sand used in the fluidized bed process developed by the TNEE Company; and (3) reaction cell filled with dolomite. The principles of calculation have been already explained (4). The catalysts used were sand and dolomite (4).

RESULTS AND DISCUSSION

Fig.2 shows the variation of the residence time necessary for tar to be completely pyrolysed. Curve I corresponds to the empty reactor. Curve I corresponds to the reactor filled with 187 of sand, the total Curve IL corresponds to the reactor filled with 187 g of tor filled with https://www.w3.org/1998/Math/MathML"> 128   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dolomite the total surface area of which is about https://www.w3.org/1998/Math/MathML"> 114   m 2 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Before starting the reaction and for each temperature, dolomite was decarbonated by heating it at https://www.w3.org/1998/Math/MathML"> 900 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in a current of air up to a total ¿isapoearance of CO. The modification of surface area that followed was not taken into account. The respective activation energies are 21.5,18.4 and https://www.w3.org/1998/Math/MathML"> 11 k c a l . m o l e - 1 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> As expected, the higher the catalytic efficiency, the smaller is the activation energy . As the surface areas of sand and dolomite available for the catalytic reaction in the reactor are of the same order of magnitude (134 me of sand and https://www.w3.org/1998/Math/MathML"> 114   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dolomite), it is possible, from the curves in Fig.4 to compare the catalytic efficiencies of sand and dolomite with respect to the empty reactor reaction for alfferent temperatures, and to compare the catalytic efficiency of sand with that of dolomite (table I). Table I : Comparison of catalytic efficiencies (V rate with sarid as catalyst) The comparison of gas from the pyrolysis of tar, either the tar pyrolysis reactor empty or filled with sand, is analogous to the gas composition of lignocellulosic materials pyrolysed at the same temperature. The results were completely different when decarbonated dolomite filled the tar pyrolysis reaction cell (Figs. 4 and 3). The first interesting observation is that there is no longer any co ; however, the composition of the other gases is not what one could expect from only the effect of CO absorption on decarbonated dolomite, as the contents of H. and CH are much higher and the contents of https://www.w3.org/1998/Math/MathML"> C n H , C H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and CO are much smaller than expected This confirms the favourable effedo of decarbonated dolomite on the formation of CH, as already pointed out by EKSTROM and al (3). When the temperature of decarbonated dolomite increased, the gas composition became slightly closer to that from pine bark pyrolysis, except for https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the content of which continued to increase. When dolomite was recarbonated and its temperature was https://www.w3.org/1998/Math/MathML"> 650 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , there was always a compositional modification, but much smaller: Hond co were modified in the same way as with decarbonated dolomite, but all the other constituents remained almost unchanged. The heating values of gases from pine bark pyrolysis and tar pyrolysed either in an empty reactor cell or in a reaction cell filled with sand do not differ from those of gases from pine bark pyrolysis only(Fig.5) A maximum seems to be reached around https://www.w3.org/1998/Math/MathML"> 500 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The restlts obtained with decarbonated dolomite are more interesting (Fig. 6). The heating values are distinctly superior to those obtained for gases crossing the sand or the empty reactor : more than 18.7 MJ m https://www.w3.org/1998/Math/MathML"> - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> instead of https://www.w3.org/1998/Math/MathML"> 15.6 M J m - 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . They seem to reach a maximum at around https://www.w3.org/1998/Math/MathML"> 650 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 18. CONCLUSION Common siliceous sand slightly increases the decomposition rate of tar from pine bark pyrolysis. On the other hand, decarbonated dolomite and even carbonated dolomite have significant catalytic efficiencies (see table 1). However, it seems difficult, if not impossible, to use them as heat carriers in a pyrolysis process such as that at present under development because they are too soft and would be quickly transformed into dust and carried along with the gases or the smoke. It is of interest to note that the mixture of molecules which compose the dolomite is a very effective catalyst, and this may constitute a starting point in the search for an efficient catalyst that will also meet all the other required qualities. 19. REFERENCES 20. (1) French Patent Pending (2) CHEMBUKULAM, S.K., DANDGE, A.S., KOVILUR, N.L., SESHAGIRI, R.K., VAIDYESWARAN, R., Ind. Eng. Chem. Proc. Res. Dev., (1981) 714-719.20 (3) EKSTROM, C., LINDMAN, N., PETTERSON, R., The Royal Institute of Technology, Stockholm (Private Communication) (4) DONNOT, A., RENINGOVOLO, J., MAGNE, P., DEGLISE, X., J. Anal. and Appl. Pyrol. (1985) (under print) Fig. 1. Experimental apparatus Fig. 2. Residence time for tar to be completely pyrolysed vs. temperature AN INTERMEDIATE CAPITAL INTENSIVE PYROLYSIS https://www.w3.org/1998/Math/MathML">   SYSTEM APPLICABLE TO DEVELOPING COUNTRIES     J.W. Tatom   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Kofi B. BotaAtlanta University223 James P. Braw1ey Drive, S.W.At1anta, Georgia 30314 - USA 21. Summary The main point of this paper is that time is ruaniag out for pyrolysis of agricultaral and forestry process wastes in IdDs. If the byproduct marketing problems it faces caunot be resolved quickly, then other technologies requiring only a fraction of the process wastes and serving onty the local, immediate needs of procesg plant opera tors will take over, rendering the vast majority of these residues economically uavailable as fuels. This is bad news for many LDCs who need every avatlable energy source. The Indfan experience with coal carbonization teaches many lessons that can be applied to this situation and, In LDCs where coal deposits are avallable and undevel oped, suggests the integration of soft coke and charcoal production and marketing. The paper argues that since the private sector lacks the means to establish a viable carbonfzation industry, goverament must temporarily intervene on the demand side to encourage utiliza tion of the char and oil products potentially avallable. In addition, the paper discusses some triresolved questions of carbonfzation plant production scale and technology. A brief review of recent techuical developments in moving-bed, partial-oxidation pyro1ysis technology in the Ph11ippines and in Thalland is presented. It is argued chat while techulcal improvements cat clearly be made, the basic Intermediate Capital Intersive design is reliable, appropriate and economical in LDCs, and is ready for commercialization. Finaliy 1t is observed that the same pyrolysis technology, with minor todifications, is applicable to the carbouization of coal. This reinforces the argument for integrating these two Industries where applicable. 22. THE PROMISE OF PYROLYSIS The promise of pyrolysis in Lesser Developed Countries as a technology for converting the vast quantities of agricultural and forestry process wastes available into clegn fuels has not yet heen realizod. In spite of the technical developments of the last ten years, there are few, if any, commercial uses of this technology befag made in the developing world - even though tt can be shown to be economically viable. While successful pilot scale pyrolysis systeras have now been built in Ghana, Indonesia, Papua New Guimea, Costa Rica, the Ph111ppines and Thailand at government and university laboratories (1-4) 1 under programs sponsored by a variety of private, government and international organizations, there has been little private sector involvement. Why is this so? Glearly the l Numbers in parentheses refer to citations listed on the References, 2 See (4) for a review of these project experiences and the associated technical and non-technical problems. need for renewable, clean burntng, indigenous fuels has not disappeared. The need Is only 1ncreasing, and the recent traglc events https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Arica portend that it will get much worse . In contrast, during the same period other conversion technologles stch as direct combustion and gasfflcation have aroused considerably greater commercial laterest at a variety of lustallations, including process plants. Thts is understandable to some degree stace there are many https://www.w3.org/1998/Math/MathML">   v a l l d   a p p l i a n t i o n e   o f   t h e s e   t e c h n o l o g i e s   t h e   t h e   b e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> valid applications of these techtologies 1 L Lib. but are they best suited to supply the euergy needs of processing plants? Typically, processing plants produce a waste stream having an energy content many times the energy demand of the facility. To 111 ustrate: (1) the energy value of wood residues from a sawmill may be ten to fifty times the mill energy needs - even after the ineffictencies of thermal and mechanical conversion are tncluded. (2) A study of one hundred randomly selected rlce mi11s out of the l2000 In the Ph111ppines (5) revealed that 84 percent produced more waste than required to run the plant, with an average producing four times the break even energy. (3) Peanut hu11s 1 a plies six feet deep 11ne the roads for miles around Dakar, Senegal, a graphic testimony of the quantity of residue avallable beyond that needed to fire the ancient, inefficient bollers that power the peanut o11 mills Therefore, from a national perspective, nefther direct combustion nor gasification, with a few exceptions, offers the best means for utilizlng proceca residues, hecause netther reculres but u small fraction of the Waste stream to supply the plant energy needs. The great matority is thus taused, teaving a masslve waste disposal problem. Thtis in this one thery https://www.w3.org/1998/Math/MathML"> 1 m p o r t a n t   a r e n g ,   t o e   u t i l i z a t   i o n   o f   p r o c e s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tion and gasification, in the Iong term, are simply not the most attractive technologies from a soctal and an environmental view, redardless of their level of development though they presently may provide a superior alteraative to imported fuel consumption. One Important reason for the commercial interest in residue buraers and gasifiers is the fact that they are desigaed to supply the ltunediate needs of an individual boiler or englae. This has given them a strong marketing advantage, since the bofler operator or gas producer is his own customer, and thus completely controls the economies and logintics of the situation. In contrast, pyrolysis produces a variety of products; 1. e. char, o11 and gas atlof which ls mot needed to fuel the plant and therefore must be sold to second parties - if the unit is to be economically viable. Typically these products, especially the char and o11, represent commodities for which there https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> no present market demand, even though that demand is latent. And therein 11es the problem. If there were long term solutions to the eaergy problem of hDCs that could avoid complete, efficient use of the great quantities of process Wastes available, the pyrolysis story would probably ead here a at least for the near future. However, it becomes clearer every day that for the developing world to survive the imininent, painful transition to wood as the fuel of the future will require takiag draconian measures. Therefore, every energy source avallable must be brought forth to f111 th1s critical period - while we walt for the trees to grow. Th1s undoubted1y w111 necessitate the full use of process and other wastes, and it additionally w111 most certainly require the exploitation of any avallable indigenous fossil fuels; e.g. coal, which is avallable in underdeveloped deposits https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a surprisiag number of LDCs. The recognition that coal and/or https://www.w3.org/1998/Math/MathML"> 11 gn 1 te https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> must play a part in this transition is not surprising, nor is it new. In fact Indla embarked on such an effort at a national scale almost 25 years ago, and today is beginning to see the frults of its labors. Moreover, the growing urbanization of the developing world, which W111 result in 45 percent urban population by the year 2000, makes Wht the development of clean burming fuels to avold further comtaminaVital the development of clean buruita fuels to avoid further containiaat tion of the environment. Awareness of this need led the Indians to develop coal carbonization technology, which in turn exposed them to the develop coal carboulzatioa techaology, which 102 turti exposed them to the was palnful, though educational, and has been recently reviewed (6) with the tdeo of trangferring the concent to other locs. of special signifithe idea of transferritg the cotrept to other LDCs. Of special siguili cance is the fact that this experience is not only relevant to the carbonization of coal, but also to the carbonization of biomass residues, and therefore teaches a number of lessons, espectally in the marketing of new fuel products. Because of the inescapable need for additional, clean burning energy sources, there can be little doubt, therefore, that pyrolysis must emerge as a basic technology in the developing world. In countries where both coal and process wastes are present, an fategration of the coke/char/tar production and marketing efforts is strongly Indicated. How carl this transitiot to pyrolysis be promoted? We believe that to facilitate raplo growth of a viable carbonization industry, there is no alternative but Eor government lavolvement to guarantee and stabilize demand for the pyrolysis products until the industry has reached a critical thresholc where commercial and domestic needs generate a self-sustaining market. The Indfans recognized the role of government https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> thelr coal carbonization industry, but approached the problem on the supply rather that the demand side with the formation of subsidized, state-owned corporations. This was not entirely successful. For this and other reasons, we believe the wisest course is to derive a system of goverument policies and, if neces sary, a temporary price support system to encourage willing entrepreneurs to enter into this activity. For example, the government itself could buy fuel from the carbonization industry. Further, https://www.w3.org/1998/Math/MathML"> 1 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> might add a tax on imported fuels for which carbonization by-products could be substituted, and it tight offer tax incentives to those who utilize these products. In heavy 1ndustry, such as cement, where huge guantities of energy are required and whtch have the flexibility of buruing a variety of fuels with little conversion costs, use of these by-products would have the effect of establishing a pricemdemand floor at a natlonal ievel. This would ulmost certainly stabilize the fledglitag carbonization fadustry. We believe that governments and international organizations Irust recognize their role in the development of a carbonization fndustry in LDCs and https://www.w3.org/1998/Math/MathML"> 1 m p l e m e n t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> programs and policies to facilitate its growth. Moreover, because the process plant owners https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lods are begluning to utilize biomass burners and gasifiers in significant quantlties, the time may soon come when these techtologies have taken over, and thus it is economically impractical to install pyrolysis plants, or any other conversion equip ment https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , to any significant extent. Thus, it is important for high level goverament decisions regarding this question to be made as soot as possible. But the needs do not end there, for many technical issues remain 3 In passing it should be noted that most of the arguments presented above should also apply to other methods for fu11 utilization of process wastes, a fact which ought to. double the pressure on governments to take 1 mediate action. Figure 1: Overall view of Philippita pyrolysis system. GASIFICATION OF AGRICULTURAL RESIDUES IN A DOWNDRAFT GASIFIER 23. SUMMARY 23.1. DESCRIPTION OF THE FUEL Fig 2a-d. Different design of the gasifier 24. RESULTS AND DISCUSSION tab 2. Tab.2 Operattng data and results of gasification tests in a down draft gasifier An energy balance over the process gives a total gasification efficiency to cold gas of https://www.w3.org/1998/Math/MathML"> 72 - 77 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> calculated on the lower heating value. At the test with cotton stall briguettes the grate was rotating during the whole run which gives an increased carbon loss and thereby a lower efficiency. Normally the grate had to be rotated only a fer minutes every hour. The measured tar content was in all tests below https://www.w3.org/1998/Math/MathML"> 1   g / N m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which is the highest value that can be accepted for a producer gas for internal combustion engines. REFERRNCES "Producer gas as fuel for motor vehicles". Överstyrelsen för ekonomiskt försvar, Stockholm, Sweden 1974. ACKNOWLEDGEMENT The authors are appreciative of the financial support for this work granted to The Beijer Institute and the sub-contractor The Royal Institute of Technology by the Swedish International Development Authority. We also acknowledge important contributions to this work by Dr Björn Rjellström and Kjell Alfvengren. SOME KINETIC ASPECTS ON THE PYROLYSIS OF BIOMASS AND BIOMASS COMPONENTS C. Koufopanos, G. Maschio, M. Paci and A. Lucchesi Dipartimento di Ingegneria Chimica, Università di Pisa, ITALY Summary An experimental and theoretical study on the pyrolysis of various biomass species and of their major components is presented. Experimental runs were carried out with the use of several thermogravimetric techniques. The obtained results indicate as the most significant parameters of pyrolysis the temperature, the solid residence time, the chemical composition of the materiat, the size and the shape of the tested particles. A lumping modelling approach is suggested for the intrinsic kinetics of the pyrolyzed particles. The biomass pyrolysis rate was related to the individual pyrolysis rate of the biomass components. For each component a reaction scheme involving three consecutive and competitive reactions was used.

INTRODUCTION

Pyrolysis is a step necessarily involved in a thermochemical conversion process of biomass (combustion, gasification, Tiquefaction). In order to optimize the whole thermochemical process it is useful to describe the pyrolysis using simple mathematical models for the intrinsic and global kinetics. We studied the effect of the most important parameters on the pyrolysis rate and especially the effect of the chemical composition of biomass on the charcoal formation. A first attempt to correlate the pyrolysis rate with the biomass chemical composition is presented.

EXPERIMENTS

We follow the progress of the pyrotysis measuring the weight-loss of single particles heated within a controlled temperature environment in an inert atmosphere (Nitrogen). Thermogravimetry Analysis (TGA) runs at a heating rate of https://www.w3.org/1998/Math/MathML"> 20 ∘ C / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were carried out in a CAHN thermobatance. In order to avoid either the heat and mass transfer phenomena effects the samples, we used in the above runs, had the form of a thin (1mm) Tayer of sawdust Isothermal mass-change determination runs were carried out in a special designed apparatus, which is described in detail elsewhere (1). We tested particles with different sizes (1-8mm) and shapes (spheres, cylindrical pellets). Flowing nitrogen was used in order to entrain the producted gas and eliminate, thus, the probable gas/solid secondary effects. Several lignocellulosic materials with a variant composition were tested (table I). TABLE I : CHEMICAL COMPOSITION OF TESTED MATERIALS ( % of dried basis) Material Hemicellulose Cellulose Lignin Extractives Ash Cotton https://www.w3.org/1998/Math/MathML"> ( 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.6 99.3 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.1 Lignin https://www.w3.org/1998/Math/MathML"> ( 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 94.0 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 6.0 OTive-husks 21.1 22.2 45.0 8.1 3.6 Beech-wood 12.7 50.5 29.6 5.3 2.0 HazeT-nuts 24.1 27.5 40.7 3.9 1.0 (1): organic components soluble in alcohol-benzene solution (2): practically it can be considered as pure cellulose (3): Tignin separed in our laboratories from olive-husks, by using the Klason method,

EXPERIMENTAL RESULTS AND DISCUSSION

The obtained experimental results suggest that the most significant pa rameters of biomass pyrolysis are: the temperature, the solid residence time, the chemical composition of biomass, the shape and the size of the particles. The differences on the behaviour of the major biomass components and of the various biomass species are cleary presented in the TGA results (fig.1,2). Cellulose is the component that, after a sudden decomposition, gives the lowest yield of charcoal, meanwhile lignin gives the highest yieTd. The various biomass species have an intermediate behaviour. We consider that the pyrolysis behaviour of the several biomass species can be attributed to the variant content of their principal components: cellutose, lignin, hemicellulose, extractives. So, olive-husks and hazel-nuts, species with rather high lignin content (table I), have a behaviour closer to the lignin one, meanwhile wood, a specie with cellulose as the dominant component, behaves in a manner more similar to the cellulo se one. Hemicellulose, the less stable and variant in the several biomass species component (2), ought to be responsible for the initial part of the biomass decomposition. Isothermal mass-change determination runs with cetrulose, lignin, wood and lucerne tend to confirm the above considerations (fig.3). The isothermal curves in fig.4 present cleary the strong effect of the operation temperature on the pyrolysis rate and on the conversion level. At temperatures higher than https://www.w3.org/1998/Math/MathML"> 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the degradation is a Tmost completed in a brief time period (smaller than 2 min). The pyrolysis continues then with a very slow rate until the final conversion is attained. The variances in the pyrolysis curves, especially in the initial part, of particles with different size (fig.5) indicate the presence of heat transfer phenomena effects. This is also confirmed from the fact that, in the case of the larger particles, the temperature inside a pyrolyzed particle arrives at the operation temperature after a noticeable time peri od (1). 25. KINETIC MODEL We suggest a model describing the intrinsic kinetics of the biomass pyrolysis. We consider that the intrinsic kinetics is reflected in the weight-loss curves of the fine particles (<1mm). For the larger particles a different kinetic scheme involving also the transport phenomena effects must be taken into consideration ( 1 https://www.w3.org/1998/Math/MathML"> ) , ( 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . As the lignocellulosic materials are extremely heterogeneous and the pyrolysis products involve a large number of substances, it is useful to represent the kinetics in terms of Tumped components. We choose as reactant lumps the principal components of biomass: cellutose, lignin, hemicellulose and extractives, and as product lumps: the charcoal, the volatile and the gaseous products. We consider that each product lump of biomass pyrolysis is the sum of the corresponding lumps which are yielded from the pyrolysis of the principal components of biomass. Each component contributes to the products formation proportionally to the corresponding contribution to the virgin biomass composition. The above consideration assumes that the biomass components act during the biomass pyrolysis in the same way as the isolated components react. The following kinetic scheme for the pyrolysis of the biomass components is suggested: https://www.w3.org/1998/Math/MathML"> A 3 1 - B * 2 ⏟ 3 C + V https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where:A represents the virgin material, B * an active intermediate, C charcoal, G the gaseous and V the volatile products. The reaction 1 follows a zero-order and the reactions 2 and 3 a first-order reaction low. Their kinetic constants are represented by Arrhenius https://www.w3.org/1998/Math/MathML">   1 1 a w https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . We fitted the above scheme on the TGA curves we have obtained for cellulose and lignin (fig. 7 ). In the case of hemicellulose and extractives as it was not possible to have a representative experimental curve, we fitted the scheme on an hypotetical curve that was formed from the difference of the TGA curves: (01ive-husks) - (Cellulose + Lignin). The system of the non-linear ordinary differential equations that describe the kinetic scheme, was solved using a 4 th kind Runge-Kutta technique and the best values of the parameters (table II) were estimated using a deepest descent algorithm and a least-square criterion. TABLE II : KINETIC CONSTANTS Component https://www.w3.org/1998/Math/MathML"> k 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> E 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> k 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> E 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> k 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> E 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Cellulose https://www.w3.org/1998/Math/MathML"> 10 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 123 https://www.w3.org/1998/Math/MathML"> 10 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 119 https://www.w3.org/1998/Math/MathML"> 10 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 129 Lignin https://www.w3.org/1998/Math/MathML"> 10 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 75 https://www.w3.org/1998/Math/MathML"> 10 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 63 https://www.w3.org/1998/Math/MathML"> 10 7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 103 Hemicellulose https://www.w3.org/1998/Math/MathML"> + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Extractives https://www.w3.org/1998/Math/MathML"> 10 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 75 https://www.w3.org/1998/Math/MathML"> 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 73 https://www.w3.org/1998/Math/MathML"> 10 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 110 840 The results of our model are in good agreement with the experimental ones (see for example in comparison the experimental and theoretical results for the pyrolysis of hazel-nuts in the fig. 6 ). CONCLUSION The above study shows that the intrinsic kinetics of the various biomass species pyrolysis can be analyzed in terms of the pyrolysis of the major biomass components. A reaction scheme of three simultaneous reactions are suggested for the pyrolysis of each component. This scheme, with the addition of a fourth reaction describing the continuous devolatilization of charcoal at the higher than https://www.w3.org/1998/Math/MathML"> 500 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> temperatures, can evaluate sufficiently the overali pyrolysis rate. A more precise description of the biomass pyrolysis can be obtained if we take also into consideration the probable physicochemical interactions between the biomass components. ACKNOWLEDGEMENT- The reported work makes part of the Ph.D.Dissertation of C. Koufopanos, grantee of the Commission of the European Communities, which is gratefully acknowledged. REFERENCES

C.KOUFOPANOS, Report, period:12.04.1983-30.11.1984 of the C.E.C grant No XII/355/82 E.

A.STAMM, E.HARRIS, "Chemical Processing of wood" Chem.Publ. Co, Inc,NY 1953. D.PYLE, C.ZAROR, "Heat transfer and kinetics in the low temperature pyrolys is of solids" Chem. Eng.Sci., Vol.39,1 pp.147-158, 1984. NOTE : the weight https://www.w3.org/1998/Math/MathML"> W ⋆ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the following figures represents the ratio: (weight - ash )/( initial weight - ash). Fig. I: TGA Curves for cellulose, lignin, olive-husks . Heating rate https://www.w3.org/1998/Math/MathML"> = 20 ∘ C / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . olive-husks and beechwood. Heating rate https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 20 ∘ C / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig.3: Isothermal mass-change determination curves for cylindrical pellets (lxl0mm) of cellulose, 1ignin, beech-wood and Fig.5: Isotherma 1. mass-change for beech-wood spheres. https://www.w3.org/1998/Math/MathML"> T = 450 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . at various temperatures. Tigh: Theoretical and experi- R. CAPART, L. FAGBEMI, M. GELUS Department of Chemical Engineering University of Compiègne (FRANCE) 26. Summary The pyrolysis of wood cylinders with diameters up to https://www.w3.org/1998/Math/MathML"> 22   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is in- vestigated with a simple device, which allows to measure in the same experimental conditions the weight loss of wood as well as the change of the temperature at the surface and inside the sample. Evaluated by differential scanning calorimetry, the heat of pyroly- sis appears to be slightly endothermic https://www.w3.org/1998/Math/MathML"> ( + 30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cal/g https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A good representation of the overall pyrolysis can be given by a mathematical model which includes the kinetics of reaction, the heat transfer by diffusion and the heat generation. 27. INTRODUCTION Irrespective of the type of gasifier (designed for the production of synthesis gas or of feed gas to a combustion engine), pyrolysis is an important stage in the gasification of wood, and can account for up to https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total volume of gas collected. As a result, a knowledge of the rate of pyrolysis is useful especially when the gasifier feed consists of relatively thick wood chips. BAMFORD et al (1) were the first to develop a mathematical model describing the thermal devolatilisation of wood. Their model requires a knowledge of the thermal diffusivity of wood and also of the heat of reaction of the pyrolysis process, which is assumed exothermic (-86 cal/g). Heats of reaction in the litterature are very variable depending on the author. The most reliable method of their determination, the differential scanning calorimetry technique, has been employed recently by Havens (2) ; this author showed that the heat of pyrolysis is in fact endothermic and relatively smal https://www.w3.org/1998/Math/MathML"> : 47 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cal./g in the case of pines, and around 25 cal/g for oak wood.

EXPERIMENTAL PROCEDURE

This consists essentially in measuring the weight loss of a wood cylinder sample in inert atmosphere, by means of a thermobalance whose furnace temperature is preset at a reference value (between https://www.w3.org/1998/Math/MathML"> 500 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 600 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). In the case of wood cylinders similar to those used in thermogra- vimetric experiments (12 cm long, 1.5 and https://www.w3.org/1998/Math/MathML"> 2.2   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in diameter), two ther- mocouples were used to record simultaneously the evolution of the tempe- ratures of the surface and centre of the wood cylinder. Differential scanning calorimetry (DSC) measurements were performed using an apparatus "THERMOANALYSER https://www.w3.org/1998/Math/MathML"> 990 it   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of DUPONT de NEMOURS, on about https://www.w3.org/1998/Math/MathML"> 10 m g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wood samples, in inert atmosphere, and using a temperature ramp of https://www.w3.org/1998/Math/MathML"> 20 ∘ C / m m . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 28. EXPERIMENTAL RESULTS Figures 1 and 2 show typical examples of the evolution of the mass, and of the centre and surface temperatures, of a wood cylinder (pine wood) rapidly plumged in the furnace, at https://www.w3.org/1998/Math/MathML"> 540 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The gradient of the temperature at the centre of the cylinder remains practically small between https://www.w3.org/1998/Math/MathML"> 360 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and then rises sharply above https://www.w3.org/1998/Math/MathML"> 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . On the other hand, it's only at the end of pyrolysis that the surface temperature of the cylinder attains that of the nitrogen gas stream present inside the tubular furnace. A DSC analysis on the char (cf. figure 3) shows very clearly the existence of an endothermic peak ohose maximum is situated at https://www.w3.org/1998/Math/MathML"> 380 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . the pine wood used, the heat of reaction of the pyrolysis process which is a function of the area of the shaded region is estimated at https://www.w3.org/1998/Math/MathML"> + 30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cal/g. 29. MATHEMATICAL MODEL OF THE PYROLYSIS PROCESS This model is developped from heat and mass balance equations on the wood sample. 30. Heat balance In the transient regime, the heat balance equation can be written, in cylindrical co-ordinates, as follows: https://www.w3.org/1998/Math/MathML"> ∂ T ∂ t = λ ρCp ∂ 2 T ∂ r 2 + 1 r ∂ T ∂ r + Q ρCp ∂ ρ ∂ t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with: T - temperature https://www.w3.org/1998/Math/MathML"> t   - time   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> r   - radius   λ   - thermal conductivity     Q - heat of reaction   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The boundary conditions are : https://www.w3.org/1998/Math/MathML"> r = 0   (axis of cylinder)   ∂ T ∂ t ( 0 , t ) = 0 r = r m a x (   surface of cylinder   ) T r m a x , t = T s ( t ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> T s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (t) being the surface temperature, measured using a thermocouple. 31. Mass balance Considering that pyrolysis is mere thermal decomposition, the mass balance concerns only the term describing the rate of decomposition. Among all the existing kinetic models, that Tang (3) best describes our experimental results. This model considers a 2 -stage decomposi- https://www.w3.org/1998/Math/MathML">   tion process, the temperature limit between stages being   325 ∘ C . The     model equations are as follows :    T < 325 ∘ C : ∂ ρ ∂ t = - 3.310 5 e x p ⁡ - 23000 R T ρ - ρ f T > 325 ∘ C : ∂ ρ ∂ t = - 6.5310 16 e x p ⁡ - 54000 R T ρ - ρ f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 32. APPLICATION OF THE MATHEMATICAL MODEL AND DISCUSSION The temperature inside the wood chip was calculated by a finite difference resolution technique of the heat balance equation. The simplifying hypothesis were as follows:

the ratio Q/\rhoCp is constant and is independant of the state of transformation of the wood

the size of the wood sample doesn https://www.w3.org/1998/Math/MathML">   † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> t change during the pyrolysis.

Below the threshold temperature of https://www.w3.org/1998/Math/MathML"> 390 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , wood is not completely pyrolysed and the thermal diffusivity ( https://www.w3.org/1998/Math/MathML"> α = λ / ρCp https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) is assumed constant and equal to https://www.w3.org/1998/Math/MathML"> 27 × 10 - 4   c m 2 / s . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Above https://www.w3.org/1998/Math/MathML"> 390 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the thermal diffusivity attains a much higher value : https://www.w3.org/1998/Math/MathML"> 120 × 10 - 4   c m 2 / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The change in thermal diffusivity corresponds to the abrupt jump in the rise of the temperature at the centre of the wood cylinder. This discontinuity is observed as from https://www.w3.org/1998/Math/MathML"> 390 - 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , temperature above which wood is supposedly completely transformed into char. On the other hand, as shown on figure 2, the temperature profile is correctly simulated, taking a heat of reaction of https://www.w3.org/1998/Math/MathML"> + 30 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cal/g. Once the model's kinetic and thermal constants are calculated by integration with respect to time of the kinetic equations, it then becomes possible to determine the density, https://www.w3.org/1998/Math/MathML"> ρ ( r , t ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which is a function of the cylinder radius and of the time of pyrolysis. The average density p(t) is obtained from integration of the following expression : https://www.w3.org/1998/Math/MathML"> ρ ‾ ( t ) = 2 r m a x 2 ∫ 0 r   m   ρ ( r , t ) rdr https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> There's good agreement between the experimental and calculated curves of mass loss, as can be seen on figure 1. 33. CONCLUSION The profile of the enthalpy-analysis curves, as well as temperature measurements inside the mass of wood, show the existence of a threshold temperature at https://www.w3.org/1998/Math/MathML"> 380 ∘ - 390 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> above which the wood is profoundly transformed the mass loss is practically invariant and heat diffusion is much more rapi.d. The mathematical model recommended is similar to that of Bamford. With calculated values of thermal and kinetic parameters, the rate and time of pyrolysis of relatively thick wood samples can be predicted. The model, by taking into account the endothermicity of the pyrolysis process, shows that the effect on the rate of heat penetration inside the wood, is negligeable. 34. REFERENCES (1) BAMFORD C.H., CRANK J., MALAN D.H. Proc. of Cambridge Phil. Soc. 42,166-1946 (2) HAVENS J.A. "Thermal decomposition of wood" Ph.D thesis, University of Oklahoma - 1970 (3) TANG W.K. U.S Forest Service Research Paper, FPL 71-1967 FIG. I : RESIDUAL MASS VS TIME (DIAMETER https://www.w3.org/1998/Math/MathML"> = 22 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MM) 846 FIG, 2: TEMPERATURE V https://www.w3.org/1998/Math/MathML">   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TIME (DIAMETER = 22 MM) FIG, 3 : DSC CURVE FOR PINE SAWDUST PLATFORM TESTS OF BIOMASS COMBUSTION AND GASIFICATION EQUIPMENT Miss Martine REYNIEIX C.E.M.A.G.R.E.F. B.P. 121 92164 ANTONY Cedex (FRANCE) 35. Summary Owing to its various research work on energy production from agricultucal wastes, C.E.M.A.G.R.E.F. is carrying out platform tests on biomass combustion and gasification equipment. Tests financed by A.F.M.E. better knowledge of specifications and performance of the available equipment with a view to helping users. Tests carried out mainly deal with home furnaces and with wood and charcoal low and thedium power gasifiers. The tests of home straw furnaces were carried out on manual and automatic feeding systems (bales, chopped straw, pellets) from 10 to 100 KW. Test runs of gasification plants concerned the whole system, including gasifier - filters - engine (generating set) from 20 to 150 KW power. The results obtained together with the lessons that can be drawn lrom the tests for developing combustion and gasification equipment are presented in this paper. 36. INTRODUCTION Development of energy production from biomass led the French manufacturers to take an interest in the market. As a result, a lot equipment was developed in both combustion and gasification fields. To provide a better knowledge of the specifications and performance of the available equipment, a test-programme (on site and on testing bench) was set up and financed by A. F.M.E. These operations should make distribution of reliable equipment easier in France as well as abroad, especially in developing cotutries. As part of this programme, owing to its research work on energy production from biomass, CEMAGREF was in charge of the platform tests on home straw furnaces and on low and medium-power gasification plants. 37. Tests on home straw furnaces: Tests were carried out on manual and automatic feeding systems (bales, chopped straw, pellets, etc.) ranging from 10 to https://www.w3.org/1998/Math/MathML"> 100 K W . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The procedure of tests which is based on the French standard NF 31 - 361 was jointly worked out by CEMAGREF and CETIAT (Centre technique des industries aerauliques et thermiques . The following features were determined for each equipment :

general specifications : conformity to plans and directions for use, size, materials, ease of utilization and maintenance, fire resistance, satety.

performance at different running rates : power, efficiency, autonomy, pollution control.

The testing bench on which the furnace was settled was a hydraulic open circuit, equipped with meastring and recording devices required for drawing up matter and energy balances (direct method and loss method). Measurements were made on stabilized rate, without using control systems BATCH CARBONISATION OF COCONUT SHELL AND WOOD WITH RECOVERY OF WASTE HEAT G. R. BREAG, A. P. HARKER and A. E. SMITH Tropical Development and Research Institute Culham, UK 38. Summary In small scale batch charcoal production, some two thirds of the calorific value of the feedstock is lost as waste heat. This paper describes technology whereby this waste heat can be recovered for use in associated processes, such as drying. Information is given on the development, application and economics of the technology Work started using coconut shell as feedstock and following pilot plant trials to prove the technlcal viability of the system, a prototype unit was developed. Subsequently the prototype was installed, commissioned and operated at a Desiccated Coconut Mill near Negombo In Sri Lanka during October-December 1983. The Unit was connected to an existing furnace/heat exchanger system modified for operation on the gases evolved during the carbonlsation process. The field trials demonstrated that the Unit as designed has a maximum capacity of

5 tonnes of dry coconut shell and yields 0.5 tonnes of saleable

charcoal. The trials also showed that the system as operated, produces charcoal and simultaneously generates process heat equivalent to approximately 180 litres of fuel oil per 10 hour operation with the virtual elimination of obnoxious fumes emitted during the traditional carbonisation process. Technical data of this system are presented and discussed; and the scope for application of the technology In the Coconut Industry in Sri Lanka is reviewed. Subsequently the system has been adapted for use with wood as a feedstock. The basis of the adaptation is described and preliminary findings outlined and dis cussed.

INTRODUCTION

In small scale batch carbonisation of charcoal, some two thirds of the calorific value of the f'eedstock is lost in waste heat. TDRI work on the introduction of improved charcoal production methods in developing countries led to consideration of the possibility of recovering this waste heat generated through the combustion of gases ard tars evolved during the carbonisation process. Scope for the potential widespread application of a waste heat recovery system In providing process heat is recognised. Among the specific drying applications for which this system might be suitable are those for coconut products, timber, tobacco, tea, coffee, cocoa, spices and in the food industry generally. The potential economic gains to industries in developing countries afforded by carbonisation waste heat technology units are considered later. However, to put the potential into perspective, some global figures of wood ard charcoal production are presented. Some https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the world's round- wood is produced in developing countries and it is estimated that some 250 million tonnes per annum of wood residues, excluding sawdust and bark, Figure 1: Average Heat Distribution of Shells

FIELD TRIALS IN SRI LANKA

ports (5) were equispaced around the few readings of exhaust gas oxygen levels were also taken and the rate of DC production measured. Molsture contents of the feedstock were determined on site and samples of feedstock and charcoal were taken for analysis on return to the UK. Typical results are given in Table I. Table I: Charcoal Quallty. Runs 1-10 From the data collected, heat and mass flows through the system were estimated and are summarised in pigures 5 & 6 The flow charts ofive a mean of the last 10 runs when a standard method of operation had been fully established (see Table II). The amount of heat accounted for, based on the net calorific value of the feedstock, 1 s approximately https://www.w3.org/1998/Math/MathML"> 82 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> * The remainder is attributed to heat losses, experimental error and heat required to raise the temperature of the system up to operational levels. Table II: Table of Results. Runs l-10 (1) nominal

It must be noted that the heat and mass flow values given in this report are estimates and do not represent absolute values. Figure 5: Average Heat and Mass Flows on an Hourly Basis

1. REFERENCES (1) EARL, D (1975). A renewable source of fuel. UNASYLVA Vol. 27 , (2) SMITH, A.E. (1985). An analytical approach to the economics of small scale charcoal production in developing countries. Tropical science, https://www.w3.org/1998/Math/MathML"> 25 ( 1 ) , 2939 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (3) BREAG, G.R. and HARKER, A.P. (1979) The utilisation of waste heat produced during the manufacture of coconut shell charcoal for the centralised production of copra. Report, Tropical Products Institute, G127, IV + 22pp. (4) BREAG, G.R., HARKER, A.P., PADDON, A.R. and ROBINSON, A.P. (1984). The design, construction and operation of a unit for the carbonisation of coconut shell with recovery of waste heat. Report of the Troploal Development and Research Institute, G182, IV + 18pp. (5) PADDON, A.R. and ROBINSON, A.P. (1984). The construction and opera tion of charcoal kilns built with locally manufactured bricks. Rural Technology Guide, Tropical Development and Research Institute, 25(1), 29-39. FAST PYROLYSIS OF CELLULOSE R.G. GRAHAM, B.A. FREEL, M.A. BERGOUGNOU, R.P. OVEREND * AND L.K. MOK Engineering Science, The University of Western Ontario London, Ontario, Canada N6A https://www.w3.org/1998/Math/MathML"> 5 B 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> *National Research Council of Canada Ottawa, Ontario, Canada KIA ORG Abstract Summary developed at The University of Western Ontario to achieve the high heating rates, short residence times, high temperature and rapid quenching which are reatired to peoduce valuable non-equilibrium chemical intermediates (i.e. ethylene, acetylene, Tight organic liquids, etc.) from carbonaceous feedstocks. Hot solids and/or hot inert gas are used to carry and transfer heat to particulate carbonaceous feedstocks (i.e. wood, cellulose, 1igntte, coal, etc.) in a very turbulent vortical contactor (THERMOVORTACTOR). This in a very turbulent vortical contactor (THERHOWORTACTOR) rapid heat transfer. Preliminary trials with cellulose (Avice? rapid heat transfer. Preliminary trials with cellulose (Avice rise to the current cellulose pyrolysis kinetics studies conducted at temperatures between 750 and https://www.w3.org/1998/Math/MathML"> 900 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and restdence times of 40 to 700 mitiiseconds (ms). Data and the resulting kinetic parameters for a first order decomposition model are reported at 800 and https://www.w3.org/1998/Math/MathML"> 900 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 2. INTRODUCTION The fast pyrolysis of biomass has exhibited promising yields of high quality chemical intermediates (i.e. ethylene, acetylene, light organic liquids). Fundamental research has indicated that olefin yields of 10 to https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by mass of the biomass feedstock can be realized and that little or no char need be formed under conditions of short vapour residence times https://www.w3.org/1998/Math/MathML"> ( > 500 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ms), high temperatures https://www.w3.org/1998/Math/MathML"> ( > 700 C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , rapid heating rates (>1000 C/s ) and rapid quenching of the reaction products https://www.w3.org/1998/Math/MathML"> ( 1,2 , 3,4 , 5 , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , . A complete characterization of fast pyrolysis and an outline of its advantages with respect to product quality and selectivity over the more conventional conversion processes, have been presented previously https://www.w3.org/1998/Math/MathML"> ( 1,2 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> At the University of Western Ontario, the first phase of a fast pyrolysis program (ultrapyrolysis) was conceptualized with the intention of engineering a continuous process which would successfully demonstrate the chemistry of fast pyrolysis. The heart of this primary objective was the development of a new ultra-rapid fluidized bed (URF) reactor design in order to exploit and optimize fast pyrolysis product yields. The preliminary results were encouraging and are reported, along with details of the design, in a report to the Canadian federal Government (1). Upon completion of the first phase of the project, the system was modified to enhance operation for kinetics modelling, and was reinstalled in a larger laboratory. At the time of writing, nearly 200 kinetics experiments had been conducted using Avicel cellulose at temperatures between 700 and 900 C and at residence times of 40 to https://www.w3.org/1998/Math/MathML"> 700   m s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This paper briefly outlines the current Ultrapyrolysis process flow scheme and the experimental operating procedure, Quantitative results are summarized for cellulose pyrolysis trials at 900 and https://www.w3.org/1998/Math/MathML"> 800 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and kinetic parameters are reported for a first order decomposition model. 3. ULTRAPYROLYSIS FLOW SCHEME The major components of the current lltrapyrolysis (UP) process are illustrated in Figure 1. Rapid mixing and heat transfer are carried out in two conical vessels known as vortical contactors or vortactors. The finet has been termed a Themmowortactor and allows heat to he transferned first has been termed a Thernovortactor and allows heat to be transferred from d hot thermofor stream fi.e. gaseous nitrogen, suspended particulate solids, or a combination of the two) to the biomass. The second is a Cryovortactor and allows fast quenching of the products by the direct transfer of heat to "cryofor" (i.e. cryogenic nitrogen). The Thermovortactor has two opposing tangential intets for the thermofor. One tangential stream effectively destroys the momentum of the other causing severe turbulence. Biomass feedstocks are then injected from the top of the Thermovortactor through an air cooled tube into the turbulent reqion where mixing occurs within 30 ms. The hot gaseous product is rapidly cooled (i.e. < 30 ms) by the injection of a single tangential stream of cryogenic nitrogen. The fast pyrolysis of biomass is initiated in the Thermovortactor and continues in a plug-flow entrained bed downflow reactor. The reactor is simply a one meter length of Inconel pipe which is housed in an electricat simply a one meter length of Inconel pipe which is housed in an electrical Themmovortactor, through the entrained flow reactor, to the Cryovortactor. With the insertion of cylindrical inserts to reduce the reactor volume and by manipulating thermofor/biomass flowrates, the residence time i. e. the time from the heating of the biomass to the exit from the reactor) can be set between 30 and 900 ms. Reactor temperatures can be set in the range of 700 to 1000 c. The up flow scheme ts described in greater detail in a previous publication (6). 4. EXPERIMENTÁL In preparation for an experiment, the system is purged with nitrogen. The furnaces are then turned on and allowed to reach their setpoint temperatures. When the desired temperatures are reached, cryogenic nitrogen is injected into the Cryovortactor. Thermofor gas is then introduced into the system and the cryogenic nitrogen flowrate is adjusted to ensure that the cryovortactor temperature is less than 350 c. During this startup period the stream exiting from the cryovortactor is sent to a bypass filter assembly and vented. The biomass feeder is activated and its feedrate is verified by directing the biomass flow to a collection device mounted on a balance. Immediately prior to the actual steady state experimental run, the themmofor/cryofor stream (which ys exiting from the Cryovortactor) is switched from "bypass" to the mass balance filter. The btomass is directed to the Thermovortactor and the actual fast pyrolysis experiment is thereby inttiated. Products are initially quenched in the Cryovortactor while additional cooling (approaching room temperature) is carried out in a water-cooled coiled tube heat exchanger. Solids and condensibles are deposited in the filter, and the entire non-condensible product gas is collected in the gas collection bags. For extremely short residence time trials (when the yield of "condensibles" increases), an electrostatic precipitator unit can easily be integrated in the downstream gas line. The steady state experiment continues for 3 to 10 minutes. Static samples are taken from the gas collection bags and analyzed after the run is completed. Gas analysis is accomplished using a Carle (Model 111-H/197A) gas chromatograph. Condensible products are extracted with a solvent and recovered in a rotary evaporator. 5. RESULTS AND DISCUSSION The results of the fast pyrolysis experiments conducted at 900 and 800 C using Avicel phlo2 cellulose (a 100 um microcrystalline powder from FMC) are summarized in Table I Representative curves of the mass yield (o) of total gas and othylene vs nesidence time (ms) are given in Finures 2 and 3, pespectively. The shape of these curves (i.e. an initial rapid rate followed by a tapering off to a constant maximum yield) is typical rate followed by a tapering off to a constant maximum yield) is typicat for all of the individudl components identified in Table l. For example, the total gas production rate (i.e. the slope of the curve) at goo c is extremely rapid up to 100 ms and then tapers off, giving a maximum yield of https://www.w3.org/1998/Math/MathML"> 81 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (by mass) at 150 ms (Fig.2). The gas yield then remains constant at least until 400 ms, which is the longest residence time studied at this temperature At gon c however the gas production rate does not taner ternperature. At 800 C, however, the gas production rate does not taper after 350 ms. These trends are also observed for the individual components. The maximum yields of ethylene (Fig. 3) are https://www.w3.org/1998/Math/MathML"> 7.2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 6.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (by Coniponents. The maximun yields of ethylene (Fig. 3) are follo and https://www.w3.org/1998/Math/MathML"> 6.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (by carbons and total unsaturates are https://www.w3.org/1998/Math/MathML"> 16 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 11 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (by mass) respectively, at https://www.w3.org/1998/Math/MathML"> 900 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Corresponding values at https://www.w3.org/1998/Math/MathML"> 800 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are https://www.w3.org/1998/Math/MathML"> 16 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> A consideration of the equilibriun composition of the water-gas shift reaction https://www.w3.org/1998/Math/MathML"> H 2 O + C O H 2 + C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 900 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and the fact that the CO, CO https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and Ho yields remain constant leads to the conclusion that the shift reaction does not play an important role in the early pyrolysis reaction mechanism (i.e, at least up to https://www.w3.org/1998/Math/MathML"> 400   m s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 900 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). In addition, the yield curves for "frackable" hydrocantons (i.e such as ethylene, acetylene, ethane) indicate that no net themml decomposition of these hydrocarbons occurs over the cesidence times studied. Therefore, primary pyrolysis appears to consist simply of the "unzinoing" of the biomass polymer followed by rapid thermal fragmentation of the monomer units. There seems to be a lag time before additional gas phase reactions, such as the inevitable water-gas shift or thermal cracking of the hydrocarbons, occur to any extent. A simple and convenient approdch to kinetic modelling assumes that cellulose decomposes directly to each individual gas component by a single independent pathway and that the kinetics of the decomposition can be represented by a unimolecular first order reaction. This approach has been widely used in representing the kinetics of the fast/flash pyrolysis of biomass and coal https://www.w3.org/1998/Math/MathML"> ( 4,7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The following rate equation is thereby derived: https://www.w3.org/1998/Math/MathML"> V = V ⋆ [ 1 - e x p ⁡ ( - kt ) ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where V is the mass yield of a component at time 't' and temperature 'T', V* is the maximum attainable yield of the component at temperature it' and long residence times, and k is the Arrhenius rate constant (k = ko exp [-E/RT]). Best fit values for the kinetic parameters (V* and k) were estimated for all major components at 900 and 800 C using a least squares non-linear regression procedure. The regression curves are indicated by solid lines in Figures? and 3 , while the experinental values are solid lines in Figures 2 and 3 , while the experimental of total gas production are https://www.w3.org/1998/Math/MathML"> 81.0 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 74.6   s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 900 c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively, and are https://www.w3.org/1998/Math/MathML"> 78.4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 10.4   s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively, at 800 C. Corresponding values for the ethylene production rate are https://www.w3.org/1998/Math/MathML"> 7.15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 21.6   s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 900 c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and https://www.w3.org/1998/Math/MathML"> 6.55 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 9.55   s - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 800 c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Upon completion of the experiments over the entire temperature range https://www.w3.org/1998/Math/MathML"> ( 700 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 900 C ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the activation energies (E) and pre-exponential constants (Ko) will be estimated for each component. The mass balance calculations are not detailed in this report. However, atter the recovery procedure (solvent extraction and subsequent filtration and rotary evaporation) was carried out for several selected Figure 2 Cellulose Pyrolysis Kinetics https://www.w3.org/1998/Math/MathML"> 900 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 800 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : https://www.w3.org/1998/Math/MathML">   Figure   3   Cet 1ulose pyrolysis Kinetics   900   and   800 ∘ C :   Ethylene Mass Yield vs Residence Tine   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CONTRIBUTION TO THE EXPLOITATION OF RECOVERED WOOD THROUGH THE DEVELOPMENT OF CARBONIZATION AND ACTIVATION PROCESSES G. SAVOIA, G. BARBIROLI, A. GATTA, R. OSTAN, G. PASQUALI Azienda Regionale Foreste Emilia Romagna - Carbolisi S.p.A. Università di Bologna 6. Summary Much quantity of wood, residual from coppices or forest - trees harvesting, or from orchards pruning,is available in Emilia Romagna and might be upgraded, to higher value products, in accordance with a project started by the "Azienda Regionale delle Foreste" and with the cooperation of some industries (Carbolisi, Cooperative, A.S.O.). A positive and economic possibility refers to the production of charcoal and its consequent activation under Carbolisi's technological principle. A carbonization process has been developed, which allows the variation of the operative conditions according to the woody raw material quality and the desired end products. Many woody species may be used, whose commercial and technological characteristics have already been detected (black pine white fir, maple, white and black hornbeam major and minor ash-tree, beechtree, chestnut-tree, neapolitan alder, locust-tree, several oak species, elm, orchards prunings) For temperature, pressure and residence time different conditions are requested for each woody essence to obtain the charcoal highest yield. The involved plant is really ver satile though great attention must be paid to the pyrolytic gases and other by products. In the activation field, the qualitative characteristics have been defined for the active carbons, in order they meet the best performances and the lowest costs throughout their applications. Significant woody materials quantities, rotational or disposable in Emilia Romagna do exist, suitable for transformation into derivatives, which, due to their intermediate added value, their applied technologies, and their involved activities, assume an highly economic im portance of productive, energetic, and environmental nature. As a reference the following data may be considered: Total wood availability 920.000 Tons/Year

from orchards pruning 720.000 Tons/Year

from harvesting inside the forest

or from outside wood workings 200.000 Tons/Year A recent feasibility report establishes the principal phases for the best valorization of the woody materials in the Region. Considering the economical and technological maturity of the ransformation systems, in Italy and abroad, the possibility appears for a differentiated program to be immediately started to reach the appropriate rentability during each step of a modern industrial utilization of the non merchantable woody materials. The development must be gradual and the greatest attention must be paid to the collection of these normally spread materials, in order its heavily negative conventional incidence be conveniently reduced. Precisely the program includes:

placement of one or more carbonization plants (Carbolisi process) and consequent addition of the activation units;

placement of one or more ethanol production plants (Inventa or Gulf processes) by acid hydrolysis;

installation of a pilot plant for the extraction and refining of the wood essential oils (in connection with the "aromatic" plants project" of the Azienda Regionale delle Foreste); - development of a new technology for the cellulose enzymatic hydrolysis; - development of cellulose aerobic degradation with microorganisms for proteic feeding stuffs production.

Among the above initiatives the first and the second might be immediately implemented with technical and economical validity, whilst the other are still under trials and must be implemented. The carbonization and activation processes too, in spite of their technological maturity, have to be started and conducted to be consequently improved by the suggestions coming from a continuous working and adequate proofs plan. Particularly, with regards to the conversion efficiency, the carbonization times, the charcoal and byproducts quality, it can be said that the operative conditions have already been properly fixed for each wood essence. In fact the commercial and technological analysis of the principal species available in the Region (black pine, white fir, maple, white and black hornbeam, major and minor ashtree, beech tree, chestnut-tree, neapolitan alder, locust tree, several oak species, elm, together with several orchards prunings) show significant differences, and that leads to different carbonization modalities (temperature, pressure, residence time). The different species and their composition are two important elements for determining the technical and productive choice: it is useful to know the content of: cellulose, lignin, essences, pigments, resins, and water of course. Samples of different kinds, typical from Emilia Romagna hills, drawn from different parts of the tree, have been tested using the conventional and official analysis methods. The analytical results show relevant variations among the tree species, with reference to the benzene/ethanol extraction, for essences, resins and pigments. The highest percentage is coming from the barks. The richest extraction contents belong to the major and minor ashtree https://www.w3.org/1998/Math/MathML"> ( 29 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.), to the white fir https://www.w3.org/1998/Math/MathML"> ( 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.) and to the black pine https://www.w3.org/1998/Math/MathML"> ( 23 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The other kinds do contain inside the bark a quantity of extractable substances in a range between 3 and https://www.w3.org/1998/Math/MathML"> 7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.; the same applies to the trunks of any species and dimension. Very interesting is the composition for lignin and cellulose as reported for different species. Lignin inside the barks: black pine https://www.w3.org/1998/Math/MathML"> ( 36 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.), white fir, oak https://www.w3.org/1998/Math/MathML"> ( 31 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. ), black hornbeam, beechtree, ashtree (major), neapolitan alder, white hornbeam chestnut-tree (18-20% w.), ashtree https://www.w3.org/1998/Math/MathML"> ( 7 - 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Lignin inside the trunks and branches: black pine ( https://www.w3.org/1998/Math/MathML"> 28 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. ), white fir ( https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.), others (14. https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.) Cellulose inside the barks: white hornbeam https://www.w3.org/1998/Math/MathML"> ( 65 %w ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , maple https://www.w3.org/1998/Math/MathML"> ( 63 %w https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) beechtree, white hornbeam, chestnut-tree (60% w.), white fir, major and minor ashtree, oaks (55-57% w.), black pine https://www.w3.org/1998/Math/MathML"> ( 38 %w . ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Cellulose inside the trunks and branches: maple, black hornbeam, minor ashtree, locust-tree, red oak, white hornbeam, chestnut-tree, neapolitan alder (78-82% w.) black pine, white fir (68-72% w.). The fixed carbon varies between https://www.w3.org/1998/Math/MathML"> 22 - 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. inside the barks and https://www.w3.org/1998/Math/MathML"> 14 - 19 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. inside all the trunks and branches. The mineral substances are highly present inside the barks: red oak, locust-tree, minor ashtree, white hornbeam, maple https://www.w3.org/1998/Math/MathML"> ( 10 - 13 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w.); They are reduced inside the trunks and branches https://www.w3.org/1998/Math/MathML"> ( 0,30,5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. ) independently from the wood essence. Inside the leaves high contents of proteins have been found: locust-tree, maple (25-27% w.), major ashtree, neapolitan alder https://www.w3.org/1998/Math/MathML"> ( 23 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , white and black hornbeam https://www.w3.org/1998/Math/MathML"> ( 19 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , other kinds (7-13% w.). The cellulose content inside the leaves (oven dry) is relevant too: red oak, white fir, major ashtree https://www.w3.org/1998/Math/MathML"> ( 21 - 24 %w , ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , all others https://www.w3.org/1998/Math/MathML"> 13 - 18 % w * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The accuracy of the results is good, because for all the samples two analyses gave coincident values, and it may be observed that the woods, where two or more different samples were available, presented a high homogeneity with reference to the cellulose, lignin, extractable substances and fixed carbon percentages. https://www.w3.org/1998/Math/MathML"> ( 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Although the wood carbonization may be considered as a relatively simple technology, to obtain economical results an optimization of several interfacing parameters must be done and a greater attention must be devoted today than it was before, especially as a function of the consequent activation phases, which offers a valorization of the wood greater than the charcoal production alone. The carbonization process involves the following operations:

Special containers loaded with wood pieces, of suitable dimensions and moisture, are intro duced into a furnace (U Type), formed with two parallel tunnels, connected by a common wall. This furnace (called reactor) includes consequentially the zone for: wood preheating and drying, containers transferring from a tunnel to the other, wood carbonizing, charcoal cooling. The heat is furnished to the wood indirectly in the carbonization zone by a proper heat exchanger, and directly in the drying and preheating ones, by combustion fumes obtai ned in an adjoining combustion chamber. The moisture free wood is separately extracted from the drying zone, and this leads to have a more concentrated pyrolytic liquid from the carbonization zone. The incondensable pyrolytic gases, generated by the carbonization me chanism, are burnt, in the said combustion chamber, to produce the heating fumes. Out of the pyrolytic vapours stream, coming from the carbonization zone, products are condensed as the vegetal tars, and the watery pyrolytic liquid from which, if required, in a separate unit acetic acid, raw methanol, distilled water, and phenolderivates by fractionation might be obtained. The containers transferring zone, between the wood drying and the wood carbo bonizing ones, operates as a cleaning room, because it prevents qualitatively different gaseous fluids from mixing in the above mentioned zones. Out of the charcoal cooling zone the containers with the charcoal are automatically unloaded; then, loaded with wood, they are ready to start the process again. (2)

The process influencing parameters are: temperature, residence time, reactor pressure, type, dimensions and moisture content of the wood. As the carbonization temperature in reases the pyrolytic products (liquid and gas) yield increases and the charcoal one decreases. The temperature variations also influence the composition of the products, including "the charcoal". Pratically, as it is expected, higher the temperature higher is the fixed carbon con tent,being all the other conditions the same. Some indications are given in table 1 (beechtree). https://www.w3.org/1998/Math/MathML"> T ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Yield % w. on d. wood Charc. Compos. % w. Charc. Moist. % Yield Fix C % w. CHAR. LIQ. GAS FIX. C VOL. ASH % 450 33 43 24 75 21 4 4 23.76 550 28.5 46 25.5 87 9.5 3.5 3 23.92 650 27.5 46.5 26 89 8 3 2.5 23.74 750 27 46 27.5 90.5 6.5 3 2 23.94 The figures show that the complexive charcoal yield decreases as the temperature increases, but with a significant and proportional increase in the fixed carbon content, in such a way that the yield referred to this last is pratically constant. Generally speaking a production of charcoal at higher carbon content is preferable, but this means a significantly higher energy requirement. Because the fixed carbon content increases by about https://www.w3.org/1998/Math/MathML"> 7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. only, between 550 and https://www.w3.org/1998/Math/MathML"> 1000 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> it is really questionable whether operating at so high temperatures is interesting or not from the economic point of view, unless one wants to prepare in this way the charcoal for the possible following activation step. The combination in the process of the temperature combustion fumes at their inlet with their quantity, the heat exchange coefficient, and the internal speed of the pyrolytic emissions from the carbonizing wood, leads to variable temperature diagrams along the axis of the carbonization zone and these contribute to know how to improve the qualitative and quantitative yields of charcoal and pyrolytic byproducts. The inclinations of the temperature diagrams, (temperature versus combustion zone length), correspond to different heating velocities, which influence the results already discussed. With reference to the physical properties of the wood essences, those with less bulk density and softer are more suitable to the carbonization and activation processes, although the more economical production of the charcoal alone is preferably made with hard woods at higher bulk density. Relevant influence is represented by the moisture, chosen around https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> w. and by the thickness which conveniently must not exceed https://www.w3.org/1998/Math/MathML"> 20   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Indicatively the economical profile of the proposed carbonization process may be summarized: process investment US. Doll. 1.000.000 logistic investment US.Doll. 300.000 TOTAL US.Doll. 1.300.000 (1 US. Doll = Lit. 2.000) - Capacity 6.000 Tons/Year, turnover on Italian basis US.Doll. 1.650.000.= wood consumption 3,8 Ton/Ton, energy consumption 100 Kwh/Ton; Costs: wood US.Doll. 627,000, labour US.Doll. 210,000 ; others (utilities, maintenance, general expenses, commercial expenses, working capital interest, a.s.o.) US.Doll. 200,000, Depreciation 10 year and capital interest https://www.w3.org/1998/Math/MathML"> 18 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> /year US.Doll. 356,000 ; Total costs US.Doll. 1,393,000 - Gross profit US. Doll. 207,000, Net profit US.Doll. 124,000 - Net profit + Depreciation US. Doll. 284,000 Gross R.O.I. (including working capital the invested money is US.Doll. 2,000,000,=), 10.35% year; Pay Out Time less than 6 years. The true valorization of the process, from the thermodynamic and econornic point of view, is the possibility to reach immediately the charcoal activation step in a separate unit by using the exceeding energy from the carbonization byproducts. This relevant aspect must be emphasized, and studies and trials must be continuously conducted to improve the activation modalities to produce the best qualitative range of "Active carbons", whose performances must meet cheaply and competitively the applications requirements. First of all researches have been oriented to the identification of the commercial and technological characteristics necessary to the market, of the several poisons adsorbers from industrial and civil waste effluents, of the drinking water treatment, of the chemical purification and so on. Great internal surface area, high adsorptive capacities, appropriate densities, good pores distribution, adequate distributive handling are problems connected with a second and more sophisticated program of research, which includes the production cost reduction of course The raw material pretreatment before the two processes is also important, and interesting results are coming out from the daily coordinated work. 7. BIBLIOGRAPHY: (1) BARBIROLI G., MAZZARACCHIO P., Studio di fattibilità sulla valorizzazione di mate riali ligno-cellulosici come materie prime nella produzione di combustibili e derivati chimici. "L'utilizzo delle risorse forestali in Emilia Romagna". Monografia dell'Azienda Regionale delle Foreste - Bologna 1984. (2) OSTAN R. Sistemi energia 1982 , Busto Arsizio - Descrizione dell'Impianto di carbonizzazione Carbolisi di Mortara (PV). RESULTS OF TESTS WITH DIFFERENT GASIFIERS FOR FARM USE Summary Alr gasiflcation ls one of the more promising energy generation technologles for the farm. The results of an exhaustive campalgn on plants having different technical characteristics, mostly funded by ENEA, are given. FOREWORD Rational application of renewable energy sources on the farm requires careful evaluation of the quality and quantity pattern of the farm s energy demand, In fact, since the cost of all renewable energy sources fa significantly higher than that of conventional energy of fossil origin, the energy supply should closely match the demand pattern so as to maximize vetlization without expensive storage systems WLth specific reference to electricity generation, the many experiments made In the past few years highlighted insoluble problems of plant complexlty when solar energy https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> used to power Rankine-cycle engines, wh1le photovoltalc cells and windmills are very expenstve and therefore scarcely competitlve. Instead, the technologies at present having a more favourable cost/ benefit ratio are biogas production from animal waste and vegetal byproduct gasificatıon. The former speciflcally finds 1ts optimum utillzation when the electricity demand is sufficiently constant with time and therefore matches biogas supply. When, as ls often the case on a farm, energy demand swings widely durlng the day or during the year, a gasifier fuelling an electric generating set undoubtedly makes better sense. In this case, fn fact, energy ts stored as blomass, which 1s much easler and cheaper to store than other forms of renewable energy, and the plant can be run only when energy 18 actually needed. Based on the above, exhaustlve experiments were run on gasifiers of various types, having different technlcal and operational characteristlcs, to evaluate their performances and assess thelr actual usefulness to agriculture 8. PLANT DESCRIPTION The plants tested break down into three maln groups: downdraft gasiflers, updraft gasiflers and fluid1zed bed gaslfiers. Spectfically, their characteristlcs are: a) Downdraft gasifler, output https://www.w3.org/1998/Math/MathML"> 45   m 3 / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> approx., feeding an electric generating set of https://www.w3.org/1998/Math/MathML"> 13 - 14   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> electric output. The fuel https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sma11-to medlum slze wood https://www.w3.org/1998/Math/MathML"> ( 50 × 50 × 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mon approx.), malze cobs, briquetted byproducts (grape seeds, sawdust, nutshells, etc.). The gasifier is manually stoked. b) Gasifier as above, with twice the output https://www.w3.org/1998/Math/MathML"> 100   m 3 / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gas, https://www.w3.org/1998/Math/MathML"> 25 - 28   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This plant is technologlcally more sophisticated, belng equipped with a pneumatic fllter-cleaning system, forced draft gas cooling and automatic stoking system with a load cell carrylng the reactor, which controls fuel supply from a storage hopper. c) Updraft gaslfier, gas production https://www.w3.org/1998/Math/MathML"> 20   m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , fed with charcoal and charcoal derivates (briquettes prepared from coal dtst and scrap under pressure with the aid of a binder), to fuel a 5 to 6 kW engine. d) Downdraft gasifier and dIrect gas combustion for hot aIr production, output 200,000 kcal/h https://www.w3.org/1998/Math/MathML"> 5,000 - 6,000   m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of air at https://www.w3.org/1998/Math/MathML"> 150 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . e) Fluidized inert bed gasifier, gas production https://www.w3.org/1998/Math/MathML"> 30   m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , fuelling speclal burners (total output 35,000 kcal/h), bulk-fed with dust and granules of ollve residue, rice chaff, ground grape seeds, sawdust, etc. smaller than 2 mm). The above plants represent different approaches, since types (a) and (b) are of medium to high technological level; (c) is a simplified plant, suitable to exploit the significant mass of currently non-utilized charcoal waste in the emerging countries; (d) is suttable for Iarge heat demand, and (e) can be bulk-fed w1th any small-slzed byproducts from food processing (oll resldues, rice chaff, etc.) or from wood working, and which could not be used in a downdraft or updraft gasifler without expensive briquetting processes. https://www.w3.org/1998/Math/MathML">   RESULTS     P   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Protracted operation (some https://www.w3.org/1998/Math/MathML"> 200   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) of the five prototypes led to the following conclusions concerning tellization and typlcal problems. Gas quality: with the four updraft and downdraft gasifiers, gas composition and heat value scarcely vary with the type of fuel, provided the latter ts of a lignocellulosic nature and its molsture content does not exceed https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by wejght. Load variations and consequent air lntake rate varlatlons of the reactor are of limited influence, provided they are kept within the design data. Heat value swings from 900 kcal./Nm under anomalous operating conditions to https://www.w3.org/1998/Math/MathML"> 1,250 - 1,300 k c a l / N m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which should be considered the maximum for this type of gas. Gaslfler efficiency: specific fuel consumption at https://www.w3.org/1998/Math/MathML"> 10 - 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> moisture, and for the blomass types mentioned above, varles from 2.2 to https://www.w3.org/1998/Math/MathML"> 1.3   k g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , depending on the load; when running at https://www.w3.org/1998/Math/MathML"> 20 - 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of maximum rated load, consumption lies around https://www.w3.org/1998/Math/MathML"> 2   k g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , while it drops to some 1.3 https://www.w3.org/1998/Math/MathML"> k g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 90 - 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of maximum rating. Gasifler efficiency at full load https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 68-70% for small https://www.w3.org/1998/Math/MathML"> ( 5 - 6   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> plants, and attalns https://www.w3.org/1998/Math/MathML"> 75 - 78 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for plants above 200 Nm https://www.w3.org/1998/Math/MathML"> / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> output, especially when the process afr is preheated by waste heat. Char build-up: 1t depends on biomass type and size; with wood of optimum size for the gasifier, char drops to a minimum https://www.w3.org/1998/Math/MathML"> ( 2 - 3 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and increases with nutshells and the tike https://www.w3.org/1998/Math/MathML"> ( 4 - 5 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Generator set efficiency: the efficiency of the gas-electricity conversion ranges Erom https://www.w3.org/1998/Math/MathML"> 13 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> minimum to https://www.w3.org/1998/Math/MathML"> 23 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> maximum when the load goes srom https://www.w3.org/1998/Math/MathML"> 25 - 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 90 - 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of rated load; when accounting for gasifier efficiency, the overall efficiency (electric power output/blomass energy input) lies between https://www.w3.org/1998/Math/MathML"> 9 - 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> minimum and https://www.w3.org/1998/Math/MathML"> 19 - 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> maximum, with low molsture, optimum s1ze blomass. Some problems were encountered in setting the speed regulator of the motor-alternator set, with consequent instability at variable Ioad Tar and oily matter build-up: with the downdraft technique, build up of heavy ofly matter (mostly of a phenolic nature) is significantly reduced. In fact, the vapours and volatile matter that distill from the biomass under the effect of heat (pyrolysis) tmmediately flow through the red-hot bed in correspondence with the biomass afr-oxidfzing zone, where they are eracked and converted fnto permanent gases. Whath the updraft technique lnstead, and when the blomass has high volatile, lignin-rich matter content, a large amount of watery and o1ly vapours rich fn actid alcohol and phenolio compotinds forms ortginetes diffleult to control alcohol and phenolic cowpounds forms, originates difficult to control mists upon gas cooling and causes operating problems. Therefore, the results confirm that the updraft technique (gastfler "in") is especially https://www.w3.org/1998/Math/MathML">   g u l t a b l e   f o r   t h e   g a s t f t a n t i o n   o f   t h a r c o a l   h a v i n g   l o b l e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> suitable for the gasification of charcoal having low volatile matter content (6-8% against https://www.w3.org/1998/Math/MathML"> 70 - 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of usual blomass). Because of the low pyrolysable matter content, the gas ts relatively clean. When air is fed Pyrolysable matter content, the gas ts relatively clean. When alr la fed under the stoker, the ashes come in contact with highly oxidizing gas and the metals of the salts contained in the ashes (sulphates, silicates, carbonates, bloarbonates, etc.) remain in the oxidtzed (maximum valence) state and have high melting temperature. With the downdraft technique Instead, the ashes are in permanent contact w1th strongly reducing gas: the salt metala tend to go over to a lover velence (sulphates to the salt metals tend to go over to a lower valence (sulphates to sulphides, oxides to metals), and form low-melting eutectics, mostly consisting of alkaline salts, with consequent softenlng and caking of the gasification residues, which tend to clog the alr path. Efflciency of the puriflcation and coollng system: all the downdraft and updraft gasiflers tested posed some operatıng problem concerning gas purification, None behaved regulariv, without clogged filters, serubher cyclons or bags and consequent, sometimes large increase of pressure drop of the gas flowing through these devices. Further, with nitrogen-rich blomass such as briquetted grape seeds, corroston sets on tn the wet coolers due to the bulld-up of ammoniacal condensates that attack metals other than stainless steel. Remarks on flufdized bed gasifler operations: the temperature profile within an inert fluidlzed bed ls very uniform (the maximum variation was some tens of degrees from spot to spot) as compared with the downdraft gasifier, https://www.w3.org/1998/Math/MathML"> 1 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which the temperature can swing by as much as 300 to https://www.w3.org/1998/Math/MathML"> 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , also in the air inlet areas. This untform temperature is due to the large heat exchange generated by the rapidly moving solid particles and does away with the harmful hot spots occuring in downdraft or updraft gasiflers However, the mean bed temperature https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at least https://www.w3.org/1998/Math/MathML"> 200   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lower than that obtainable In the downdraft system, and the esothermal reactions developIng CO and https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are not as strong, with consequent larger amount of inert gases in the gaseous phase. For equal combustion alr/fuel ratios, owing to the lower temperature the biomass ylelds https://www.w3.org/1998/Math/MathML"> 10 - 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> less gas, and a correspondıng quantity of residues bulld up in and tend to swell the bed. The gas has slightly poorer quality, Its heat value ls lower (some 1,000 kcal/Nm ) 3 and density greater. The heat value can be ralsed to 1,200-1,300 kcal/Nm by runnlng at lower air/fuel ratios so that the gas is enriched by high energy content hydrocarbons formed by the cracking of the primary breakdown products of biomass in an aIrless environment. In this case however, the combustion resldues grow to some https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of biomass, with a further negative effect on the gaslfication efficiency. 9. CONCLUSTON Notwithstanding the problems encountered, which show further development work to be needed, the operating characteristics of the plants tested prove gastfication to be of viable interest. Durlng the tests the plants showed falr overall efficiency, and, when fed with the proper fuel, ran 10. MAIN REFERENCES Specific biomass consumption versus electric power in plant A and B. 11. ENVIRONMENTAL ASPECTS OF BIOMASS GASIFICATION Dr.P. Schulze Lammers Technische Universität München Bayer. Landesanstalt für Landtechnik Vöttingerstr. 36 D-8050 Freising 12. Summary In the gasification of biomass, two steps in the process should be examina- ted with respect to their environmental acceptability. Liquid by-products are produced during gasification, which could represent a severe environ- mental burden Noxious substances are also released into the atmosohere by the exhaust of producer gas engines. The liquid condensate can be rendered harmless to the environment, however, the technology is expensive. The active slime method should be considered for large amounts of con- densate. Smaller amounts can be disposed of in a harmless and energetically efficient way by heating it to approximately https://www.w3.org/1998/Math/MathML"> 900 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The CO and NO emis - sion from a producer gas engine are less those from a diesel engine.. 13. RELEVANT ENVIRONMENTAL ASPECTS OF GASIFICATION The thermochemical gasification of plant material is accompanted by the release of condensable components. The condensate contains water resul- ting from the moisture in the feedstock as well as that formed by partial combustion, and chemical reaction by-products from the plant material. The amount and concentration of noxious substances in the condensate varies according to gasifier type (downdraft, updraft, fluidized bed), how- ever, it is expected that the condensate will have to be treated and dispo- sed of in all gasifiers. The problem of contaminated-water treatment and disposal will always occur when the raw producer gas is cleansed with gas scrubbers. In the framework of a R+D project supported by the German Ministry for Research and Technology, a counter-current gasifier was investigated in collaboration with the M.A.N. -Neue Technologie, Munich. With grain straw and wood as feedstocks, the results reported here were obtained in a series of measurements. The condensate from the counter-current gasifier contains water and chemical components. The amount of water was determined through elementary mass balances. Figure 1 shows that in addition to the water resulting from the moisture in the fuel, water is also formed chemically. The chemical components are shown in Table 1 . The component with the highest concentration is acetic acid at 26 g per liter of condensate. More important for the environment, however, is the presence of phenols and cre- sols due to their toxic effects. The total contenct of organic carbon (Toc), representing the amount of unidentified components, is also included in Table 1 along with the biochemical (BSB) and chemical (CSB) oxygen demand. The latter values are especially important when employing the active slime method for disposal. Investigations https://www.w3.org/1998/Math/MathML"> ( 1,2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> have shown that the oxygen demand can be reduced by approximately https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with the active slime method. A second possibility is heating or combusting the condensate. Figure 1: Condensate production versus fuel consumption (wet) for wood Table 1: Concentration of the relevant condensate components https://www.w3.org/1998/Math/MathML"> ( CSB = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> chem. oxygen demand, BSB= biochem. oxygen demand, TOC= total organic carbon) Average Variation pH Value 4,2 0,5 Pheno1 https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2,4 0,7 Creso1 https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 1,3 0,4 Acetic acid https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 26,0 13,0 Methanol https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4,1 2,2 CSB https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 107,0 33,0 BSB https://www.w3.org/1998/Math/MathML">   TOC   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> ( g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 60,0 19,0 https://www.w3.org/1998/Math/MathML"> (   g / 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 47,0 23,0 Figures 2 and 3 show the dependence in the amount of the most important combustion products https://www.w3.org/1998/Math/MathML"> C O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C x H y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the furnace temperature. At https://www.w3.org/1998/Math/MathML"> 900 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the flue-gas is nearly free of contaminates. From Figure 4 , the amount of condensate (in relation to the consumed fuel), which can be injected into the combustion chamber, can be deduced. To guarantie complete combustion at sufficiently high temperatures https://www.w3.org/1998/Math/MathML"> 900 ∘ ( ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a maximum of https://www.w3.org/1998/Math/MathML"> 0,4   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> condensate per kwh of producer gas as fuel should be burned. This is the case when the oxygen content in the flue-gas (excess combustion air) is to be held very low. Figure 2: CO-emission of the furnace with condensate injection Figure 3: CH-emission of the furnace with condensate injection 14. ENVIRONMENTAL ASPECTS OF GAS UTILISATION Gasification serves the conversion of a solid fuel into a gaseous fuel. The greater technological effort compared with simple combustion is justified when subsequently, a more valuable end-energy can be generated. Producer gas, therefore, appears predistined for an application in engines. The exhaust can be a relevant factor effecting the environment. The Figures 5 and 6 give the results of an exhaust gas analysis for a producer gas engine https://www.w3.org/1998/Math/MathML"> ( 125   k W , 12.5 : 1,211 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Figure 5 : CO-emission of the engine https://www.w3.org/1998/Math/MathML"> ( 97   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at various ignition points versus air mixture The nitrogen oxide content rises sharply when the ignition is advanced and the air mixture reduced. The co emission, on the other hand, has its minimal value at https://www.w3.org/1998/Math/MathML"> = 1.15 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Compromises in the reduction of harmful emissions have to be made when tuning a producer gas engine, just as is the case for internal combustion engines with other fuels. Figure 6: https://www.w3.org/1998/Math/MathML"> N O x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -emission of the engine https://www.w3.org/1998/Math/MathML"> ( 97   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at various ignitions points versus air mixture REFERENCES: (1) SCHULZE LAMMERS, P.: Kenngrößen der thermischen Gegenstromvergasung von Weizenstroh und ausgewählter Holzbrennstoffe, Diss. TU-MünchenWeihenstephan, 1984 (2) LEUCHS, M.; P. SCHULZE LAMMERS: Vergasung von Biomasse und Nutzung des Gases zum Antrieb von Motoren, Endbericht zum https://www.w3.org/1998/Math/MathML"> F + E - V V   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Haben https://www.w3.org/1998/Math/MathML"> 03 E - 4469 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> B des BMFT Author: Dipl-Ing Kurt W Jaster FRITZ WERNER Industrie-Ausrüstungen GmbH D-6222 Geisenheim, West-Germany 15. Summary In view of the fact that the supplies of crude oil will soon be exhausted and due to increasing oil prices technologies of alternative energy generation gain new significance. The well-known technology of wood gasification was taken up, and modern applications of the fixed-bed gasifier with co-current gasification is described. The future will show the introduction of the fluidized-bed gasification and it will indicate the construction of a prototype plant. 16. INTRODUCTION Technological processes of ten have a habit of reappearing in a modified form many years after the original invention was first presented However, there must be an economic necessity if the reincarnation is to be successful. The generation of combustible gas out of wood and biomass similar to wood is a well-known technique. However, to be applied in our present era it must correspond to the state of modern plant development, and it must be more economical compared with common processes for the generation of energy. In the years from 1930 to approximately 1950 gas if iers for lump wood were wide-spread due to well-known reasons. The units were manufactured in massproduction, and since liquid fuels were scarce, they were largely used on vehicles. The gasifiers were inexpensive. However both, the gasifier and the engine supplying power, had a short servicelife. During those years this fact did not really matter for badly driven was still better than a good brisk walk. Due to the substantial increase in cost of crude oil, and being under the spell of the fact that these energy resources will soon be exhausted, scientists and engineers began to be reminiscent of technologies able to replace oil, and if possible, able to dispose of waste materials. It is small wonder that in this context the wood gasifier of the thirties and forties was taken into serious consideration. This particular unit used to replace oil then. Therefore, the question rises whether it should not be capable of regaining similar importance in our present era. Reminiscences transfigure and the disadvantages of the gasifiers are slightly superseded upon reflection. Forgotten are the extensive maintenance, the substantial reduction of the engine output, the bad load change behaviour and the bulky fuel. Virtually forgotten is also the black slop of condensate which was disposed of underhand, a fact which still sends shivers up the spine of eco-activists. It can easily be understood that a modern wood gasifier only stands a chance if it can surmount the disadvantages of historical units. The characteristics of the modern, ideal gasifier are: mostly automatic operation low maintenance first class aas cleanina excellent load change behaviour minimizing of the condensate different fuels must be tolerated high efficiency. Unfortunately there is no ideal gasifier, and every scientist and engineer is forced to make compromises. Thus however, to successfully approach the ideal requirements, FRITZ WERNER is busy with the development of gasifiers by two different procedures: co-current gasification in the fixed-bed fluidized-bed gasification. The following chapters shall provide a close description of these units. 17. THE CO-CURRENT GASIFICATION IN THE FIXED-BED The co-current gasification in the fixed-bed is a development which applies the process of the famous down-stream gasifier but it has hardly any resemblance with the WW II model. The fuel supply (lump, dry wood) can still be done manually, however, it is usually arranged automatically. The biggest problem to be solved was the level sensing in the hot generator vessel as it sends out the signal to the conveying system filling the hopper. The next step was to solve the problem of the gas tight fuel charger. The valves must be gas-tight, and by no means should they be covered with wood tar. Step three is the gas flow in the gasifier. The gas flow must guarantee the cracking of all long-chained hydrocarbons; thus only carbonmonoxide, carbondioxide, hydrogen, methane in small quantities and nitrogen result. Step four comprises a gas cleaning of high quality so that modern engines with their low mechanic tolerances are not damaged. Step five is the conception of the gas cooling with dew point regulation; thus only a small amount of condensate must be disposed of. All five problems have been solved and FRITZ WERNER is in a position to offer gasifier for an output range of 20,40 and https://www.w3.org/1998/Math/MathML"> 60 k W e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These units work in suction operation. Therefore the gas flow occurs due to the suction stroke of the gas engine. unfortunately it was not possible to design these units as light and as small so that they could still be fitted onto vehicles. Their exceptional application is the stationary generation of mechanical (electrical) and/or thermal energy. The gasifiers described above are still equipped with a charcoal bed in the reduction zone which must be renewed regularly. Experiences have shown that according to the properties of the wood the charcoal bed must be replaced every 50 to 100 operating hours. However, the larger charcoal pieces may be reapplied. For an output range of 200 to 300 kwe a unit was built in the course of development which no longer requires the renewal of the reduction zone. The essential changes compared to the smaller models are: the gasifier operates in pressure operation the gasification air is supplied as unper and lower air the resulting ashes are disposed of via a turning grate the inside of the gasifier is equipped with refractory Iining The unit is designed for continuous operation and high availability. The units described comply largely with the ideal gasifier mentioned at the beginning of this report. Their only restriction is the fuel. Only lump wood with a moisture content of https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dry-basis is acceptable. A higher fuel tolerance cannot be obtained in the chosen gasifi- cation principle - co-current in the fixed-bed. New methods had to be found to avoid this handicap.

THE FLUIDIZED-BED GASIFICATION

The main goal of this development is to reach a high fuel tolerance and to obtain outputs up to 2 MWe or https://www.w3.org/1998/Math/MathML"> 10 M W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> thermal. Granular biomasses such as saw dust, wood shavings and tree bark but also agricultural residues like chopped straw, peanut shells, rice husks etc. shall be applied. The first step of development shall exceptionally serve to use wood wastes. The agricultural materials which due to their low ash melting point are quite problematic will be dealt with in a second step. The fluidized-bed was chosen as gasification principle since the fixed-bed has failed. Furthermore it was stipulated that no carrier media such as sand to stabilize the fluidized-bed shall be applied to simplify the process. So far experiments with pilot plants were conducted which have shown encouraging results. This was also the reason that a prototype of almost commercial size was tackled. Test runs with test plants have been conducted. However in the course of these tests it was realized that a stepwise scale-up will be necessary as usually in process development. The next step will be the construction and operation of a 200-300 kWel pilot plant equipped with all items which may be critical. Details of the fluidized-bed process are given in the joint data and flow sheets. Fig. 1. 40 MWE fixed bed gasifier in Indonesia FLUIDIZED - BED GAS GENERATING PLANT 18. https://www.w3.org/1998/Math/MathML">   GASIFICATION OF BIOMASSES     BY FTW-GASTETCATTON PROCFSS   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> BI   HIW-GASIFICATION PROCESS   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> H. Teggers, H. J. Scharf and L. Schrader Rheinische Braunkohlenwerke AG, Kö1n, FRG. 19. Summary The High-Temperature WinkIer (HTW) process is developed by the Rheinische Braunkohlenwerke AG (Rheinbraun) in cooperation with the engineering contractor uhde GmbH (Uhde) on basis of the atmospheric winkler process. By increasing pressure and temperature an improvement of carbon conversion and gas quality and an essentially higher gas output could be reached in a 25 t/day pilot plant on stream since 1978. On basis of these good results a large demonstration plant for gasification of Rhenisch brown coal to about 300 million m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> synthesis gas per year is under construction and will go on stream in mid-1985. The Rheinbraun HTW-process is also further developed for other carbonaceous materials. In a small process development unit of about https://www.w3.org/1998/Math/MathML"> 40   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> throughput various types of coal as well as wood and peat have been tested. Peat additionally successfully has been tested in the a.m. pilot plant. 20. INTRODUCTION Rheinische Braunkohlenwerke AG (Rheinbraun) has been developing the High-Temperature Winkler (HTW) pocess for fluidized bed gasification of Rhenish brown coal and other carbonaceous materials. The HTW development is based on the successful operation of two atmospheric Winkler gasifiers at Union Rheinische Braunkohlen Kraftstoff AG (URBK), WesseIing, a subsidiary of Rheinbraun (1). The development to the HTW process resulted in three additional achievements of economical importance: - Recycle of coal fines which are entrained from the fluidized bed increased the carbon conversion rate from about go % to Inore than https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

The increased pressure lead to higher reaction velocities and a higher specific gas output per cross-section unit.

Increased temperatures of the raw gas leaving the gasifier resulted in a reduced methane oontent and an increased carbon conversion rate and thus in a higher yield of syngas.

DESCRIPTION OF THE HTW PILOT PLANT

Basic design and operating data for the HTW pilot plant Which was started up in mid- 1978 have been obtained from the operating results of a process development unit (PDU) located TEMPERATURE WINKLER PROCESS

RESULTS OF THE HTW PILOT PLANT TESTS

FEEDSTOCKS FOR THE HTW PROCESS (3) (4)

So far Rhenish brown coal has been processed mainly in the pilot plant. However, a great variety of other carbonaceous materials is also suitable for the gasification applying the HTW process. Gasiticotion pressure: 1 bor, energy loss. https://www.w3.org/1998/Math/MathML"> 10 % , C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -conversion https://www.w3.org/1998/Math/MathML"> 95 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> SYNGAS PRODUCTION FROM WOOD BY OXYGEN GASIFICATION UNDER PRESSURE G. CHRYSOSTOME and J.M. LEMASLEFRAMATOME - Division Creusot-Energie 21. Summary The research developped during the past four years led to the concep- tion of a two steps process. The first one is composed of a fluidized bed gasifier where wood chips are continuously converted in a steatn and oxygen stream at https://www.w3.org/1998/Math/MathML"> 700 - 800 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The gas leaving that first stage of gasification mainly contains https://www.w3.org/1998/Math/MathML"> C O , H 2 , C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and H20 but also significant amounts of CH4 and higher hydrocarbons; such a gas is not suitable for methanol synthesis. In the second step, the raw gas leaving the fluidized bed gasifier reacts with additional oxygen into a partial oxidation reactor; methane and higher hydrocarbons are cracked at https://www.w3.org/1998/Math/MathML"> 1300 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and converted into https://www.w3.org/1998/Math/MathML"> C O , H 2 , C O 2 , H 20 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> An atmospheric pilot has been operated at Le Creusot since 1980, at a wood capacity of https://www.w3.org/1998/Math/MathML"> 400   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Long duration runs since the end of 1982 have confirmed expected results in terms of methanol yield (a poten- tial production of https://www.w3.org/1998/Math/MathML"> 0,5   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> methanol per kg dry wood gasified has been formed, with the syngas produced, at the Lurgi Gmbh Company, Frankfurt. A pressurized pilot unit based on the same process will be implemented at Clamecy (department of Nievre - France) with the financial help of the A.F.M.E. ("French Agency for Energy Savings ) and the E.E.C. The nominal capacity of this unit will be 60 tons per day (dry basis) of wood under a 15 bars pressure. Preliminary testings of the pilot plant of Clamecy should begin in 1986. 22. INTRODUCTION The "New Products" Service of CREUSOT-ENERGIE extended its activities four years ago to the development of new gasification and combustion pro- cesses. Within this service, the Laboratory of Energetic Testings was erec- ted in 1980. First, an atmospheric pilot unit was built for the experimen- tation of the oxygen gasification of wood in a fluidized bed in order to generate a syngas (for methanol production). That research has been led with the financial support of the A.F.M. E. "French Agency for Energy Savings") and the European Communities (DG XII, in the "methanol from wood" program). The construction of the atmospheric pilot plant has been achieved by the end of 1980. Since that date, experiments on various materials have been run on wood, straw pellets, pine bark, sugar cane bagasse pellets. 23. DESCRIPTION OF THE PILOT Figure I : CREUSOT-ENERGIE Process Schematic diagram of the atmospheric pilot plant ( https://www.w3.org/1998/Math/MathML"> 400   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wood) The pilot is composed of a https://www.w3.org/1998/Math/MathML"> 500   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in-diameter fluid-bed gasifier and a https://www.w3.org/1998/Math/MathML"> 800   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in-diameter secondary reformer. The gasifier is made of a steel casing with outside insulation. At the bottom, a fluidizing grid ensures the injection of an oxygen-steam mixture. The height of the gasifier is https://www.w3.org/1998/Math/MathML"> 5   m . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> In the upper part of the gasifier, a 700 mm in-diameter disengaging height ensures lower velocities of gases and so lower fine particles elutriation. Wood chips https://www.w3.org/1998/Math/MathML"> ( 50 × 20 × 10 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ma max.) are fed by a semi-continuous feeding system into a https://www.w3.org/1998/Math/MathML"> 0,7   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> charge hopper, then fed into a variable rotating screw feeder for adjustable feed-rate. Wood chips then fall down into a rotary valve and finally are fed into a second screw feeder at a high rotating rate for rapid transfer towards the hot zone of the reactor. The gasifier is equipped on its whole height with 18 thermocouples (cliromel alumel). The pressure above the fluidized bed and in the overall pilot is regulated jtust below the atmospheric pressure. The dry gas composition is measured with an infrared analyser for co and https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a paramagnetic analyser for 02, a gas chromatograph for CH4, C2H4, https://www.w3.org/1998/Math/MathML"> C 2 H 6 , H 2 ,   N 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Ar. An argon tracer is injected, at a controlled flow-rate in the gasifier, allowing to deterrine the dry gas flow-rate produced by the installation and so, to perform mass and energy balances. Abstract The raw gas leaving the fluidized bed gasifier enters into the secondary reformer where oxygen is also injected. The secondary reformer is a 5 m height vertical cylinder, refractory lined, allowing to work at temperatures greater than https://www.w3.org/1998/Math/MathML"> 1300 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Temperatures in that reactor are measured with six thermocouples (Pt - Pt.Rh). As at the outlet of the fluid bed gasifier, gases are analyzed. The gas leaving the secondary reformer is then cooled into a scrubber, sucked up by an exhauster and incinerated at the flare. The wood feed-rate is measured by accurate weighing of each charge fed At the beginning of each test, preheating of reactors is performed by natural gas combustion. The main set of results has been obtained during 3 long duration runs (100 hours each in stabilized gasification conditions) which were performed in november 82, december 82, march 83. Also, a 24 hours long duration run has been realized, at a https://www.w3.org/1998/Math/MathML"> 400   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wood feed-rate, in march 84 , at a wood moisture of 15 % on a wet basis. That last run was the guarantee run performed for the C.E.C. The following table I presents this set of experimental results and their comparison with the expected results of the pressurized pilot 3. EXPERIMENTAL RESULTS Atmospheric pilot (Le Creusot) Pressurized pilot (Clamecy) Status PROVEN ESTIMATED Wood moisture (%) 15 15 Fluid bed T ( https://www.w3.org/1998/Math/MathML">   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) 700-750 700-750 Secondary reformer T ( https://www.w3.org/1998/Math/MathML">   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) 1210-1450 1300 O2 tota1/wood (kg/kg dry) 0,57 0,60 Steam/wood (kg/kg dry) 0,08 0,40 Carbon conversion (%) 99,3 100 Dry gas production (Nm3/kg dry wood) 1,35 1,34 Composition Co (% vo1./dry gas) 42 32,4 CO2 23,9 38,8 CH4 0,7 30,9 Thermal yield (%) 69 27,4 LHV gas/LHV wood 3,0 Tons potentia1 methanol per ton dry wood 0,49 69 Table I : Experimental results 4. PRESSURIZED UNIT OF CLAMECY The second phase in the development of the syngas from wood production process of CREUSOT-ENERGIE has been starting up in early 1984. The A.F.M.E. brought its financial support to the engineering and construction of the pressurized pilot plant of Clamecy (department of Nievre) The aim of the project is to built and to experiment a pressurized gasification unit, of a https://www.w3.org/1998/Math/MathML"> 60 t / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day dry wood capacity. The main equipments of the pilot will be :

the fluidized bed gasifier fed with wood chips, oxygen and steam

the secondary reformer fed with the raw gas coming from the gasifier and with secondary oxygen, to convert methane and higher hydrocarbons,

the gas treatment (scrubbing-cooling...) allowing to burn the gas in a boiler.

The operating pressure should vary between 10 and 25 bars. The wood moisture will be about https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The schematic bloc-diagram of the unit is represented on figure II. The nominal operating conditions of the pilot are:

pressure : 15 bars

dry wood feed-rate: https://www.w3.org/1998/Math/MathML"> 2500   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> moisture: https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 02 flow-rate: https://www.w3.org/1998/Math/MathML"> 1490   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> steam flow-rate: https://www.w3.org/1998/Math/MathML"> 1000   k g / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The expected characteristics of the syngas which is delivered at the battery limits are : raw gas flow-rate: https://www.w3.org/1998/Math/MathML"> 3700 N m 3 / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dry gas flow-rate: https://www.w3.org/1998/Math/MathML"> 3350 N m 3 / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

dry gas composition (% volume):

CO: 39

https://www.w3.org/1998/Math/MathML"> H 2 : 31 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

CO2: 273

For this project, cREUSOT-ENERGIE and the A.F.M. E. are associated in a pool of Economic Interest named ASCAB, which means "Association for the development of substitute motor-fuels from wood gasification" . The demonstration unit of Clamecy will be operational in 1986. temoérature de pyrolyse isotherme soit atteinte le plus rapidement possible de facon que la frootion restante aus moment où tomuilibre est atteint, soit suffisante. De même pour la mesure non isotherme il est important que la température mesurée représente la température de https://www.w3.org/1998/Math/MathML"> 1 † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> échantillon. Les mesures isothermes ont eu pour objectif essentiel de se placer dans des conditions permettant de comparer 1 e comportement thermique d'un bois de sapin et de son écorce en fonction des parametres principaux suivants :

teneur en oxygène du milieu de 0 à https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

température de https://www.w3.org/1998/Math/MathML"> 290 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> à https://www.w3.org/1998/Math/MathML"> 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

taille de l'échantillon de 50 à 1000 um.

Compte tenu de lijmprécision sur la mesure de la température de 1'échantillon au cours de la pyrolyse, les mesures isothermes ne permettent pas d'accéder aux paramëtres cinétiques des réactions de pyrolyse. Les mesures effectuées en dynamiaue dans des conditions où le contrôle de la température de léchantillon est satisfaisant, permettent de déterminer les paramëtres cinétiques du bois et de l'écorce de sapin, de la cellulose et d'apprécier notamment les énergies d'activation des diverses étapes de la pyrolyse. 24. ETUDE THERMOGRAVIMETRIQUE ISOTHERME La thermobalance utilisee" permet de suivre la perte de poids d'échantillons pulvérulents placés dans une coupelle en acier inoxydable de 3 om de diamètre suspendue à une balance électronique. La température du miIieu est mesurée en plusieurs polnts proche de l'échantillon au moyen de thermocouples Pt/pt Rh https://www.w3.org/1998/Math/MathML"> 10 % . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Le débit de gaz circulant dans le réacteur permet diassumen une vitesge linéaire dans le tube de réaction voisine de https://www.w3.org/1998/Math/MathML"> 0,5   m / s . ( N . T . P . ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Ces conditions sont proches de celles susceptibles d' être rencontrées dans des chaudieres domestiques ou industrielles. Le choix des températures de pyrolyse a été fait de façon a mettre en êvidence, pour chaque atmosphère de dégradation et chaque êchantillon, le rôle fondamental que joue la température autout d'une valeur critique qui sespere nettement une dévolatieation lente d'une dévolatisation rapide. Cette façon de procéder a pour objectif d'indiquer, dans des conditions réalistes de réaction, la température au dessus de laquelle il est néces https://www.w3.org/1998/Math/MathML">   r e a l i s t e s   d e   f e a c t i o n ,   l a   t e m p e r a t u r e   a u l   d e s s u s   d e   l a q u e l l e   i l u e s t   n e ́ c e s u m a t i o n   c o m p a t i o n g e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> avec l'alimentation d'un foyer. Ainsi comme l'indique la figure 1 , pour le bois de sapin en présence d'air et pour une taille de particule comau bout de 400 secondes a https://www.w3.org/1998/Math/MathML"> 320 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; pour le même temps de contact seul https://www.w3.org/1998/Math/MathML"> 23 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de la masse initiale a été gazéifié à https://www.w3.org/1998/Math/MathML"> 306 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Des courbes analogues, quoique moins marquées ont été obtenues pour le bois et 1 'écorce de sapin en présence d'azote. On admet généralement que le régime qui controle la décomposition thermique des matériaux cellulosiques est fonction du rayon des particules r soumises à dégradation. Ainsi MAA (3) a montré que pour https://www.w3.org/1998/Math/MathML"> r < 0,1   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> la réaction chimique contrôle le processus alors que pour r>3cm Ie transfert de chaleur dans la particule est 1 'étape Iimitative. Nous allons voir à partir des résultats expérimentaux suivants l influence de la taille de la particule sur le taux de dégradation des echantillons de sapin placess dans les conditions exposés précédemment. Les figures 3 , 4 montrent en fonction de l'atmosphere réagissante, https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> influence de la taille de I'échantillon sur le taux de dégradation.

Les expériences à température isotherme ont été effectuées au cours d'un séjour en Finlance (VTT Iaboratory Jyväskylä);la description du dispositif expérimental figure dans (2) THERMAL DEGRADATION OF FIRWOOD AND FIRBARK INFLUENCE OF SIZE

AND GAZEOUS ATMOSPHERES J.R. RICHARD and C. VOVELLE de Recherches sur la Chimie de la Combustion et des Hautes Temperratures 45045 ORLEANS CEDEX 25. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Thermal degradation of firwood, firbark and cellulose has been investigated by thermogravimetric analysis The experimental device allowed to work with a 1 - 10 g powdered specimen and a carrier gas flow rate equal to https://www.w3.org/1998/Math/MathML"> 401 / min . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> This flow rate corresponds to a linear velocity close to.5m/s. This velocity simulates the conditions prevailing in domestic or industrial Classical thermogravimetric conditions (temperature increasing at a rate equal to https://www.w3.org/1998/Math/MathML"> 5 ∘ C / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) as well as isothermal conditions have been LSed. The main objective was to compare the kinetics of thermal degradation of heart and bark when some key parameters of the experiment were varied

the temperature of the isothermal experiments;

the oxygen content (between O and https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) ;

the size of the powdered sample (in the range 50 - 1000 um).

The effect exerted by each parameter on the maximum rate on the extent of the thermal degradation are described in the paper A simulation model has been used to calculate the kinetic parameters of firwood, firbark and cellulose from the experiments performed with a temperature increasing linearly. In the case of wood, various withl temperature Lncreasing linearly. In the case of wood, various possible to show that the maximum mass loss rate can be calculated with the kinetic parameters obtained for pure cellulose.

INTRODUCTION

La pyrolyse des composess cellulosiques a eté tràs largement étudise au moyen de techniques diverses. Parmi celles-ci les méthodes d'analyse thermogravimétriques sont les plus courantes. Dans ce travail deux méthodes thermogravimétriques ont été utilisées

une méthode isotherme; elle implique la détermination de la variation de la perte de poids en fonction du temps à température constante.

une méthode non isotherme souvent appelée dynamique ; elle implique

la variation de perte de poids en fonction du temps pour une augmentation de la température préalablement déterminée. Chacune de ces méthodes présente des avantages et inconvénients (1). Ainsi pour obtenir des données cinétiques, il est indispendable que la Fig.1 - Influence de la tempéraFig. 1 Influence de la temperam ture, coeur de sapin, air,500,1000 m 1000pin a ete gazêlie. Fig.2 - Influence de la dimension de l'échantillon, écorce de https://www.w3.org/1998/Math/MathML"> s a p i n , N 2 ,   T = 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig.4 - Influence de la taille de l'échantillon, écorce de sa- On peut constater qu'er' présence diazote il faut attendre https://www.w3.org/1998/Math/MathML"> 1200   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> environ avant que le taux de degraticin de libcorce de sapin de taille ticin de https://www.w3.org/1998/Math/MathML">   l i t a r o r c e   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> comprise entre 500 et 1000 un soit identique a la dégradation obtenue pour des échantillons inférieurs à https://www.w3.org/1998/Math/MathML"> 63   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Poukn https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d' oxvgène, li influence de la taille des particules est encore importante puisque comme https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> indique la fig.3, https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> du matériau est gazéifié pour un échantillon de tailile inférieure à 63 m au bout de 1000 s. alors que pour ce même temps https://www.w3.org/1998/Math/MathML"> 55 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> environ de la masse d'échantillons de taille comprise entre 500 et https://www.w3.org/1998/Math/MathML"> 1000 μ a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> eté gazéifié. Fig. 3 - Influence de la dimension de l'échantillon, écorce de sapin https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de https://www.w3.org/1998/Math/MathML"> O 2 ,   F = 350 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig.5 - Influence de la nature et Fig.5 rofluence de la nature et de la dimension de l'échantillon https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de https://www.w3.org/1998/Math/MathML"> 0 ,   T = 350 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> echantillons de 63pu pin,air,T https://www.w3.org/1998/Math/MathML"> = 306 ∘ C   10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de 0 , https://www.w3.org/1998/Math/MathML"> T = 350 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> La fig. S montre le comportement du bois et de lácorce de sapin; on note qu'apres https://www.w3.org/1998/Math/MathML"> 600   s , 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> de la masse des echantillons de https://www.w3.org/1998/Math/MathML"> 63 μ s o n t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> gazêifies alors que seul https://www.w3.org/1998/Math/MathML"> 55 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> le sont pour des echantillons de https://www.w3.org/1998/Math/MathML"> 1000 / m . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Commentaires et discussion Si l'on se reporte aux diverses courbes rendant compte de I influence de la dimension des particules sur la perte de masse des échantillons. certains résultats peuvent paraître surprenants. En particulier il nous certains resultats peuvent paratitre surprenants. An particulier il nous faut chercher une explication aux differences de taux de gazeirication Cette question est importante car un grand nombre de modèles de pyrolyse de particules de grande dimension utilise les resultats obtenus avec des materiaux pulvérulents: les particules de grande dímension sont souvent considérées comme une réunion de petites particules qui sont chauffées différemment en fonction de leur position à 1 intérieun de l'échantillon. La production locale de matiere volatile est obtenue en intégrant la somme de la matière volatile de chaque particules plus petite. On suppose ainsi que la vitesse des réactions de pyrolyse est "infinie" mais que "I'équilibre de densité" instantané dépend de la température locale instantanée. Les différences observées sont glles dues à la cinétique ou au transfert de chaleur ? Le transfert de chaleur vers la surface de la particule est dû à l'effet combiné de la convection des gaz et du rayonnement des parois du four. Or les mesures de température sont effectuées dans la couche gazeuse et non a la surface de l'échantillon ; bien que ce phénomène ne soit pas très important il est possible que l'absorptivité du rayonnement soit plus grande potir la cotiche de petites particules Dans les expériences décrites, 1.épaisseur de la couche de particule est voisine de https://www.w3.org/1998/Math/MathML"> 3   m m ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> avec les échantillons de diamètre proche de 1 mm, la couche ne peut pas ôtre considénée comme un continutm at il est vraisemblable que la conduction de chaleur dans la couche composée de grosses particules est plus faible. Ainsi RAO (4) a montré que le flux de chaleur dans l'état stationnaire était la moitié de celui calculé pour un continuum. La conduction transitoire dans la couche engendre un délai dans la pyrolyse et I'êchantillon n'est plus chauffé de facon isotherme. Si l'on suppose que https://www.w3.org/1998/Math/MathML"> λ / pc = 0,18   m 2 / s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> épaisseur de la demi-couche d'échantillon voisine de https://www.w3.org/1998/Math/MathML"> 2   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , le nombre de Fourier devient pour https://www.w3.org/1998/Math/MathML"> t = 60   s , F o = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at/ https://www.w3.org/1998/Math/MathML"> R 2 = 2,7 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Cet ordre de grandeur signifie que la conduction transitoire a un certain effet ajouté ả celui de la cineetique. Autour de https://www.w3.org/1998/Math/MathML"> 350 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> la pyrolyse atteind son maximum et elle est très sensible à une petite variation de température (5), il est possible qu'une variation de la conduction de chaleur de la couche de particules cause un changement dans la température moyenne de l'échantillon et cette variation de température peut engendrer un changement important dans la variation de la masse de l'échantillon, comme l'indique pour l'air la f'ig.1. Ce sont là quelques unes des raisons susceptibles d'expliquer les différences observées; il https://www.w3.org/1998/Math/MathML"> n ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est pas possible pour le moment de quantifier les différents effets énumérés. Ces résultats expérimentaux permettent d'apprécier les différences de comportement du bois et de lécorce de sapin dans des conditions de température susceptibles d'être rencontrées dans certaines parties de gazéifieur ou de foyer. 26. ETUDE THERMOGRAVIMETRIQUE DYNAMIQUE ET SIMULATION Les techniques de calcul generalement utilisees pour determiner les paramètres cinétiques de dégradation thermique d'un matériau solide ne orennent en compte quiune réaction globale. Dans le cas du bois, qui comprend plusieurs constituants cette procédure conduit souvent à dispersion importante des valeurs obtenues selon la fraction du thermogramme retenue pour les calculs (6). Au cours de ce travail, nous avons utilisé une procédure différente pour la détermination de ces paramètres. Elle repose sur l'utilisation https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> un programme de simulation qui calcule la Les paramètres cinétiques obtenus pour la cellulose pure permettent de rendre compte du maximum de vitesse observé expérimentalement. REFERENCES (1) WENDLANT,W, Thermal methods of analysis, John WILEY and Sons, 1974. (2) SAASTOMOINEN, J . AHO,M., The simultaneous drying and pyrolysis of single particles. Int.Symp. on alternative fuels. Dct. 84 TULSA, OKLAHOMA. (3) MAA,P.S. Comb. and Science Technology 1973,7, pp 257-269. (4) RAO,S.M. et al. Ind. Eng. Chem. Fundamental 1984,23,294-298. (5) VOVELLE C. et al.,19th Symp. on Comb./Comb. Institute 1982, 797-805. (6) VOVELLE C. et al. Kinetics of thermal degradation of wood and cellulose by T.G.A. Comparison of the calculation Techniques, A.C.S. Annual Meeting, Washington, 1983. GASIFICATION OF RICE HUSK IN A SMALL DOWNDRAFT MOVING BED Abstract R. Manurung https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and A. A. C.M, Beeneckers https://www.w3.org/1998/Math/MathML">   * * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Twente University of Technology, The Netherlands Summary The design and operating characteristics of a new and simple continuous downdraft gasifier for rice husk gasification are presented. With this gasifier all the notorious problems with respect to solids flow, that prevented application of downdraft gasification for rice hulls at a small scale up till now, have been solved. Features are: no throat or other obstacles that may hamper solids flow; open air suction over the whole cross section to avoid hot spots; continuous ash removal by a rotating grid. The construction is simple and cheap and can be done 1ocally. Reactor capacity tested is 10 - 25 kg per hour which suits the gasifier for small scale rural applications in developing countries. Operating data are presented in the paper. 27. INTRODUCTION Up till now a number of problems related to the properties of rice htsk, prevented the application of simple downdraft gasifiers for rice husk gasification at the https://www.w3.org/1998/Math/MathML"> 10 - 50   k g / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> scale which is the relevant capacity for the major part of attractive rural applications in developing countries (rice mill powering, water pumping, etc.). These problems are [1-5]:

poor flow due to low density and swelling in the pyrolysis zone

poor oxygen distribution due to small particle size

sintering arising from oxygen distribution

lack of a well designed continuous ash removal system.

Recently, an important investigation on small continuous moving bed rice husk gasification was published by Kaupp (1). However, after construction and operation trials of four prototypes, Kaupp had to abandon the concept of a continuots moving bed rice husk gasifier with a locally fixed fire zone. So, for a start, we tried to solve the problems that so far hampered the reliable operation of a small scale moving bed gasifier at a capacity scale of 5-IO HP. With the gasifier we ultimately developed all problems mentioned above indeed have been overcome. It has the following features:

no throat or other obstacles that may hamper solids flow

open air suction over the cross section to avoid hot spots

continuous ash removal by a rotating grid.

Present address: Institute of Technology Bandung, Dept. TK, Bandung, Indonesia.

**Present address : Groningen University, Dept. Chemical Engineering, also for corre- Nijenborgh 16, Groningen, The Netherlands. Such a rice husk gas ifier with an internal diameter of https://www.w3.org/1998/Math/MathML"> 0.45   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has beer tested at a range of specific loads. The first restlts are presented in this paper. 28. PROCESS PRINCIPLE The process principle basically is not different from that of the conventional downdraft moving bed gasifier but the design has been thouroughly adapted to allow for a smooth and continuous gasification of rice hulls at a small scale. The rice husk is introduced continuously at the top of the gasifier and flows downward by gravity only. The present design is open at the top. It is not an essential feature but it adds to the simplicity of the design and to reduce investment costs. Essential new features to allow for a smooth flow of the rice husk are the absence of a throat, which is typical for a conventional downdraft gasifier, and the installment of a rotating scraper for continuous ash removal which is usilal1y not found in conventional downdraft designs. It is essential howt ever in continuous gasification of particles which keep their shape upon gasification as is the case with rice husk. Air is sucked from the open air into the bed all over the cross sectional area of the bed surface. The absence of any type of nozzles for air introduction is another feature of the present design. It is essential for gasification of rice hulls, to avoid hot spots and by that to keep away from sintering probe lems that may hinder solids flow. More over, a uniform introduction of air over the entire cross sectional area generates a uniform oxidation zone over the same area with a rather constant radial temperature profile, low enough to avoid sintering and high enough to convert the major RG 1 SET-UP OF GASHFCATION SYSTEM part of the tar components originating from the pyrolysis zone. Additionally, conventional nozzles generate caves with poorly flowing solids like rice husk and cause a higher backmixing of pyrolysis products upstream the pyrolysis zone thus initiating swelling in that region which is another reason for the experimentally observed hampered solids flow in rice husk gasification with conventional downdraft reactors. Ash is collected in a conventional water seal from which it can be removed either periodically or continuously by conventional techniques. A special problem is that sinking of the particles depends on char burn out. Therefore a special device is installed in the water seal to cope with floating particles. This new feature of the design consists of a rotating screw which transports also low density particles to the bottom in the direction of ash outlet. The rotation rate ratio between the ash scraper and the rotating screw essentially is a constant, independent of reactor load, so that, for improved simplicity, both devices can be driven by one single engine with a variable gear. FIG. 2 DOWNORAFT RICA HUSK GASFIER WTH ASH REMOVALSYSTEMS Downstream gas treating is conventional and needs no further descriptíon. Figure 1 shows the total setup whilst Figure 2 shows details on the design of the new gasifier.

EXPERIMENTAL RESULTS

The operating conditions tes ted areshown in Table I. The maximum specific load was limited by the capacity of the downstream equipment rather than by the gas ifier proper. The rice husk properties are given in Table II. The experimentally observed a ir-dry fuel ratio, the gas production per kg fuel and the gasification efficiency are all given in Figure 3. Favourable gasification loads are in the order ot https://www.w3.org/1998/Math/MathML"> 100 - 150   k g / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . hr or higher. A further improvement of the gasification efficiency can be exthe gasif jer. The composition of the the gasifjer. The composition of the solids residue is given in Figure Figure 5, all as a function of reac- kgkhr https://www.w3.org/1998/Math/MathML"> N m 3 / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> m system) Table I. Operating variables of https://www.w3.org/1998/Math/MathML"> 0.45   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tor load. Table I. Operating variables of https://www.w3.org/1998/Math/MathML"> 0.45   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> continuous downdraft rice husk Fuel https://www.w3.org/1998/Math/MathML"> : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Northern Italy rice husk Moisture content https://www.w3.org/1998/Math/MathML"> : 0.115 - 0.125   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> water/ kg wet material Feed rate https://www.w3.org/1998/Math/MathML"> : 10 - 25 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Producer gas flow rate https://www.w3.org/1998/Math/MathML"> : 11.5 - 40   k g / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Peak bed temperature https://www.w3.org/1998/Math/MathML"> : 700 - 1000 N m / h r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Bed height https://www.w3.org/1998/Math/MathML"> : 0.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Pressure https://www.w3.org/1998/Math/MathML"> : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> atmospheric (open system) Fuel : Northern Italy rice husk Moisture content https://www.w3.org/1998/Math/MathML">   :   Northern Italy rice husk     : 0.115-0.125 kg water/ kg wet material   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : 0.115-0.125 kg water//kg wet material Table II rice husk properties (d.a.f. basis; wt%) FIG 5 PRODUCT GAS TAR CONTBI AS A FUNCTIOK OF PRODUCT GAS RATES REFERENCES

Kaupp, A. Gasification of Rice Hulls, Theory and Practice; German Appropriate Technology Exchange, Fed. Rep. of Germany, 1983

Beenackers, A.A.C.M. and Van Swaaij, W.P.M. "Gasification of Biomass, A state of the Art Review" A.V. Bridgwater, Thermochemical Processing of Biomass, Butterworths, (1984) 91-136.

Aarsen, F.G. van den, Beenackers, A.A.C.M. and Van Swaaij, W.P.M. "Performance of a Rice Husk Fuelled Fluidized Bed Pilot Plant Gasifier" Producer Gas 1982, The Beyer Institute, Stockholm (1983) 383-391.

Beenackers, A.A.C.M. "Development of a Small Moving Bed Rice Hull Gasifier by ITB and THT"; one year Research Proposal for Robert Manurung. Twente University, Enschede, The Netherlands, March 1983. Susanto, H. Beenackers, A.A.C.M. and Van Swaaij, W.P.M. "Moving Bed Gasifier with Internal Recycle of Pyrolysis Gas". Producer Gas 1982, The Beyer Inst., Stockholm (1983) 317- 334.

Beenackers, A.A.C.M. and Manurung, R., Producer Gas 1984 , The Beyer Institute, Stockholm, in press. FUEL- AND SYNTHESIS GAS FROM BIOMASS VIA GASIFICATION IN THE CIRCULATING FLUID BED

P. MEHRLING and R. REIMERT LURGI GmbH, D-6000 Frankfurt/Main 29. Summary Gasification of biomass yields a most universally applicable intermediate or final product gas. LURGI selected the Circulating Fluid Bed principle (CFB) for its new biomass gasification process. This process principle has been applied very successfully in other industries (calcination, combustion) for more than one decade. The applicability of CFB to wood gasification has been demonstrated in several pilot plant test runs. Test results corroborated the expected process advantages, e. g. tar-free gas, high specific throughput, good part-load behaviour, broad range of feed particle sizes. Based on the pilot plant data on the one hand, and on the extensive experience with pressure gasification, gas cleaning and gas processing plants on the other, plant concepts were established for comproduction of power and process heat and for methanol production. Cost estimates show under which conditions these processes are economically attractive.

CFB Reaction System

Biomass have become more and more interesting as a fuel or as a raw feed material for synthesis processes. To comply with clients' requests and demands, LURGI decided to develop a wood gasification process considering that gasification offers most general utilization patterns (1). A gasification process working according to the Circulating Fluid Bed principle (CFB) promised to fulfill the following requirements:

handling a broad spectrum of biomass

allowing for a high throughput in the range of 10-100 MW thermal

producing a synthesis gas feasible for routing it directly into LURGI methanol synthesis without further reforming

avoiding highly complex machinery.

The CFB reactor may be placed in the transition range between the stationary bubbling bed with defined surface and the forced pneumatic transport reactor (Figure 1) (2). The CFB system is characterized by an almost uniform distribution of solids over the total reactor height with high amounts of solids recycled via the recycle cyclone making this a permanent constituent of the reactor system. The external circulation is accompanied by an inner recirculation of material due to constantly changing densly packed strands and clusters, causing particles to sink countercurrently to the upstreaming gas. Sponsored by EC, GD XII, and by BMFT of Germany The CFB operates with optimum effect in the range of maximum possible slip velocity for the given particle spectrum. This creates extremely good heat and mass transfer which enables a rapid heating of the feed material, combined with an excellent reaction rate at constant temperature in the circulating fluidized bed system as a whole. LURGI's experience with CFB goes back into the sixties, when this development started. Up to now, more than 35 industrial plants have been insta1led for different endothermic heterogeneous gas-solids reactions working according to the CFB principle. Furthermore, since mid 1982 one CFB combustion plant is in operation, three other plants are currently under construction. 30. Experimental program During several test runs totalling about 1700 operating hours including two long runs of https://www.w3.org/1998/Math/MathML"> 100   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and very recently of https://www.w3.org/1998/Math/MathML"> 200   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the feasibility of CFB-Biomass gasification was proven and a set of design data established. The gasification experiments have been conducted in LURGI's two pilot plants in Frankfurt. The existing pilot plant with a thermal capacity of https://www.w3.org/1998/Math/MathML"> 0,5 M N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> could advantageously be used after some modifications to perform most of gasification tests. Additionally a long duration test with airblown wood gasification has been performed in LURGI's https://www.w3.org/1998/Math/MathML"> 1,5 M W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> thermal pilot plant. Table I summarizes the parameters varied during these tests. Table I Test parameters varied during CFB-pilot-tests Kind of wood Beech-, Pine-, Poplar-, Spruce-Wood Grain size Gasification agent 0xygen/steam, air https://www.w3.org/1998/Math/MathML"> 630 - 800   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Temperature Atmospheric Pressure Bed Material Wood-char, sand, https://www.w3.org/1998/Math/MathML"> A l 2 O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Throughput Up to https://www.w3.org/1998/Math/MathML"> 250   k g d a f / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (in 0,5 MN plant) The first column of Table II gives typical results of air blown gasification. The figures indicate a high efficiency of the CFB process and a gas sultable to be used as a fuel gas with a HHV of 5 oo ku/min. When combusting the gas, the https://www.w3.org/1998/Math/MathML"> S 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> emissions are far below any level set by environmental protection rules. In contrast oxygen blown gasification produces a gas comprising high amounts of CO plus https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , a moderate amount of methane and https://www.w3.org/1998/Math/MathML"> C 2 - C 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrocarbons, indicating that this gas can be used, for example, for methanol synthesis. High values for cold gas efficiency and carbon conversion are common for both modes of operation. The low figures for https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C n H m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the fact that the gas is absolutely free of tar are beneficial for the further use of the raw gas. In addition to the evaluation of test results at optimum operating conditions, the influence of the most important parameters determining the gasification behaviour were studied as well. Table II CFB Biomass Gasification Test results and extrapolated figures Temperature, moisture or steam addition and specific heat losses of the plant were found to be of major influence. Type and size of the wood are rather less important. Heat losses are, of course, something very specific for the individual plant. However, since heat losses have a strong influence on raw gas composition, they had to be carefully examined for the sake of data extrapolation. Extrapolated data based on pilot test results are given a7so in Table II. Quatitatively, the test results can be summarized as follows:

Wood gasification in a CFB reactor is feasible.

High carbon conversion results in favourable specific consumption and production figures.

High specific throughput allows for high-capacity plants.

Small amount of methane makes gas suitable for direct routing into synthesis processes without previous or simultaneous reforming.

Tar-free gas indicates a high environmental acceptability of the CFB gasification process.

No inert bed material needs to be added.

1. Commercial application With the comprehensive pilot tests presented above, a sound basis was attained for commercialisation of CFB Biomass gasification. Potential fields of commercial application of fuel gas is the direct heating of goods in kilns and the cogeneration of power and heat. Figure 2 Block Flow Diagram of CFB gasifier to fuel production plant for direct combustion and Figure 3 Costs of fuel gas via CFB-gasification depending on woodprice METHANE FROM BIOMASS - PROCESS OPTIMISATION 2. INTRODUCTION 3. REFERENCES Table 1 Summary Outputs for Reference Case Study A. Capital Cost, Utilities and Manpower Summary FIGURE 1 REFERENCE CASE PROCESS SEQUENCE FIGURE 2 METHANE COST VS PRESSURE AND SCALE OF OPERATION SENSITIVITY OF THEORETICAL GASIFIER PERFORMANCE TO SYSTEM PARAMETERS Chemical Engineering Department, Aston University, Birmingham B4 7ET, UKUher A Douter Bridgwater

Surmerary

A robust equilibrium model of blomass gasification has been developed and subjected to a thorough sensitivity analysis across a wide range of parameters. Some of the slgniflcant results are graphically presen- ted. The theoretical performance https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> compared with practlcal results so as to better understand the thermal processes involved; develop more robust predictive models; and hence construct reliable deslgn models. 4. INTRODUCTION Despite extensive experience with many operating gasifiers, there is still poor understanding of the effect of changes in operating conditions on gasifier performance and product quallty. A frst step towards a better understanding https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to examine a thermodynamic model of a gasifier assumed to operate with all products in thermodynamic equillbrium. The polnt at which solid carbon just disappears (1.e. the solid carbon boundary) repres- ents the optlmum operating polnt as in an ideal downdraft gasifler or Ideal fluldised bed gasifier. Some attention has already been pald to deviations from ideality https://www.w3.org/1998/Math/MathML"> ( 1,2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and further results from comparisons of https://www.w3.org/1998/Math/MathML"> 1 deal https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and real performance are included. 5. THERMODYNAMIC MODEL A thermodynamic model of a https://www.w3.org/1998/Math/MathML"> C - H - O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> system may be constructed to represent three situations of declining carbon concentration in the gas phase (2): with sol1d carbon present as occurs in pyrolysis; the unique polnt at which the solld carbon just disappears; and with an excess of oxygen, which is the region in which most gaslflers operate with typically a https://www.w3.org/1998/Math/MathML"> 30 - 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> excess of oxygen over that required to operate on the solid carbon boundary. Generalısed studies on the C - H - O system are restricted to ldeal gas mixtures with families of curves at different temperatures and proportions of C,H and https://www.w3.org/1998/Math/MathML"> O ( e g 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A sensitlvity analysis to explore the effects of changes in any operational parameter in a gaslfier starts from the base case summarised in Table 1 with the varlations in parameters studied. 6. RESULTS Only a few results can be shown graphically. Flgure l compares real and predicted fdeal performance under 1dentical condltions, while Figures 2 - 7 show some results of the sensltivity analysis with gas higher heating value, gasification temperature, and composition of outlet gas. The base case is marked on each curve by an "o" The comprehensive results include the alternative base cases of air and oxygen gasiflcation, with a selected range of the above parameter changes. Real processes wLIl, of course, operate with many, if not a11, of the variables deviating from ideality and the base case conditions, and this effect is shown in Figure l. CONCLUSIONS These results, whlle purely theoretical, are a valuable ald ln predfcting trends in real systems under different conditions. A further application is in generating plausible pred1ctive models of gasifier performance. 7. REFERENCES

Belleville, P and Capart, R; in "Thermochemical Processing of Biomass https://www.w3.org/1998/Math/MathML">   ' ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Edited by A V Bridgwater, Chapter 13. (Butterworth 1984 ).

Figure 1 THEORETICAL GASIFIER PERFORMANCE AGAINST ACTUAL PERFORMANCE https://www.w3.org/1998/Math/MathML">   Figure   2   THEORETICAL GASIFIER PERFORMANCE AGAINST     HOISTURE CONTENT OF BIOMASS   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MOISTURE CONTENT OF BIOMASSAIR GASIFIER 8. WOOD LIQUEFACTION : TOTAL MASS AND ENERGY BALANCES X. DEGLISE, D.MASSON, H.KAFROUNI, A. LADOUSSE Laboratoire de Photochimie Appliquée, Université de Nancy I BP 239-54506 VANDOEUVRE LES Nancy Cedex - FRANCE 9. Summary Beech wood is converted to an oil, water soluble products and gases if heated in the presence of water, alkaline catalyst and carbon monoxyde in a rocking batch reactor. The higher heat of combustion of oil increases with the reaction temperature but the highest oil yield (43%) and energy recovery in oj1 (63%) are obtained for the reaction temperatures around https://www.w3.org/1998/Math/MathML"> 300 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> If the reaction is carried without CO, the conversion and the oil yield are lowered of about https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at all temperatures. 10. EXPERIMENTAL The wood 1iquefaction reaction was carried out in a 500 cm shaked batch autoclave. The reaction vessel is charged with https://www.w3.org/1998/Math/MathML"> 40   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of beech wood (moisture content https://www.w3.org/1998/Math/MathML"> 10 % ) , 250   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of water and https://www.w3.org/1998/Math/MathML"> 4   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of catalyst (Na, CO https://www.w3.org/1998/Math/MathML">   3 , 10 H 2 O . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The reactor is flushed out and then pressurized with carbon monoxide to the selected stanting pressure (O to 10 M Pa), after which it is heated to the desired temperature https://www.w3.org/1998/Math/MathML"> 230 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 340 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The system is then held at this reaction temperature during https://www.w3.org/1998/Math/MathML"> 30 m n . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The autoclave is cooled to room temperature. The total amount of the gas resulting from the reaction is measured and then is analysed by gas phase chromatography. The aqueous phase is decanted and weighed. A part of organic products dissolved in this phase is extracted by dichloromethane. The oil phase adhers to the wall of the reactor and is recovered by dissolving in acetone. After solvent evaporation, oil is weighed, a part is used for carbon and hydrogen analysis and the higher heat of combustion is measured on an other part. The oil yield (%) Is : https://www.w3.org/1998/Math/MathML">   mass of acetone soluble product     initial mass of dry wood   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The residual. solid phase is removed by filtration of the acetone dissolved oil phase and then washed with acetone and weighed. The relative conversion (%) is defined as : https://www.w3.org/1998/Math/MathML"> 1 -   mass of residual solid phase     initial mass of dry wood   × 100 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 11. ROLE OF THE CO PRESSURE At a reaction temperature of https://www.w3.org/1998/Math/MathML"> 300 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , neither the conversion nor the oil yield are increased when the initial pressure of co is higher than https://www.w3.org/1998/Math/MathML"> 1,5 - 2,0 M P a . ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> table 1 https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The Co pressure does not have any significant effect on the oil composition. For these reasons, all the experiments reported so far have been carried out at an initial co pressure of https://www.w3.org/1998/Math/MathML"> 1,5 M P a . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> AQUEOUS PHASE The mass of water and water soluble products does not change significantly with the reaction temperature (table 4). https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of this phase are extracted with dichloromethane. The higher heat of combustion of the so obtainedproduct is https://www.w3.org/1998/Math/MathML"> 26000   k J / k g . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Table 4: mass recovery https://www.w3.org/1998/Math/MathML"> T ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> mass (g) oil solid aqueous phase phase phase 270 14.7 2.6 13.1 10.2 300 15.0 2.0 12.5 11.1 340 11.6 1.7 13.8 13.5 initiat mass: dry word : https://www.w3.org/1998/Math/MathML"> 36   g . 00 : 4.6   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ENERGY RECOVERY For a typical run, the higher heat of combustion of the reactant https://www.w3.org/1998/Math/MathML"> ( 36   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of wood and https://www.w3.org/1998/Math/MathML"> 4,63   g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> C O ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is https://www.w3.org/1998/Math/MathML"> 766   k J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . After the liquefaction reaction, this energy is recovered in the heats of combustion of the reaction products and in the heat of reaction. Table 5: energy recovery Table 5 energy recovery T https://www.w3.org/1998/Math/MathML">   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Hil Higher heat of combustion solid phase aqueous phase gas phase E 280 454 54 200 20 728 https://www.w3.org/1998/Math/MathML"> (   k J ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 290 451 76.5 188 26.5 742 38 300 447 60.5 221 25.5 754 320 416 54.5 209 24.5 704 340 376 51 209 30 666 24 Table 5 shows that the higher heat of combustion of oil decreases with the reaction temperature and represents https://www.w3.org/1998/Math/MathML"> 63 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the injtial energy at https://www.w3.org/1998/Math/MathML"> 280 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and less than https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 340 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The experimental determination of the aqueous phase combustion enthalpy is not very accurate ( https://www.w3.org/1998/Math/MathML"> ± 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and then the calculated heats of reaction show only a slight exothermicity of the reaction around https://www.w3.org/1998/Math/MathML"> 300 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 12. CONCLUSION In our experimental conditions, the best oil yield and energy recovery in oil are obtained for a reaction temperature of https://www.w3.org/1998/Math/MathML"> 300 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . https://www.w3.org/1998/Math/MathML"> 44 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the initial wood mass are then converted into an oil whose highest heat of combustion is https://www.w3.org/1998/Math/MathML"> 30000   k J / k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and which contains https://www.w3.org/1998/Math/MathML"> 63 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the initial energy of the wood. When the reaction is carried without co, these yields are lowered of about https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> but the oil caracteristics (composition and H.H.C.) are the same. 13. STUDY OF THE DIRECT LIQUEFACTION OF WOOD C. BESTUE-LABAZUY, N, SOYER, C. BRUNEAU, A. BRAULT Laboratoire de Chimie Organique et de I'Environnement, Ecole Nationale Supérieure de Chimíe de Rennes, Avente du Gênêral Leclerc, 35000 RENNESBEAULIEU - FRANCE, avec la collaboration des:

C.E.A. (C.E.N. Saclay, Dpt/SPIN, 91190 Gif-sur-Yvette, France)

CEMAGREF (Parc de Tourvoie, 92160 Antony, France)

TOTAL (C.F.P., 5, rue Míchel Ange, 75016 Paris, France)

14. Summary The catalytic activity of several iron additives was investigated during the liquefaction of poplar wood in water at https://www.w3.org/1998/Math/MathML"> 340 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Among all the additives that were tested, iron powder exhibited a catalytic effect towards the production of oil. A systematic study of the influence of the initial pressure (in the range 1-40 bars) and the volumetric composition of the gas phase (hydrogen-helium mixtures) was also made. A mathematical model was established that pointed out the fact that only the initial pressure had an influence on the yield of oil and that the reaction of liquefaction was not favoured towards the yield of oil by the presence of initial hydrogen. So a yield of product soluble in acetone of about https://www.w3.org/1998/Math/MathML"> 45 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was obtained from a starting pressure of an inert gas (40-60 bars: helium) with a percentage of iron equal to 14 wt 7 on dry wood. A stoíchiometric equation for the líquefaction reaction is proposed which agrees with experimental results regardless of the initial gas composition. 15. INTRODUCTION La 1iquêeaction thermochimique du bois par des procëdess utilisant des catalyseurs mêtalliques a dëja éte développée et a conduit des résultats encourageants (l) (2) (3). La recherche d'additifs métalliques moins onéreux nous a conduit a tester l'activité de plusieurs composess à base de fer.Pour une approche du mécanisme de la réaction de liquéfaction, 1'étude de l'influence de la pression initiale du gaz et de la nature de ce gaz, hydrogëne ou gaz inerte, a été entreprise lors d'expériences réalisées dans l'eau à https://www.w3.org/1998/Math/MathML"> 340 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 16. PARTIE EXPERIMENTALE Dans une expérience type, 70 & de bois de peuplier (Robusta https://www.w3.org/1998/Math/MathML"> + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> I 222 ) sous forme de sciure sêchêe à 1 air https://www.w3.org/1998/Math/MathML"> ( ∼ 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d'humidité), 300 g d' eau et 1 e catalyseur êtaient mélangés puis introduíts dans un rêacteur de 1 litre. L'autoclave êtait pressurisé a la pression requise d'hydrogëne (l-63 bars). Les liquéfactions effectuées en l' absence d' hydrogène initial étaient réaIisées sous pression initiale d"hêlium: ce gaz inerte était choisi pour cette étude fondamentale, en raison de sa compatibilité avec le système chromatographique de détection des gaz et de son comportement thermique assez voisin de celui de l'hydrogène. La température ētait amenée à https://www.w3.org/1998/Math/MathML"> 340 ∘ C ± 5 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> en une période de 1,5 h. Cette température était maintenue 30 mn puis la température était abaissée rapidement par une circulation d'eau dans un réfri- gêrant interne. Les gaz récupérés. essentiellement CO, CH, CO et H, Étaient analysés par chromatographie en phase gazeuse. L" huile formêe était extraite de la phase aqueuse avec https://www.w3.org/1998/Math/MathML"> 1,2   L d e C H 2 C l 2 , 1 es https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> goudrons adhérant aux paroís de l'autoclave étaient récupérës avec https://www.w3.org/1998/Math/MathML">   2 O , 8   L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> " acétone, et les produits solubles dans la phase aqueuse étaient extraits en continu avec de l'êther éthylique. La distillation des solvants d'extraction conduisait. a partir de la fraction CH,Cl, à une huile noire lëgẽrement fluide à la température ordinaire (viscositê a https://www.w3.org/1998/Math/MathML"> 100 ∘ C : 10 - 25 c S t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et quasiment anhydre https://www.w3.org/1998/Math/MathML"> ( < 1 % ) ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> la fraction acêtone donnait des goudrons non fluides. Le solide récupéré par filtration (rësidu ferreux https://www.w3.org/1998/Math/MathML"> + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> charbons) était analysê par diffraction de rayons X selon la méthode Debye-Scherrer. 17. RESULTATS ET DISCUSSION

Examen de plusieurs additifs a base de fer

https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydroxyde ferrique, https://www.w3.org/1998/Math/MathML"> F e 3 O 4 , 1 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> oxalate de fer et https://www.w3.org/1998/Math/MathML"> 1.3 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> poudre de Ier) ont êté testés comme catalyseurs dans des expériences de líquéfaction réaliseses avec une pression initiale d"hydrogëne de 63 bars. Les rêsultats (4) indiquent qu'un catalyseur est nécessaire pour obtenir des rendements en hujle acceptables; sans additif, le rendement en huile https://www.w3.org/1998/Math/MathML"> n ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est que de 17,6 %. Parmi les composess testés, la poudre de fer (15 g) donne les meilleurs rendements avec un taux de conversion supérieur a https://www.w3.org/1998/Math/MathML"> 96 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Fe, 50 um https://www.w3.org/1998/Math/MathML"> ( 0,04 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> m https://www.w3.org/1998/Math/MathML"> / g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) https://www.w3.org/1998/Math/MathML"> 38,5 % ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fe https://www.w3.org/1998/Math/MathML"> 0,3   m 2 / g : 34,8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Aucune difference slgnificative n'est apparue entre les comportements de ces deux qualíés de fer (même utilisêes en faibles quantités) ce qui écarterait l' hypothèse d' un effet catalytique de surface. 17.1. Influence de la pression initiale et de la fraction molaire Après avoir remarqué que la quantité d'hydrogène rëcupêrë après les Iiquêfactions réalisëes en présence de poudre de fer êtait superrieure ou egale à celle fournie au départ de la réaction, des expériences sous pression initiale de gaz inerte ont été envisagées. E11es ont été rêalisées seIon un plan factoriel dessais comprenant deux variables : la pression initiale et la fraction molaire d'hydrogêne (dans des mélanges hydrogẽnehêlium), dans les domaines respectifs de 1-40 bars et 0-1, et avec 15 g, de poudre de fer (150 \mum). Le facteur de réponse mesure expérimentalement était Le pourcentage d'huile https://www.w3.org/1998/Math/MathML"> g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d'huile soluble dans https://www.w3.org/1998/Math/MathML"> C H 2 C l 2 / g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bois anhydre) x 100)]. La dëviation standard pour le facteur de rêponse 2 calculêe à partir des expériences réalisées aux points moyens (pression initiale : 20 , 5 bars et fraction molaire d'hydrogène : 0,5 ) êtait de 1,3 %. Les rêsultats de ll expériences ont permis d'établir un modēle mathématique valíde. Le calcul. sur ordinateur des differrents coefficients a conduit à 1 équation quadratique : https://www.w3.org/1998/Math/MathML">   Rendement en huile   % = 30,7 - 1,8 P 0 - 2,5 X H + 0,77 P 0 2 + 3,95 X 2 H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Po: Pression initiale; https://www.w3.org/1998/Math/MathML"> X H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> : fraction molaire d https://www.w3.org/1998/Math/MathML">   ' h y d r o g e n e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Aucune interaction significative n'ētait trouvée entre les deux paramętres. Compte tenu du taux de reproductibilite du rendement en huile, il ressort que, dans le domaine étudié, ce rendement est peu influencé par la fraction nolaire d'hydrogẻne, mais qu'il est par contre favorisé par une forte pression injtiale. Des expériences rëalisées avec une pression initiale de 63 bars, https://www.w3.org/1998/Math/MathML">   ⊤   ' e s t - a - d i r e   u n e   p r e s s i o n   s u p e ̂ n i e n r e   a   c e l l e s   d u l   d o m a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bars, ctest-aldire une pression superieure a celles du domaine choisi pour te plan factoriel, conduisent en présence ou en l'absence d'hydrogène inithat, a des rendements en hutle du wêne ordre de gratueur que ceux obtenus vorisee vis-a-vis du rendement en huile par https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> absence d'hydrogène initial,batas. Pour les experriences correspondant à la Figure I. le fer a toujours 3.4. Equation stoechiométrique tir des expériences se rapportant a la Figure I êtaíent toujours voisines, comme l'étaient aussi celles des goudrons et celles des produits extrajts de la phase aqueuse. Les quantitess respectives de produits de la phase (5) SOYER, N. , FREDON, C., BRUNEAU, C. and BRAULT, A. (1983). Chemica1 Study of the oils of Liquefaction of Poplar Wood, in Comptes Rendus de l'Atelier de Travail sur la Liquéfaction de la Biomasse, Sherbrooke, Canada, Septembre 29-30, 1983, NRCC 23130 National Research Council of Canada, Ottawa, p. 184-190. REMERCIEMENTS : Nous remercions le Prof. M. MAUNAYE (E.N.S.C. Rennes) pour sa précieuse assistance apporté dans 1'analyse des résidus ferreux par diffractométrie R.X. DIRECT THERMOCHEMICAL LIQUEFACTION OF PLANT BIOMASS USING HYOROGENATING CONDITIONS D. MEIER, D. R. LARIMER and O. FAIX Federa 1 Research Center for Forestry and Forest Products, Institute of Wood Chemistry and Chemi cal Technology of Wood 18. Summary The direct liquefaction by means of catalytic hydrogenation has been investigated using different lignocellulosic feedstocks as well as their constituents: holocellulose, cellulose and lignin. The following inout materials were converted to an oil using palladium as catalyst: spruce and birch wood, spruce and birch holocellulose, cellulose, pine bark spruce and bagasse organosolv lignins, and birch Willstätter lignin. The liquid products were separated into water, acetone- and di chloromethane soluble (oil) fractions. The oils obtained were characterized and separated into neutral, weakly and strongly acidic fractions. The calorific values were calculated from the results of the C/H-analysis. 19. INTRODUCTION The direct conversion of lignocellulasic materials into renewable raw materials. The oil produced could serve as a source for renewable raw materials. The oil produced could serve as a source for chemi cal feedstocks or as a fuel. Principally there exist two routes for the direct conversion which have been mainly investigated. Based on the early studies by Appell (1) several groups have treated lignocellulosic feedstocks with aqueous alkaline solutions using pressurized carbon monoxide at temperatures around https://www.w3.org/1998/Math/MathML"> 35 C C   ( 2 - 4 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Other experiments were carried out with pressurized hydrogen and transition metal catalysts in the presence of aqueous and non aqueous mediums at similar temperatures https://www.w3.org/1998/Math/MathML"> ( 5,6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Wood has been mainly used as input materials for the conversion processes. Little is known about the lique-faction of annual plants and the components of the lignocellulosic material: carbohydrates and lignin. Therefore, in this study the liquefaction of different bicmass feedstocks and constituent components was systematically researched to get more information about the behaviour of plant biomass during liquefaction. 20. EXPERIMENTAL WORK A wide variaty of biomass types was selected for our experiments: spruce wood (Picea abies L. Karst), birch wood (Betula spp.), bagasse from sugar cane (Saccharum officinarum L.), barley straw (Aordeum vulgare L.), pine bark (Pinus sylvestris L.), cellulose (MN https://www.w3.org/1998/Math/MathML"> 3 CO https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> HR MachereyNagel), isolated holocellulose from spruce and birch, isolated organosolv lignins from spruce and sugar cane bagasse, and isolated Willstätter lignin from birch. All of the biomass samples were ground to particle sizes from 0.1 to https://www.w3.org/1998/Math/MathML"> 0.5   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and then mixed with water to form aqueous slurries. After adding the catalyst (1% Pd based on https://www.w3.org/1998/Math/MathML"> 0 . d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wood) the slunry was filled into https://www.w3.org/1998/Math/MathML"> 25 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stainless steel autorlaves and an initial hydrogen pressure of https://www.w3.org/1998/Math/MathML"> 6 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bar was established. After reaching the maximum reaction temperature of 375 C within 15 minutes the reaction was imrediately stopped by quenching the autoclaves under running water. The liquid products were separated into water, acetone- and di chloromethane soluble (oil) fractions. The results are presented in Table I. Additionally the oils were fractionated into neutral, weakly and strongly acidic fractions. The liquid-liquid extraction procedure used for this analytical step is illustrated by Figure I, and yields on each fraction are shown in Table II. Furthermore, the elemental composition was determined of the starting materials and of the product oils on a Carlo Erba 1104 elemental analyser. The results are presented in Table III. 21. RESULTS AND DISCUSSION As Table 1 shows the highest oil yields were obtained from spruce and bagasse organosolv lignins ( https://www.w3.org/1998/Math/MathML"> 64,0 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 60.7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively). In comparison to the condensed Willstätter lignin which yielded only https://www.w3.org/1998/Math/MathML"> 33 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of an oil, the high oil yield of the organosolv lignins can be attributed to their low molecular weight and better solubility. 0il yields of the carbohydrate feedstocks were obtained in the range of 29 to https://www.w3.org/1998/Math/MathML"> 31 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , whereas the wood materials yielded https://www.w3.org/1998/Math/MathML"> 46 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (spruce) and https://www.w3.org/1998/Math/MathML"> 41 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (birch) of an oil. The higher lignin content in the softwood seems to be responsable for the higher oil yield. The annual plants yielded https://www.w3.org/1998/Math/MathML"> 41 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> oil, while pine bark yielded only https://www.w3.org/1998/Math/MathML"> 20,7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of an oil indicating that this feedstock is an unsuitable material for liquefaction under the conditions applied. As Table I shows, the a cetone fractions origi nate predominately from lignin degradation products. The water soluble products, on the other hand, are formed to a large extent out of carbohydrate degradation products. The amount of solid residue formed was for most of the feedstocks very low. The high yield of charred residue from pine bark corroborates that this feedstock is not suitable for liquef action. The results of the liquid-liquid extraction of the oils, presented in Table Il, demonstrate that the bulk of the extractable compounds have a weakly acidic and neutral character. As was expected weakly acids (phenols) are derived from lignin. The strong acid fraction is formed to a large extent from degradation products of carbohydrates. Although the yield balance is negative this extraction method is corvenient for the characterization of oils from different feedstocks or processes. As can be seen from Table III the oils produced have much higher heating values than their corresponding feedstocks. Since the calorific value of the lignin oils does not increase significantly it seems not recommendable to liquefy lignin for energetic purposes. Furthermore, the total energy balance is negative in spite of the very favorable increase in heating values of the oils in comparison to their starting materials. ACKNOWLEDGEMENT This work was financially supported by the Federal Ministry for Food, Agri culture and Forestry, project number 81 NR 006 . 22. REFERENCES (1) APPELL, H.R., FU, Y.C., FRIEDMAN, S., YAVORSKY, P.M. and WENDER, I. (1971). Converting organic wastes to oil, a repli shable energy source. US Bureau of Mines, RI 7560 . (2) DAVIS, H.G. (1983). Direct liquefaction of biomass, final report and summary of effort 1977-1983. Lawrence Berkeley Laboratory, LBL16243. (3) SCHALEGER, L.L., FIGUEROA, C. and DAVIS, H.G. (1982). Directliquefaction of biomass. Biotech. and Bioeng. Symp. 10,3. (4) EAGER, R.L., MATHEWS, J.F. and PEPPER, J.M. (1982) Liquefaction of aspen poplar wood. Can.J.Chem. Eng. 60,289 . (5) KRANICH, W.C. and WEISS, A.H. (1980). Oil and gas from cellulose by catalytic hydrogenation. Can.J.Chem.Eng. 58,735. (6) FREDON, C., SOYER, N., BRUNEAU, C. and BRAULT, A. (1983). Chemi cal study of the thermal and catalytic liquefaction of poplar wood. Proc. 2nd Internat.conf. on Energy from Biomass, Ap1. Sci. Pub1. Ltd. London-New York, 930 . 23. Btonass 011 (400 mg) extract wit Saturared aq. https://www.w3.org/1998/Math/MathML"> N a 2 H C O 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> C H 2 C l 2 - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ayer 24. Figure I Liquid-1 iquid extraction scheme for product oils Table I Percentage yield of liquefaction products Table II Percentage yield of liquid-liquid extraction products * based upon feedstock oil Table III Elemental composition and calorific value of feedstocks 25. LE PRÉTRAITEMENT, L'HYDROLYSE, LA PYROLYSE ET LA LIQUÉFACTION par Ralph P. Overend Consell National de Recherches Ottawa, Canada, KlA OR6 et t Esteban Chornet Universite de Sherbrooke Sherbrooke, Quê., Canada, J1K 2R1 26. Summary Historically, liquefaction approaches have tried to transform https://www.w3.org/1998/Math/MathML"> 11 gn o - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cellulosics into organic liquids vla integral routes. The net result is the non-selective solubllization of the dffferent macromolecular compounds initialiy present. The products thus obtained are of 11ttle value as fuels and require extensive deoxygenatlon. Moreover. the rheological constralnts inherent to the continuous processing of 1ignocelluloslc are seldom considered in the integral routes when studled at the laboratory level. Recent advances in the knowledge of ultrastructure and macromolecular degradation of the polymeric constituents of biomass permit to envisage a sequentlal approach by means of which def1bration and deflbrillation precede the necessary depolymerization to achieve solubi11zation. By proper cholce of temperatures, solvents, and mechanochemlcal effects, the fractionation of 11gnocellulosics can be achieved and a de-facto selective separation of polymeric families ls then posslble. Thls paper presents the arguments In favor of a sequential approach to liquefaction and tries to unlfy the pretreatment with subsequent thermal decomposition and actd-base (hydrolysis) steps which are closely related to liquefaction. 27. INTRODUCTION La valorisation de la blomasse par vole de sa conversion en produits 11quides suscept1bles d' être ut111sés so1t comme combust1bles ou carburants de substitution, soit comme produits ch1miques particuliers est connue sous le nom générique de llquéfaction. Dans les schémas classiques la liquéfaction est conçue comme la transformation thermochimlque de la biomasse en presence d'un solvant aqueux ou organique. Le concept traditionnel peut être résumé comme suit: I1 est à noter que ce schéma a été appliqué depuls plusleurs années sans tenfr compte de deux caractéristiques essentielles de la biomasse: son "ultrastructure" et sa "nature polymérique identifiable" ce de ces deux caractéristlques de la biomasse est capltale aussi bien en ce qui concerne les aspects rel1és au génie de procédés (1.e. propriétes de transfert) que pour un cholx des approches thermo-chimiques à adopter visant l'obtention de produtts chlmiques valorisables.

ETAPES LORS DE LA LIQUEFACTION

Les étapes sulvantes sont présentes lors de la liquéfaction: (i) DÉsaggrégation structurelle https://www.w3.org/1998/Math/MathML"> → https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> deffibration Cette étape consiste essentlel lement en la destructlon de la lamel- la intermédialre et la liberration des cellules (1.e. fibres) réstil- tantes. La lignine et les hemicelluloses composant la lamella sont ainst solubllisēes. (11) Defibrillation La paroi primaire et les parois secondalres sont altérées par ac- tion thermo-mécano-chlmique ce qui permet 1 "ouverture du réseau microflbrilaire qui enferme les macromolecules cellulosiques. Lors de cette action, les hemice1luloses présentés entre les espaces f1br1llaires sont solubllisées même à des températures relativement faibles ( 180-220° C) (1.11) Dépolymérısation Les différentes macromolécules constitutives sont dépolymérisees par actions thermique, chlmlque ou mécano-chimique. Il est à noter que le "contrôle" de ces dêpolymérisations est cructal pour obtenir une distribution voulue ou adequate des prodults. Lors de la dépo- 1ymérisation, une solubilisation accrue accomplie. (1v) Déoxygénatıon En augmentant la température du traitement ou par action catalyti- que la déoxygénation des prodults dêpolymêrisés est progress1vement accomplie. C'est alnsi que la décarboxylation et la déshydration sont observées. Par action hydrogenante ultérieure, les composants oxygénés résultants lors de la solubllation (alcools, aldehydes, cêtones, etc.) peuvent être progresslvement rédults a un coût toutefols eleve en hydrogene compte tenu des exigences stoechlometriques. Les etapes (1) et (11) const1tuent le prétraftement et sont lmportan- tes dans les domaines biotechnologiques car elles permettent une accessi- bilité accrue aux enzymes lors de la désaggrégation de l'ultrastructure cellulosique. L"etape dépolymérisante peut etre accomplie par action thermique (1.e. pyrolyse), par action thermo-chimique (1.e. hydrolyse ou solvolyse catalytlque) ou par action thermo-mécano-chimique (i.e. en présence de réglmes fluldodynamiques appropriés). Le problême essentlel de toute llquéfactlon est que les fam111es polymeriques constituantes majeures de la blomasse (1.e. les hemicellulo- ses, la lignine et la cellulose) ont des réactivités differrentes (volr Tableau ci-dessous) lors des étapes (iil) et (iv) et le controle de la réactivite et surtout de la sélectivite lors de leur transformatıons re- présente un défi constdérable si la solubillsation des trols familles est votlue dans une seule étape de liquéfactıon Intégrale. Le Tableau cl-jolnt presente un sommalre des conditlons réactionnel- les type associées à la liquéfaction. 3

PRODUTTS DE LIQUÉFACTION

Des multiples travaux de caractérisation ont eu lieu traitant solt de produtts de ligurfaction par pyrolyse out par action solvolytiaue (ous hydrolytique) en pressence ou non de catalyseurs. Deux phases 11quides sont à considérer:

une phase aqueuse, provenant des réactions de déshydratation et riche en composants oxygênês de falble polds molecculalre (acides, aldehydes et alcools dérivés essentiellement des fractions hydrates de carbone)

une phase organlque, les hulles, fortement aromatique et qui dans Ie cas de liquéfaction intégrale par vole solvolytique présente la composition sulvante (Elliott et Davis):

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PERSPECTIVES DU MARCHE ENERGÉTIQUE POUR LES PRODUITS DE LIQUÉFACTION Sur une base de contenu énergétique équlvalent, les prodults issus de la liquéfaction et susceptibles d'etre utilisés comme combust1ble (1. . les hulles) ont un cout de production qui, en moyenne, represente deux fols le prix du brut pétrolter (en $ fin 1984).

Aussi, et sur une base de composition chimique, les produits de liquéfaction sont excessivement phénoliques et trop fortement oxygenes pour être considérés comme possible substituts aux gasolines ou aux carburants diesel actuels. Un raffinage coûteux, et encore à être quantitativement prouvé, devra etre mis au point avant de pouvolr consldérer les prodults de llquéfaction raffinés comme possibles substituts aux carburants dérivess du pétrole.

STRATEGIE ALTERNATIVE

Compte tenu des contraintes lmposees par la constitution même de la biomasse une alternative de valorlsation dolt être développée en partant de la reconnaissance des contraintes ultrastructurelles ainsi que de la nature polymerique des constituants majeurs. Cette constatation nous amêne à considerrer une approche séquentielle visant la séparation des fam1lles macromoléculaires constituantes afin de minimiser la sévérité des procêdés de conversion ainsi que maximiser la valeur ajoutée des produits issus de chaque étage de fractionnement. Une approche unifiée peut être envisagée alnsi: 28. REMERCIEMENTS Les auteurs sont reconnaissants au CRSNG, CNRC, EMR-Ottawa, MER-Ouébec et le programme FCAR pour des subventions concernant les projets 11quéfact1on. 29. RÉFERENCES (1) CHORNET, E. et OVEREND, R.P. (1985). "BIomass Liquefaction: An Overview" dans Fundamentals of Thermochemlcal B1omass Conversion, Elsevier, 967-1002. (2) YOUNG, R.A. et Dav1s, J.L. (1985). "Thermochemical Fractionation and Liquefaction of Wood" dans Fundamentals of Thermochemical Biomass Conversion, Elsevier 121-142. (3) CHORNET, E. et OVEREND, R.P. (1985). "BLomass Liquefaction: Prospects and Problems" dans Proc. Bioenergy 1984 Goteborg, Sweden, Probpects (4) RLLIOTT, D.C. (1985). "Analysis and Comparison of Products from Wood Liquefaction" dans Fundamentals of Thermochemical Biomass Conversion, Elsevier, 1003-1018. (5) DAVIS, H.G. (1983), "Direct Liquefaction of Blomass", Report LBL No. 16243 , Fina1 Report and Summary, prepared for US-DOE, Contract No. DE-AC03-76SF00098, 82 pages. A TECHNO-ECONOMIC COMPARISON OF BIOMASS THERMOCHEMICAL LIQUEFACTION PROCESSES https://www.w3.org/1998/Math/MathML">   Y. SOLANTAUSTA and P.J. MCKEOUGH     Technical Research Centre of Finland   02150   Espoo   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 30. Summary A techno-economic comparison of thermochemical processes for producing both fuel https://www.w3.org/1998/Math/MathML"> 0 i 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and gasoline substitutes from biomass is presented. Direct liquefaction processes (high-pressure hydrogen ation, pyrolysis), which are at an early stage of development, seem to be competitive with the more established processes (indirect liquefaction involving gasification). Direct processes have higher thermal efficiencies and they may be more adaptable to sma11 scale production. At present the products of these processes can not, however, compete economically with conventional liquid fuels. 31. INTRODUCTION Liquid fuels can be produced from biomass by various thermochemical methods. Processes based on these methods are at different stages of development. Some of the processes are at a rather advanced level of development (indirect liquefaction involving gasification) whereas others are only at the bench scale level (most of the high-pressure hydrogenation and pyrolysis processes). In this study, techno-economic assessments of the various processes have been carried out. Process concepts, based on the available experimental data, were first compiled. Then the material and energy flows of a 1000 dry t/d plant were calculated, followed by equipment sizing, investment cost estimation, and comparison of the production costs of the liquid fuels. Also a technical comparison of the processes was made. This type of study can be used not only to compare the relative merits of different processes under development, but also to focus future research onto the most important problems. 32. PROCESSES EVALUATED The comparison of the processes was primarily done on the basis of the equivalent fuel oil production costs. This does not mean that fuel oils are the desired end products, but rather emphasizes the fact no other proper way of comparison was available. Not a lot is known about the upgrading of the primary oils. A total of 9 processes were evaluated, six producing fuel oil substitutes (primary oils, methanol) from both peat and wood, and three producing gasoline from wood. Note that the data base available for the evaluation of the gasoline processes was very limited. Production of primary liquids

PERC/W. High-pressure hydrogenation in recycle oit (wood as feedstock), based on the process originally developed at the Pittsburg Energy Technology Centre (PERC), USA.

FLASH/W. Flash pyrolysis of wood based on the process being developed at the University of Waterloo, Canada.

MEOH/W. Pressurized fluidized bed gasification of wood, methanol synthesis.

Peat feed

H-PEAT/P. High-pressure hydrogenation in recycle oil (peat as feedstock), based on the concept evaluated at VTT, Finland.

FLASH/P. Similar to concept 2, but employing peat as feedstock.

MEOH/P. Similar to concept 3, but employing peat as feedstock.

Production of gasoline from wood

PERC/G. Catalytic hydrogenation of the primary oil produced by

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Concept 2 . MTG/G. Catalytic conversion of methanol to gasoline according to the process developed by Mobil.

Simplified block flow diagrams of concepts 1-6 are presented in figures 1-3. Full details of the designs are provided in references (1) and (2) Table I summarizes the main material flows of the processes. In order to compare the different primary products they were first classified into one of the grades of fuel oil defined by ASTM (3). Then on the basis of their energy contents and the corresponding fuel oil prices their values were determined. Most of the data required for calculating the material flows was obtained from laboratory scale experiments. However, for some cases (PERC, MEOH, MTG) data from larger experimental units (PDU, pilot) was available.

COMPARISON OF THE PROCESSES, PRIMARY LIQUID FUELS The overaT7 thermat efficiencies of the processes are presented in table I. The highest efficiencies can be obtained with the high-pressure hydrogenation processes, PERC and H-Peat, https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively. Also wood pyrolysis yields a higher efficiency than indirect liquefaction (60% compared to https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ).

Total capital requirements for the process concepts presented range from 60 . https://www.w3.org/1998/Math/MathML"> 10 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> USD to more than https://www.w3.org/1998/Math/MathML"> 200 ⋅ 10 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> USD, the lowest for flash pyrolysis and the highest for H-Peat (table II). For a plant processing biomass a low capital requirement is a distinct advantage because of the widespread nature of biomass resources and their low energy density. The lowest primary liquid production cost can be obtained with the flash pyrolysis processes. The cost-value ratio of the products (production cost divided by equivalent fuel oil value) is around 1,5 for these processes, and approaches 1,0 at low raw material prices (fig. 4).

GASOLINE PRODUCTION FROM WOOD (fig. 5)

An attempt was a lso made to compare processes producing gasoline from wood. It should be noted, however, that less is known about the upgrading of the primary oils from pyrolysis and hydrogenation (direct liquefaction) compared to methanol conversion to gasoline (MTG-process). It appears that higher efficiencies can be obtained with the direct processes (table III). Also the gasoline production costs appear to be lower for these processes. It should be noted that a slight decrease in the cost-value ratio occurred when the upgrading step was added to the PERC process (from 2.1 to 2.0 ), whereas for the flash pyrolysis process the ratio increased (from 1.6 to 2.2 ). Thus in the latter case the further upgrading step actually decreased the competitiveness of the process. All the options appear to be uneconomic at the present time (but insufficient data precludes any firm conclusions being drawn). 33. CONCLUSIONS It appears that both higher thermal efficiencies and lower liquid fuel production costs can be obtained with flash pyrolysis and highpressure hydrogenation processes than with the more established indirect Iiquefaction processes involving gasification. More research is required to exploit the potential for improvement offered by the newer processes. 34. ACKNOWLEDGEMENTS This study is in part based on results obtained in an international co-operative project organized by the International Energy Agency. The sponsors of this project were National Research Council of Canada, Ministry of Trade and Industry, Energy Department (Finland), National Energy Administration (Sweden) and Department of Energy (USA). The rest of the study is part of a separate research project financed by the Finnish Ministry of Trade and Industry, Energy Department. 35. REFERENCES (1) McKeough, P. et a 1.., Techno-economic assessment of selected biomass liquefaction processes. Stockholm 1983. IEA Co-operative project D I (BLTF). Final report, vol. 5. Publ. National Energy Administration, Sweden. (2) Elliott, D.C. Analysis and upgrading of biomass liquefaction products. Stockholm 1983. IEA Co-operative project D I (BLTF). Fina 1 report, vol, 4. Publ National Energy Administration, Sweden (3) Solantausta, Y. and Asplund, D., Methanol from peat. Technicat and economic aspects in Finland. Symposium on Peat as an Energy Alternative, December 1-3,1980, Arlington, Virginia, USA. Fig 1. Block diagram of a flash pyrolysis process https://www.w3.org/1998/Math/MathML"> ( F T a s h / W , F l a s h / P ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , production of primary oil. 940 Fig 2. Block diagram of a high-pressure hydrogenation process (PERC, H-Peat), production of primary 011. Fig 3. Block diagram of an indirect liquefaction process https://www.w3.org/1998/Math/MathML"> ( M e O H / W , M e O H / P ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , production of methanol. PRICE OF RAN MATERIAL USD/GJ OPEAC O MEOHIW Fig 4. Effect of the price of raw material on the cost-value ratio, primary liquids. Basis as table II. Fig 5. Effect of the price of raw material on the cost-value ratio, gasoline. Basis as table II. Table I. Overa11 material and energy flows of the process concepts, primary liquid fuels. Concept Feed materia1 Feed in t/h Electricity demand MW Liquid product Liquid product but t/h Byproduct Overa 11 therma1 efficiency % (LHV) PERC Wood 83.3 12.2 Primary oi1 19.2 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 72 FLASH Wood 83.3 9.0 Primary oi1 29.6 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 60 MEOH Wood 83.3 20.6 Methano1 23.7 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 51 H-PEAT Peat 83.3 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Primary oi1 11.2 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 60 FLASH Peat 83.3 4.0 Primary oi1 MEOH 13.8 Methano1 24.7 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 43 Table II. Comparison between process concepts, primary liquid fuets, as of January 1984 Gulf coast. Plant capacity 1000 dry t/d, service life 20 a, rate of interest https://www.w3.org/1998/Math/MathML"> 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (annuity 0.1019 ). Wood cost 30 USD/wet t, milled peat 16 USD/wet t. Concept Total capita 1 reguirement https://www.w3.org/1998/Math/MathML"> 10 USD   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Operating cost 10 https://www.w3.org/1998/Math/MathML">   USD/a   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fixed Production cost USD/GJ (LHV) Cost-value ratio PERC/W 120 10.5 25.3 10.0 2.1 FLASH/W 60 6.8 23.6 9.5 1.6 MEOH/W 170 14.9 29.5 16.3 2.4 H-Peat/P 220 17.3 11.2 13.6 2.0 FLASH/P 60 5.9 12.3 8.1 1.5 MEOH/P 175 15.2 20.2 13.5 2.0

production cost/ equivalent fuel oil value

Table III. Comparison between process concepts producing gasoline from wood, as of January 1984. Basis as table II. Concept Overa11 therma 1 efficiency % (LHV) Product cost Cost-value USD/GJ USD/t PERC/G 50 17.5 760 2.0 FLASH/G 46 19.2 830 2.2 MTG/G 42 21.0 910 2.4 The bulk of research carried out for producing liquid fuels (including engine fuel) was anayzeds, except for conventional acid hydrolysis and biological processes. The main conclusions of this survey are presented:

In the study of direct liquefaction including chemical reactants, the alkaline CO-steam process (Process Develpment Unit at Albany - USA), and its recent developments, were taken into special considaration, because the extent of the results obtained allows to point out the reasons for its failure. In particular, a complete chemical reactional mechanism for biomass components can be built, so that one can select which chemical conditions are liable to lead to much better results, through a reduction and stabilisation of low molecular weight depolymerisation products.

Some thermal processes (pyrolyses) lead to promising results : the vacuum pyrolysis, the solvolyses (liquid or super-critical solvents), the pyrolysis in water under pressure with a very rapid heating and quench, as means of global treatment ; as for a separate use of the hemicellulose/cellulose/lignin fractions, the supercritical extraction (ethanol : water) and the sequential extraction with water. The analysis of the results obtained, through a correlation with the conventional schema of pyrolysis reactions, enables to understand which physical patameters are important to enhance the quantity and quality of the liquid product, but also permits to determine the limits of such thermal processes.

In conclusion, such an investigation allows to select which physical and chemical reactional conditions may lead to interesting processes, and what produts might thus be obtained.

36. 1 - INTRODUCTION "Thermochemical liquefaction" as a direct process leading to liquid fuels production is mainly concerned with depolymerization and deoxygenation of biomass. The research works carried out in this field were studied and 14 results were selected. The conclusions drawn up are presented in this report : are there promising tracks in new processes especially for the production of vehicular fuels? 37. 2 - MAIN PROCESSES AND RESULTS The reacting conditions and main results are listed in Table I. The processes can be classified into three types, according to the operating conditons:

a direct liquefaction including chemical action : the solid biomass is severely treated in one step for liquefaction and reduction ; the product obtained is partially upgraded if necessary, in order to mainly yield hydrocarbons. The PERC process is to be considered, as well as Nickel or Iron catalyses, or'alkalinereaction without reducing gases.

a two-step liquefaction involves firstly a cheap step for biomass depolymerization, ie solvolysis or pyrolysis, and secondly, an upgrading of the crude liquid or its cuts, leading to hydrocarbons, alcohols, and phenols.

The pyrolysis may be a conventional carbonization, or may be carried out to enhance liquid production, i-e, a rapid, flash, or vacuum pyrolysis, or a "hydropyrolysis" which is a rapid pyrolysis of biomass in water under pressure. The only solvolyses considered there (for their good results) are specific ones : either supercritical extractions, or the UDS process which includes a mechanical defibration pretreatment (severe depressurization) and high heating rates (2). 38. - a separation of biomass polymers: The solid biomass is partially depolymerized to yield separate cuts : 1 - carbohydrates derived species in a solvent (cellulose and hemicellulose), leading to sugars by a hydrolysis or a thermolysis ; a final hydrogenation of fermentation yielding alcohols. 2 - polyphenols in a solvent (lignin), giving phenol, guaíacol and similar species, either used as chemical products, or hydrogenated to BTX. Numerous processes folow this general schema ; we have only considered two original ones : an elution in water at two temperature levels with very controlled kinetics, and a supercritical extraction with an ethanol : water variable ratio solvent. 39. RESULTS :

Pyrolyses (excluding hydropyrolysis) are characterized by a high char yield (at least https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) - the oils obtained have a high water content, i-e high fluidity and oxygen content - their chemical composition, organic acids https://www.w3.org/1998/Math/MathML"> ( 10 - 20 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , ketones, aldhydes, furans, phenols and methoxyphenols mainly, explain their thermal instability ; the upgrading attempts have therefore failed so far (except perhaps for heavy tars of conventional carbonization). So their only use would be as burning fuel.

For the most interesting process (flash pyrolysis), the estimated cost is similar to that of fuel https://www.w3.org/1998/Math/MathML"> n ⋅ 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , taking their difference in energetic value into account (Biomass: https://www.w3.org/1998/Math/MathML"> 30   s / m a f t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in all cases). Considering their low heating value and high corrosivity, they should be used only as mixtures with petroleum fuel or coal, and thus can be expected in two cases

for refuses or sewage sludge disposal, when cheaper than burning,

as a by-product of carbonization, when charcoal is economic, thus considering only over-investment for condensation and storage of liquids.

Liquefaction under pressure (including UDS process), possibly with a chemical action, have a low char yield https://www.w3.org/1998/Math/MathML"> ( < 3 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . As compared with pyrolysis, the oils have a lower water content, i-e a higher viscosity and lower oxygen content. It should be noted that the oxygen content of dry oils is always the same, except under efficient reducing conditions. The main interesting point is that, thanks to both their chemical composition (phenols and polyphenols, methoxyphenols, naphtols, cyclic ketones, https://www.w3.org/1998/Math/MathML"> < 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> acids) and thermal stability, the oils can be upgraded to https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrocarbons through a catalytic hydrogenation https://www.w3.org/1998/Math/MathML"> ( 300 ⋅ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , CoMo https://www.w3.org/1998/Math/MathML"> + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> S). The estimated cost for these final products in a PERC (2) (3) is 3 to 4 times that of gasoline, but only 1,2 times that of other substitutes from biomass, i.e Methanol https://www.w3.org/1998/Math/MathML"> + https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MTG Mobil or vegetable oil esters. Anyway, new proesses like the UDS can be cheaper than PERC and thus give economical gasoline.

Supercritical solvolyses have not proved yet feasible because of solvent incorporation into the product, leading to a high cost.

Hydropyrolysis has given only limited results, but as far as we know, it is similar to liquefaction under pressure for one part (lowchar yield) and to pyrolyses for another (chemical composition of the oil). This latter point suggests that a global hydrogenation would be difficult ; but a the chemical species are in limited number in the product (phenolics from lignin and sugars or their degradation products from cellulose), the operating conditions would be well adapted to a separation process as described above.

Separation processes yield an interesting rate of non-degraded sugars but are not to be used as yet : the sugars are diluted in one case and the loss of ethanol is unknown in the other.

40. 3 - INTERPRETATION The analysis of these results allows us to determine which operating conditions can give valuable products at reasonable costs. The results are not affected by the process type https://www.w3.org/1998/Math/MathML"> i - e : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> direct or 2 step liquefaction but they mainly depend on the two following criteria : a) chemical conditions : the mechanisms probably invoived in different reactions are shown in fig.I. In all cases, the depolymerization of biomass is obtained. But, to yield low molecular weight deoxygenated products, the condensation of primary products by a reduction should be stopped : a Hydrogen transfer through catalyst (metal complexes in water ?) or H. donor polar solvents recycled (alcohols, hydroxy. aromatics ? ). This chemical action may take place in-situ or in a second step: anyway it must be rapid and efficient, the intermediates being very reactive. b) physical conditions : When comparing the results with the classical model of biomass pyrolysis mechanisns, various alternatives to enhance liquid production can be pointed when selecting the operating conditions: heat and mass transfer possible with a large granulometry ; a delayed quench and low dilution ; a localisation of chemical reactants for an optimum efficiency (protect catalysts from solid particles poisoning, linit hydrogen consumtion by avoiding aromatic cycle saturation,...). 41. 4 - CONCLUSION 42. a) What products can be obtained ?

a low-grade burning fuel by pyrolysis in a specific economic context

vehicular fuel: *aliphatic and aromatic hydrocarbons through hydrogenation of phenolics and cyclicketones (direct liquefaction under pressure)

alcohols through reduction of sugars and intermediate products of cellulose degradation + hydrocarbons fromthe lignin fraction hydrogenation.

43. b) What priorities for research ? Concentrate the efforts on processes taking the above criteria into account especially a reduction strictly adapted to depolymerization/condensation kinetics, in one or a few steps, but involving a separation of biomass polymers if the kinetics appear as incoherent. Therefore, the following points schould be studied :

optimization of reaction kinetics and solvents

adapted configuration for hydrogenation (in situ with a special design or upgrading),

integration of such elementary steps in a flobal biomass separation process,

concurrent economic evaluation.

44. REFERENCES (1) ESNOUF (C.) 1985 - Thermochemical Liquefaction of biomass : A Review submitted for publication. (2) CHORNFT (E..) & OVEREND (R.) 1984 - Biomass Liquefaction : Prospects and Problems. Bionergy 84 conference - Göteborg-Sweden. (3) WILHFLM (D.J.) & al 1981 - Transportation fuel from biomass by direct liquefaction and hydrotreating. SRI International. Entrichl contitions Table I Fig. II IMPROVEMENT OF THE ETHYLENE GLYCOL WATER SYSTEM FOR THE COMPONENT SEPARATION OF LIGNOCELLULOSES D. Gast and J. Puls Institute of Wood Chemistry and Chemical Technology of Wood D-2050 Hamburg 80, Federal Republic of Germany Summary Kinetio aata for the delignification of birchwood were determined for the ethylene glycol-water system at 180 . 190 , and https://www.w3.org/1998/Math/MathML"> 200 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Delignification occurs in two distinct phases according to first order reactions. The activation energies IOr the Iirst and the second delignification phases were found to be https://www.w3.org/1998/Math/MathML"> 81.2   k J / g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> * mole and https://www.w3.org/1998/Math/MathML"> 135.5   k J / g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . mole respectively. Upscaling of the process from the laboratory to the 10 l scale yielded products for further investigations on possible applications. The chemical composition of pulps and the adhesive strengths of phenolic resin-lignin mixtures are discussea.

Introduction

Chemical pulping processes such as kraft and sulfite involve high capital costs and pollution problems. The development of alternative technologies has therefore been pursued Eor a long time. Organosolv pulping has been proposed as an option. In most cases low boiling alcohols such as methanol. ethanol or butanol were tested as delignifying agent. Kleinert (1) proved, that mixtures of ethanol and water were more effeca tive than ethanol alone. The use of ammonium sulfide in aqueOus methanol solutions was proposed by Chlang and sarkanen (2) The MD-organosolv process is based on the use of methanolwater-sodium hydroxide solutions (3). phenol pulping is an example Eor pulping with a high boiling solvent under atmospheric pressure (4). We have compared the pulping efficiencies of customary low- and high boiling alcohols in mixture with water and found ethylene glycol among the high boiling alcohols to be even more effective than the commonly used low boiling alcohols (5). Organosolv systems using high boiling Solvents offer some advantages concerning the process conditions. The pressure in the system corresponds to the partial pressure of water at the required temperatures, losses of solvent and danger of fire on account of the volatility are drastically reduced. Our interest concentrated on the development of c. non-toxic, sulfur-free pulping process without using greater amounts of inorganic chemicals. Ethylene glycol seemed to meet the requirements for such a process and therefore was chosen as solvent for further investigations on time and temperature effects and for upscaling experiments.

Experimental

Batch delignification studies for kinetic data aquisition were conducted according to https://www.w3.org/1998/Math/MathML"> ( 6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Cooks in the semi-technical stage were performed in a quasi continuous digester system. RATE CONSTANTS AND ACTIVATION ENERGIES IN ETHYLENE GLYCOL-WATER PULPINS Table I Table II All values based on fibre material *) Ethylene glycol : water https://www.w3.org/1998/Math/MathML"> 1 : 1 , 190 ∘ C , 90 m l n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ethylene glycol-water lignins as extenders in phenolformaldehyde (Phe) resins Table III HYDROTHERMOLYSIS OF SHORT ROTATION FORESTRY PLANTS G.BONN, W.SCHWALD, O.BOBLETERInstitute of Radiochemistry, University of Innsbruck, AustriaV.I.BENEAStatiunea Experimentala Silvica Cornetu, Bucuresti, Romania Statiunea Experimentala Silvica Cornetu, Bucuresti, Romania SUMMARY Hydrothermolysis is a newly developed method to obtain low molecular substances from plant biomass https://www.w3.org/1998/Math/MathML"> ( 1 - 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In this process the hemicellulose is solubilized at approx. https://www.w3.org/1998/Math/MathML"> 200 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , the cellulose is converted to oligomeric and monomeric carbohydrates as well as further degradation products such as hydroxymethylfurfural (HMF) and furfural at approx. https://www.w3.org/1998/Math/MathML"> 280 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and lignin is degraded at temperatures above https://www.w3.org/1998/Math/MathML"> 300 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by the use of water only as elution medium. The possibility of employing short rotation forestry plants (poplar wood) for this purpose was investigated. 45. EXPERIMENTAL Hydrolysis Apparatus and Reaction Conditions The hydrothermolysis was carried out in an apparatus consisting of a https://www.w3.org/1998/Math/MathML"> 10 m l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volume reaction vessel (4). A high-pressure pump delivered water through a preheating unit into the electrically heated reaction vessel. The pressure in the reaction vessel was adjusted by a metering valve to ensure that the water remained in the liquid phase during the experiment. 46. Analysis The analyses of the wood samples were carried out using the TAPPI Standards. The gluco-oligomers were analyzed using GPC (5), monosaccharides and further degradation products by HPLC (6-9). 47. RESULTS AND DISCUSSION Hydrothermal degradation experiments were carried out with poplar wood as starting material, which was supplied from a Romanian short rotation forestry culture. From chemical assays, conclusions were drawn regarding degradation characteristics and carbohydrate yields. Apart from dry weight and ashes, the following determinations were carried out in compliance with familiar analysis procedures: benzene/alcohol extract, holocellulose, α-cellulose and lignin content. Table I gives the chemical raw material analysis of Populus deltoides without bark, first from a biennial, then from a four-year-old sample. TABLE I Chemical raw material analysis of Populus deltoides 2 years 4 years lidity (%) 6.1 5.6 Sh (E atro) (%) 1.3 0.6 enzene/alcohol tract (%) 3.9 3.3 locellulose (%) 84.8 86.0 -cellulose (%) 45.2 46.4 gnin (%) 16.3 18.8 Hydrothermolysis of poplar wood (Populus deltoides) To investigate what influence is exerted by the age of the fast-growing wood types just described, two-and four-year-old samples with and without bark were subjected to hydrothermolysis at different degradation temperatures. At a temperature of https://www.w3.org/1998/Math/MathML"> 277 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a flow rate of 10 https://www.w3.org/1998/Math/MathML"> m I / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the maximum recidence time of the dissolved material inside the reaction vessel is about 1 minute. The degradation came about shown in https://www.w3.org/1998/Math/MathML"> F i g . 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for a four-year-old Populus deltoides without bark, and in Fig.2 for the same material, at a reaction temperature of https://www.w3.org/1998/Math/MathML"> 287 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The maximum concentrations of xylose and glucose obtained in the main fraction are specified in Table II. The follow-up reactions that lead to furfural and HMF from xylose and glucose were also determined quantitatively and are depicted in Figs.1 and 2 . From degradation and analysis data obtained by GPC and HPLC several parameters characteristic of the hydrothermal process can be derived, making allowance for the age of the wood samples used. Fig.3 shows the main fraction of the hydrothermal degradation of poplar wood (4-year-old) without bark and Fig.4 the same species with bark. In Fig.4 the molecular components first eluted probably originate from the soluble portion of bark. A further significant difference is obvious in the oligomer distribution and the monomeric sugar yield. Barkless material upon hydrothermolysis yields more glucose than wood material containing bark. In Fig. 5 the reaction course of the characteristic hydrothermolysis products using HPLC is shown. Apart from the gluco-oligomers, cellobiose, glucose, xy lose, fructose, glyceraldehyde, 1.6-anhydro-B-D-glucose as well as the heterocyclic sugar degradation products HMF and furfural are detected. From most of the degradation series, it was ascertained that, in all, more solid dissolves when barkless wood is used. The time at which maximal solid concentrations appear in the eluate is dependent on how much bark was present in the wood samples. Four- and two-year-old species with bark produce roughly the same glucose yields. These experiments showed that the two year old poplar wood yielded lower sugar concentrations than the four year old specimens. As expected the barkless samples gave higher sugar yields than those with bark. In preliminary experiments it was proved that the overall yield can be Considerably increased by low temperature hydrothermolysis (at approx. https://www.w3.org/1998/Math/MathML"> 200 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C) with an additional enzymatic saccharification. TABLE I I Hydrothermolysis of Romanian poplar wood without bark (4-year-old) degradation temperature https://www.w3.org/1998/Math/MathML"> 277 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 287 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> residue (%) dissolved solid (%) maximum solid matter concentration (mg/ml) max. glucose concentration (mg/ml) max. xylose concentration (mg/ml) 11.3 5.8 rig.3 lipc chromatogram of a hydrothermally degraded poplar wood sample (4-year-old) without bark. Column, Bio-Gel P-2; flow rate, https://www.w3.org/1998/Math/MathML"> 0.12 m l / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; detection, RI. 1… glucose, 2-8… gluco-oli gomers, https://www.w3.org/1998/Math/MathML"> 9 … × y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lose, 10… HMF Fig.4 GPC chromatogram of a hydrothermally degraded poplar wood sample year-old) with bark. Column, Bio-Gel P-2; flow rate, https://www.w3.org/1998/Math/MathML"> 0.12 m l / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; detection, RI. 1...glucose, 2-9...gluco-oligomers, 10...HMF Fig.5 HPLC chromatograms of the main fractions https://www.w3.org/1998/Math/MathML"> ( 7,8 , 9 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from hydrothermolysis of poplar wood without bark at a reaction temperature of https://www.w3.org/1998/Math/MathML"> 284 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Column, u Spherogel https://www.w3.org/1998/Math/MathML"> × 7.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Carbohydrate and ion exclusion micro-guard (cation H); mobile phase, water; flow rate, https://www.w3.org/1998/Math/MathML"> 0.6 m l / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; column temperature, https://www.w3.org/1998/Math/MathML"> 85 ∘ C ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> detection, RI; 1… glucose, 2… cellobiose, https://www.w3.org/1998/Math/MathML"> 3 … DP https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 3 (DP=degree of polymerization), 4… xylose, 5… fructose, 6… glycera Idehyde, 7…1.6-anhydro-ß-D-glucose, 8… HMF, 9… furfura 1 1. ACKNOWLEDGEMENT The authors are indebted to the Bundesministerium fuer Wissenschaft und Forschung (Vienna) for their financial support. 2. REFERENCES

BOBLETER, 0 and PAPE, G. (1968). Verfahren zum Abbau von Holz, Rinde oder anderen Pflanzenmaterialien. Austrian Patent 263661

BOBLETER, 0., BONN, G. and CONCIN R. https://www.w3.org/1998/Math/MathML"> ( 1980 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Hydrothermolys is of biomass-production of raw-material for alcohol fermentation and other motor fuels. Alternative Energy Sources III, Vol 3, p 323, Ed.: Veziroglu, T.N., Hemisphere Publ. Corp., Washington, USA

BONN, G. CONCIN, R. and BOBLETER, O. (1983). A new process for the utilization of biomass. Wood Sci. Technol., 17:195 4. SCHWALD, W. and BOBLETER, 0. (1984). Recycling durch Hydrolyse von Rohbaumwolle und Baumwoll-Gewebeabfä 1 len. Chemiefasern/Textilind., 34/86:527

SCHWALD, W., CONCIN, R., BONN, G. and BOBLETER, O. (1985). Analysis of oligomeric and monomeric carbohydrates from hydrothermal degradation of cotton-waste materials using HPLC and GPC. Chromatographia 20/1:35

BONN, G. and BOBLETER, 0. (1984). Analysis of biomass degradation and fermentation products by ion exchange HPLC. Chromatogram-Beckman, 5/2:8

BONN, G. and BOBLETER, 0. (1984). HPLC-Analysis of plant biomass hydrolysis and fermentation solutions. Chromatographia, 18:445

BONN, G., PECINA, R., BURTSCHER, E. and BOBLETER, 0. (1984). Separation of wood degradation products by high-performance liquid chromatography. J.Chromatogr., 287:215

BONN, G. (1985). HPLC - elution behaviour of oligosaccharides, monosaccharides and sugar degradation products on series-connected ion-exchange resin columns using water as mobile phase. J.Chromatogr., 322/3:411 SYNTHESIS OF SEVERAL ALCOHOLS FROM BIOMASS GASES WITH ZEOLITE CATALYSTS

3. Summary From synthesis gases (CO, H_2) we have studied catalytic synthesis of homologous alcohols with catalysts prepared from zeolites : principally https://www.w3.org/1998/Math/MathML"> 13 X https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and modernite associated with some transition metals Iike copper and zinc. Synthesis is realised in a dynamic reactor under pressure (50 bar) and under temperatures from https://www.w3.org/1998/Math/MathML"> 250 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 400 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . We have obtained interesting results for some catalytic compositions. Synthesis is principally oriented to butanol with a selectivity of https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a conversion rate of carbon monoxide of https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These results depend from several paraneters: rature of the zeolite, nature and concentration of metals presents in the zeolite, reduction conditions of catalyst, crossing time on gases of the catalyst, gases compositions. 4. INTRODUCTION Des efforts de recherche considérables ont été consentis pour développer des procédés de transformation de gaz de synthèse en carburants ou intermêtiajres de synthèse. La synthèse Físcher-Tropsch, développée durant la seconde guerre mondiale en Allemagne n'a continué à être utilisée que dans les régions où les circonstances locales êtaient favorables. https://www.w3.org/1998/Math/MathML"> D ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> autres procédés existent, on citera notamment la synthèse isobutylique, aboutissant principalement à la synthèse d'alcools dont le nombre d'atomes de carbone ne dëpasse pas 6 ; un certain nombre de réactions parasites interviennent egalement de façon notable (cokéfaction, formation de CO2). Il est important de souligner que ces réactions nécessitent à la fois des pressions et des températures élevées https://www.w3.org/1998/Math/MathML"> 300 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> à 400 bar, 350 a https://www.w3.org/1998/Math/MathML"> 500 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Pour rendre ces reactions intëressantes sur le plan technique et économique, il est nécessaire de mettre au point des catalyseurs fonctionnant a des pressions et temperratures abordables et permettant de bons rendements. Ces catalyseurs doivent être sélectifs thermiquement et mécaniquement stables De l'ensemble des catalyseurs utilisés pour la réaction d' hydrocondensation du monoxyde de carbone orientèe vers la synthèse https://www.w3.org/1998/Math/MathML"> d ' al https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cools, on rem tiendra principalement les deux couples CuO-ZnO et ZnO-Cr_{ } https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Notre laboratoire a mis au point un catalyseur particulierement actif pour la synthêse du méthanol à partir du couple Cu, Zn. Les tests catalytiques sont effectués dans une unité fonctionnant sous pression en régime 5. PREPARATION DU CATALYSEUR 6. TESTS CATALYTIQUES A partir de notre catalyseur, on obtient principalement le butanol seIon 1'équation équilibrée ci-dessous : https://www.w3.org/1998/Math/MathML"> 8 H 2 + 4 C O ≠ C 4 H 9 O H + 3 H 2 O + Δ H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Comptetenu de 1' exothermicité de la rêaction, nous avons effectué une approche thermodynamique en vue de : - déterminer la quantité de chaleur dégagée dans nos conditions operratoires et prévoir 1'évacuation de cette chaleur.

prévoir les limites de conversion dans nos conditions opératoires.

Les paramêtres expérimentaux suivants ont êté successivement envisagés : rapport molaire https://www.w3.org/1998/Math/MathML"> H 2 / C O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , temps de passage du gaz de synthêse sur le catalyseur, température dé synthëse. L"analyse des produits condensés a permis de mettre en évidence la prêsence de méthanol, ethanol, isopropanol, isobutanol, eau, dimethylether et cetones diverses. La concentration en isobutanol de la phase condensée dêpasse 40%, la somme des concentrations des autres alcools n'excède pas https://www.w3.org/1998/Math/MathML"> 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ce qui représente une sélectivité en isobutanol supérieure à https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lorsque 1'eau est êliminēe. Les effluents gazeux sont êgalement analysés et sont principalement constitués https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hydrocarbures saturés https://www.w3.org/1998/Math/MathML"> C H 4 , C 2 H 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et https://www.w3.org/1998/Math/MathML"> C 3 H 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et également de https://www.w3.org/1998/Math/MathML"> H 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et CO n'ayant pas réagi. Les résultats expérimentaux concernant la conversion du monoxyde de carbone en isobutanol pour un rapport molaire https://www.w3.org/1998/Math/MathML"> H 2 / C O = 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sont rêunis dans le tableau suivant : 961 Temps de contact 0,4 0,8 1,2 1,6 (seconde) temperrature ( https://www.w3.org/1998/Math/MathML">   ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C) 180 4 5,6 6,9 8,4 200 5,6 7,9 10 13,0 210 8,1 10 11,9 15,7 220 10 11,3 14 17,8 240 15 16,1 17,5 23 260 12,0 12,5 15,2 20 La figure https://www.w3.org/1998/Math/MathML"> N ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> l représente les variations de la conversion du monoxyde de carbone en fonction de la température pour differents temps de passage. Les courbes ont des allures en cloche tres caracteristiques. On constate un maximum de conversion voisin de https://www.w3.org/1998/Math/MathML"> 250 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et que pour un temps de passage de 1,6 seconde, les valeurs de la conversion sont voisines des valeurs a 1 iequilibre. La figure https://www.w3.org/1998/Math/MathML"> N ∘ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> représente les variations de la conversion du monoxyde de carbone en isobutanol en fonction du temps de passage pour différentes temperratures. Figure https://www.w3.org/1998/Math/MathML"> N ∘ 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure https://www.w3.org/1998/Math/MathML"> N ∘ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Les variations du rapport https://www.w3.org/1998/Math/MathML"> H 2 / C O https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ont également été envisagées (figure https://www.w3.org/1998/Math/MathML"> N ∘ 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . https://www.w3.org/1998/Math/MathML"> V ( m 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> La conversion croit avec le rapport H /CO; il nous est apparu intéressant https://www.w3.org/1998/Math/MathML"> d t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> utiliser le rapport 3 pour https://www.w3.org/1998/Math/MathML"> 1 ⊤ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> essentiel de nos tests. Ce rapport permet en effet une augmentation relative importante de la conversion. 7. CONCLUSION Nous avons ainsi pu mettre au point un catalyseur a la fois actif et sélectif pour la synthèse de 1'isobtatanol. Les conversions du monoxyde de carbone atteint https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et la concentration de https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> isobutanol dans la phase liquide dépasse https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (en dehors de 1 eau). Ce catalyseur presente une activité catalytique très stable dans le temps puisque nous n'avons observé aucune chute de conversion notable même après 500 heures de fonctionnement. La mise au point de catalyseurs de même type est susceptible d" https://www.w3.org/1998/Math/MathML"> e ˆ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tre Étendue a https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> autres types de supports et avec d'autres éléments de transition en proportions variables, ceci en vue d'orienter la sêlectivité vers https://www.w3.org/1998/Math/MathML"> d ' a u t r e s a l c o o l s . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> En outre, notre dispositif expérimental est susceptible d' être utilisép avec deux lits catalytiques successifs ce qui peut également permettre 1'ëlargissement des possibilités de synthèse, à partir du mélange Co, H 2 vers la production d'hydrocarbures notamment. 8. REFERENCES (1) MASSON, C., BOURREAU, A., LALLEMAND, M., SOUIL, F. et GOUDEAU, J.C. https://www.w3.org/1998/Math/MathML"> ( 1980 ) , 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> st Conference "Energy from Biomass", Brighton, Nov 80 . (2) GOUDEAU, J.C., BOURREAU, A. et KABBARA, N. (1982). 2^nd Conference "Energy from biomass", Berlin, sept 82 . INVESTIGATIONS ON METHANOL CATALYTIC SYNTHESIS FROM BIOMASS GASES : OPTIMIZATION OF THE PROCESS ON A NEW CATALYST A. BOURREAU, J.C. GOUDEAU, L. JULIEN, A. NEMICHE, F. SOUIL Université de Poitiers Groupe de Recherches de Chimie Physique de la Combustion Domaine du Deffend Mignaloux Beauvoir 86800 SAINT JULIEN L'ARS FRANCE Abstract SUMMARY The research began several years ago on methanol catalytic synthesis from biomass gases has permitted to us to test some catalysts under a pressure of 50 bars with gases mixtures containing impurities (1), (2). Interpretation of obtained results has permitted to optimize conditions of methanol synthesis with a catalyst prepared in our laboratory. The new reactor was realised with two successive catalytic beds and we have studied the following parameters stability of the catam lyst with temperature and during the time, influence of preheating of synthesis gases on conversion rate principally molar ratio https://www.w3.org/1998/Math/MathML"> H 2 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> CO]. From results obtained we have entered kinetic study of the reaction to precise some steps of the catalytic reaction.

INTRODUCTION

Le méthanol peut être obtenu à partir d'un gaz de synthèse par la réaction : La gazéjejcation est un procédé et une possibilité de transformation de la biomasse pour la production de gaz de synthèse. Diverses réactions interviennent et donnent des mélanges gazeux dont les constituants principaux sont le monoxyde de carbone (CO), 'hydrogẽne (H https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ), 1 e dioxyde de carbone https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , le méthane https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et éventuellement d https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> autres hydrocarbures, I'azote lorsque cette gazéification est effectuée à l'air. Les gaz de synthèse ainsi obtenus peuvent être utilisables pour la synthèse de combustibles líquides tel que le méthanol. Nous nous sommes interressés à ce probleme et divers travaux ont êté réalisés au GRCPC, notamment la mise au point d'un catalyseur pour la synthèse a basse pression, 1'étude de 1'influence de certains gaz sur les paramêtres de la synthêse, comme https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> azote, I'ammoniac, le méthane et divers hydrocarbures (1) (2) (3). A la lumiere de ces travaux, nots avons mis au point une installation expërimentale nous permettant :

de mener les études de la synthèse en https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> absence de l'influence des diffusions externe et interne

d'optimiser la conversion du monoxyde de carbone en méthanol

de realiser une étude de 1'influence du préchauffage du gaz d'alimentation et une eventuelle utilisation de la chaleur de reaction pour ce prechauffage.

9. CONDITIONS EXPERIMENTALES L Installation de synthesse mise au point au laboratoire fonctionne er régime dynamique sous une pression maximale de 60 bar, et permet divers modes de fonctionnement (fig 1). Pour ces êtudes, le mêlange gazetıx est constitué de monoxyde de carbone et d'hydrogëne dont le rapport molaire https://www.w3.org/1998/Math/MathML"> H C O = 2 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Les pressions partielles du monoxyde de carbone et de 1 hydrogene ainsi que la pression totale sont maintenues constantes (Ptotale https://www.w3.org/1998/Math/MathML"> = 50 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> bar). Nous avons étudié 1influence de la température et du temps de passage sur le taux de conversion du monoxyde de carbone en méthanol avec le catalyseur type MC l mis au point au laboratoire. L'étude de la stabilite du catalyseur en fonction du temps a montré que, si la température reste inferieure a https://www.w3.org/1998/Math/MathML"> 350 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , pratiquement aucune perte d'activite du catalyseur https://www.w3.org/1998/Math/MathML"> n * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est observée bien que le temps de fonctionnement soit très long (250 heures). Par contre, un fonctionnement de 5 heures sous https://www.w3.org/1998/Math/MathML"> 350 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> suffit pour provoquer une dësactivation importante. L'intervalle de température consídérê pour cette étude est https://www.w3.org/1998/Math/MathML"> 230 - 320 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Dans le but d'optimiser la conversion, nous avons envisagé deux modes opératoires différents: l'êtude de la synthẻse avec deux lits catalytiques successifs et l'influence du préchauffage du gaz d'alimentation. 10. SYNTHESE DU METHANOL SUR DEUX LITS CATALYTIQUES SUCCESSIFS Dans les mêmes conditions de température et de temps de passage, nous avons comparé les résultats expérimentaux obtenus avec un seul réacteur et ceux obtenus avec deux rêacteurs en série avec refroidissement intermédiaire, Ces résultats montrent les variations du taux de conversion en fonction de la température pour differrents temps de passage du mélange gazeux sur la catalyseur (fig 2).

2 lits catalytiques avec refroídissement intermêdiaire

https://www.w3.org/1998/Math/MathML"> - - - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Lit catalytique FIGURE https://www.w3.org/1998/Math/MathML"> N ∘ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Abstract Nous avons pu mettre en évidence que " "itilisation de deux réacteurs en sërie améliore la conversion du monoxyde de carbone en mêthanol par rapport à https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> utilisation https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> un seul réacteur. Ces résultats sont en parfait accord avec les calculs théoriques pré- L'augmentation relative de la conversion est de https://www.w3.org/1998/Math/MathML"> 1 ⊤ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ordre de https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pour une température de https://www.w3.org/1998/Math/MathML"> 250 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> et un temps de passage de 0,5 seconde. Cette augmentation relative diminue avec le temps de passage (fig 3). Pour les tempêratures supêrieures à https://www.w3.org/1998/Math/MathML"> 290 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , les taux de conversion obtenus avec un seul réacteur et deux rëacteurs en sërie tendent à s'ägaliser (on est proche de 1 êquilibre thermodynamique). Cette étude est réalisêe pour une éventuelle évaluation de 1 êconomie de 1'énergie consommée pour le chauffage du gaz avant son contact avec le La méthode utilisée consiste à envoyer le gaz d'alimentation préalablement préchauffê a travers le lit catalytíque chauffê à la tempêrature 4. INFLUENCE DU PRECHAUFFAGE DE GAZ D 'ALIMENTATION FIGURE https://www.w3.org/1998/Math/MathML"> N ∘ 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FIGURE https://www.w3.org/1998/Math/MathML"> N ∘ 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Nous constatons que le préchauffage de gaz d'alimentation n'a pratiquement pas d influence sur le taux de conversion du monoxyde de carbone en méthanol si la température de préchauffage ne dépasse pas https://www.w3.org/1998/Math/MathML"> 200 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Pour une température du lit catalytique fixe et égale à https://www.w3.org/1998/Math/MathML"> 260 ∘ C , 1 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> conversion du monoxyde de carbone, en fonction de la temperrature du préchauffage des gaz d'alimentation et pour différents temps de passage. augmente légêrement jusqu'à https://www.w3.org/1998/Math/MathML"> 200 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Mais au-delà de cette température, la conversion chute très vite. Cette baisse rapide peut être attribuée à la surchauffe du grain du catalyseur qui provoque une désactivation de celuiCi https://www.w3.org/1998/Math/MathML"> ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fig 4 https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Il est donc envisageable d'utiliser la chaleur dégagée par la réaction pour préchauffer les gaz d'alimentation, la température du préchauffage ne devant toutefois pas dépasser https://www.w3.org/1998/Math/MathML"> 200 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 5. CONCLUSION Nous avons ainsi abordé dans cette etude l optimisation de la synthese catalytique du mêthanol sur un catalyseur a base d oxydes de cuivre et de zinc mis au point au laboratoire. Les synthèses ont étê conduites sur des mélanges exclusivement composes de gaz ptrs: monoxyde de carbone et hydrogëne. Le montage expérimental rêalisé qui comprend deux reacteurs en série permet de négliger toute influence macroscopique sur la réaction de synthèse. Après une étude paramétrique portant sur les facteurs suivants : H./CO, nous avons envisage successivement deux modes de fonctionnement de notre dispositif expérimental. https://www.w3.org/1998/Math/MathML"> D † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> une part, le fonctionnement avec deux lits catalytiques successifs identiques, étude qui nous a permis https://www.w3.org/1998/Math/MathML"> d † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> augmenter la conversion du monoxyde de carbone de façon treas importante, et, d'autre paxt, Ie fonctionnement avec prêchauffage du gaz de synthèse. L https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> optimisation de cette réaction de synthèse sera poursuivie par 1 हैtude des differrents modes de fonctionnement non encore testes dans le but d'aboutir à une meilleure connaissance de la réaction : approche du mécanisme réactionne 1 notamment. 11. REFERENCES (1) MASSON, C. BOURREAU, A., LALLEMAND, M., SOUIL, F, et GOUDEAU, J.C. https://www.w3.org/1998/Math/MathML"> ( 1980 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . lst Conference "Energy from biomass", Brighton, November 1980 . (2) GOUDEAU, J.C., BOURREAU, A. et KABBARA, N. (1982). 2nd Conference "Energy from biomass", Berlin, September 1982 . (3) GOUDEAU, J.C., BOURREAU, A. et SOUIL, F. (1983). A1ternative Energy Sources. Vol. V. Elsevier, Netherlands. THE SOLID-LIQUID TRANSFER PROCESS IN A SLIGHTLY HYDRATED HETEROGENEOUS MEDIUM : AN ORIGINAL WAY TO SYNTHETISE ORGANIC CHEMICALS FROM BIOMASS M.E. BORREDON, L. RIGAL, M. DELMAS and A. GASET Laboratoire de Chimie Organique et d'Agrochimie, Ecole Nationale Superieure de Chimie, Institut National Polytechnique 118 , route de Narbonne, 31077 TOULOUSE Cédex, France 12. Surmary The plant polymers constituent the principal part of biomass can be readily valorizated in new chemicals with high yields and very good selectivity after primary breakdown using the solid liquid transfer process. The reactions proceed in a heterogeneous medium which involves a solid alcaline hydroxide or carbonate, an organic solvent, the substrates and a small quantity of water which acts as catalyst. 13. INTRODUCTION The value of biomass as a source of mid weight capacity chemical products 1ies in the fact that it provides specific products which can not be created through petrochemistry. These products such as 2-furancarboxaldehyde, 5-hydroxymethyl 2-furancarboxaldehyde, dianhydrohexitols, phenolic aldehydes readily available from hemicellulose, hexoses, polyholosides and lignins are of great interest for their intrinsic qualities. Traditional synthetizing techniques in organic chemistry using a carbonyl function applied to biomass extracted aldehydes such as furfurol, hydroxymethylfurfurol or phenolic aldehydes give poor results in terms of reactivity and selectivity. For these reasons, such techniques are not useful on industrial scale. Furthermore, the furanic cycle through obviously interest, presents particular antibacterial and fireretarding characteristics within its inner structure. This dictates that, for each transformation to be considered, new synthetizing techniques must be defined in relation to the specificity of the biomass extracted molecules. 14. RESULTS AND DISCUSSION We report herein on the reactions realized in slightly hydrated heterogeneous solid-Iiquid medium. This new synthetizing technique uses a solid base (alcaline, hydroxide of carbonate), a liquid organic phase, usually a mixture of an organic solvent and the reagent issued from biomass, with a carefully controlled amount of water. The water molecules localized at the interface of the two phases play an unexpected and critical rol, similar to a phase transfer catalyst. In this way new alkenes, oxirans, unsaturated nitriles and ethers are synthetized under very mild experimental conditions. The 5 -hydroxymethyl-2 furancarboxaldehyde used in the experiments is obtained according to our original process (1) which involves a triphasic system created with D-fructose as model substrate, a cation exchanger and extracting solvent. The system was applied to the processing of plant materials extracts ilke inulin from Jerusalem artichoke (1). 15. Alkenes The Wittig reaction carried out under solid liquid phase transfer conditions using an alkaline carbonate usually yields high amounts of the corresponding alkene (table 1). The stereochemistry of the double bond depends of the protic or aprotic character of the solvent in relation to the solvation effect of the hydroxyle function on the intermediate betalne or oxaphosphetane. The potassium carbonate avoids the Cannizzaro and the aldolic reaction and does not promote any elimination reaction form the phosphonium salt used in slight excess.

Pheromone Diptera musca domestica.

The operation of the Wittig reaction in solid-liquid heterogeneous slighr ty hydrated medium therefore appears as a process that can readily be transported on a larger scale and is thus iiable to make easier the synthesis of fury1, pheno1ic or longchain alky1 alkenes https://www.w3.org/1998/Math/MathML"> ( 2 - 7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . 16. Unsatured esters The so called Wittig-Horner reaction using potassium carbonate in a slightly hydrated organic solvent allowed the synthesis of a new class of furyl and phenolic α unsaturated esters (table 2) https://www.w3.org/1998/Math/MathML"> ( 10,11 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   Table   2   K 2 C O 3 / H 2 O C 2 H 5 O 2 P O C H 2 C O O C 2 H 5 + R C H O R - C H = C H - C O O C 2 H 5 1,4   di.oxane   R   Yield (\%)     Ref.     Fury1   90   (11)     5-hydroxyme thylfury1   90   (11)     p-hydroxypheny1   88   (11)   C H 3   (   C H 2   )   4 C H 2 95   (11)   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The reactions are selective and show a particularly high conversion rate of E-ethylenic esters especially with regard to furyl aldehydes which is the essential difference between this and other previously reported proce-dures concerning such molecules. The reaction https://www.w3.org/1998/Math/MathML">   t   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> s stereoselectivity can be attributed to the marked stabiIization of the intermediate oxyanion which thus promotes the existence of a stable form precursor of the E isomer. 17. Oxirans The condensation reaction between furfural or terpenyl ketones and a sulfonium salt (table 3) using the solid-liquid phase transfer process in the presence of an excess of potassium hydroxide (alkaline carbonates are ineffective) led selectively and quantitatively to the corresponding oxiran. The use of polar solvents such as acetonitrile together with the control of the hydratation rate of the reaction medium promoted the formation of the oxirans at the expense of the Cannizzaro or aldolic reactions. In this way the first direct synthesis of 2-furyloxiran from furfural was realized (8). 18. Unsaturated nitriles Un1ike the oxiran synthesis the reactivity of acetonitrile with potas sium hydroxide is worked to give unsaturated nitrile after reaction with 2- furancarboxaldehyde. The reaction was generalized to numerous aldehydes (table 4). 19. Ethers The solid-liquid transfer process applied to etherification of hydroxyle function involves the reaction of dimethylsulfate or an alkyl bromide in the presence of solid potassium hydroxide 1,4-dioxane or DMSO and a small quantities of water (table 5). * Yield in diether The reactants are used in stoechiometric amounts. The work up is very easy. Dimethylisosorbide was thus obtained for the first time in a quantitative yield (12). 20. CONCLUSION The easy an efficient synthesis of numerous compounds, new for the most part, corroborates the major interest of solid-liquid phase transier processes in the functionalization of the molecules originating from the primary breakdown of plant polymers. The biomass can be considered as a source of starting materials that are liable to be used on a large scale since they can lead to various and valuable applications. The promising economical aspect, as a result of the simplicity and of the low cost of the processes and materials involved, opens new prospects for this kind of molecule in polymer chemistry as well as in fine chemistry Table 4 https://www.w3.org/1998/Math/MathML"> R - C H O + C H 3 C H K O H / H 2 O C H 3 C N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> R - C H = C H - C N https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> R Yie1d Z/E Fury1 98 25/75 Pheny1 98 20/80 Anisy1 90 18/82 Table 5 https://www.w3.org/1998/Math/MathML"> R - O H + R ' X   organic solvent   K O H / H 2 O = R - O - R ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 21. REFERENCES (1) RIGAL L. and GASET A. (1983). Biomass, 3, 151. (2) LE BIGOT Y., DELMAS M. and GASET A. (1982). U.S. Patent 4.346.040. (3) LE BIGOT Y., DELMAS M. and GASET A. (1982). Synthetic Communication, 12, 107 and 1115 . (4) https://www.w3.org/1998/Math/MathML"> L E - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BIGOT Y., DELMAS M. and GASET A. (1985). U.S. Patent 4.501.910. (5) LE BIGOT Y., DELMAS M. and GASET A. (1983). Tetrahedron Letters, 24, 193. (6) AREKION J., DELMAS M. and GASET A. (1983). Biomass, 3, 59 . (7) LE BIGOT Y., DELMAS M. and GASET A. (1983). J. Agric. FOOd. Chem., 31 , 1096. (8) BORREDON M.E., DELMAS M. and GASET A. (1983). European Patent https://www.w3.org/1998/Math/MathML"> n ∘ 832006862 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (9) BORREDON M.E., DELMAS M. and GASET A. (1983). Biomass, 3, 67. (10) LE BIGOT Y., DELMAS M. and GASET A. (1983). European Patent, https://www.w3.org/1998/Math/MathML"> n ∘ 8315753 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (11) MOULOUNGUI Z., DELMAS M. and GASET A. (1984). Synthetic Communication, 14 , 701 . (12) https://www.w3.org/1998/Math/MathML">   ACHET D., DELMAS M. and GASET A. (1985). Synthesis (in press).   - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BIOCONVERSION OF ORGANOSOLV LIGNINS BY DIFFERENI TYPES FF FUNGI A. HAARS, A. MAJCHERCZYK, J. TROJANOWSKI and A. HUTTHERMANN Forstbotanisches Institut der Universität Göttingen Büsgenweg 2,3400 Göttingen, F.R.G. Sumary Organosolv lignins from a pilot plant were incubated with fungi from different ecological types and the bioconversion rates were compared to results obtained for https://www.w3.org/1998/Math/MathML"> 14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -labelled organosolv lignins prepared by the same pulping procedure. The data obtained by the radiorespirometric method were in accordance with the findings for the technical lignins: 1.) White-rot fungi were capable to convert the lignin by splitting the aryl-ether linkages. 2.) A water-soluble acid-precipitable polymerizate (WSAPL) was formed, part of which had humin-like properties, e.g. not soluble in organic solvents after drying. The amount of humin-like substance was dependent on extracellular phenoloxidase activity. 3.) The molecular weight distribution and the phenolic hydroxyl content of WSAPL as determined by IPSEC (Ion pair size exclusion chromatography) was markedly changed after fungal attack depending on the type of fungus. 22. INTRODUCTION The organosolv process, among other novel technologies, is considered to have the best economical prospects because the pulp is of satisfying quality and the sulfur-free (1), low molecular weight lig nin can be separated in a more or less unchanged structure. Compared to the sulfur containing byproduct lignins (kraft lignin and lignosulfonate) these properties are supposed to facilitate microbial access of organosolv lignin. Therefore, the purpose of our work was to evaluate the bioconversion reactions of fungi from different ecological types (white- and brown rot, soil fungi, mycorrhizal fungi etc.) on lignins obtained by organosolv pulping. The problem was approached using two different methodologies: 1.) Using https://www.w3.org/1998/Math/MathML">   14 C - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> abelled organosolv lignin, prepared by pulping https://www.w3.org/1998/Math/MathML">   14 C - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> labelled wood from beech saplings 1, as substrate for mycelia of white-rot fungi and protoplasts 2 of Heterobasidion annosum, and measuring the https://www.w3.org/1998/Math/MathML"> 14 C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -release by the radiorespirometric method and 14C-labelled soluble and insoluble fractions in the culture fluid. 2.) Using technical organosolv lignins 4 , kindly supplied by the MDNicolaus corrp. Munich, as substrate for several fungi and measuring the bioconversion to soluble, insoluble and mycelium-bound fractions quantitatively by gravimetry and UV-spectroscopy and monitoring molecular weight changes by IPSEC (Ion pair size exclusion chromatography 5 . 23. Results and Discussion 1.) The most prominent linkages in lignin are the aryl-ether linkages which connect the C-2'-position of the side chain of one monomer unit with the aromatic ring of another unit. The capacity of fungal cultures to split the aryl-ether linkages in https://www.w3.org/1998/Math/MathML">   14 C - o r g a n o s o l v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lignin is indicated by the https://www.w3.org/1998/Math/MathML"> 14 C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> release from https://www.w3.org/1998/Math/MathML">   14 C - 2 ' - ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> side chain https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> carbons (Fig. 1). Heterobasidion annosum and Pleurotus florida as well as the isolated protoplasts, were also capable to convert the https://www.w3.org/1998/Math/MathML">   14 C - o r g a n o s o l v https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lignin to water-soluble and high polymeric products which could be fractionated in a dioxane-soluble and a dioxane-insoluble (humin-like) fraction. The surprising high conversion activity of protoplasts towards organosolv lignin make them interesting as a first step in developing an "in vitro" lignin-converting system. Fig. 1. Degradation of https://www.w3.org/1998/Math/MathML">   14 C - 2 ' - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (chain) of organosolv lignin by mycelia 2.) Seven representative fungi of the types listed in Tab. 1 were incubated as liquid stationary cultures with 18 suspensions of technical organosolv lignins. After an appropriate cultivation period the biomass yield and phenoloxidase (PO; E.C.1.14.18.1) activities were tested and the bioconversed lignin was fractionated into water-soluble acid-precipitable lignin (hSAPL), acidsoluble low molecular weight material (AS), water-insoluble dioxane-soluble lignin (WIL) and mycelium recovered lignin (ML). Uninoculated lignin cultures https://www.w3.org/1998/Math/MathML"> C 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> served as controls. All fractions were quantitatively weighed and tested by UV-spectroscopy and IPSEC. The results obtained by the radiorespirametric method for https://www.w3.org/1998/Math/MathML"> H ⋅ a . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are in accordance with the data presented in Tab. 2: two whiterot fungi (바.므. and I. https://www.w3.org/1998/Math/MathML"> b _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .) solubilize a considerable part of the lignin (WSAPL-S), whereas in all other cultures the WSAPL-content decreased, possibly due to metabolization or acidification of the medium by secretion of organic acids 6 . https://www.w3.org/1998/Math/MathML">   TAB   1   Fungi   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The organosolv lignins induced high PO activities in cultures of P.V., P.f., H.a. and I.b.. Oxidative polymerizing reactions in these cultures led to marked decrease in the phenolic hydroxyl content of WSAPL-S ( 678 lower than in C https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -WSAPL ) and to the formation of a "humin-like"-substance (WSAPL-H), which after drying was no more soluble in dioxane or other organic solvents. In cultures of https://www.w3.org/1998/Math/MathML"> g _ _ ⋅ g _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . and https://www.w3.org/1998/Math/MathML"> S _ _ ⋅ p https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . containing no and negiligible amounts of extracellular PO activity, respectively, the phenolic hydroxyl content remained unchanged and no or barely detectable amounts of humin-like substances were formed. The concentration of low molecular weight aromatic substances decreased in all cultures. The remaining portion contained also newly formed substances which were released into the culture medium as response to the presence of lignin (evaluated by Sephadex LH2O GPC and TMC (data not shown). Changes in the molecular weight distribution of the bioconversed lignin fractions were monitored by IPSEC. Ifignin samples were chromatographed on PSM https://www.w3.org/1998/Math/MathML"> 60   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 1000   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> colums (Dupont) in IHF as mobile phase containing an alkylammoniumchloride as solubilizer for the bioconversed part of lignin insoluble in organic solvents (humin-like substance) and to prevent adsorption and aggregation effects 5. Fig. 2 shows that considerable changes occurred in the region 2000 - 30000 Daltons of WSAPL depending on the type of fungus and PO activity, whereas WIL remained nearly unchanged. For straw and kraft lignins it was also found that the water-soluble fractions are better degraded than the crude preparation 7 . Table 2 The mycelium bound lignin seems to be an intermediate between WSAPL (compare the peak at Mw 6000 , which is present in WSAPL also) and wIL (compare the high amount of lignin in the molecular weight region 10000 - 30000 Dalton) As was demonstrated before 8 , active lignin degraders are not only found among basidionycetes of the white-rot type: C.g. - an ectomycorrhizal Deuteromyoete which was found to be an active decamposer of 14C-ring-labelled DHP was more active than our strain of S.p.. 24. REFERENCES (1) CRANFORD, D.L. , CRANEORD, R.L. and POMEMTO, A.L. (1977). Preparation of specifically labelled https://www.w3.org/1998/Math/MathML">   14 C - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lignin and https://www.w3.org/1998/Math/MathML">   14 C - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (cellulose)-lignocelluloses and their decomposition by the microflora of soil. Appl. Environm.Microbiol. 33, 1247. (2) TROJANOWSKI, J., HUTTERMANN, A., HAIDER, K. and WESSETS, J.G.H. (1985) . Degrdation of lignin and lignin related compounds by protoplasts isolated from Fones annosus. Arch. Microbiol. 140, 326-330. (3) HAIDER, K. and TRAJANOWSKI, J. (1975). Decomposition of Specifically https://www.w3.org/1998/Math/MathML"> 14 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> -Labelled phenols and Dehydropolymers of Coniferyl Alcohol as Models for Limin Degradation by Soft and White Rot Fungi. Arch. Microbiol. 105, 33-41. (4) EDEL, E. (1984). Das MD-Organosolv-Verfahren. Sonderdruck "Innovationen im Zellstoffkocher", dpw Deutsche Papierwirtschaft 1/1984. (5) MAJCHERCZYK, A., HAARS, A., TAUTZ, D. and HUTIERMANN, A. Manuscript in preparation. (6) CHEN, C., CHANG, H. and KIRK, T.K. (1982). Aromatic acids produced during degradation of lignin in spruce wood by Phanerochaete chrysosporium. Holzforschung 36,3-9. (7) JANSHEKAR, H. , HALIMEIER, T. and BRONN, C. (1982). Fungal degradation of pine and straw alkali lignins. European J. Appl. Microbiol. Biotechnol. 14, 174-181. (8) TROJANOWSKI, J., HAIDER, K. and HUTTERMANN, A. (1984). Decomposition of https://www.w3.org/1998/Math/MathML">   14 C - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> abelled lignin holocellulose and lignocellulose by mycorrhizal fungi. Arch.Microbiol. 139, https://www.w3.org/1998/Math/MathML"> 2 O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . THE FRACTIONATION OF LIGNOCELLULOSIC SUBSTRATES BY STEAM EXPLOSION AND THE SUBSEQUENT CONVERSION OF THE VARIOUS COMPONENTS TO SUGARS, FUELS AND CHEMICALS J.N. Saddler, E.K.C. Yu, M. Mes-Hartree, N. Levitin and https://www.w3.org/1998/Math/MathML"> H . H . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Brownell Biotechnology and Chemistry Department, Forintek Canada Corp. 800 Montreal Road Ottawa, Canada, K1G https://www.w3.org/1998/Math/MathML"> 3 Z 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 25. Summary Several years ago we evaluated various chemical and enzymatlc methods of converting lignocellulosic resldues to fermentable sugars and reactive lignin we have focused on the use of hydrofluoric acid and organosolv pulping, and cellulases from Trichoderma species as the best respective methods for chemically and enzymatically hydrolysing llgnocellulosic substrates. Although relatively high concentrations of sugars could be obtained by the chemical hydrolysis methods, the liberated sugars proved difficult to ferment while the Iignin component appeared to be much more condensed than that obtained from steam exploded wood. Steam exploston was the preferred method of pretreatment for enhancing enzymatic hydrolysis because of the relatively low pretreatment costs and because of the ability to fractionate the substrate into three product streams. Water extraction of steam treated aspenwood chips removed over https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the hemicellulose. This pentosan rich stream was hydrolysed by mild H_ SO_ or fungel celluslages then fermented to butanol by clostridium acetobutylicum or butanediol by Klebsiella pneumoniae. The water extraction step also removed inhibitory materials which were produced during Lon https://www.w3.org/1998/Math/MathML"> 8 tep   a l s o l r e m o v e d   i n h i b i t o r y z m a t e r i a l s   w h i c h   w e r e   p r o d u c e d   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> pretreated aspenwood removed over https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the original lignin. This left a cellulose rich residue which could be used as the substrate for growth and enzyme production of various cellulolytic fungi and which could be readily hydrolysed to fermentable sugars. 26. INTRODUCTION Most of the current research into the conversion of renewable, biomass resources was motivated in the past by escalating oil prices. Although this concern has been alleviated to a large extent by the current oil glut there should still be a general concern that oil is a diminishing resource and that the price will invariably rise in the long term. Canada Is in the fortunate position of having vast resources of timber on which much of its economy and trade are based. This resource was originally advocated as the lignocelluloslc substrate on which a bioenergy industry could be established. However much of the needed technology has proven more difficult to achieve than was originally planned while the traditional forestry based industries have not been convinced of the validity of this whole approach. The industry does recognise however that there are problems with residue utilisation and that the productivity of the forest has to be greatly enhanced. As approximately https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the tree is not 27. RESULTS AND DISCUSSION When we Lnltiated our biomass converslon programme several methods of enzyinatlc and acid hydrolysis were examined to see what yields of glucose and xylose could be obtained and to also characterize the different types of lignin derivatives that were obtained we found that dilute sulphuric acid hydrolysis resulted in the https://www.w3.org/1998/Math/MathML"> 11 beration https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of approximately https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the cellulose component as gltucose, which was slmilar to the values obtained by other workers (Saeman, 1982). In contrast, we have found that hydrolysis with hydrogen fluoride resulted in high sugar yields with very low levels of sugar decomposition. The effect of varlous parameters such as hydrolysis time at https://www.w3.org/1998/Math/MathML"> 0 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and at https://www.w3.org/1998/Math/MathML"> 20 ∘ C , H F / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wood ratios of 10:1 and 5:1 and Water content of the HF on glucose and xylose yields are shown in Table l. Highest glucose yields were obtained with an HF/wood ratio of 5:1 after a reaction time of 45 minutes at https://www.w3.org/1998/Math/MathML"> 0 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The presence of https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> water in the HF did not appear to adversely affect the glucose and xylose yields. We are presently comparing enzymatic and midd acid post hydrolyois methods of fractlonating the soluble oligosaccharides obtained by HF hydrolysis as well as ensuring that the 11berated sugars are readily fermented. This work has been paralleled by a similar approach which has used organosolv pulping as the means of solubllising the cellulose and hemice,11ulose components which have been further hydrolysed by enzymes or mild acid hydrolysis preliminary results indioate that a more desirable lignin is obtained by this latter method as the lignin obtained from HF treated aspenwood appears to be highly condensed. We have found that 1.1gnin obtained by the alkali extraction of steam exploded aspenwood also appears to be highly reactive and has many potential applications such as an adhesive used for composite wood construction (Calve & Shlelds, 1982 ). Steam explosion appears to be an excellent method for pretreating lignocellulosic substrates as https://www.w3.org/1998/Math/MathML"> 1 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> enhances their enzymatic hydrolysis and permits the fractionation of wood into its different components. A schematic representation of our bloconverslon process based on steam explosion and enzymatic hydrolysis is shown in figure 1. We have found that approximately https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of a pretreated wood substrate is required to "generate" enough cellulase to hydrolyse the remaining https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to glucose. This ratio varles depending on the nature of the cellulase system and the type of lignocellulosic substrate which is belng hydrolysed. After an extensive screening of cellulolytic fungi we have found that various Trichoderma species seem to be among the most cellulolytic microoganisms (Saddler, 1982). Trichoderma harzianum produced a complete cellulase complex, after growth on steam exploded wood fractions, which was able to hydrolyse most of the cellulose and hemicellulose of various steam exploded wood fractions to their component monosaccharides (Saddler et al, 1982 a) Previously we had shown (Saddler et al, 1982b) that a combined hydrolysis and fermentation (CHF) approach to converting pretreated wood to ethanol was advantageous as it reduced the inctdenee of contamtinat an and reduced end prodtict inhthelton of the enzymes by the continuous fermentation of the liberated sugars to ethanol. As other workers had indicated that ethanol was inhibitory to T. reesel. cellulases (Ghosh et al, 1982) we wanted to ensure that this was not the case with cellulases from T. harzianum. It was apparent (Table 2) that none of the cellulase activities were greatly affected while xylanase activity seemed to be enhanced when the enzyme reactions were supplemented with increasing concentrations of ethanol. Previously we had shown (Saddler et al https://www.w3.org/1998/Math/MathML"> 1982 a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) that approximately https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the hemicellulose component of steam exploded aspenwood could be extracted by a further washing with mlld alkall. Although the hemicelluLose rich water soluble fraction contained inhibitory material which restricted enzyme hydrolysis and fermentation of the sugars this material has been successfully used as a substrate for butanol and butanediol production (Yu et al, 1984). We are currently assessing different applications for the various lignin types that are obtained after the fractionation of pretreated lignocellulosic substrates. It would appear that the bioconversion of lignocellulosic residues to Euels and chemicals can be a valid proposltion, providing the cost of the substrate is inexpensive. If this technology is to achieve full commercial viability, development at the pilot plant level must be complemented by continued research into the fundamental mechanisms of the bioconversion process. 28. REFERENCES (1) CALVE, L. and SHIELDS, J.A. (1982). Proc. Fourth Bioenergy R & Seminar, March 29-31, Winnipeg, Canada pp. 403→407. (2) GHOSH, P. PAMMENT, N. B, and MARTIN, W.R. B, (1982) , Enzyme Microb, Technol. 4 425-430. (3) SADDLER, J.N. (1982). Enzyme Microb. Technol. 4 414-418. (4) SADDLER, J.N., BROWNELL, H.H., CLERMONT, L.P. and LEVITIN, N. (1982a) Biotechnol. Bioeng. 24 1389-1402. (5) SADDLER, J.N., HOGAN, C. , CHAN, M.K.-H. and LOUIS-SEIZE, G. (1982b). Can. J. Microbiol 28 1311-1319. (6) SAEMAN, J.F. (1982). Proc. Roy. Soc. Can. Symp. on Ethanol from B1omass, Winnipeg, Canada pp. 231-246. (7) YU, E.K.C., DESCHATELETS, L. and SADDLER, J.N. (1984). Biotechnol. Lett. 6327-332. Table 1. Effect of various parameters on glucose and xylose yields after the hydrolysis of aspenwood by I.1quid HF Table 2. Effect of increasing ethanol concentration on the cellulase activity of culture filtrates derived from T. harzianum grown on https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Solka Floc Ethano1 Conc % Enzyme activity (% of original) https://www.w3.org/1998/Math/MathML"> β - glu c o s i d a s e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Filter Paper Xylanase 0.0 100 100 100 100 0.5 98 100 91 103 1.0 99 98 90 113 2.0 102 96 108 110 3.0 98 97 93 106 4.0 99 96 93 113 5.0 94 96 92 113 FIGURE . Process Scheme for Conversion of Aspenwood to Ethanol. CHEMICALS FROM SUGAR INDUSTRY WASTE PRODUCTS 29. Summary The potential of Agricultural wastes as renewable source of energy is wellknown. The sudan boasts of worlds biggest integerated sugar industry the K.S.C. (Kenana Sugar Co.) , and biggest agricultural co-operative (Gezira scheme), and yet no attempt seems to have been made to tap the vast potential of its agricultural waste products. The paper describes the results of preliminary study about the chemicals that could be obtained from the wastes of above mentioned sugar industry and Sudan as a whole. The authors wish to show that in present circimstances in most of the developing cotintries it is the only way to obtain chemicals and energy rather than from expensive and advanced petroleum based technology (suitable for industrialised countries only). 30. INTRODUCTION Biomass has received increasing attention (l-2) as a possible source of chemicals. Production of ethanol from biomass is already established and no doubt will grow in Euture. However until recently the potential of biomass for commodity chemicals was not clear because of the cost Iactor. It is to be emphasised here that a clear distinction is to be made between the industrialised and the developlng countries in Africa, Asia and far East. It is not only the cost factor but the bal ance of payments situation which counts. A recent I.M.F. report (3) states that most of the African countries are under heavy debts. In case of Sudan the same report says that up to https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of export earnings could go Eor debt service. Thus the whole approach to chemical and energy production in developing countries (in Africa) must change. The bitter Iact is that they simply do not have elther the technology or the resources for purchase of chemicals or these countries is to go for biomass both for chemicals and energy. AGRICULTURAL WASTE UTILIZATION IN SUDAN The Sudan has both natural resources and conditions 31. Table 1 https://www.w3.org/1998/Math/MathML">   Proposed Scheme for Sugar Industry Waste Utilization   (   Production of Furfural and Ethanol)   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Production of Furfural and Ethanol) Product Quantity/Cost/Revenue/annum 1) Bagasse 300,000 Tons 2) Molasses 105,000 Tons 3) Furfural 24,000 Tons (total production possible but proposed plant size 4) Ethanol 5,000 Tons) 5) Cost of the plants 26,000 Tons ( 35 million litres) a) Furfural 5 mi11ion US. dollars b) Ethanol https://www.w3.org/1998/Math/MathML"> 15 m i l l i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> US. dollars 6) Revenue from sales 2 million US. dollars a) Furfural https://www.w3.org/1998/Math/MathML"> 10 m i 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ion US. dollars b) Ethanol 16 - https://www.w3.org/1998/Math/MathML"> 17 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7) Expected returns (profits) Note: Production figures above are for K.S.C. alone, the Sudan as a whole. 32. https://www.w3.org/1998/Math/MathML">   REFERENCES   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1) KLAUSMEIR, Chemicals from biomass, proceedings of fifth symposium on biotechnology for fuels and chemicals May 21-25, 1984, editor Charles D. Scott, John Wiley (ISBN 0572-6585 ). (2) Regional Investment Promotion Meeting, sponsored by, UNIDO, Khartoum, 4-8 March, 1985. (3) ARAB NEWS (Saudi Arabia), 18 February, 1985. (4) Same as (1) (5) PATRAU, J.M., By-products of the cane sugar industry, Second Edition (1982), Elsevier (New York). NEW PROCESS FOR THE FABRICATION OF ETHYL ESTERS FROM CRUDE VEGETABLE OILS AND HYDRATED ETHYL ALCOHOL R. STERN, G. HILLION, P. GATEAU and J.C. GUIBET Institut Français du Pétrole 33. Summary The objectif of the research was to see if it is possible to prepare, easily and economicaly, ethyl. esters from various vegetable oils by using a hydrated ethyl alcohol and crude oil which may be very acidic. The esters produced are intented to be used as diesel oil substitutes in engines equipped with direct injection which means that a high degree of purity must be attained. The process described comprises different stens and reaches 98 or more purity of the ester, a very low degree of acidity and a yield of 96 to https://www.w3.org/1998/Math/MathML"> 97 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on a one-ton pilot-plant scale or more. The alcohols may contain up to https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> water and the oils the same amount of free acid. Examples are given with cotton-seed oil, palm oil, palm kernel oil, rapeseed oil and coconut oil. Some esters were tested on a bench for engines before experimentation with tractors. The different parameters of the process are considered. 34. Introduction The high price of the vegetable oils prevents from planning production of gasoil substitutes with them. But in some circumstances, this production becomes of actual interest -when there is overproduction of oil in a remote country as for example in Africa or a small island where gasoil is expensive to deliver -when big amounts of toxic oils are growing -when it remains in an oil factory a cheap fraction of an oil, such the solid fraction of a palm oil or the so called "fatty acids" coming from the refining In these cases the only problems are technical as we must generally be able to produce the gasoil substitutes without big investments. The objectives are given below. 35. Detailed objectives a) The fabrication of ethyl esters on a small scale such as cooperative, farm, village or plantation. b) The goal is to use the esters as a substitute for diesel oil in all engines, even those equipped with DI injection. c) The raw materials come directly from an extruder or a small press and can be very acidic. d) The alcohol may be very hydrated with a titer of 96 %, 92 %, https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> e) A.1. the chemicals and absorbents should be readily available. f) The process equipment should be standard but corrosion resistant . g) The alcohol should not be evaporated at the end or reused, which means that it cannot be used in great excess. h) The yield of ester should attain at least 95 weight o bt if ble more than https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> i) The purity should exceed https://www.w3.org/1998/Math/MathML"> 97 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with by products not dangerous for the engine. j) The glycerine produced should be easy to handle or to purify. k) No water whasing should be required should be required to prevent pollution. Finally, the problem has to be solved in the light of economic ecoIogical. and technical consideration to obtain a process on a "soft" technology basis. 36. Method used Reaction 1 and 2 show that for a good conversion water and glycerine have to be eliminated. https://www.w3.org/1998/Math/MathML"> C H 2 - O C O R 1 C H - O C O R 2 + 3 C 2 H 5 O H C H 2 - O C O R 3   triglycerides ethyl alcohol     RCOOC   2 H 5 + H 2 O   ester water   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1   C H 2 - O H R 1 C O O C 2 H 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The reaction proceeds through a 5-step process where every step is tant but simple. A. In the first step the oil and alcohol react to produce an ester with 80-90 % conversion in the presence of an acidic catalyst. After 3 to 6 hours, depending on the type of alcohol used and the temperature, nearly https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the glycerine and some times more for the water are removed in a separate phase. The interesting feature of this step is that previous drying of alcohol or refining of the oil is not necessary. B. The second step consits in esterifying the free acid present in the ester. This is done by simply heating the solution of ester and alcohol with the catalyst that has not been eliminated in the glycerine phase. After 1 or 2 hours we reach a concentration of acid lower that 1 % if at the same time we eliminate the water. C. We can now introduce an alkali catalyst to obtain 96 to 98 % conversion for the ester. By adding 1 to 2 weight % of water we obtain a glycerine phase that contains traces of the acidic catalyst used before, together with all the g.ycerine, some of tha alcohol, water and fatty acid salts. D. In another repeating step a quantitative conversion and purification is ensured. E. Finally the last traces of alkali are eliminated by passing the esters containing from 5 to https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> alcohol through an absorbent column. Eventually to get more than https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yield of esters we can remove the acid and ester which had been carried away in the basic glycerine phases and, after neutralisation, recycle them in the oil. FLOW SHEET c) The Conradson value on https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> residue is generally lower than d) The presence of alcohol in the ester at that end improves the quality of the esters though the cetane number is reduced from 52 with, for example, pure palm ethyl ester to respectively 50.5,42,35 and 23 with 10,20,30 and https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethyl alcohol https://www.w3.org/1998/Math/MathML"> ( 93 % ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> e) In 10 houns from 1t palm oje, https://www.w3.org/1998/Math/MathML"> 0.33 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethyl alcohol ( 93 %) https://www.w3.org/1998/Math/MathML"> 0.01 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> catalyst and https://www.w3.org/1998/Math/MathML"> 0.04 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> water we can produce 1.1.t ester t alcohol and https://www.w3.org/1998/Math/MathML"> 0.28 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of a glycerine phase. The only products consumed are the catalysts and 40 liters of water, besides energy. This work has been done with the financial aid of AFME (Agence Française pour la Maftrise de l'Energie). 37. BIODEGRADATION OF NATIVE CELLULOSE F. ALFANI, L. CANTARELLA, A. GALLIFUOCO, L. PEZZULLO, M. CANTARELILA Department of Chemical Engineering, University of Naples, P. 1e Tecchio, 80125 Naples, ITALY. 38. Summary The effectiveness of enzymatic saccharification of cellulose is improved carrying out the reaction with mixtures of two cellulases froproved carrying out the reaction with mixtures of two cellulases yield of cellulose conversion becomes https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> higher than the maximum yalue reached with a single enzyme and glucose selectivity attains a value reached with a single enzyine and glucose selectivity attains a level close to https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The hydrolysis of olive husks and straw was inves tigated in the present study. Moreover, the residual oligosaccharides can be conveniently converted to glucose in a second reactor throughout the catalytic action of A. niger immobilized in a gel layer of polyalbumin onto the surface of a membrane. The reaction obeys a combined diffusional and kinetic mechanism of control and enzyme thermal deactivation is prevented up to https://www.w3.org/1998/Math/MathML"> 45 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Finally, product and substrate inhibitions, which limits β-glucosidase activity, were studied. 39. INTRODUCTION The results discussed in the present communication refer to an experimental investigation which is part of a wider project on the development of a two step process for the enzymatic hydrolysis of lignocellulosic raw materials. In the course of former studies the following conclusion was reached In spite of the numerous biomass pretreatments suggested in the Literature (1), native cellulose cannot be completely degradated to glucose in a single step by the action of the actually available cellulase complexes, and a further conversion of the oligosaccharides, catalyzed by a preparation rich in B-glucosidase is advisable. On the other hand, among the cellulase enzymes, the β-glucosidase component is the most difficult to handle since it is thermally unstable and its activity is curtailed by product inhibition. The research in progress aims to prove the advantages of immobilizing this enzyme in membrane reactors. The biocatalyst is physically entrapped in a gel layer of a natural polymer, a technique which was successfully tested with other enzymes and is very simple to be adopted. In order to avoid costly operations for the extraction and purification of the B-glucosidase from the complex, which unavoidably would increase the costs of glucose production, a crude cellulase complex has been immobilized. In this experimental work cellulase from Aspergillus niger was tested. Moreover, since the relative presence of amorphous and well organized regions in the cellulose structure, their mutual physical and chemical interactions, the degree of polymerization of the cellulose chains, and the resistances induced by the presence of other components, mainly hemi- Figs. 1,2 - Saccharification yield, x, and Glucose selectivity, S%, vs. wt % of A.niger in the enzymic mixture. polymers cannot be fermented and therefore glucose concentration in the products must be maximized. The data of Fig.2 indicate that, depending on cellulase source, glucose selectivity s, wholes of glucose per hroles of https://www.w3.org/1998/Math/MathML">   t o t a l   r e d u c i n g   s u g a r ,   v a r i e s   w h i t h   o f   o f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> total reducing sugar, varies with enzyme percentage, but never reaches https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the range of cellulase composition which gives raise to the highest production. Therefore a second step of reaction is necessary for converting the oligosaccharides this could be performed converting the oligosaccharides. Ihis could be performed with either a soluble or an immobilized enzyme since substrates are small and water soluble molecules. Moreover, it would be also possible either to concentrate Eirstly the sugar solution up to https://www.w3.org/1998/Math/MathML"> 100 - 110   g / l , w h i c h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is a minimum economical value for carrying out the subsequent fermentation, or to work with the dilute solution whích flows out from the first reactor. For the reasons specified in the introduction an A. niger complex instead of purified β-glucosidase (5) was used in this study. Firstly the reaction was carried out with soluble enzyme, but the experimental evidences were negative. The enzyme is thermally unstable, its half 1 ife ranges between 316 hours at https://www.w3.org/1998/Math/MathML"> 30   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 34 hours at https://www.w3.org/1998/Math/MathML"> 50 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The https://www.w3.org/1998/Math/MathML"> k i n e t i c s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of enzyme deactivation obeys a first order rate equation and its activation energy is 21.100 cal/gmole. Moreover, a non competitive product inhibition takes place and substrate inhibition significantly occurs at cellobiose concentration greater than https://www.w3.org/1998/Math/MathML"> 10 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which corresponds to roughly 3.5 g/1. The following rate equations were derived for cellobiose hydrolysis at https://www.w3.org/1998/Math/MathML"> 30   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 45   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in different ranges of operational conditions which allow to neglect cellobiose and glucose inh ibition respectively : Product inhibition https://www.w3.org/1998/Math/MathML"> r G = 332 ⋅ S ⋅ E 0.59 ⋅ 1 + I 0.33 + S ⋅ 1 + I 1.19 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Substrate inhibition https://www.w3.org/1998/Math/MathML"> r G = 2073 ⋅ s ⋅ E 1.98 + s + s 2 26.5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where I and S represent glucose and cellobiose concentrations (mM), E is the enzyme amount https://www.w3.org/1998/Math/MathML"> m g E https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> r G https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is the reaction rate of glucose production ( limoles/h mg_. Therefore, in a second phase of the investigation, the kinetic behaviour of the immobilized A. niger was tested. The cellulase was physically entrapped in a gel of polyalbumin following the procedure described in (7). The immobilized enzyme, see Fig.3, is very stable in the whole range of investigated temperature and cellobiose inhibition becomes evident at higher concentration, https://www.w3.org/1998/Math/MathML"> 20 m M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The extent of product inhibition remains comhigher concencration, https://www.w3.org/1998/Math/MathML"> 20   m u t   t h e   e x t e n t   o f   p r o d u c t   i n h i b i t i o n   r e m a i n s   c o m m i n g e r s e d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> parable with the corresponding value of the free enzyme. Moreover, che data of Fig.3, were plotted in a Lineweaver-Burk diagram and the calculated value of the anparent Miohaelis constant, Km, was 2.14 mM, greater than the corresponding one of the free enzyme, 1.98 mM. Furthermore the activation energy decreases from 10.310 cal/gmol for the soluble cellulase activation enerby decteasestrom 0.310 callarol forthe to 8.940 callgmol for the immobilized one. Therefore, working with A.miger entrapped in polyalbumin a combined kinetic and diffusional mechanism of control takes place and the enzyme thermal stability is good for a prolonged process time. However, since product and substrate inhibition continue to play an important role, it would be better to concentrate the solution after the second step of reaction. Finally, experiments were carried out to determine the optimal length of cellulose saccharification process. The specific rate of glucose production r per mg of enzyme at different substrate concentration is plotted versus process time in Fig.4 and indicate that the conversion of amorphous cellulose is very rapid and almost https://www.w3.org/1998/Math/MathML"> 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the asymptotic biomass conversion occurs in 20 hours. Abstract To sum up, the body of experimental results suggests the following process layout: a) hydrolysis of biomass with a mixture of T. Viride and A. niger, in soluble phase using a membrane reactor in order to limit product inhibition, b) subsequent conversion of unreacted oligosaccharides With an immobilized cellulase rich in p-glucosidase, such as A. niger, c) final ultrafiltration of sugar solutions for increasing the glucose REFERENCES (1) LADISCH, M.R. (1979). Process Biochemistry, 21-25 (2) ALFANI, F. , CANTARELLA, M., SCARDI, V. (1983). J. Membrane Sci. (3) https://www.w3.org/1998/Math/MathML"> 16   ALFANI, F.   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , CANTARELLA, M., SCARDI, V. (1984). Energy form Biomass, Series E, 5, Palz W. and Pirrwitz eds, 336-43. (4) ALFANI, E., CANTARELLA, M., ERTO, L., SCARDI, V. (1982). In "Energy from Biomass", Proceedings 2nd E.C. Conference, Strub A., Chartier P. and Schlesser G. eds., 1000-1006. (5) NELSON, N. (1944). J. Biol. Chem., 153, 375-80. (6) GIANFREDA, L. and GRECO, G. jr. (1982). Energy from Biomass, 3, Grassi G. and Palz W. eds., 260-65. (7) SCARDI, V., CANTARELLA M., GIANFREDA, L., PALESCANDOLO, R., ALFANI, F. GRECO, G. jr. (1980). Biochimie, 62, 635-43. STUDY OF ENZYMATIC HYDROLYSIS OF ALKALI PRETREATED ONOPORDUM NERVOSUM C. MARTIN, M.J. NEGRO, M. ALFONSEL, F. SAEZ, R. SAEZ and J. FERNANDEZ División de Biomasa, Programa de Energías Renovables, Junta de Energía Nuclear. Madrid. Spain 40. Summary The effect of a pretreatment by alkali on the enzymatic hydrolysis of biomass of ' Onopordum nervosum is studied. The optimum values of pretreatment parameters were experimenta.lyy determined in order to maximize the availability of cellulose fraction to enzymatic hydrolysis. Treatments were carried out at alkali concentration, temperature and reaction time ranging from of to https://www.w3.org/1998/Math/MathML"> 2 % , 25 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 150 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 0 to 90 minutes respectively. Enzymatic hydrolysis of pretreated and unpretreated substrates was studied at 2 and 48 hours using a cellulase preparation from T. reesei omg414 at a final FP activity of https://www.w3.org/1998/Math/MathML"> 18 I U / g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of substrate. The higher cellulose conversion yield (about 78%) and saccharification efficiency https://www.w3.org/1998/Math/MathML"> ( 50 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were obtained when 0. nervosum biomass was treated with a 1% alkali solution at https://www.w3.org/1998/Math/MathML"> 100 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for 10 minutes. 41. TNTRODUCTION Biodegradation of lignocellulosic materials has become one of the most promising prooesses in the biotechnology field. The possibility obtaining this menewahle meroumoe in lamges quantities as well as the fast development of the technology for enzyme production and fermentation, permit the forecast of enzymatic hydrolysis of lignocellulosics as a feasible process from an economica. and technical point of view. However, the characteristics of lignocellulosic biomess, mainly the crystallinity of native cellulose and its association with lignin makes the pretreatment of this material necessary to increase its susceptibility to enzymatic hydrolysis. Many physical and chemical treatments have been described in the last few years (1). Results reported by some of these show the effectiveness of the use of alkali to pretreat lignocellulosic materials with a similar composition to https://www.w3.org/1998/Math/MathML"> 0 . _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> nervosum (2) (3). This endemic plant of the Iberian Peninsula can be considered an interesting lignocellulosic biomass source for its transformation to fermentable sugars due to its high crop productivity (20Tn/Ha) hardiness and composition (30-35% of cellulose, 65-70% of holocellulose and 15-19% of lignin) (4) The aim of this work is to determine the most effective conditions for a maximum cellulose recovery of solid residue after alkali pretreatment of 0. nervosum biomass, as well as an optimum glucose yield in the enzymatic hydrolysis of this residue. 42. MATERIAL AND METHODS The dried thistle was hammer milled and sieved through https://www.w3.org/1998/Math/MathML"> 2   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . diameter. Pretreatments were performed at https://www.w3.org/1998/Math/MathML"> 100 ∘ , 120 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 150 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in a silicone bath using https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> 2 % N a O H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> solution with a final substrate concentration of https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Reaction times ranged from o to 90 minutes. Substrate composition, in cellulose and lignin, was determined by total hydrolysis with https://www.w3.org/1998/Math/MathML"> H 2 S O 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (5). Enzymatic hydrolysis was carried out at https://www.w3.org/1998/Math/MathML"> 50 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in https://www.w3.org/1998/Math/MathML"> 0.05 M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> citrate buffer https://www.w3.org/1998/Math/MathML"> ( p H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 4.8) with a 5% substrate concentration. A cellulase preparation from T. reesei Qyill was added to an enzymatic activity for each 100 mog. substrate of 1.8 UI (filter paper activity) and 4 nKat ( β - glucosidase activity). Reducing sugars were analyzed by Nelson-Somogyi method and glucose by an enzymatic test (Boehringer Manheim) 43. RESULTS AND DISCUSSION The thistle, O.nervosum, used in this work contains https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cellulose, https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reducing sugars, https://www.w3.org/1998/Math/MathML"> 17 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lignin, https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ash and https://www.w3.org/1998/Math/MathML"> 7.8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> proteins (other components have not been analyzed). The effect of different pretreatment conditions on solid residue recovery and reducing sugars, glucose and lignin content in the residue after treatment is summarized in Fig. 1. The yield of solid residue decreases sharply when substrate is treated at high alkali concentrations, with a maximum solubilization taking place during the first 30 minutes. Termperature also increases the extent of solubilization mainly when short reaction times are studied. Lignin fraction is more solubilized than hemicellulose or cellulose, although with severe pretreatment conditions even 50 f of cellulose (Table I and Fig. 1d) can be removed. Under mild conditions (i.e. https://www.w3.org/1998/Math/MathML"> 100 ∘ C , 1 % N a O H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 10 minutes) https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total lignin and https://www.w3.org/1998/Math/MathML"> 35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of reducing sugars are removed, leaving https://www.w3.org/1998/Math/MathML"> 64.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of solid residue with a glucose recovery of https://www.w3.org/1998/Math/MathML"> 77.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Fig. https://www.w3.org/1998/Math/MathML"> 1   b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The relative enzymatic hydrolysis rate (at 48 hours) of the pretreated thistle is shown in Flg. 2 and Table I. Saccharification efficiency and celkulose to glucose conversion have been plotted versus alkali concentration for the different temperatumes and reaction times used. Saccharification efficiency (SE) (6) and cellulose conversion (CC) have been calculated as follows: https://www.w3.org/1998/Math/MathML"> S E ⁡ ( ) ̸ = G y / G t   C C ⁡ ( ) ̸ = 100 G y / G r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> G y = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Percentage of glucose obtained in the enzymatic hydrolysis of pretreated substrate. https://www.w3.org/1998/Math/MathML"> G t = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (cellulose content (expressed as glucose percentage) of untreat. subs.)/ (Percentage of solid residue after pretreatment). https://www.w3.org/1998/Math/MathML"> G r = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Cellulose content (expressed as glucose percentage) of pretreated substrate When the pretreatment was carried out at https://www.w3.org/1998/Math/MathML"> 25 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 90 minutes the relative enzymatic hydrolysis of solid residue (evaluated at 48 hours) increases when increasing alkal https://www.w3.org/1998/Math/MathML"> ≠ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration At the highest concentration saccharifioation efficiency and cellulose conversion were respectively enhanced, 1.6 and 2.4 times based on the corresponding values for unpretreated thistle (Fig. 2a). However, for https://www.w3.org/1998/Math/MathML"> 100 ∘ , 120 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 150 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , no significant differences were observed when alkali concentration was increased from https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Increments obtained for these temperatures reached values of 2.3 (SE) and 3.6 (CC) times based on unpretreated thistle (Fig. https://www.w3.org/1998/Math/MathML"> 2 b https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 20 ). The effect of the pretreatment time depends on the severity of the other treatment parameters. For https://www.w3.org/1998/Math/MathML"> 100 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> an increment in the reaction time produces a slight enhancement of the enzymatic hydrolysis rate. However, when higher temperatures are considered https://www.w3.org/1998/Math/MathML"> 120 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 150 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the effect is rather different (Fig. https://www.w3.org/1998/Math/MathML"> 2 c , 2 d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and Table I). As can be seen in Fig. https://www.w3.org/1998/Math/MathML"> 2 d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a drastic decrease of enzymatic conversion takes place when times higher than 10 minutes are studied, with values for cellulose conversion and saccharifleation efficiency at https://www.w3.org/1998/Math/MathML"> 150 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 30 or 90 minutes being even Iower than that obtained for unoretreated thistle. This Ejo l: Yieid of recutuing sugars, glucose, lignin and solid resicue Fig 2: Cellulose conversion based on potential glucose in oxiginal material) after 43 h. of enzvmatic hyarolysis. behavior is difficult to understand taking into account the high delignification extent as well as the glucose recovery rate in the pretreated residue observed in these cases (Fig. 1d). The highest relative extent of enzymatic hydrolysis at 48 hours has been found when pretreatment was run under mild conditions (1.e. 100, 120 or 150" for 10 minutes and an alkali concentration 18). Under these conditions saccharification efficiency and cellulose conversion reached values of about 50 % and https://www.w3.org/1998/Math/MathML"> 78 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively. Values for relative enzymatic conversion at initial rates ( 2 hours) reveal the same profile as that obtained at 48 hours (these results are not shown here). TABLE I.- Influence of pretreatment of 0 . nervosum biomass in: glucose yield based on potential glucose in original material (G); conversion of cellulose to glucose by enzymatic hydrolysis at 48 hours (CC); sacchariffication effficiency (SE) and Kg. of glucose after enzymatic hydrolysis/Ton of dry thistle (G/Ton). 44. CONCLUSION From these results it can be concluded that alkali pretreatment under mild conditions greatly improves the enzymatic hydrolisis of thistle (the yield of glucose/Ton of dry thistle could be increased from https://www.w3.org/1998/Math/MathML"> 68 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . for untreated substrate to https://www.w3.org/1998/Math/MathML"> 155 K g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . under the most effective conditions studied) without a high economic and energetic input in the process balance. Due to the low β- glucosidase activity used in the experiments, further work with an improved enzymatic activity is necessary in order to opmitize the efficiency of hydrolysis. 45. REFERENCES (1) CHANG, M. M., CHOU, Y. C. and TSAO, G.T. (1981). Structure, Pretreatment and Hydrolysis of Cellulose. Adv. Biochem. Eng. Vol. 20 15-41. (2) MACDONALD, D.G. et al. (1983). Alkali Treatment of Corn Stover to Improve Sugar Production by Enzymatic Hydrolysis, Biotechnology and Bioengineering. Vol. 25 2067-2976. (3) GHARPURAY, M.M., FAN, L.T. and LEE, Y.H. (1983). Wood and Agricultural Residues. Published for Isoltes by Ac. Press. (4) FERNANDEZ, J., MANZANARES, P. and MANERO, J. (1985). Onopordum nervosum boiss as a Potential Energy Crop. Published in these Proceedings. (5) DUNNING, J.W. and LATHROP, E.C. (1945). The Saccharification of Agricultural Residues. Ind. Chem. Vol. 37 24-27. (6) GoULD, J.M. (1984). Alkaline Peroxide Delignification of Agricultural Residues to Enhance Enzymatic Saccharification. Biotechnology and Bioengineering. Vol. 2646-52. of different fungi to produce enzymes capable of cleaving Lignin linkages and for producing cellulose saccharifying enzymes will be discussed, with particular emphasis on the Lignin degraders. 46. RE FERENCES

Blanch, H.W. and Wilke, C.R. (1982). Sugars and Chemicals from cellutose.

Crawford, D.L. (1981). Microbial conversion of lignin to useful chemicals using a lignin-degrading streptomyces.

z. Biotechnology and Bioengineering symp. No. 11.275-297. Freer, s.n. and Detroy, R.W. (1983) Characteristization of cellobiose fermentation to Ethanol by Yeasts. Biotechnology and Bioengineering https://www.w3.org/1998/Math/MathML"> 25 : 541 - 557 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Osore, H. (1983). "Mission-oriented Research on the Biology and Biochemistry of microorganisms from African termites for improved biomass degradation", Annual Report, ICIPE (1983).

47. IMPLEMENTATION (a) Developed Countries (b) Developing Countries DR. GEORG SCHÖRNER FORSCHUNGSINSTITUT FUR ENERGIE- UND UMWELTPLANUNG The Austrian Research Institute for Energy and Environmental Planning 48. Summary In the course of a research project for the Government of lower Austria (the biggest province of Austria; I. 4 mill. Inhabitants; with a considerable quota of forest and agriculture) our insti- tute calculated in which way the forest and waste products could be used for energy purposes. Two processes are estimated to give the best results: gasification and pyrolysis. Today this could be the best way for conversion of biomass to fuel (gas, pyrolysis oil and solid fuels). By using in engines electricity is produced and heat for domestic purposes. Our institute worked out the following topics during our research work for this study: Capacity of biomass in lower Austria for each village (agriculture resiaues, energy crops, wastes Erom household and industries; wood and wood products; regional distribution; temporal disposition etc.); Szenarios 1990 and 2000; Detailed international reqistration of the state- of-the-art-systems (gasification and pyrolysis); Computerized optimation models for regional distribution and application of Such small (and possible mobile) units; Investment and operati- onal costs, cost-benefit-szenarios, plannea state assistance and subsidies. 49. BIOMASSE Die Ausfinrungen und Berechnungen haben eindeutig gezeigt, daß in Niederösterrejch, dem größten österreichischen Agrarland, ein beachtliches Potential an Biomasse bereitsteht, das heute nicht oder nur sehr unvollständig genutzt wird. Da selbst bei unveränderten Rahmenbedingungen mit einer Steigerung der Ernteexgebnisse bis in das Jahr 2000 gerechnet werden kann, scheint es angebracht, dieses Energiepotential nutzbringend zu verwenden. Stellt man sich auBerdem ein geänder- tes Anbauverhalten vor (mit Forcierung des Anbaus von Biomasse), so kann mit einem steigenden Biomassepotential gerechnet werden. Rund 36 " des Energiebedarfes der niederösterreichischen Haus- halte könnte mit Energie aus heimischer Biomasse abgedeckt werden. DaB hiebei mehr Arbeitsplätze im länalichen Raum geschaf- fen werden und der tandbevolkerung Mehreinnahmen zufallen wir- den, ist unverkennbar und sollte auch aus dieser sicht Ansporn sein, in diesen Bereich ein größeres schwergewicht zu legen (abgesehen noch von der volkswirtschaftlichen Bedeutung fur den Staatshaushalt und hinsichtlich von Deviseneinsparungen). Planned mobile biomass units (model) 50. Summary My poster deals briefly with a "new", also internationally so, especially powerful possibility of energy. Biogases, which already nowadays are produced from nearly all organic materials in kilowatt and increasingly bigger megawatt effects, offer great readiness, when rapidly taken in use, in the generation of e.g. electricity, cooling, heating, drying, hydraulics and pneumatics. This energy is gained from homemproduced raw materials or all their wastes, and can be produced in most countries. Microbiologically obtained, economical also in large-scale processes, biogases proper containing 60-80 of methane burn more effectively than different kinds of thermochemical (biomass - etc) gases in burner and boiler or engine systems. We can therefore talk about biogas economy and multiple power plants run by "molecular power stations". References can be found in very many countries. In this way solar energy can be harnessed by a natural accumulator for known and absolutely reliable end uses. 51. DEFINITION In using the general term of "biogases", we include here all gaseous fuels which are either obtained microbiologically (biotechnically) from different organic materials, or thermochemically from biomasses. Even though the previously mentioned forms are produced in nature, it is possible to speed-up the process of splitting the molecules. When speaking of this substance, we are mainly referring to marshgas and other anaerobically produced gases which contain methane, such as those found in refuse dumps and mines, or those which come from sewage sludge digesters, even though the general term. "biogas" would be more salable. Both the carbon monoxide and hydrogen contained partially oxidized gases, and the pyrolyzed gases represent the thermochemical group. 52. SOURCES As in nature, we also can prockue biogases from plant and animal wastes in completely oxygen-free circumstances and under various temperature conditions. In addition, we can use biomasses which have been cultivated for this purpose. In our processes all these organic carbon-containing substances are fed into suitable reactors after they are ground, and the produced gases are further purified if deemed necessary. Because energy transfer in the form of gas is cheaper than in the form of heat, users can be situated far from reactors, particularly if the gas is in enriched form, or there are huge amounts in question. 1. APPLICATIONS Even though biogases differ Erm one another chemically, they can be burned in mostly the same ways: e.9. in boilers or in combustion engines (incluaing gas turbines, stirling etc). At present, the best possible method is the aual-fuel system. If, for some reason, the slpply of biogas is disrupted, or if it is erom the beginning more economical to build a plant of more suitable size, it is possible to use for example petroleum products or natural gas as a second fuel. A correctly built burner or engine adaptation shifts automatically to use the reserve (and ignition) fuel. Besides producing heat, both adaptations can be combined with electricity production, hydraulics, pheumatics or heatpumping. This means again cooling and drying possibilities and, if needed, additional heating. 2. MARKETING Biogas potential has already been partially charted in Finland and it amoears to be very large. Its vse is mainly connected to agriculture, the home and organically-based industries. Biogas reactors can be found in all of those sectors in Nordic Countries, in addition to those that are sold mnder international licences. All the eoutment, also the small. sized, will become less expensive as the choice of materials grows. In most cases we obtain the biogas (nearly) free of charge, from for example water protection processes. In the Federal Republic of Germany, there operates a large IO MN biogas heatpump, which takes the heat from the same place after the waste water is purified. Because the time of "molecular power stations", multiple energy plants and biogas economy has begun, I urge the formation of the "International Biogas Society" in order to speed-up all development in this field. 3. FINLAND 1984 4. General The oldest sewage plant in our capital Helsinkj has been producing biogases by the anaerobic method since 1932. This plant was the first one to do so in the Nordic Coutries. In addition to some fuel experiments conducted on cars in the https://www.w3.org/1998/Math/MathML"> 1940 ' s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML">   1 50 ' s ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> biogases from the newer reactors (digesters) have been continuously used when necessary, especially to rotate 200 - 1000 kW electric generators. The increase in the price of oil has also led to some use of biogases for heating in agricultural, domestic and industrial sectors. In the same way the use of air compressors with a combustion engine and "cost free" biogases at a sewage plant has been found to be so econorical that more are planned, in spite of cheap nuclear power. The rotation of the cold compressor (the main component of the heatpump system) has also been taken into our calculations; the same sewage flows usual.1y contain raw materials for the biogases as well as heat for the heatpump. In addition to sewage, the first experiments to collect biogases from refuse tips and marshes are just about to conmence in Finland. The anaerobic gasification of the biomass cultivated for this purpose has also been planned, in addition to the three different types and dissimilar sizes of pyrolize-gas plants already existing. 5. Types of Biogas Reactors So far, there are some 14 biogas plants in use in the 84 towns in Finland. In adaition to this, 6 biogas reactors are also in use in industry, and 7 in agriculture. The larger biogas plants in the towns are most frequently concrete constructions built on the spot, whilst those used in the food and forest industries are made of steel. Smallex steel constructions (of approximately up to https://www.w3.org/1998/Math/MathML"> 150   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) mainly suitable for the thicker domestic and agricultural sludges are produced industrially in shorter series. There are about 10 of these in use in Finland, and a similar number, or licences, have been sold to neighbouring Sweden, Denmark and the soviet Union. Because biogas yields are high and procuction costs low from those reactors, many enquiries about them are now also being received from overseas. Uses and equipment The boilers for the burning of biogases are mainly Finnish made, as is the world's smallest https://www.w3.org/1998/Math/MathML"> 15   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dual-fuel burner. When the gas supply is disrupted for some reason, the burner switches over automatically to burn for example light fuel oil and then back again when the normal supply is resumed. Motors of a corresponding dual-fuel type (e.g. gas-diesel) have only been used in the larger sizes. However, because of the aforementioned reliability and efficiency, attempts are now being made to choose smaller ones too for the same reasons. With the dual-fuel possibilities there is no need to store gas, and storage is used only in large town plants. Until now purification of the biogases is limited. In spite of our cold climate it is not even dried for the short underground transfer by plastic pipe. 6. COLIABORATION Our company is already in collaboration with many Finnish and foreign experts and manufacturers, in order to rapidly and vigourously develop biogases for the benefit of everybody. 7. NEW DOMESTIC RENEWABLE ENERGY THROUGH A Further actuantages: Control of pathogens, pollution & odour via sewage and waste treatment

The residue product is a excellent natural fertiliser

Both the burner and/or engine shift auto matically to the back-up fuel when necessary DUAL FUEL SYSTEMS:

Guarantee operations in the case of biogas disuption

Enable optimum plant dimensioning even during initial phase when biogas supply is limited

Safe also in the event of possible

fluctuations in https://www.w3.org/1998/Math/MathML"> C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> content of biogas COSTS:

Biogas almost tree of charge as a

by-product of water protection processes

Storage for tuel oil is cheaper than

for biogas

Biogas transport is more economical than

transport of hot or cold water (or steam) in district heating or cooling systems in district heating or cooling systems

Prices for reactors and equipment will

go down as development proceeds it is time to form an WHERE: The biogas system is feasible aimost every. where when YOU want more "molecular" power stations", multiple energy plants, and biogas economy. "INTERNATIONAL BIOGAS SOCIETY"! 8. Summary 9. INTRODUCTION 10. REFERENCES AN ECONOMIC ANALYSIS OF THE ENERGY VALORISATION OF CEREAL STRAW IN FRANCE V. REQUILLART National Institute for Agronomic Research Rural Economics Laboratory 78850 Thiverval-Grignon (France) Abstract https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The notion of an available straw vein, although it may provide an approximate idea of the scope https://www.w3.org/1998/Math/MathML"> [ 5 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> million metric tons for France] is nevertheless insufficient. Indeed, it gives no indications as to the cost of access to the resource. The latter, depending on whether or not there is intra-consumption, varies between 30 and 50 French of hot there is intra-consumption, varies between 30 and 50 French the point of view of energy valorisations, straw has a certain number of points in its favour, and the economic interest of the course is fairly considerable. Schematically, utilisation on farms is of considerable interest from the economic point of view, and utilisation off the farm is possible in certain cases, although the economic interest is then more limited. The production of pellets seems to be possible in lucern and pulp dehydration factories. In spite of these economic advantages, development in the field is slow [in 1983, approximately 100000 metric tons of straw were used in France for producing ener gy]. Analysis of the behaviour of the various parties participating right along the course makes it easier to understand the slowness of this development. The main delaying factor is the insignificance of the individual economic stakes involved, which stems from the atomisation of the resource.

INTRODUCTION

Cereal straw has a great many advantages insofar as concerns its valorisation in the energy field. It is an agricultural by-product, dry when harvested [maize canes are excluded in this context], and is available in large quantities; access and harvesting are easy. However, in spite of these advantages, one cannot fail to observe that the development of these utilisations has been extremely slow. It is estimated that, for 1983, approximately 100000 metric tons of straw were used for producing energy. For this reason, after having set out the economic interest of the various courses for valorising straw, we will analyse some of the delaying factors which oppose their development. 11. The supply of straw In 1980 , the surface area planted with cereals was 7.6 million hectares [approximately 18.6 million acres], which represents an average produce of approximately 26 million metric tons of straw. This produce is distributed between about 600000 farms. Such dispersion over a very large number of economic participants is one of the main characteristics of the vein. Obviously, part of this produce is already used, mainly for stock farming purposes [see table 1]. Of these 26 million tons of straw produced on average, about 5 million tons are available for new uses, without in any way competing with traditional utilisations. This evaluation is an average value which may vary enormously from one year to the next, and concerning which the medium term development is not known. Also, this value gives no information at all on the cost of access to the biomass. For this, supply graphs must be drawn in order to obtain a ratio between For this, supply graphs must be drawn in order to obtain a ratio between the price and the quantity available. The drawing up of supply graphs at regional level reveals the revenue phenomena - on the one hand the differential rent resulting from the various production conditions of the different farmers and, on the other hand, the absolute rent corresponding to the acquisition by the producer of a revenue without labour. In this way, the economic behaviour of the farmer will not be the same if he uses straw at its mineral value (at about 30 to 50 francs per ton, depending on the species), whilst if he sells it, the price will rarely be less than 100 francs per ton, which represents an acquisition of an income amounting to approximately 50 francs per ton. 12. The economic interest of courses valorising straw for energy From the point of view of the producer of straw, the threshold cost of straw represents the minimum selling price of the resource (below this value, the sale would lead to a loss for the seller). From the point of view of the utiliser, the interest price represents the maximum purchase price of the resource (beyond this value, the purchase would lead to a loss for the utiliser). The difference between the interest price and the threshold cost, after deduction of packing and transport costs, represents the economic surplus produced by the course. 2.2. Results The main results are set out in tables 2 to 4 . They can be summarised as follows:

On the farm, the courses are highly profitable. Indeed, on the one hand, the cost of the resource is low (70 francs per ton in a great many cases) and, on the other hand, the cost of competitive energy is high. Finally, one participant only intervenes, which means that he will acquire the total amount of the surplus.

Off the farm, the courses are generally less profitable. On the one hand, the cost of the resource once it has reached the utiliser is amplified by transport costs and by rents. On the other hand, the competition of the other energy vectors such as heavy fuel, natural gas, coal and electricity, is extremely severe. The surplus provided by the course is thus less reliable and, further, this surplus must be shared between the various participants.

The "straw pellet" course should also be mentioned. Indeed, whilst the threshold cost of pellets produced in a specific factory may at present be too high, the same does not apply to pellets produced by lucern and pulp dehydration factories, which can manufacture pellets at marginal cost. Consequently, it would appear possible to create, around dehydration plants, poles of utilisation for fuel pellets, both at individual and at small collective levels.

Nevertheless, in spite of the micro-economic interest of the courses, the development of energy utilisations for straw is fairly slow. In order to explain this situation, the economic behaviour of the parious participants who intervene right along the courses must be examined.

The economic behaviour of the participants

to be reasonable. The courses to be favourised are utilisation on farms theating and dryingl, the use of pellets close to dehydration units, and certain collective utilisations in regions where competition from other vectors is less severe. In relation to other agricultural by products, straw was a priori the most well suited from the point of view of energy valorisation. The complete analysis which has been made of the course thus leads one to adopt a reserved attitude insofar as concerns the short-term development of the energy utilisation of other agricultural by-products. 13. Bibliography Pyc.Editions - AFME - Paris. 157 p. SOURIE Jean-Claude 1981 - Production de paille de céréales comme source de combustible et produTts associés Etude https://www.w3.org/1998/Math/MathML"> n ∘ 2 : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Méthodologie micro-économíque CCE - DGRSE - projet Eontrat n 326-78-10 ESF, 38 p + annexes. 14. Table 1 - Straw utilisation in France 15. - Production - https://www.w3.org/1998/Math/MathML"> 26 M t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> baled .................................................................... https://www.w3.org/1998/Math/MathML"> 18 M T https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

Animal bedding :

Others :

non harvasted ............................................................. 8 MT

burnt .................................................................. https://www.w3.org/1998/Math/MathML">   1   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Mt

soil incorporatad..................................................... 7

AVAILABLE FOR NEW USES https://www.w3.org/1998/Math/MathML"> ≃ 5 M t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 16. [*] for new installatians Table 3 - Straw in bales off farm useg the price of pelteta is https://www.w3.org/1998/Math/MathML"> ⩾ 600 F F / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

treshold cust of straw pellets produced in dehydratation factories is minor than

they are produced in specific factories. INTEGRATION AND ASSESSMENT OF BIOMASS RESEARCH INFORMATION BY USE OF SYSTEM ANALYSIS J. W. Mishoe Professor of Agricultural Engineering University of Florida Gainesville, Florida 32611 USA Abstract Summary The Institute of Food and Agricultural sciences (LFAS) at the University of Florida, in cooperation with the Gas Research Institute is operating a research program to develop an econoni- cally feasible system to produce and convert biomass to methane for use as energy. The research methodologies include using systems modeling and computer simulation to aid the researchers in setting research priorities and to assess the impact of new information on the performance of the system. The interactive systems model, BIOMET, consist of process oriented models for the crops of Napiergrass and waterhyacinth and we are currentiy including reactor driven conversion models. In addition, biomass transpor- tation, biomass harvesting, economics and energetics are included to produce simulated outputs of systems economics, energetics, methane yield and biomass yield as influenced by management and environmental conditions. Simulation studies indicate that water- hyacinth yields vary from 37 tha to 63 tha in response to harvest schedule. Transoortation cost for Napiergrass contribute $ igni- ficantiy to gas cost, however by increasing yields on fields sites close to the conversion facility can help reduce the total cost. 1. INTRODUCTION Biomass is a source of energy that can provide an important contribution to the energy supply in developed countries with regions having a favorable climate. Feedstocks can be derived from various sources including waste and biomass grown specifically for energy production. options exist that combine bjomass production with other necessary operations such as using waternyacinth to aid in cleanup of waste water or eutrophic lakes by growing the crop directiy in the enriched water. The resultant biomass can then be converted to high quality energy by the use of anaerobic digestion for methane production. The University of Florida in cooperation with the Gas Research Institute is conducting a research program with the goal of developing a commercia!ly viable system for the production and conversion of biomass feedstocks to pineline quality methane gas (4). As part of the research program a systems analysis project was implemented to assess the cost sensitive parameters to allow priority research to focus on areas with the greatest potential of reducing gas cost. Members of the systems teams consist of engineers, economists, statisticians, and computer specialists working with the experimentalists. The system under study consists of a central conversion system with biomass produced on a regional basis and transported to the conversion facility after harvest. The components of the system can be defined as the biomass production harvesting, transportation, and conversion. To analyze the system we have defined the economic and energetic characteristics of each component and in the case of the crop production and the conversion, we also model the performance of the component in response to component design management, and environmental inouts. The objective of this paper is to describe the approaches and methodologies used by the systems group and to present selected preliminary results of the analysis. 17. METHODOLOGY The component models have been integrated into an overall system Teve? mode? called BIOMET (3). The first operation in the interactive mode BIOMET is to define the configuration of the system to be simulated. The options include crop selection field https://www.w3.org/1998/Math/MathML"> s i z e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and location, conversion reactor type, harvester type and size, transportation type and stze, costing parameters, economic parameters, and gas demanc (Figure 1). BIOMET uses this information to select the number of trucks and harvesters needed and to estimate a narvest demand schedule. With this configuration the simulation begins and the ability of the system to preform as demanded is determined. If any component becomes imiting, the appropriate economic and energetic factors are recorded. The output reports summarize the actual performance of the system, reporting biomass and gas yields and the respective costs. BIOMET differs from essentially ali analysis procedures found in the biomass literature in that the simulation of the physical and biological processes are included in the analysis. This capability is important because it allows for the analysis of various management factors that cannot be considered other Wise. For example, variations of sequential management inputs stich as fertilizer application, harvest rates, planting density, etc. can be used to determine the resultant crop growth because the crop model can integrate the accumulative effects of weather and management. Current?y BiomET includes crop models for Napiergrass and waterhyacinth. Each crop model consist of component models to maintain the growing medium balance for nitrogen and water and for carbon, water, and nitrogen balance of the plant. Each of the crop models are different based upon the functional and parametric changes necessary to accurately describe each crop, however the basic carbon balance structure of the model can be expressed in a generic format. For each crop https://www.w3.org/1998/Math/MathML"> dw / dt = ( Pg - RoW ) / ( ϕ + Gr ) - S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where dw/dt is the rate of biomass accumulation, Pg is gross photosynthesis, Ro is the coefficient of maintenance respiration, W is the total biomass, ϕ+Gr are the conversion efficiency terms and s is the rate of biomass loss form the crop due to senescence. For a given crop type, the coefficients can be defined as a function of crop stage and environmental temperatures. Pg is defined as a function of itight Tnterception and the crop stresses. This takes the form of https://www.w3.org/1998/Math/MathML"> Pg = KR f N f U f T f L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> where K is a crop coefficient, R is the ambient solar radiation and fuy https://www.w3.org/1998/Math/MathML"> f 1 , f 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> f 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are functions ranging in value from 0 to 1 that are related to plant nitrogen, plant water, air temperature, and crop light interception, respectively. Figure 2 compares waterhyacinth model simuTations to measurements of waterhyacinth growth for the conditions used in the simulation. Figure 1. Block diagram summarizing available menu selections from the BIOMET program The simulation of the conversion process in the current example analys is is limited to an overall efficiency of the conversion system based upon the quantity of biomass input. The conversion type and size was held constant and the economics were based upon the utilization of the selected facility. In BIOMET an estimator model uses the monthly gas demand to determine the total annual biomass requirements. From the biomass demand and the user-supplied monthly gas demand, a monthly biomass demand is computed once the simulation begins, if biomass demand cannot be met the gas output is reduced and the variable cost are computed based upon the actual throughput. The BIOMET cost model calculates the initial investment (for biomass feedstocks and methane production) prior to simulation based upon user-defined scenarios, and then accumulates the variable costs during simutation. The levelized cost model uses these costs to calculate the levelized-cost-of-service price. Intial investment and variable cost are calculated separately for Napiergrass production, harvesting, and for conversion. Waterhyacinth costs are based on a winch-boom design (5). The user is limited to a choice of fours sizes estimated to produce feedstock for 0.1,0.5,1.0 and https://www.w3.org/1998/Math/MathML"> 3.010 12 B T U / y e a r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> conversion plants. Capital investment and variable cost are estimated based on the user-supplied geometry, size, and operating parameters. Napiergrass production, harvesting, and transportation costs include both capital investment and variable operating costs. Components of the initial capital investment include: harvester, trucks, and initial land rental, crop management (fertilizer, pesticides, etc.), labor, fuel, and machine operating maintenance. Figure 2. Example simulation using the waterhyacinth model from BIOMET (Data collected by Reddy (1)). 18. RESULTS AND DISCUSSION To examine the cost sensitivity of biomass due to transportation, BIOMET Was used to simulate a 3200 ha farm with the conversion cost, numbers of harvesters, and production cost held constant. In Table 1 only the number of trucks varied to meet the distance requirements. The biomass cost increased from https://www.w3.org/1998/Math/MathML"> $ 2.11 $ / 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BTU using six trucks to 4.63 https://www.w3.org/1998/Math/MathML"> $ 10 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BTU using 70 trucks with to distance was changed from https://www.w3.org/1998/Math/MathML"> 0.1   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 100   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . In the second example the distance was help fixed at https://www.w3.org/1998/Math/MathML"> 20   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the number of trucks were varied from 9 trucks to 31 trucks (Table 2). Below 19 trucks the transportation was limiting and above this excess trucks were available. Because capital cost are a minor part of the total production cost results indicate that capital intensive transportation that reduce variable cost can reduce total transportation cost. From a cost viewpoint it is important not to allow transportation to limit the system.Table 1. A 3200 ha Napiergrass farm various distances from DISTANCE TRUCKS DISTANCE TRAVELED CAPITAL https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COST VARIABLE https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> COST Km https://www.w3.org/1998/Math/MathML"> 10 3   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - . - $ / 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.1 6 60 0.12 1.99 10 12 1212 0.12 2.24 30 25 3540 0.15 2.73 60 44 7031 0.18 3.46 100 70 11686 0.21 4.42 Table 2. Simulations of a 3200 ha Napiergrass system https://www.w3.org/1998/Math/MathML"> 20   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> from the conversion site (2). NUMBER OF BIOMASS DISTANCE CAPITAL https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> VARIABLE https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> SYSTEM https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TRUCKS HARVESTED TRAVELEO COST COST COST https://www.w3.org/1998/Math/MathML"> t / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 10 3   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - … - $ / 10 6 B T U … … https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> - … https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9 13.5 567 0.12 4.05 10.04 12 20.1 1102 0.12 3.06 8.23 15 26.3 1778 0.13 2.60 7.32 19 31.9 2376 0.14 2.48 7.01 31 31.9 2376 0.15 2.49 7.03 1 The Canital and

The capital and variable cost included are for biomass production. 2. Includes a constant cost of https://www.w3.org/1998/Math/MathML"> 4.39 $ / 10 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> BTU for conversion.

The development of BIOMET is an on going activity that has not been completed. It however is a very useful tool for integrating new research information and determining the impact on the overall performance of the system. Results indicate that methane produced from biomass can be cost competitive with other energy sources. It however will require the continuation of focused research efforts to develop the necessary technologies and the procedures to manage these technologies. REFERENCES

Lorber, M.N., J.W. Mishoe and K.R. Reddy. 1984. Modeling and analysis of waterhyacinth biomass. Ecol. Modeling 24:61-77.

Mishoe, J.W., W.G. Boggess and D.W. Kirmse. 1984. BIOMET: A simulation model for study of biomass to methane systems. Proceeding of the IGRC. Washington. D.C. USA. 10 pages.

Mishoe, J.W. M.N. Lorber, R.M. Peart, R.C. Fluck and J.W. Jones. 1984. Modeling and analysis of biomass production systems. Biomass 6:119-130.

Smith, W.H.. P.H. Smith and J.R. Frank. 1982. Biomass feedstocks for methane production. In: Proceeding of 2 nd EC Conference on Energy from Biomass. App Tied Science Pub1., New York, USA. pp122-126.

Warren, C.S., eta1. 1984. Evaluation of the lake apopka natural gas district task report. RSH, 6737 Southpoint Dr. S., Jacksonville, F1. CONVERSION OF LIGNOCELLULOSIC MATERIAL TO ETHANOI INFLUENOE OF RAW MATERIAL YIELD AND HEMICELLULOSE UTILIZATION ON SALES PRICE OF ETHANOL

J. Felber, M. Schiefersteiner and H. Steinmü1ler VOEST-ALPINE AG, P.O. BOX 2, 4010 Linz/AUSTRIA 19. Summary In the late https://www.w3.org/1998/Math/MathML"> 70 ∘ s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> an Austrian Consortium consisting of the STEYRERMUHL-PAPIEREABRIKS- und VERLAGS AG, the VOESTALPINE AG and the Universities of Graz was formed to develop a new process for the production of monosaccharides Erom renewable carbohydrate sources, in particular lignocellulosic material. After detailed examination of Various hydrolytic processes it was decided to intensify work on enzymatic hydrolysis. The composition of this group brought the great advantage that it could focus not only on one problem but could also research into the total process. This included pretreatment, enzyme production, hydrolysis, by-product utilization and energy supply The raw materials studied most thoroughly la our program were waste paper and wheat straw. since these lignocellullosics are available in large quantities in Austria. Until now all endevour to produce ethanol out of lignocellulosic biomass on an industrial scale failed due to uneconomical production. Thus it is evident that the economy of such a process is very dependent not only on the yield of sugar, which is strongly affected by the rem spective pretreatment, but also on the utilization of the hemicel lulose. Summarizing it can be said that the cellulose has to be degregated to a high extent and that the hemicellulose must be utilized to reach a feasible project. 20. GENERAL DESCRIPTION The raw raterials studied most thoroughly in our program were waste paper and wheat straw, since these lignocellulosics are available in large quantities in austria. From the wide range of possible materials we also tested rice husks, sugar cane bagasse, palm oil residues and cotton stems. The theoretically possible quantity of sugars obtainable from waste paper and wheat straw - as estimated by our standard method (Esterbauer et al, 1982) is: 1026 (per https://www.w3.org/1998/Math/MathML"> 100 g r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dry matter rice husk waste paper wheat straw Glucose 38,3 48,0 42,00 Mannose 4,0 11,4 0,38 Xylose 18,5 4,9 25,50 Galactose 1,2 1,4 1,90 Arabinose 2,7 0,9 4,30 Our program has now reached a stage where the available data can be used for a feasibility analysis of a full scale industrial plant based on wheat straw. This plant is designed for the daily production of 80,000 litres of ethanol and single cell protein, furfural or furfurylic alcohol. The necessary enzymes are produced by the fermentation of hydrolysis Lesidue with Trichoderma reesei sva 22, a residue adapted mutant of QM 9414. The following picutures show the linkage of the respective processing areas: 1027 21. BIOENERGY IN REGIONAL ENERGY SYSTEMS - Department of Forest Economics Agricultural University of Norway BOX 44, N-1432 AS-NLH, NORWaY 22. Summary Up to now biomass in Norway is majnly used non-commer- Cially as firewood in households and as mill residues in the forest industry. There are on the market commercial bioenergy systems that should be economically feasible The hypothesis is that there exist institutional barriers that make a further development at the commercial bio- energy sector aifficult. The Hadeland project studies this problem on a cegional level. A regional bioenergy com- mission consisting of representatives from the most im- portant interest groups serves as reference group for the project. Ine commission tries to establish press contacts, to inform local politicians and to stimulate potential bioenergy investors. The research project consisting of a systems study and a study of the work in a bioenergy commission, is planned to be completed by the end of 1985. Preliminary figures show that there exists a large unused bioenergy potential in the region. The systems study will hopefully identify feasible projects to utilize a part of this potential. The work in the commission has so far been fruitiul and it seems that at least some of the barriers initially alscussea could be overcome through co- operation and aiscussion between the interest groups at the bioenergy sector. 23. INTRODUCTION Bioenergy is not likely to play a major role in the national energy system In Norway. On the regional level, how- ever, the impact of bioenergy might be considerable. Up to now biomass is mainly used non-commercialıy as firewood in holise- holds and as mill residues in the forest industry. What possi- bilities does biomass have as a commercial energy source? After five years of bioenergy research in Norway we have some technical and economical knowledge about bioenergy systems. We also think that some of these systems are competitive in the market. When starting the project we identified the most important barriers for commercial bioenergy utilization to be: Figure 1. Map of Hadeland

REGIONAL REFERENCE GROUP

Without local involvement from the beginning such a study would be meaningless. We therefore contacted some selected 24. PRELIMINARY EXPERIENCES AND CONCLUSIONS POSSIBILITIES OF RELIEVING THE EEC AGRICULTURAL MARKET THROUGH ENERGY PRODUCTION E.G. RAPE AND SHORT-ROTATION FORESTRY https://www.w3.org/1998/Math/MathML">   R. Apfelbeck   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML">   TU - MUNICH     Bayer. Landesanstalt f ü r Landtechnik     D -   8050   Freising   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 25. Summary In the European Community, an excess of 10-16 mio ha of farmland for agricultural production is expected by 1990 . Presently, the expenditures for regulating the market due to overproduction run at 850-1300 DM per ha of equivalent export land. The production of energy sources, both short-rotation forestry and rape cultivation can result in net savings of more than https://www.w3.org/1998/Math/MathML"> 700 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha only if the energy is utilised locally by the producer. The overproduction of agricultural products is continually becoming a larger problem in the European Community. In 1984 , the Community harvested 150 mio t of grain, which represents a degree of self-sufficiency of https://www.w3.org/1998/Math/MathML"> 130 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The calculatory overproduction of wheat is 24 mio t. On the other hand, the annual consumption of about 400 mio t of crude oil is almost completely imported. The production of biomass on excess land could partly replace the energy imports. According to HEIDRICH'S calculations, an equivalent import surface of https://www.w3.org/1998/Math/MathML"> 5.8 m i o https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha for food production was still required in 1973 for self-sufficiency, while in 1982 an excess of 4.2 mio ha already existed. From figure 1 it is clear that by 1990 , the overproduction will represent 10 - 16 miot. Figure 1: Trend and projected values of the supply situation in the EEC-9 converted to surface equivalents (according to HEIDRICH) The production increases have led to continually increasing subsidues derived from the Community budget (see Fig.2), such that the expenditures wi11 soon exceed incomes. In Figure 3 it can be seen that a subsidy of 850-1300 DM per ha of surface equivalent already arises; for sugar beets up to 4.100 DM. Figure 2: Development of expenditures of the common market listed according to purpose. margin. Figure 3: Producing area, export area and market subsidies in the EEC-9 (according to HEIDRICH) These expenditures reach a level, which corresponds to a half to one gross As a possible alternative to reduce the overproduction, the cultivation of biomass crops is to be discussed. If biomass could be produced on the entire agricuTtura 1 area at https://www.w3.org/1998/Math/MathML"> 2 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of crude oil equivalent per ha, https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the crude oil imports could be substituted. The percentage of bioenergy on agricultural excess lands would be max. https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Apart from ethanol production, rape cultivation and short-rotation forestry can be considered, since the products produced could be used directly at the farm site. 26. SHORT-ROTATION FORESTRY With this alternative, 10.000-12.000 poplar slips are planted per hectare After 2 vears of weeding and annual fertilization. the entire wood material is harvested in 5 year-intervals as chips. The https://www.w3.org/1998/Math/MathML"> 11 fetime https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of such a system is estimated at is years. At the Hessischen Forstlichen Versuchsanstalt, Hann. Münden, the average annual dry-weight growth was 10 - 15 t per ha in the period fg79- 33. The best varieties even reached https://www.w3.org/1998/Math/MathML"> 25 - 30 t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (dry matter). The advantages of this production method:

Wetland sites are possible (high precipitation, pastures)

Reduced use of weed killers

Soil erosion is hindered

Harvest time in the winter months

These are offset by the disadvantages:

Production techniques in trial stage

Storage and drying not yet determined

27. - Large transport capacities required- Extended capital binding, liquidity problems- Market introduction as a product necessary In Figure 4, the expenditures are illustrated for a 1 ha short-rotation forestry plot. The initial costs in the first year are about 8.000 DM, harvest costs https://www.w3.org/1998/Math/MathML"> 100 D M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (dry matter) and the costs for ventilation drying are 25 DM/t (dry matter). An interest rate of https://www.w3.org/1998/Math/MathML"> 7 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for debts and 5 % for credits is assumed. As a substitute for oil, the wood chips are to be used at the farm site and the cost is set at https://www.w3.org/1998/Math/MathML"> 260 D M / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (dry matter).

1 instailation costs

[imin harvesting costs Thervest 28. Cum harvesting costs n 80000 5/20,75/2344 180 630 1330 for 1330 forestry plot of With the above assumptions, a satisfactory income or savings can be expected only if the initial productivity is above 15 tdry matter/ha annually. Cost reductions are possible in the harvesting and drying processes. Detailed results from the test plantings should be awaited. 29. RAPE CULTIVATION The cultivation of rape is well known. Figure 5 shows the composition of the plant and its uses. Figure 5: Composition and the possible uses of rape The method has the following advantages:

Production techniques known

Fuel production for vehicular power (substitute for diesel)

If rape oil is not chemically treated (trans-esterification), only few diesel engines can be considered (Elko, KHD). Rape straw can substitute heating oil and rape meat can be fed to livestock. Figure 6 shows the range of possible substitution or saving values with the use of rape as an energy crop. Figure 6: Economic evaluation of the energetic use of rape at the farm site Depending on market situation and the given farm operation, net savings of 700 - 1200 DM/ha are possible with the local use of rape products at the farm. Further investigations of both energy crops are necessary for an exact economic analysis. Even under more unfavourable conditions as considered here, a transfer of market subsidues into energy crops can lead to savings in the EEC budget. With a change of direction toward energy production, however, considerable organizational problems are also to be expected. 30. REFERENCES (1) BATEL, W.: Pflanzenöle für die Kraftstoff- und Energieversorgung, GrundTagen der Landtechnik, Bd. 30, Nr. 2, 1980 (2) BUSCH: Mündliche Mitteilung, 1985 (3) DIMITRI, L.: Schriftliche Mitteilung, 1984 (4) ELSBETT, L.: Prospektmateria 1, 1984 (5) V. GELDERN, W.: Rund neun Mio. Tonnen Weizen nicht absetzbar, Süddeutsche Zeitung, 09.01.1985 (6) HOFSTETTER, E. M.: Feuerungstechn ische Kenngrößen von Getreidestroh, Dissertation, Weihenstephan 1978 (7) KHD-Information: Prospektmaterial 1984 (8) SCHAFER, R.; E. HEIDRICH: EinfluB und Nutzung von Biomasse als Energieträger auf die arbeitswirtschaft1iche Lage, die Energiesituation und die Agrarmarktprobleme der Europäischen Gemeinschaften, Endbericht zum Vorhaben ESE-R-065-D (B), Studie 2/1, 1984 (9) WEISGERBER, H.: Klonvergleichsprüfungen bei Schwarz- und Balsampappeln im Kurzumtrieb, Vortrag auf Tagung "Ad-hoc Committee on Biomass Production System in Salicaceae, Ottawa, Kanada, 1984 THE ECONOMICS OF THERMOCHEMICAL ROUTES FROM WOOD TO LIQUIDS I. A. MICHAFLTS Cambridge Energy Research Group Cavendish Laboratory Madingley Road Cambridge, UK CB3 OHE 31. Summary Several research groups and companies are working on the technologies for converting wood to liquid fuels. The technologies include those for producing synthesis gas followed by methanol, gasoline or fischerTropsch liquids, as well as direct liquefaction using a solvent and catalyst. Process yields, capital costs and running costs have been predicted, with varying degrees of confidence. Most predictions suggest that at the present price of fuels from petroleum, none of the technologies is likely to be economic. Central estimates for the best developed, indirect methods give fuel costs at around https://www.w3.org/1998/Math/MathML"> $ 11 / GJ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , which compares with a price of around https://www.w3.org/1998/Math/MathML"> $ 5 / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for international1y traded gasoline. Improvements in processes seem unlikely to reduce costs below https://www.w3.org/1998/Math/MathML"> $ 8 / GJ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . A simple spreadsheet programme designed for comparative assessment of Euel conversion technologies in developing countries is applied here to 1iquid fuel production. It is seen that countries with foreign exchange problems - either an overvalued currency ox worsening terms of trade - may find these technologies attractive. Discounted cash flow analysis is used to compare the effects of technology improvements with those of the economic environment on ftrel cost. The results make clear the attractiveness of a direct liquefaction process, if one was developed to a commercially viable stage. 32. INTRODUCTION Evaluation of fuel conversion technologies hinges on the economics. The normal method used is discounted cash flow analysis, giving the product price needed to pay for the project costs. Several organisations have made assesgments of wood conversion technologies. These indicate that the cost of transport fuels from wood is likely to be two or three times the price of internationally traded fuels from oil (now about $5/GJ). For this reason much attention is being paid to finding ways of reducing the cost. As capital comprises https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the conversion cost for most processes, most attention is paid to this factor. Process efficiency is also extremely important. plant costs depend almost entirely on the amount of wood processed, not on the output level, so product cost is inversely proportional to yield. While lowering costs brings forward the time at which these products can compete with fuels from oil in affluent countries, some may already be attractive in countries experiencing severe economic difficulties. In order to facilitate assessment of different technologies in diverse economic climates, a spreadsheet programme has been wiltcen using cost-benefit analysis The programme calculates the price of internationally traded oil for which the product is a desirable substitute. It allows for variations in capital costs, wage rates and so on, as well as for different rates of escalation of wages, energy prices, plant costs etc. This paper demonstrates the kind of restlts obtained when stich analysis is used on four technologies producing transport fuels from wood.

THE TECHNOLOGIES

The technologies considered here are; 1) Gasification of wood in a Winkler or Westinghouse type fluld bed gasifier, followed by methanol synthesis by the ICI or Lurgi low pressure process. 2) Methanol production as in 1), followed by conversion to gasoline by the Mobil process. 3 ) Gasification followed by Fischer-Tropsch synthesis in a liquid phase reactor, and then upgrading to transport fuels. 4) Direct liquefaction of wood by the PERC process. Capital costs and efficiencies are given in table I. The technologies are reviewed in detail in ref. (1), except Fischer-Tropsch synthesis which is reviewed in ref. (6). TABLE I: Investment and Product Yields for Reference Technologies *1000 dry tonnes wood/day Methanol synthesis is the best established process, and although as a whole it is not in comnercial use, gasification and methanol synthesis are practised at a commercial level. The literature is extensive, and only three references https://www.w3.org/1998/Math/MathML"> ( 1 - 3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are given here. There is broad agreement about capital costs; the figure of https://www.w3.org/1998/Math/MathML"> $ 125   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (1984 US$) used here is representative of values obtained after extensive use of the Chemical Engineering Plant Cost Index, and scaling plant size to 1000 t/d, (Ref. 4 shows that investment is related to output Q by https://www.w3.org/1998/Math/MathML"> I = I 0 Q 0 . 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) The Methanol-to-Gasoline process is less well established, and not yet comnercially proven. Capital costs are estimated (1) at around I7% on top of methanol synthesis costs. The efficiency of the MrG process is high, and heat recovery allows the loss of thermal efficiency in the overall process to be as low as https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (5). The cost and efficiency used here are representatiye of values from the literature. Fischer-Tropsch synthesis has been considered less for wood because of high capital cost and low efficiency. However the process is commercially established for the conversion of coal in south Africa. The presence of. deisel fuel in the product may be an advantage in some countries. There are several versions of the process, which catalytically converts synthesis gas to hydrocarbons. The version used here is the liquid phase process. This has severaI advantages over the Synthol and Arge processes used in South Africa, including a low H. Co reaulirement in the synthesis gas, lower capital cost and higher selectivity in the product. The data used here is based on ref. (6) and data for wood gasification on ref. (1). Refining of the product is about https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the cost, although this might be reduced by refining the product from several plants at a central refinery. The PERC process is at a very early stage of development, and costs and yields are correspondingly uncertain. Although the figures used here from ref. (1) imply excellent yields and low cost compared with other processes, there are several technical difficulties which may be costly to overcome. The process, like coal liquefaction, involves slurrying wood in recycled oil, which acts as a solvent while the wood is reduced at high co pressure. The product is high in oxygenates and low in hydrogen, and upgrading comprises https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of capital costs. The product is diesel or jet fuel, which would be preferable to methanol or gasoline in many countries. Running costs for the processes vary between sources. Operation and maintenance charges are normally assumed to cost a percentage of plant investment per annum. Labour and feedstock costs are dependent on location and vary by an order of magnitude. The base values used here are given in table II. TABLE II: Assumptions for D.C.F. Calculations Construction period 3 years Plant life 20 years Discount rate https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Load factor https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Annual costs: Materials https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Investment Utilities https://www.w3.org/1998/Math/MathML"> 2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Investment Catalysts https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Investment Labour a https://www.w3.org/1998/Math/MathML"> $ 50 / s h i f t ; $ 0.79   m / a n n u m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Feedstock cost https://www.w3.org/1998/Math/MathML"> $ 25 / d r y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonne Q1.8.5 GJ/tonne

ECONOMICS

Table ITI gives the results of discounted cash flow calculations for projects using the four technologies. TABLE III: Breakdown of Product Cost: 1984$/GJ (%) Technology Methano1 synthesis Gasoline synthesis FischerTropsch PERC process Capita1 5.21 https://www.w3.org/1998/Math/MathML"> ( 50.5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 6.72 https://www.w3.org/1998/Math/MathML"> ( 52.5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7.61 https://www.w3.org/1998/Math/MathML"> ( 52.5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 5.00 https://www.w3.org/1998/Math/MathML"> ( 49.9 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> O & M 2.58 https://www.w3.org/1998/Math/MathML"> ( 25.0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3.34 https://www.w3.org/1998/Math/MathML"> ( 26.1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 3.78 https://www.w3.org/1998/Math/MathML"> ( 26.1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.48 https://www.w3.org/1998/Math/MathML"> ( 24.7 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Feedstock 2.28 https://www.w3.org/1998/Math/MathML"> ( 22.0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.45 https://www.w3.org/1998/Math/MathML"> ( 19.2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.78 https://www.w3.org/1998/Math/MathML"> ( 19.2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 2.29 https://www.w3.org/1998/Math/MathML"> ( 22.8 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Labour 0.26 https://www.w3.org/1998/Math/MathML"> ( 2.5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.29 https://www.w3.org/1998/Math/MathML"> ( 2.3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.33 https://www.w3.org/1998/Math/MathML"> ( 2.3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.26 https://www.w3.org/1998/Math/MathML"> ( 2.6 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Tota1 10.33 https://www.w3.org/1998/Math/MathML"> ( 100.0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 12.80 https://www.w3.org/1998/Math/MathML"> ( 100.1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 14.50 https://www.w3.org/1998/Math/MathML"> ( 100.1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 10.03 https://www.w3.org/1998/Math/MathML"> ( 100.0 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> It is seen that capital costs comprise about https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of product cost for each process. Capital related costs, including maintenance materials etc., comprise https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total. Feedstock cost is relatively unimportant and direct labour costs are very smal1. Product cost is determined mainly by the plant investment and process efficiency. Capital costs are highly uncertain, Ref. (1) estimates the range in the estimates for different technologies. For this reason sensitivity analyses are given for just one base case investment. Table IV shows the results of TABLE IV: Sensitivity of Product Cost Base case; Labour https://www.w3.org/1998/Math/MathML"> $ 0.79   m / y r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Base case cost https://www.w3.org/1998/Math/MathML"> $ 10.83 / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Discount rate https://www.w3.org/1998/Math/MathML"> 10 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Product https://www.w3.org/1998/Math/MathML"> 10 T J / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> day Feedstock https://www.w3.org/1998/Math/MathML"> $ 25 / t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Item varied Product cost https://www.w3.org/1998/Math/MathML"> $ / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Capital https://www.w3.org/1998/Math/MathML"> - 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> + 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9.2 to 14.9 Discount rate https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9.0 to 13.0 Feedstock https://www.w3.org/1998/Math/MathML"> - 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> + 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9.6 to 12.0 Labour https://www.w3.org/1998/Math/MathML"> $ 0.1   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> $ 4   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 10.6 to 12.0 Labour & feed https://www.w3.org/1998/Math/MathML"> $ 0.1   m & - 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9.4 Yield to https://www.w3.org/1998/Math/MathML"> $ 4   m & + 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to 13.2 Yield & capital 11 TJ https://www.w3.org/1998/Math/MathML"> / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dy https://www.w3.org/1998/Math/MathML"> & - 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 9.8 to 12.0 For comparison; cost of gasoline from oi1 is currently https://www.w3.org/1998/Math/MathML"> $ 5 / G J https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ed relative to diesel by different amounts in table V. Fischer-Tropsch synthesis becomes more attractive than the MTG process if the discount is more than https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , but both processes become increasingly unattractive. Methanol would become even less attractive than MTG because of the cost of engine modifications and changes in distribution infrastructure. Although the PERC process appears extremely attractive by comparison, the figures used for efficiency and cost were speculative, and rely on successful development of the process. TABLE V: Economic Influences on Cost 33. CONCLUSIONS While liquid fuels from wood are likely to cost twice as much as oil products in the forseeable future, the technologies may still be desirable in certain circumstances. Improvements in technology could make them viable in countries with foreign exchange problems able to build their own plant. Althotgh the PERC process appears the most desirable in this analysis it is not sufficiently developed, and the data is too uncertain, for the results to be meaningful. The results do show that successful commercialisation of the process would be beneficial. The overall effects of a project on the economy need to be taken into account in its assessment. This paper lliustrates the effect such consideration can have. A proper assessment requires extensive evaluation of these effects. 34. REFERENCES 1.) U.S. DOE. "Technical & Economic Evaluations of Biomass Utilization Processes; Technical Report no. I" Sept. 1980. DOE/ET/20605-T4. 2.) Wan E.I., Simmons J.A., Price J.D., "Rconomic Evaluation of Indirect Biomass Liquefaction Processes for Production of Methanol a Gasoline https://www.w3.org/1998/Math/MathML">   ' ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Biomass Liquefaction Processes for Production of Methanin Energy from Biomass & Wastes VI, Florida Jan. 1982. 3.) Brandon https://www.w3.org/1998/Math/MathML"> 0 . H . , K i n g G . H . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Kinsey https://www.w3.org/1998/Math/MathML"> D , V . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> "The Role of Thermochemical Processing in Biomass Exploitation" in Thermochemical Processing of Biocessing in Biomass Exploltation in Thermoch 4.) Reed T.B. "Biomass Gasification: Principles & Technology" ch. 13. SERI Golden, Colorado. 5.) Lurgi Express Information. "Gasoline Production from Natural Gas or Coal" presented at KTI Symposium, Nov. 1980 , Los Angeles. 6.) Holmes J.M., Hemming D.F., Teper M. "The Cost of Liquid Fuels from Coal Part II: Fischer-Tropsch Liquids" IEA Coal Research Nov. 1984 . 7.) Squire L., van der Tak H.G. "Economic Analysis of Projects" The World Bank 1975. CHEMICAL INVESTIGA TIONS IN THE SWEDISH AGROBIOENERGY PROJECT O. THEANDER Department of Chemistry and Molecular Biology Swedish University of Agricultural Sciences P.O. Box 7016, S-750 07 UPPSALA, Sweden Abstract https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The chemical characterization of a series of crops from the Swedish Agrobioenergy Project - including cereals, sugar beets, fodder beets, Jerusalem artichoke, Salix clones, lucerne and garden orach-and of botanical fractions such as grain and straw or residues after biogas production, is presented. The chemical composition and yield per hectare of individual chemical components within a type of crop show a large variation between varieties, cultivation site and time of harvesting. We have, for instance, found starch values in the grain of winter wheat varieties to vary between 63-73 % of dry matter. For ash, cellulose, hemicellulose and Klason lignin in straws from wheat, barley and oats the ranges are generally 3-11, 33-40,29-33 and https://www.w3.org/1998/Math/MathML"> 16 - 21 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , respectively. The yields of straw from these experimentally cultivated cereals have varied between 8.6 and 16.9 tonnes dry matter/ha. This indicates a great potential for increasing and controlling the yields of various chemical components in the future by plant breeding and suitable choice of variety and cultivation system. In connection with the project new improved methods have been developed for the analytical determination of sucrose (in beet crops), starch and the lignocellulose components in various plant materials. We have, for instance, found that the conventional automatic method for sucrose analysis of sugar beets, based on optical rotation, gives too high values when applied on fodder beets. 1. THE ANALYTICAL METHODOLOGY When we work with chemical characterization of plant materials in connection with animal and human foods or with crops or fractions from agriculture or forestry of interest as raw products for fuels or other technical products, we generally follow the fractionation - analysis scheme summarised in Fig. 1. For the extraction with aqueous ethanol or acetone and the organic solvents we have found that ultrasonic treatment (at https://www.w3.org/1998/Math/MathML"> < 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) is not only effective but also more convenient and harmless for some thermolabile components than the conventional refluxing (1). This treatment is done in a centrifuge tube, where the sample can be retained during the various extraction-, washings- and centrifugation steps. For removal or analysis of starch we have found that a combined gelatinization/starch hydrolysis with the heat-stable α-amylase Termamyl https://www.w3.org/1998/Math/MathML"> 120   L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Novo A/SJ) and amyloglucosidase ( https://www.w3.org/1998/Math/MathML"> E C 3.2 . 1 . ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Boehringer and Mannheim) - is very effective and reproducible https://www.w3.org/1998/Math/MathML"> ( 1,2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig. 1. Procedure for fractionation and analysis of plant materials. Gas-liquid chromatography on capillary columns (GC) is an excellent method for efficient separation and accurate determination after derivatization of, for instance, fatty-, resin- or phenolic acids, low-molecular sugars or the neutral polysaccharide constituent sugars released by hydrolysis. On the other hand, highpressure liquid chromatography (HPLC) offers an alternative convenient procedure, where derivatization generally is not necessary, with increasing improvements and applications. The decarboxylation method, which we use for determination of the uronic acid content of pectins and acid hemicelluloses, does not suffer from interference by other components as occurs in colorimetric methods and is very accurate and reproducible https://www.w3.org/1998/Math/MathML"> ( 1,3 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

THE CHEMICAL COMPOSITION OF DIFFERENT PLANT MATERIAL

Sucrose-, starch-, lignocellulose and protein sources Based on the analytical methods discussed above, Fig. 2 shows some examples from our chemical characterization of some typical plant materials rich in sucrose, starch, lignocellulose (fibre) or protein being studied in the Swedish Agrobioenergy Project (compare the paper by U. Wünsche). Sugar beets or fodder beets are the main sucrose crops in Sweden and for some years we have compared the sucrose production of a series of cultivars grown in different parts of the country (for an example, see Fig. 3). Although the main technical use or potential for sucrose is for production of ethanol and other fermentation products or chemical conversion products such as sugar alcohols, esters and ethers, the pulp residue with its high pectin content also has an interesting technical potential. Potatoes and cereal grains are the main Swedish sources of starch, with also lignocellulose and, in particularly in grains, protein as interesting fractions. Potatoes are already an important raw material in Sweden for production of industrial starch and starch derivatives and other products. For an increasing utilization of starch for such products, however, and in particular for ethanol production (in combination with various side-products), we consider the most interesting sources to be wheat and barley. Straw and the Salix clone from the Swedish Energy Forestry Project represent plant sources rich in lignocellulose with the three giants in the globally produced biomass, namely cellulose, hemicellulose and the phenolic polymer lignin as the predominating components. Besides the utilization of such materials for solid fuels, animal feed, paper, textiles and building materials, they have also a great future potential via various pretreatments, fractionation and hydrolysis processes now being intensively studied all over the world for production of ethanol and various chemicals and polymers. Lucerne, finally, represents a crop with a more even distribution of the three main fractions lignocellulose, protein and extractives (mainly low-molecular weight compounds, extractable with water and/or organic solvents). Other examples with several main fractions are rapeseed and other oil-seeds and the overground part of Jerusalem artichoke. 35. https://www.w3.org/1998/Math/MathML">   Studies on wheat   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Table 1 shows some examples of the yields of straw and grain from the Swedish trials with different high-yielding winter wheat varieties in different years and at different localities. Although these cereals were experimentally cultivated (with stubble height https://www.w3.org/1998/Math/MathML"> = 5   c m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) the results clearly indicate that the total yield of biomass can be quite impressive for several of the cultivars at a locality (near Uppsala) which can be considered as reasonably average for Sweden as a whole. Based on our chemical studies, the yields in Table 1 indicate that a future production under our conditions of about 5 tonnes/ha of both starch and cellulose, 4 tonnes of hemicellulose and 3 tonnes of lignin might be possible. The starch values in the grain of these winter varieties have varied between 63 and https://www.w3.org/1998/Math/MathML"> 73 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of dry matter. For straw from wheat, barley and oats we have generally found the ranges 3-11, 33-40, 29-33 and 16-21 % for ash, cellulose, hemicellulose and Klason lignin respectively (4). In the hemicellulose fraction xylose is the major component, considerable amounts of uronic acids, arabinose and acetyl groups are also present, and the sugar units mannose and galactose as well as two phenolic acids represent minor constituents. Table 1. Yields of harvested straw and kernels from different winter wheats; Ultuna, Sweden (given as dry matter tonnes/ha) Variety Straw Grain 1982 1983 1982 1983 Holme 15.1 10.8 6.3 5.7 Alcedo 8.6 11.2 5.7 5.9 Brigand 8.6 8.7 5.7 6.5 Ural 10.0 10.7 6.5 5.3 W W 28020 13.8 12.6 6.4 5.7 W W 28204 16.9 11.1 6.4 5.4 SvU 75630 15.3 12.0 6.8 5.1 Sv 76477 12.3 11.1 6.5 5.9 LP 468971 11.6 11.7 6.0 6.1 Folke https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 11.2 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 5.9 Studies on sugar-and fodder beets, Jerusalem artichoke, lucerne and garden orach Finally, I will present some glimpses from the chemical investigations on some other crops in the project. Fig. 3 shows the yields of sucrose per hectare from a series of beet crops cultivated near Uppsala (not a normal district for growing sugar-beets, which are normally cultivated in the south of Sweden). We have made a critical study of methods for analysis of sucrose in beet crops (5) and have found HPLC to be particularly specific and convenient. However, if the conventional automatic analysis based on optical rotation is used, as in the sugar industries, without taking into account the difference in dry weight between sugar beets and fodder sugar beets, the sucrose production of the latter will be strongly over-estimated (indicated in the figure). Suctose batsed on MPLC analysis and dry weight Additional sucrose if anatysed by automatic polarimetry Fig. 3. Production of sucrose from beet crops cultivated near Uppsala, Sweden. Fig. 4 illustrates our studies on biogas production from high biomass-yielding crops such as Jerusalem artichoke, lucerne or a more unconventional crop such as garden orach (6). It shows the chernical composition of the residues (calculated on the original material) after the anaerobic digestion in comparison with that of the fresh crop. Studies on ruminants indicate that these residues have a potential primarily as nitrogen supplements to diets low in nitrogen. 36. REFERENCES (1) THEANDER, O. and WESTERLUND, E., in "Handbook of Dietary Fiber in Human Nutrition" (ed. G. E. Spiller) CRC Press, Inc., in press. (2) SALOMONSSON, A.-C., THEANDER, O. and WESTERLUND, E. (1984). Swedish J. Agric. Res. 14, 11-117. (3) THEANDER, O, and AMAN, P. (1979). Swedish J. Agric. Res. 9, 97-106. (4) THEANDER, O. (1985), in "New Approaches to Research on Cereal Carbohydrates" (eds. R. D. Hill and L. Munck) Elsevier, Amsterdam, 217-230. (5) MALMBERG, A., MALMROS, O., THEANDER, O. and TJEBBES, J., Proc. Bioenergy, in press. (6) LINDBERG; J. E., MALMBERG, A. and THEANDER, O. Submitted to Animal Feed Science and Technology. ENERGETIC OPTIMIZATION OF BIOMASS IN THE FARMING SYSTEMS OF MARGINALISED AREAS - LABOUR AND CAPITAL RESTRICTTONS - ECONOMIC ANALYSIS J.P. CHASSANY Institut Natıonal de la Recherche Agronomique Economie et Soclologle Rurales - Montpellier (FRANCE) 37. Summary The economic survival of farmers in marginalised mountain reglons implies a diversiflcation of activities. Moreover the isolation means heavy fuel consumption. In order to reduce their energetic dependance and to optimize thefr surplus labour force a group of breeders from the southern French Alps produce blogas by methanisa- tion of manure to supply domestic needs and to supply fuel for their cars. Production of fuel requires a methane compression at 300 bars. Strict regulations force the promoters (CUMA des Sources - La Bâtie des Fonts, and IRCHA - CNRS Montpelifer) to remove completely SH2 and H20 from the gas. The tests show that methane fuel can be obtai- ned on the farm in absolute safety. On the other hand the use of too old dry and strawed manure results in mediocre production. The Working of the installation requires long workıng periods especially for the preparation and introduction of the organic substrates. The micro-economic calculation shows that payment for work is guaranteed provided that 50 in https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of gas is obtained per day and that a too high profltabllity of capltal is not given priority Finally this deve- lopment proved to be a soclal apprenticeship for the parties invol- ved which resulted in delays, overcosts and a fall in efficiency as far as the introduction into the system of initial activities is concerned. 38. THE CONTEXT The process of marginalisation in mountaln regions is familiar and thus needs no further introduction. In the Haut-Diols, this marginalisa- tion takes the form of a very noticeable trend in agricultural abandon and a serious population drain. The foreseeable increase in the cost of energy may yet worser the situation (1). Situated In the south of French Alps, in the Diols, which is the severest and most difficult region, the GAEC exploitations, which set up a methane fermentation system using sheep and goat manure, had to cope with various serious restrictions:

geographlcal environmental restrictions : altitude higher than 1,000 m, very difficult climate which makes the shelter of the flocks necessary

throughout the winter, a relatively overgrown terrain and low fodder productivity

restrictions linked to socio-economic problems: isolation, difficult access, problem of children's schooling, an active aged population which is dying out, difficult access both to property and to use of the land, foreseeable variation in the price of mutton following Great Britain's entry In the EEC, dlfficulties in marketing goats https://www.w3.org/1998/Math/MathML">   ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> cheese ;

restrictions linked to the exploitations themselves : problems of balancing the cultivated surfaces for the feeding of the flocks and the pasture surfaces in such a way as to limtt as much as posolble the intermediate consumption; problems of growth and modernisation of the explottations where the breeding howses in particular were no longer workable: the valorigation of labour whtoh has little to do during the winter; ; problems of controlling spontaneous woody vegetation in pasture areas.

All these restrictions are characteristic of the agricultural production systems studled in disinherited mountain areas where ovine and caprine breeding dominate. A positive economic balance sheet can only be reached by guaranteelng a winter-time maxlmal self-supply of animal foodstuffs, which causes a late lambing in the spring and restricts the etaggering of productton throughout the vear. However the passage of Btabgering of productlon throughout the sear. However the passage of ted land and thus entails improvements which are expensive in energy and fertiliser. All this together with low production and uncertaintles linked to marketing, weaken the production system. In these conditions, the exploitations in these areas have to diversify their activities in order to lncrease their incomes and to allow a relative accumulatlon. Thus, in the beginning two breeding concerns ( 350 meat ovines and https://www.w3.org/1998/Math/MathML"> 70 m l l k https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and meat caprines) made up from the Common Agricultural Exploitation Group (GAEC) with a th1rd, came together to manage a group of lands distributed in the following way : Cultivable Terrain Woods Total Lands Pastures Moors 432 GAEC 1 23 70 225 39 GAEC 2 36 6 20 81 A1re d https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Anja1 6 30 20 25 572 Ha 65 Ha 100 Ha 265 Ha 142 Ha 572 https://www.w3.org/1998/Math/MathML"> 64 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the lands are in quasi owership, 46 % belng tenant farming ( 23 % written lease, https://www.w3.org/1998/Math/MathML"> 23 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> spoken lease). A sheep enclosure was bullt in 1981 and cheese dairy installed and this, together with the direct sale to Nice and Valence allowed a betcer valorisation of the goat milk production. A scheme to install modern goat enclosure was completed in 1984. A sawmill allows the valorisation of the vast wooded areas and supplies the wood needed. Thanks to the knowledge acquired, a construction SICA has been created and soon a scheme for a country at valence wf11 be completed, which willaliow the sale of farm produce. A part-time job is guaranteed at the GPO. Full time work for 9 manpower units is thus projected. The scheme for the lnstallation of a methanic fermentation unit was an extra element in the diversiffcation plan. Due to the foreseeable increase in fossile energy prices, it also aimed at reducing the energetic dependance of the exploitations by supplying the fuel necessary for different vehicles - tractors, lorries, cars; the breaking of https://www.w3.org/1998/Math/MathML"> 1 solation https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> belng a major problem in this area - and for the sawmill which currently uses electricity. Some of the gas produced https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> also used for dowestic needs as well as for the cheese dalry. Finaliv, the compost from the methanic fermentation makes an excellent nonpathogenic fertiliser: logically this should cause doubts about manuring policy in these exploftations (cultivated and non-cultivated lands) and be taken tnto account for the final balance sheet. It thus can be seen that the project is being introduced into a complex and diversifled system, which brings a regular supply of biomass to the fermenters, a relatively continuous use of the energy produced by

THE MAIN LESSONS

production, perfect purification of the biomass and its compression are

Biomass as an energy source in the French context, promises and constraints THE ECONOMIC DILEMMA OF BIOMASS IN TWO GRAPHS J.C. SOURIE National Institute for Agronomic Research Rural Economics and Sociology Station 78850-GRIGNON FRANCE 39. Summary The various economic and social obstacles to the energy valorisation of biomass were analysed in a recent article [1]. One of these, which appears essential to us today, will be developed here. It is a matter of understanding why the economic surplus disappears as soon as the energy valorisation of biomass is removed from the subterranean economy field and placed in that of trading economy. This disappearance of the surplus stems both from an amplification of costs due to collection, and from a reduction in the utilisation value of the biomass on an enlarged scale.

OBSERVATION : IN FRANCE, SUBSISTANCE FARMING TODAY IS STILL THE MAIN MEANS BY WHICH BIOMASSES ARE VALORISED.

In 1973 , about 2 Mtoe of wood were used on farms for heating. In 1985, approximately 10 years after the first oil crisis, 4 Mtep of dry by-products were used by farmers and by wood transformation industrialists. In spite of the considerable increase in the price of oil since 1973, subsistance farming of dry by-products is still the main means by which biomasses are valorised, whilst trading valorisation is having difficulties in developing. What are the reasons for this? This is what we are going to try to explain by economic considerations.

SUBSISTANCE FARMING AS A CREATOR OF ECONOMIC SURPLUS (Graph I).

Biomass does not set the lead price of energy. If it is to develop, it has to be cheaper than its competitors and, above all, cheaper than coal. This leads to a utilisation value. The latter depends on the price of the fossil vectors which are replaced and on the costs involved by the transformation of the biomass into final energy. The biomass demand curve [D] is the result of the utilisation values. If the cost of the biomass is in zone A, the fossile vectors are more economical and will meet energy demands at a lesser cost. If it is in zone B, the situation is reversed. Curve [0] is the supply curve in a situation of subsistance farming. It is obtained from the individual supply curves which are in turn based on the marginal cost of the resource. In this situation, the cost is generally low. Indeed, on the one hand the cost of transporting and packing the biomass is frequently small and, on the other hand, the route will very frequently operate using fixed production factors at a zero opportunity cost. In this way, the recovery of the biomass will often make it possible to valorise permanent and underemployed manpower and equipment at certain times of the year. Under such conditions, with the utilisation value frequently greater than the cost, a surplus (which is represented by the area between curves [0] and [D]) is obtained by the producers, who are also the utilisers. Requillart [2] has estimated this surplus for the combustion of cereal straw. 40. TRADING EXCHANGES AND DISAPPEARANCE OF THE SURPLUS With subsistance farming, only a small quantity of resources can be used under suitable economic conditions. Energy self-sufficiency, or the valorisation of all a producers resources, is not necessarily justifiable irom an economic point of view, This means that, if the resource is to be exploited more completely, a market must be set up between the producers and the utilisers. In this case, however, the surplus disappears because of the coming into play of two phenomena which reinforce it a amplification of the costs of the biomass leads to an upward movement of the supply curve; reduction of the utilisation values is expressed by a downward movement of the demand curve. How to explain this scissor effect which causes the surplus to disappear? Insofar as concerns the supply, transport and packing costs lead to a first cost increase but, contrary to what is commonly assumed, these are not the only factors which do so. Two other mechanisms influence the increase. In the first place, the producer's behaviour will change. Io start with, he will want to obtain remuneration from all the production factors employed, including the available fixed factors which had not previously been monetarised on account of their availability. After this, the decision to sell assumes that the individual stakes will be too small on account of the risks undergone and the organisational stringencies. Since each producer owns a small quantity of the resource because of the parcelling of the production structures, a sufficiently attractive price must be proposed by the purchaser to incite the producer to make the exchange. This phenomenon has been measured by Cochin [3]. Secondly, costs will also be increased by rents. The purchaser, faced with a multitude of different bidders, will have to line up his purchase price on the proposal made by the last bidder necessary to attain the quantity required. This last bidder, qualified as marginal, sets the price which is imposed on all. Under such conditions, differential rents will fall to the best-placed bidders. The utilisation value will diminish simultaneously to this. Several phenomena are at the basis of this reduction : on an enlarged scale, biomass undergoes very heavy competition from fossil vectors which are even cheaper (natural gas, heavy fuel and coal). Also, a legitimate desire for reliable supply will lead any biomass utiliser to equip himself with a bi-energy system. This slows down the scale effects. Finally, the rate of return of the capital will be that of industry which, on average, is greater than that of agriculture. 41. CONCLUSIONS For the reasons set out, the valorisation of biomass is limited to the field of subterranean economy, and it almost exclusively concerns dry by-products. as for the exploiting of energy cultures, this makes all the surplus disappear on account of the production costs and the competition for allocating the land. The economic constraint described is of a durable nature because, fundamentally, it stems from the atomisation of the production structures, structures which develop extremely slowly, as we know. This is one of the essential reasons why the growth in the production of energy from biomass will remain so slow. In [1] additional production of 2 Mtoe is anticipated for the nineties. This is the dilemma which must be solved if biomass is to become an energy in its own right. State aid cannot suffice today. Increased productivity on the one hand and the increase in the price of oil, inevitable at long-term, on the other, should make it possible within a time which is difficult to predict, for trading exchanges of biomass to emerge, no doubt in connection with a synergy between food and industrial valorisations organised around various industrial poles. The organisation of short trading circuits, especially with one finality only, does not appear today to meet the demands of the industrial valorisation of biomass, which are competitivity and security. 1. REFERENCES [1] SOURIE, J.C., and JAYET, P.A. - Les valorisations énergétiques des biomasses. Difficultés et promesses. Revue de l'ENERGIE, Oct. 1984, https://www.w3.org/1998/Math/MathML"> n ∘ 367 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Paris, pp.643-652 [2] REQUILLART, V. - Valorisation énergétique des pailles de céréales. PYC Edition, 1984, Paris, 157 p. [3] COCHIN, B. - Un modèle économique de filières de récupération des pailles. INRA Economie Rurale, GRIGNON, 10p. 1977. FUEL ETHANOL IN BRAZIL AND THE IMPLICATIONS FOR CONTROL OF LEAD ADDITIVES IN THE EEC COUNTRIES F, Rosillo-Calle Technoloy Policy Unit University of Aston, Gosta Green, Birmingham, UK Summary Nearly 30 countries, industrialized and developing ones, have or are planning alcohol fuel programmes. This world-wide attention stems planning alcohol fuel programmes. This world-wide attention stems from oil price increases in the 1970s, foreign exchange considerations, boosting properties of alcohols, the fact that it can be produced locally, and the minimum adjustment requirements of many engines now designed to run on petroleum fuels. In the U.S. alcohol blends now contribute between https://www.w3.org/1998/Math/MathML"> 4.5 % - 5.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the US gasoline market. But it is Brazil who has the world's largest alcohol fuels programme aimed at substituting fossil fuels. From 1975-1984 Brazil has produced https://www.w3.org/1998/Math/MathML"> 39.1 × 10 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> litres of alcohol, mostly for fuels (fig.I). About 1.8 million vehicles are alcohol-fuelled; the rest, circa https://www.w3.org/1998/Math/MathML"> 8   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ., run on https://www.w3.org/1998/Math/MathML"> 20 - 3 / 80 - 77 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol/gasoline blends. In https://www.w3.org/1998/Math/MathML"> 1984 c . 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of all vehicle sales were powered by alcohol (fig.II). It is possible that 11-14 million cars will be fuelled by alcghol by the year 2000; consumption estimates put it at https://www.w3.org/1998/Math/MathML"> 28 - 60 × 10 9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> litres if alcohol was to replace diesel oil in Brazil. The growing demand for unleaded gasoline has further highlighted interest in alcohol fuels. The ProAlcool has enabled Brazil to accumulate much experience and technological know-how in alcohol fuel technology. This paper will examine the utilization of alcohol in cars and heavy vehicles, alternatives to diesel oil under study, the properties of ethanol as booster, emissions control and its relevance to Western Europe (WE). 2. Innovations During the first years of the ProAlcool preference was given to the passenger car which has reached already a maturity stage. A more recent development has been the utilization of ethanol in trucks and tractors which represents a new phase of ProAlcool (fig.III). By 1987 the sugar and alcohol industries would be using exclusively ethanol fuelled equipment with special allowances for reduced quantities of diesel oil and dual-fuelled engines. There are already various engine systems ready to enter this market. (A) Otto-cycle, alcohol engines which includes: (i) original petrol engine design; (ii) original diesel engine design; (iii) specifically designed engines for alcohol. (B) Diesel-cycle alcohol engines, this includes: (i) additives + alcohol; (ii) pilot-ignition. As for tractors, the world's first commercial alcohol-powered tractor - the CBT-3000, was launched in May 1980 and today all major manufacturers have alcohol models. Almost https://www.w3.org/1998/Math/MathML"> 55 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Valimet sales and https://www.w3.org/1998/Math/MathML"> 36 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of Massey Ferqusson's in early 1984 were alcohol models. In just a few years Brazil has been able to transfer 60 years of experience with the gasoline engine on to the alcohol engine, though experiments with the alcohol car go back to the 1920s. Four major features can be distinguished in the history of the modern alcohol-fuelled vehicle. (A) From 1975-1979 it consisted mostly of an experimental fleet and major R & D efforts. (B) 1979-80 when government and industry signed the first agreement for mass production of alcohol cars; significant fuel improvements were achieved. (C) The 1981-82 period sees the rapid expansion of sales. (D) 1983 onwards, consolidations of the aicohol vehicles, commercially and technically. Though the first model consisted basically of minor modifications, it is a new mechanical concept with 300 engine parts, different to the conventional gasoline engine. The Otto-cycle alcohol engine has a thermal efficiency of https://www.w3.org/1998/Math/MathML"> 36 % - 38 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> against https://www.w3.org/1998/Math/MathML"> 27 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the equivalent gasoline https://www.w3.org/1998/Math/MathML"> ( 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in Brazil) and could be further improved to c. https://www.w3.org/1998/Math/MathML"> 42 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , that will more than compensate for the lower calorific value of ethanol. Although many innovations need to be incorporated, particularly microelectronics, most technical problems caused by the atcohols have been solved. The most serious problem concerns diesel fuel substitutes, for which a diversified policy is being pursued. 3. ProOleo This programme commenced in 1979 with the aim of finding a solution to Brazil's diesel problem. The results have not been entirely satisfactory for economic and political reasons rather than technical ones. Firstly there have been conflicting priorities and objectives between Federal Government and the heavy vehicle manufacturers. Government demanded that the diesel-cycle engine should be manufacturers. Covernment demanded that the diesel-cycle engine should bel more suitable to existing engines should be found because of the high investment required for engine modification. A compromise between these two views seems to be emerging. Secondly the large amount of vegetable oil required, in addition to the high demand for cooking oil and the high price in the international market, makes this option politically unattractive. Hence a number of alternatives are being pursued: (a) changing the refining cracking system so as to produce the maximum possible amount of diesel oil from a barrel of petrol; (b) use of ethanol as diesel oil possible amount of diesel oil from a barrel of petroly (b) use of ethanel as diesel ethanol; (ii) dual-injection motor - this involves the use of a small amount of diesel to ignite combustion by adding a second ignition pump; this can replace https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of to ignite combustion by adding a second ignition pump; this can replace efficiency has been achieved; (iv) substitution of the Diesel-cycle by the Otto-cycle engine. This option is being promoted by the sugar-alcohol industry; https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (c) use of engine. This option is being promoted ty the sugar-alcohol industry https://www.w3.org/1998/Math/MathML"> ( https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ch https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> use of additives either to ethanol or diesel; (e) diesel + methane in https://www.w3.org/1998/Math/MathML"> 60 % - 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blendings, additives either to ethanol or diesel; (e) diesel + methane in https://www.w3.org/1998/Math/MathML"> 60 % - 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> blendings, under investigation including methanol. (ff) development of a new engine or modifying significantly the diesel-cycle engine. important options, veqetable oils and additives. 4. Vegetable Oils Despite all the difficulties this option remains one of the most promising. The alternatives investigated include: (a) direct use of vetable oil. This includes (i)utilization of https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vegetable oil; (ii) vegetaole oil + diesel; (iii) vegetable oil + which includes (i) oil catalistic cracking; (ii) thermal cracking (fig.IV) 5. Additives This is becoming increasingly important in many countries like the United States and Western Europe due to requlatory steps to reduce the use of organic lead compounds in gasoline. Important replacement candidates for tetraethyl lead and tetramethyl lead are ethanol, methanol, methyl butyl ether (MTBE) among others. In Brazil many tests have been carried out to establish the validity of ethanol as an octane enhancer and gasoline extender (fig.V). These findings demonstrate: (i) a lower fuel consumption due to an increase in engine efficiency; (ii) lower cost in the refinery process which use less refined oil; (iii) non-use of tetraethyl lead as an octane booster. A https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol blend increases the MON to a minirnum of 80.3-84.3, depending on the composition of basic gasoline. The use of unleaded gasoline in Western Europe by 1987 will demand significant changes in fuel, engine, refining process, etc. A complete changeover to 95 RON unleaded gasoline will require additional investment of https://www.w3.org/1998/Math/MathML"> $ 2.7 b n . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Unleaded gasoline will add https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> extra cost and https://www.w3.org/1998/Math/MathML"> 5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fuet increase - due to exhaust emissions control - to a typical motorist, and diesel fuel quality will deteriorate with cetane number dropping 3-5 points by https://www.w3.org/1998/Math/MathML"> 1995 . 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Most of these problems could be partly avoided if an ethanol blend is used in Western Europe. Brazil's experience demonstrates the advantages of using ethanol as an octane booster and for emissions control. Other important additives include the tetrahydrofurfuryl nitrate (THFN) and tri-ethylene glycol dinitrate (TEGDN) which can be obtained from renewable raw materials. The THFN is produced from furfuryl obtained from sugar cane bagasse, but can be obtained from straw, cotton seed, corn cobs, industrial fibrous waste, etc. The TEGDN is produced from ethanol via ethane and subsequent nitration by conventional means. Both are excellent boosters, particularly with diesel oil blends. 6. Emissions Numerous studies have confirmed the effectiveness of ethanol in reducing ernissions, particularly in U.S. and Brazil. Fig.VI shows the main findings by CETESB, in Sao Paulo, after eight years of research. It is particularly positive with https://www.w3.org/1998/Math/MathML"> C O , H C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> C O x https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> emissions, the main pollutants associated with vehicles. Aldehydes emissions are much higher, but it is less serious. Other data with regard to https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> alcohol cars shows a https://www.w3.org/1998/Math/MathML"> 66 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lower https://www.w3.org/1998/Math/MathML"> C O , 25 % - 79 % H C ; 11 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in NOx when compared with gasoline, 6 while experiments in Fard Brazil 1980 models https://www.w3.org/1998/Math/MathML"> 20 % / 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol gasoline blends, shows a https://www.w3.org/1998/Math/MathML"> 57 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> reduction in https://www.w3.org/1998/Math/MathML"> C O , 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in HC and https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> increase in https://www.w3.org/1998/Math/MathML"> N O x . 7 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7. Economics There exist two main and simple ways of exploiting the properties of ethanol (i) by producing low octane gasoline; (ii) by increasing the octane value of all motor fuels so that compression ratios can be increased. Though there exists uncertainty in the amount of premium fuel that can be saved at the refinery by using ethanol as a boosting additive, estimates range from zero to https://www.w3.org/1998/Math/MathML"> 60,000 B T U / g a l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of ethanol used, depending on the gasoline pool, the octane boost achieved from ethanol etc. The OTA estimates on energy saving of https://www.w3.org/1998/Math/MathML"> 0.4 g a l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . of gasoline equivalent for each gallon of ethanol used, based on an average of a good octane requirement of https://www.w3.org/1998/Math/MathML"> 91.8 8 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 8. Conclusion Brazil's experience demonstrates the validity of ethanol as octane booster and for lowering emissions. The EEC will need large investment to change over to unleaded gasoline. italy is already considering the ethanol option. Brazilian know-how and experience could easily be transferred since major European companies are involved. Hence the utilization of ethanol gasoline blend in the EEC should be recommended because (i) its effectiveness as octane booster and less environmentally hurtful fuel, has been largely demonstrated; (ii) a proportion of ethanol can be obtained within the EEC, particularly from agricultural surpluses. Eliminating sugar beet surpluses will also assist Third World sugar cane producing countries whose markets for sugar have been eroded by heavily subsidised EEC exports: (iii) large energy savings in the refining orocess are possible. Buying unleaded gasoline is not only more expensive, but would further increase external vulnerability; (iv) ethanol cost can be greatly reduced, production costs in the US are much higher than in Brazil; (v) Brazil has an enormous potential for ethanol production and already is looking for alternative markets for its large surpluses. 9. References

Bindell, H.W. (1984) Implementation experiences with MWM PID Diesel Engines burning Alcohol as Main Fuel; Proceed. IV Intern.Sympos. of Alcohol Fuels Technology, Canada May 21-25: 56-62.

Ventura, M. et ai (1982). First Results with M.Benz DI Diesel Engines Running on Monoesters of Vegetable Oils; Int.Conf. on Plant and Veg. oils as fuels, Fargo, N.Dakota. US.

Mercedes Benz do Brasil.

Anon. EEC Lead ruling a boost for oxyginated uses, European Chem.News, 73(1145)20 Sept.1984. Road Transport Fuels in W.E., Chemical Systems International Report.

O Estado de Sao Paulo, 15 Sept, https://www.w3.org/1998/Math/MathML"> 1984 p . 70 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

ACT. Conselho Nacional do Petroleo (C.N.P.)Feb/1984.

Celestino Rodriques, E. (1983), Solucao Energetica, Editoras Unidas, S.Paulo. https://www.w3.org/1998/Math/MathML"> 215 f f https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 8. OTA (1980) Energy From Biological Processes, Vol.II, Technical and Environ, Analysis: 204-207.

Hall, D (1984) Photosynthesis for Energy. Advances in Photosynthesis, Vol.II, Martins and Junk Publishers, The Hague.

10. RESIDUE BRIQUETTING IN DEVELOPING COUNTRIES S.Joseph and D.Hislop, Intermediate Techriology Deveiopment Group 11. St KHMARY Briquetting projects in developing cotntries have largely failed. Equipment is aften large scale. expensive. energy intensive and difficult to maintain and rapair. Planners rarely match the briquettes produced to user needs, Cr consider the need for stove modifications, or for marketing or distribution requirements. The paper indicates a yytematic approach to briquetting projects. and outiines recent developments in raw material treatment. These ciramatically reduce energy requirements for briquetting and widen technology choice, especially in small scale briquetting 12. BACKGROUND The experience of briquetting in developing countries is not encour agings especialiy et the smail scales with would allow the use of de-centralised sources of residues and create employment in rural areas. The few viable plants tend to be medium to large scaies using residues from agricultural processing plants to which they are 1inked. Therm are several reasons for this. First, briquetting equipment is usually designed in and for developed Cotntries. It uses high pressures, and production is often affected by the lack of technical skills, spares (especially af dies), and the lack or high cost of diesel or electric power. Second, Supplies of residues are often thnreliable because of fluctuations in crop production, other uses of residues closer to their source, and transport problems. Third, although the briquettes may be Suitable for industrial use, in domestic stoves they are often inconvenient, inefficient, br give off unpleasant simoke and funes: user aceeptance in a number of well-documented cazes has been minimal. Careful study of user requirements and Pe-design af stoves can overcome these problems, but this is often a major undertakingy and one rarely acknowledged by those propasing or undertaking briquetting projects.

EXAMPLES OF BRIQUETTE PROJECTS.

An example of a briquetting project which failed to take into account some of these issues comes from the Gambia. In 1980 the manttacture of chareoal was banned, and a iquetting plant was installed at a targe groundnut shelling plant near Successfully, but they were accepted neither by the existing fuel marketing and distribution systems nor by consumers. Retailers did not have adequate storage space and had to travel to obtain supplies: existing charcoal stoves would not burn the briquettes efficientlys and produced an acrid smoke 13. THE NEED FOF NEW APPROACHES TO BRIQUETTINE.

EXISTING TECHNOLOGY CHOICES FOR BRIQUETTING.

WIDENING THE TECHNICAL OPTIONS AT THE SMALL SCALE.

technologiess ITDG has investigated inore efficient and lower cost methods of briquettino, especially an the small seale. The work of the Shell Research Certre in Amsterdam and of Reed (3), Suggested that grinding or pre-heating the raw material might reduce the power required for briquettina. alow higher quality briquettes for a given energy input, lower wear on dies, or a combination of these. The principle is that as partitulate ligneous biomass materials are heated at about 220C thermal decomposition begins. Initially, water arid CO2 are given off, and then the volatiles. As this happens the fibres beain to saften the energy required for a qiven dagrae of compaction is greatly recluced, and the volatiles act as a binder Reed (3) Stiggested that briquettes with a density of 1-1.1 tonnelcu. metre and shelf lives of at least one manth could be produced from ligneous materials preheated to certain temperatures for certain periods of time at pressures of https://www.w3.org/1998/Math/MathML"> 15 - J 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MPa, with energy inputs of less that io kwh/tonne. AN BCONOMIC PROCESS FOR THE PRODUCTION OF A DIESEL FUEL SUBSTITUTE FROM EDIBLE OIL FRACLLONS H.P. Kreulen, H.C.A. van Beek, E. van der Drift, G. Spruijt Summary This paper is a presentation of a study to investigate the reaction variables of the transesterification of high melting palm oil fractions with ethanol and to determine the economic viability of the production of mono-esters as a diesel fuel replacement in developing countries.

INTRODUCTION

mhe regearch into the performance of vegetable oil esters as alternative diesel fuels has made considerable progress in recent years. The reports given at the International Conference on Plant and Vegetable oils as Fuels in Fargo. August 1982 (1), 73 th AOCS Annual Meeting in Toronto, May 1982 (2) and https://www.w3.org/1998/Math/MathML"> 74 th https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> AOCS Annual Meeting in Chicago. May 1983 (3) show promising results as demonstrated in various types of diesel engines. A main limiting factor for further development is the high price of vegetable oils related to petroleurn products. Tropical countries, where the oil palm is grown have the advantage of the highest yielding oil producer. Harvests of 4.500 kgs/ha annualıy are common. The worla market price for palm oil. which is one of the less expensive oils, is about uss 550 per ton; about twice the import price of diesel fuel. Furthermore vegetable oils are primarily considered as a food product in these countries. It is possible however to separate palm oil by selective fractionation into a liguid edible oil and a solid product With a melting point of https://www.w3.org/1998/Math/MathML"> 56 ∘ C r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which is unsuitable for human consumption. Ethylesters were made from the low value fraction and alcohol produced Erom sugar cane molasses. Cost price calculations inaicate that the diesel fuel substitute can be produced for approximately us$ 210 per ton. The authors are. https://www.w3.org/1998/Math/MathML"> 8 . P https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Krevlen, Senior consultant. HVA-International BV. Amsterdam, The Netherlands. H.C.A. van Beek. Professor. E. van der Drift en G. Spruyt graduate students, Laboratory of Chemical Technology. University of Technology, Delft, The Netherlands. 14. THE PROCESS 15. 1 Recovery of the High Melting palm oil Fraction In the majority of the tropical countries where palm oil is produced, the oll is separated into a liquid and a Solid fraction by a single fractionation process. (4) The 1 IUUIda Lraction with a melting point of https://www.w3.org/1998/Math/MathML"> 21 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has a Yield of approx imately 60 per cent. This yield can be improved to a level of 70-75 per cent by double fractionation. In this process palm oil is cooled to a temperature of https://www.w3.org/1998/Math/MathML"> 20 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C. where after the solid fraction is separated by filtration from the liguid oil. The solid fraction is, after heating, cooled to https://www.w3.org/1998/Math/MathML"> 38 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The solid part with a melting point of https://www.w3.org/1998/Math/MathML"> 56 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is separated by Eiltration from the liguid part, which is recycled to the entering palm oil for fractionation at https://www.w3.org/1998/Math/MathML"> 20 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Diagram 1 shows the material balance of the double fractionation process. 16. pecycle 15 tons Diagram 1 Process for double fractionation The solid fraction, separated at https://www.w3.org/1998/Math/MathML"> 38 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> representing 25 - 30 per cent of the palm oil, contains 70 per cent palimitic and stearic glycerides The fat is unsuitable for human consumption by reason of the melting point of https://www.w3.org/1998/Math/MathML"> 56 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> It can therefore be considered as a by-product, that only can be exported to industrialized countries at a low price. The fat is suitable for the production of monoesters. Ethanol is a common proauct in tropical countries, produced from the by-product molasses of cane sugar factories. Mhe production of absolute alcohol as a substitute for gasoline in automobiles is included in the energy programs of many developing countries. It is worthwhile to investigate the dehydration step to absolute alcohol with a hygroscopic solution of potassiumcarbonate in glycerol, described by Mariller. 17. 2.2 Ethanol Table 1. Conversion rates and properties of palm oil KOH gram conversion o specific gravity g.inl. https://www.w3.org/1998/Math/MathML"> - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> kinematic viscosity cSt https://www.w3.org/1998/Math/MathML"> 40 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> refractive index 0.10 80 0.864 4.4 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.25 82 0.852 4.6 https://www.w3.org/1998/Math/MathML"> - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.50 84 0.847 4.5 1.4439 1.00 94 0.856 4.6 1.4447 Literature 80-99 0.870 4.4 1.4552-1.4530 18. DISCUSSION From the results obtained it can be concluded that conversion of high melting palm oil fractions into ethylesters by transesterification in ethanol using Kof as a catalyst proceeds rapidly at https://www.w3.org/1998/Math/MathML"> 80 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and results in a high yield. The fact that this yield increases with increasing catalyst concentration must be ascribed to the fact that part of the catalyst is inactivated during the process. This inactivation is probably due to the presence of small amounts of water which causes hydrolysis of the esters and results in the formation of fatty acids. The latter can react with the catalyst to form the corresponding inactive potassium salts. This implicates that the highest yield found can also be obtained with the lower concentration of catalyst if more rigourous exclusion of water is applied. High conversions are of importance for economic reasons but also because the product then has a low residual fatty acid triglyceride concentration The high reaction rates obtained even with the lowest catalyst concentration indicates that the process can be very effective and is probably also suitable for continuous operation The ethylesters obtained were found to possess similar Specific gravity, viscosity and refractive index as the corresponding esters produced from other vegetable oils. The conclusion can therefore be arawn that those esters can also be suitable for substitute diesel fuels.

ECONOMY

In Table 2 the estimated costs for the processing of 6,000 tons of diesel oil substitute per year are detailed. The revenue for the by-product glycerol is not included in the calculations. THERMOCHEM ICAL PROCESSING OF LIGNOCELLULOSIC RESIDUES: ALTERNATIVES IN THAILAND D.L. PYLE & C.A. ZAROR Department of Chemical Engineering, Imperial College, London SW7 2BY ABSTRACT The feasibility of using solid residues depends critically on local conditions. This work examines residue avallability in Thailand - based on field work studies - and then compares options for thermochemical processing on the basis of economic and non-economic Indicators. The methodology and the detailed results should be of interest to other applications. I) INTRODUCTION Enormots amounts of solid residues are generated yearly 1 n many Third World countries. They are often inadequately utilised although potential products may be in demand. The current economic climate and the need to develop local industry make it urgent to seek efficient uses for such resources. However, the question of residue utilisation Involves technical, economic, social, and political issues, and complete assessment of alternative uses is lengthy and costly. We outline here a methodology for preilminary selection. The discussion of the method is 111ustrated by evaluating alternative uses (for energy) of residues in Thailand. II)PRELIMINARY ASSESSMENT OF RESIDUE USE: LIGNOCELLULOSICS IN THAILAND Figure 1 outlines a method for selecting the most attractive options for development or investment. The flrst stages are concerned with generating a set of technologies which are technically and economically feasible. Decisions must reflect the uncertainties ln the procedure; options are only rejected if clearly unfeasible. The final stage is to produce a qualitative decision matrix on which the attributes of the technologies are displayed on a simple ordinal scale. The procedure is discussed very briefly here, together with the stimiary results of our study on resource use in Thailand. a) Assessment of resources: A complete survey of resource avallability needs extensive fieldwork: for preliminary assessment, production statistics supplemented by selected visits should suffice. The exclusion of non-commercial production from statistics is often a source of error: estimates of residues available will be very approximate. Agriculture accounts for about a quarter of Thailand's GNP and occuples more than three quarters of its population. considerable solid residues are generated at harvest and industrial processing. Table 1 shows estimates of some principal cellulosic residues and their energy content. The net availability of residues depends on current use: dataespecially on non-commercial use - is often very poor. It is however necessary for estimating net availability and opportunity costs; the latter is discussed in more detail below. particular technology ( https://www.w3.org/1998/Math/MathML"> K ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) (obtained from literature or by short cut estimation), For https://www.w3.org/1998/Math/MathML"> R = K / K ' > 1 + h e o p t i o ni   s p r o m j a i n g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for the option is unattractive. Intermediate values indicate that further study might be justified. Finer ranking will depend on the accuracy of estimates the sengitivity of the net revenue to coets ahould always be inspected; this is quantified as the percentage change In breakeven capital investment per unit variation in input and output. When markets exist appropriate prices can be used, accounting for taxes or subsidies. Where commodities are not marketed, opportunity costs can be estimated given alternative uses and competing products. Estlmation of the value of erop residues is controveratal (Lockereta (1981)). Two sets of costs are involved: those in collecting and delivering the residues: and their opportunity costs. The procedure can be adapted to include social costs and benefits. The availabllity and cost of the residues are crucial in the studies here. Some are conveniently avallable and underused; many however, are dispersed and their uses (and opportunity costs) unknown. In practice, estimating opportunity costs is a major problem due to the uneven patterns of use, and the lack of data on the effects of farm size and location. For simplicity we take two values for the opportunity cost: a) zero, b) 500 Baht/tonne dry matter (around half the average price of fuelwood) https://www.w3.org/1998/Math/MathML"> ( 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Baht https://www.w3.org/1998/Math/MathML"> = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> USSO.043). e) Assessment of environmental impact. Amongst the issuesto be analysed ire: the current environmental benefits / costs of residues and wastes and thelr treatment; environmental effects of the new technology and products (eg. new sources of pollution) These must be studied fin the https://www.w3.org/1998/Math/MathML"> 11 ght https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> legislation, existing abatement procedures etc. The complete study (Pyle & Zaror https://www.w3.org/1998/Math/MathML"> ( 1984 ) ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> d1scusses these issues in detail. They are generally more relevant to the disposal of liquid wastes. III) Assessment and Conclusions. A complete report is beyond the scope of this paper. Here we report only part of a wide-ranging study (Pyle and Zaror (1984)): the assessment procedure concentrates mainly on economic viability. Table 3 summarises the results. In all cases, feasibllity improves with larger scales. Charcoal production is very sensitive to the opportunity cost of the raw material: it is non-feasible for non-zero https://www.w3.org/1998/Math/MathML">   O p p o r t u n i t y   c o s t   o f   t h e   r a w   w a t e r i a l i   i t   i s   n o m - f e a s i b l e   f i o r   n o n v e r t https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with recovery of saleable liquids, and, more so, when https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the charcoal is turned into activated carbon. Activated carbon production alone (case 4) ls the least sensitive to the residue cost and performs well under the conditions reported here. The degree of complexity of the technologies considered differs considerably. Charcoal is produced using fairly simple and Inexpensive technologies. Case 2 implies the condensation of troublesome llquids: the technology is more sophisticated and capital intensive, but experience in Brasil shows that relatively inexpensive and simple designs can be used. This would require a major R&D effort in Thatland. Cases 3 and 4 require high temperatures and tight control, and are unlikely to be suitable for village industry; investments, skills and technical support requirements are high. Although Case 4 is the most attractive, the technology would have to be imported, with increased burdens on the balance of payments. TABLE 1: AGRICULTURAL RESIDUES IN THAILAND . Production Year 1981/82 (*) Non dry basis, as left after harvesting. TABLE 2: OPTIONS FOR CROP AND AGRO-INDUSTRIAL WASTE UTILIZATION Processes: THERMOCHEMICAL BIOCHEMICAL CHEMICAL EXTRACTION Products: X SOLID FUELS X X X X LIQUID FUELS X X GAS FUELS X FEEDSTUFFS X X X CHEMICALS & OTHERS TABLE 3: Comparison of alternative uses KEY: Disc. Rate https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , USS 1=23 Baht, 270 days/year, V.H, Very High, H. High, M. Moderate, L.=Low Case 1= Charcoal, Case 2=Charcoal+Liquids, Case 3= Charcoaltactiv. Carbon, Case 4= Activ. Carbon Te Prod./Te Residue : Charcod. 0.3, Liquids https://www.w3.org/1998/Math/MathML"> = 0.12 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Activated Carbors=0.1 Product Prices 'ooo Baht/Te: Charcoal=1.8, Lifuids=12, Activated Carbon=36 REFERENCES Earl D.E.(1975), Forest Energy & Economic Development, Clarendon Press OXford Foley G. & Barnard G.(1983), BIomass Gasification in Developing Countries, Earthscan, Techn. Report No.l, IIED, London Lockeretz W. https://www.w3.org/1998/Math/MathML"> ( 1981 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Energy in Agriculture, p. 71, vol. 1, no. I Pyle D.L. & Zaror C.A. (1983), 'Pyrolysis of Biomass', Proceedings of the Indian Academy of Sciences, Section C, vol.5, Pt.4, Dec.1982. Pyle D.L. & Zaror C.A. (1984), Agroindustrial Wastes in Thailand: A Survey and Assessment of Treatment Methods, TISTR Report, ASEAN/EEC Scientific and Technological Cooperation Program, London/Bangkok. Rehm H, & Reed G.(1982), B1otechnology, 8 vols., Verlag Chemie, Weinheim, Florida-Basel. Soltes J.E. & Elder T.J. https://www.w3.org/1998/Math/MathML"> ( 1981 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Chapter 5 in "Organic chemicals from Biomass", ed, by I.S.Goldstein, CRC Press Inc., Florida. USAID https://www.w3.org/1998/Math/MathML"> ( 1979 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Project Paper for Renewable Non-Conventional Energy, Proj. No. 493-0304, USAID/Thailand, May 1979. ENERGY FROM BIOMASS (PROGRAMME & POLICIES) D.P. Vimal & N.P. Singh Dept. of Non Conventional Energy Sources Ministry of Science & Technology, New DeThi Summary Biomass in its various forms offers potential scope to meet energy needs on a decentralised basis. With a view to bridge over fuelwood shortage and explore substitutes for fossil fuels, a number of programmes have been initiated by the Dept of Non Conventional Energy Sources (DNES) which include: establish ment of biomass research centres under different agro-climatic regions, briquetting of agricultural and forest residues, alcohol production from energy crops, gasification of biomass, production of petrocrops and their conversion into petroleum hydrocarbons and development of a self-reliant energy system in agro industries. National Project on Biogas Development (NPBD), Community Type Biogas Plants (CTBP) and National Project on Improved Chulhas (NPIC) are some of the extension programmes initiated by the Department. During the Seventh Five Year Plan (1985-90), it is to meet local needs in the domestic, agricultural, industrial and transportation sectors to a significant extent. 19. Scope and Objectives of Biomass Programme Wood and agricultural residues have been in use since times immemorial but it is only recently that serious thought has been given to the problems of biomass conservation, production, conversion and utilisation on a rational and scientific basis. There are a variety of sources, diversity of technologica options and a multiplicity of limiting factors: thus the whole problem has to be viewed in the form of 'management issue' so as to innovate different systems to deal specifically with the local conditions. The following are the main objectives of the biomass programme:

Conservation of biomass (wood, residues) through popularisation of improved chulhas;

Production of woody biomass on sub-standard soils;

Improvement of fuelwood yielding plants through cytogenetical, physiological and cultural practices;

Assessment of both terrestrial and aquatic biomass available in the country;

Minimisation of energy needs in agriculture through recycling of organic wastes;

Finding alternatives to diesel fuel through the use of non-edible oils and bio-solar fuels.

Development of producer gas technology based on wood and agricultural residues for electrification, lift irrigation and in automobiles;

20. Energy Plantation for Power Generation and Other Local Needs 21. Biomass Based Gasifier Programme 22. Establishment of Biomass Research Centres It has been estimated that demand of fuelwood in India would be about https://www.w3.org/1998/Math/MathML"> 225 m i 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lion tonnes in 2000 AD. No reliable data is available on the total fuelwood production and the likely deficit after a period of about 16 years. However taking this shortfall of the order of https://www.w3.org/1998/Math/MathML"> 137 m i l 10 n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> tonnes, it is evident that nearly 34 million ha of the land would be required on the basis of about dour oven dry tonnes of wood per ha/year. Keeping in view the present land use pattern and per capita areas in deficit states, the only alternative under this situation lies in emphasising upon the concept of energy plantation. This programme concerns :lith the selection of species having high calorific value, fast growing, good cropping, high adaptability, use of establishment, nitrogen fixing ability with multiple uses particularly suitable as animal feed. Recognising the need for augmentation to strengthen the R&D efforts to generate research information on potential species in various agroclimatic zones so that these could be tested on specific Tocation. The success of firewood plantation depends, however, on proper selection of site, optimisation of cultivation practices - see germination, nursery practices, maintenance, spacing and tree density. Much of the techniques currently used in agriculture will have to be employed in energy foresty if tree productivity is to be maximised. During the Seventh Plan, it is proposed to establish 12 biomass research centres in addition to 3 already functioning at NBRI Lucknow, MKU, Madhurai and Garhwal University, Srinagar. 23. Solid Fuel Programme Briquetting of farm residues and forest wastes offers potential scope to provide a substitute for solid non renewable fuels like coal and renewable sources like wood to meet fuel shortages both in the domestic and industrial sectors. Therefore, several processes are available for briquetting wastes/ residues but no information is available on the comparative economic and energetics of these options. In order to make this proposition of commercial value, it is essential to investigate the effect of different types of binders, moisture content, pressure and temperature of competletion on briquetting of residues as well as the energy requirements per unit output of briquetted fuels. 24. Bio-Solar Fuel Programme Shortage of bio-solar fuels is one of the main limitations in large scale use for motive power. It has been estimated that the total requirement of alcohol by 1990 will be about 1610 million litres per annum but alcohol from molasses would hardly provide https://www.w3.org/1998/Math/MathML"> 950   m 1 itres https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , thus a gap of https://www.w3.org/1998/Math/MathML"> 650   m 1 itres https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This calls for tapping of non-convetional sources of energy sugar/starch like cassava, sugarbeet, sweet sorghum palrah palm and date pa https://www.w3.org/1998/Math/MathML"> 1   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are potential sources of alcohol, but their competition as a source of food is one of the ma in limiting factors in making use of these crops as a source of energy. Intensive efforts on increasing their productivity can help to meet both the needs. consistent with creation of agro-industrial complexes and generation of employment potential in these areas. During the Seventh Plan, it is proposed to increase the production potential of energy rich crops, setting up pilot plant facilities for alcohol production, and utilisation of these fuels in small utility 2 stroke S.J. engine, multicylinder automobile engines, small utility multifuel C.I. engines, and for gas turbine applications. 25. Petro-Crops In order to search for alternative liquid hydrocarbon materials of about the same aggreate chemistry as the current petroleum products, a collaborative project entitled introduction, screening and cultivation of potential petrocrops and their conversion to petroleum hydrocarbons, was initiated jointiy at NBRI, Dehradun. During the first phase a list of 186 species belonging to six laticiferous families, viz, Euphorobiaceae, Asclepiadaceae, Urticaces, Apocynnceae, convolvulaceae and Sapotaceae was prepared. Wide distribution, sufficient latex content and selecting the species. The second phase of this project relates to techno-economics of cultivation of promising species, building up of Germplasm Bank of Latex bearing plants, development of agrotechniques for maximum biomass production of prospective plant species; standardisation of techniques for hydrogeneration/determination of composition of the products as well as their evaluation. The work of hydrocarbon plants is in a nascent stage and needs intensification from various aspects. 26. Exploration and Survey on Availability of Biomass Despite the fact that a large number of institutions are working on energy from biomass in the country and significant developments have taken place for product development from wastes/residues; but no reliable data is available on quantitative basis. This calls for collection of information on the following aspects; estimates of their potential and actual availability cropwise/industrywise, seasonwise and spatial distribution, existing utilisation pattern technological developments for using surplus residues/byproducts and identification of opportunities for seeting up new projects. 27. Future Plan up to https://www.w3.org/1998/Math/MathML"> 2000 A D https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> During the Seventh Plan, it is proposed to develop a multi-dimensional biomass programme convering all the five components, viz - availability, production conversion, utilisatisation and conservation particularly in the field of improved chulhas, energy plantations, biomass gasification solid fuel production and manufacture of alcohol from non-conventional energy crops. R&D efforts will be stepped up so as to provide scientific and technological basis to the promotional and develomental activities. The following are the main achievements expected at the end of the Seventh Five Year Plan:

Signficant awareness on the conservation of biomass through maximum and efficient utilisation of improved chuThas.

Management practices for the production of biomass and sub-standard soils in differnt agro-climatic zones.

Use of gasifiers based on wood and residues for stationary and mobile applications in agricultural and transportation sectors.

Establishment of decentralised energy generation systems in various agro-industries, viz, rice milling, sugar industry, oilseed processing industries, dairies, sawmills, etc.

Pilot plant production of alcohol from ligno-cellulosic materials and energy crops. - Commercial manufacture of solid fuel based on residues and forest biomass, with and without briquetting.

Biomass-based substitutes to diesel fuel and petroleum based lubricants.

Information on the availability of biomass-organic residues, aquatic biomass, forest biomass, energy trees and shrubs in different locations.

Pilot plant production of biological hydrogen.

Accelerating the pace of development in selected priority areas through foreign collaborative programmes.

Establishment of advanced centres for biomass energy studies.

Thus by the year 1990 , it is hoped that the stage will be set to make biomass programme - a peoples' movement where all activities relating to production, conversion, utilisation and conservation of biomass will be taken up on decentralised basis to meet local needs in the domestic, agricultural, industry and transportation sectors to a significant extent. 28. Acknowledgment The authors are thankful to Shri Maheshwar Daya 1, Secretary, Dept of NonConventional Energy Sources for giving permission to publish this paper. K.S. ONG C.F. LAU Kuala Lumpur 22-11, Malaysia Shell (M) Trading Sdn. Bhd. Kuala Lumpur, Malaysia Abstract Summary A biogas plant operating under local conditions was investigated. Performance characteristics such as gas production race, pH level, carbon dioxide content and temperatures were obtained. Chicken droppings and palm oil. effluent were used separately as raw material for the digesters. Batch as well as continuous slurry feed operations were employed. The results of these preliminary investigations are presented. 1. INTRODUCTION The development of biogas in Malaysia was initially slow and 1imited to a few interested individuals and research organisations with a few scattered digester plants installed throughout the country mainly for lighting and cooking in pig farms. Lately however, with the advent of the energy crisis and a public awareness towards agricultural waste pollution in the country attention was focussed on the treatment of palm oil sludge. The traditional practice of discharging waste effluent into nearby rivers and streams have resulted in the destruction of aquatic life. For the more ecologymminded mills effluent discharge was made into holding ponds prior to release into the rivers. In fact, these ponds were nothing more than providing an open-pit type of digester with the biogas thus generated being allowed to freely mix with the surrounding air and hence producing the familiar stench associated with such a system, The anaerobic digestion of palm oil sludge is presented in Quah (1). With the potential and ability to supply electricity to the National grid all eyes are now focussed on this future development. At the University of Malaya, studies were made (2, 3) to investigate the performance characteristics of a biogas plant operating under local conditions with a primary view to obtain the optimum operating conditions. Chicken droppings and palm oil effluent were used. In both the investigations, solar heated water was used to heat up the slurry in an attempt to improve the rate of production of the biogas. 29. EXPERIMENTAL EQUIPMENT AND PROCEDURE The experimental set-up illustrated in Fig. 1 consisted basically of a digester, a gas receiver and a solar water heater. The digester was essentially two concentric circular cylinders forming an external water jacket and fitted with a manually-operated screw-type slurry feeder, a manually-operated multi-paddle blade-type agitator, valved outlets for gas discharge, scum discharge and slurry discharge. The gas receiver consisted of a closed end cylinder inverted over another water-filled cylinder. Counter weights attached to the inner cylinder allowed the pressure of the gas generated to be varied. Other important features included a gas trap and a safety valve at the top of the gas receiver. The solar water heater was of the conventional flat plate type operating under thermosyphon flow conditions to supply heated water at around https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to the water jacket. The following outlines the general procedure followed in the operation of the plant: (i) Fresh slurry was injected into the digester via the screw-feeder while digested slurry was discharged from the discharge pipe at the bottom. (ii) Biogas generated in the digester flowed from the top of the digester tank to the gas receiver tank via a plastic hose. The gas receiver tank rises as the volume of gas generated increased. The gas pressure was controlled using the counter weights. (iil) Gas from the gas receiver was discharged for testing via the gas trap through a plastic tube. The plant was operated for 2 years. In the first year, chicken droppings were used as raw material and palm oil effluent in the second year. Slight modifications were made to the plant during year 2 to improve handling aspects of the palm oil effluent. Results are shown in Fig. 2.

RESULTS WITH CHICKEN DROPPINGS AS RAW MATERIAL

Fresh chicken droppings were mixed with water in the ratio of 1:1.25 by volume and infroduced in batches into the digester via the slurry feeder until it overflowed from the scum discharge pipe. The scum discharge valve was then closed, the gas outlet valve opened and the slurry was agitated regularly. Total slurry content was https://www.w3.org/1998/Math/MathML"> 0.2   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per batch. Ihe gas production rate, carbon dioxide content of the gas, pH of slurry and temperature of slurry were measured over a 40 day observation period. Results showed that the daily gas production rate reached a maximum of https://www.w3.org/1998/Math/MathML"> 0.18   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the third day of digestion. Towards the eighth day, gas production rate was https://www.w3.org/1998/Math/MathML"> 0.10   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> with https://www.w3.org/1998/Math/MathML"> 43 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> carbon dioxide content. This gas was combustible. On the tenth day, gas was produced at a rate of 0.16 m https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . After this time, the gas production rate showed an overall decreasing trend with a few minor upswings down to about https://www.w3.org/1998/Math/MathML"> 0.015   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after thirty-five days. The total volume of gas produced over 28 days was https://www.w3.org/1998/Math/MathML"> 3.14   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which amounted to https://www.w3.org/1998/Math/MathML"> 93 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the volume expected from the https://www.w3.org/1998/Math/MathML"> 0.085   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of chicken droppings used. However, the incombustible gas produced during the first seven days was https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the total volume of gas produced. Hence the total volume of usable gas produced was about https://www.w3.org/1998/Math/MathML"> 0.065   m 3 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The carbon dioxide content of the gas rose to a maximum level of https://www.w3.org/1998/Math/MathML"> 63 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the fifth day. The carbon dioxide content began to decrease after six days until it was at about https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> after about thirty days. The pH level dropped to a minimum value of 5.6 from 7 after about seven days. After this, it began to increase to a near constant value of between 7.5 to 8 after thirty days. It was observed that carbon dioxide content increased as pH level decreased. The slurry and water jacket temperatures could not be controlled and they were obgerved to vary by https://www.w3.org/1998/Math/MathML"> ± 3 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> dependent upon ambient conditions. It was not possible to conclude qualitatively the effects of temperature to gas production rates. However, from preliminary studies, it was found that temperatures of https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> were more favourable for gas production than say https://www.w3.org/1998/Math/MathML"> 30 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

RESULTS WITH PALM OIL EFFLUENT AS RAW MATERIAI

Batch and continuous digestions of palm oll effluent were tested over a total period of https://www.w3.org/1998/Math/MathML"> 3 1 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> months. Anaerobic fermentation of organic fibres in palm oil effluent is quite complex and it wotld be beyond the scope of the FIG. I ILLUSTRATION OF EXPERIMENTAL BIO-GAS PLANT 30. GENERAL OVERALL VIEW FOR DEVELOPMENT From these preliminary results it is difficult to say whether batch or continuous digestion method is preferred. Much would also depend upon the practicality of operating the plant. The main criteria being to educate the user to control the mixture composition and regulation of pH and temperature levels. More work would have to be done by biochemists to identify and to determine the optimum operating characteristics for maximum gas production. Once these are known, Engineers can then design the plant to suit these conditions. Agricultural extension workers could then dessiminate the information and to assist in setting up actual plants in the rural areas. Financiers would have to be brought into the scene to finance the programme as rural farmers are not able to afford them no matter how low the capital costs are. In short, a general strategy would have to be formulated by the local Government or an International Agency in order to promote the use of biomass as an alternative energy resource. 31. CONCLUSIONS The preliminary results obtained provided useful data for the design and planning of future biogas plants using chicken droppings or palm oil effluent in Malaysia. Mixture composition, pH level and digester temperatures are important controliing factors. Further work should be performed to study the fermentation processes for optimum plant performances. 32. REFERENCES (1) QUAH, S.K. and GILLIES, D. (1981). Practical experience in the production and uses of Biogas. Workshop on Palm Oil By-Product Utilization, PORIM-MOPGC, Kuala Lumpur. (2) NG, K.C. and WONG, K.W. (1979). Biogas plant design, construction and test. Thesis Report, Mechanical Engineering Department, University of Malaya, Kuala Lumpur. (3) CHAN, J.H. and GOH, P.S. (1980). Biogas plant for palm oil effluent. Thesis Report, Mechanical Engineering Department, University of Malaya, Kuala Lumpur. 33. THE BIOMASS ROLE IN THE BRAZILIAN 34. ENERGY BALANCE I.GOCHNARG, BSCHE, MSCHE G. L.GRDSZMANN, BSCE, MBA INSTITUTO DE PESQUISAS TECNOLUGICAS IPT - CIDADE UNIVERSITARIA 05508 - SÃO PAULO - SP BRAZIL This paper charactertzes the Brazlitan energy problem, degoribes the strategy conceived to solve 1t and the role played by biomass energy car rigrg within this strategical framework. Position data on the Brazilian ethanol, firewood/charcoal and vegeta ble ofls programs is furnished. 35. THE BRAZILIAN ENERGY PROBLEM Brazil with a population of 130.000.000 inhabstants and an area of 8. https://www.w3.org/1998/Math/MathML"> 512.000   k m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was among the ten major economies of the western warld in 1983 , with a GNP estimated around 220 b1111on US$. Historically the Brazl.1an economy has been penalyzed by inflation ra tee around https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a. combined with the higher interest rates of the early bo's, besides triga gering an ever increasing inflation rate https://www.w3.org/1998/Math/MathML"> [ 211 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> a. a. In 1983 https://www.w3.org/1998/Math/MathML"> ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (4) have con quently for the country increasing indebtedness. aeing one of the mein cauges of the Brazilian ever growing indebteness the petroleum account was recognized by the Brazillan government, in l979, as being one of the most important tools to loosen the foreign constraints affecting the country's economy. Within this framework the Brazilian energy problem was characterized as belng a typlaal Imports substitution problem. Typloal but prior once that the expedlture with snergy importation was the one that offered the greatest potential for substitution on a medium term basis and conse arentiy could play a major role in the relleve of arazil's finternational debt burden.

THE BRAZILIAN ENERGY STRATEGY

The Brazllian energy strategy aims to reduce the country's petroleum eccount by appropriate implementation of governmental programs in the following areas:

anergy conservation

national o1. production

petroleum substitution

The results of the implementation of this strategy may be seen in Ta ble I. that reflects the evolution af the Brazillan Bngrgy demand by car rier as well as in Table II. that presents the net expenses [CIF] wIth petroleum Importation. 36. THE BIOMASS ROLE As per the Braz1llan Ministry of Mines and Energy data, almost https://www.w3.org/1998/Math/MathML"> 31 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the Brazllian energy damand in l9B3 were met by blomass derlved fuels. Their contribution to the national energy balance in 1983 reached almost 41 m1111on toe; figure that represents B8% of the Brazilian consumotion of petroleum derivates in that year. Table III. sintheslzes the Brazilian biomass program retionale. brief description of the stage of development and contribution of the main biomass energy carriers https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> furnished below. On November 1975 the Brazil1an government launched the PROALCOOL Pro gram (National Alcohol Program). Counting on a strong technical and ecr nomic support this program is already in its third stage with a produc tion goal of 14.3 b1llion liters per year by 1987. Unt11 August 1984 the Executive Commission of the Brazilian Alcohol Program (CENAL) has approved 541 alcohol plant projects: 236 of these units are annexed plants and 305 are autonomous ones. Almost https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of both kinds of plants run solely on sugar-cane. (3) The production capactty al ready approved by CENAL peaches I 5 lion l1ters per year and the real out-put for the 84/85 crop ls estimated at 9,4 billion liters. (3) Ethanol is being consumed In three basic ways:

as gasol1ne extender (anhydraus alcohol)

as gasol1ne substitute (hydrated alcohol)

As chemical feedstock

Nowadays Brazll runs a fleet of almost https://www.w3.org/1998/Math/MathML"> 8 m i l l l o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vehfoles on gasohol (78% gaso1fne https://www.w3.org/1998/Math/MathML"> + 22 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol) and almost 1.800.000 veh1cles on stralght ethanol. 600.000 alcohol powered vehicles are expected to be added to the pure ethanol fleet in 1935. Table IV. presents data on the evalutian of the Brazllian ethanol and gasoline consumptlon. Besides its use as fuel ethanol is also being used to displace petro leum as chemícal feedstock. In 1983 four hundred million liters of etha nol were consumed by the alcoholchemical Industry. [1] Two complementary energy carriers are being obtained as by-products of the ethanal program: bagasse and methane. The amount of bagasse produced In 1983 was equivalent to https://www.w3.org/1998/Math/MathML"> 9 , 367.10 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> toe. https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of this total was used for non-energy purposes, https://www.w3.org/1998/Math/MathML"> 44 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was consumed by the ethanol producing system and https://www.w3.org/1998/Math/MathML"> 36 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was emploied as fuel o11 substı tute by the industry. (1) For a long time methane could be obtained by stillage biodigestion but just now this route became economically feasible with a technologloal breakthrough on the blodlgestion process developed by IPT. W1th a residence time of 18 hours, instead of the usual 20 to 30 days, IPT process allows the implantation of biodigestıon systems that make economic sense. For instance, a system for a https://www.w3.org/1998/Math/MathML"> 120.0001 / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ethanol plant, treating https://www.w3.org/1998/Math/MathML"> 1,500   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of stillage per day, allowing the d1splacement l.930 m of diesel per crop, would require an investment of l, 400,000 uS$ that covers the biadrgestion system (450,000 US$) and the methene purifi cation, compression and storage facilities https://www.w3.org/1998/Math/MathML"> ( 950,000 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> US$ $. 37. 1 ETHANOL 38. 3.2 FIREWOOD AND CHARCOAL Firewood and charcoal play an important role in the Brazilian energy balance. As presanted in Table I their contribution for the energy supply In 1983 reached almost https://www.w3.org/1998/Math/MathML"> 24 , 200.10 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> toe. This flgure is almost 6.5 times the ethanol share in the 1983 Brazllian energy balance. Reforestation https://www.w3.org/1998/Math/MathML"> 1 s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> an important actırity for the contlnous contribution of these energy carriers. In this sector Brazl.1 occupies the 5 th place in the international ranking of reforestation activities lmore than 400.000 ha were reforested In 1980) and Braz1lian private companies are among the ones with best know-how on short rotation sivicultural practices. 39. 3.3 VEGETABLE DILS Brazil hag peen studylng the use of vegatable ofls in Dlesel engines since 1978. A huge research and experimentation program concluded in l984 [OLVEG], coordinated by the Brazllian Ministry of Industry and Trade, has demostrated the teohnical faasibllity of using transestherffied vegetable olls as Diesel gxtender or substitute in cargo and public transportation systems. The main sources of oll considered were: soybean, sunflower, palm and macauba. Although temhnically feasible this route is not economically sound for the time being. It may be implemented on a short term notice in case of severs supply crisis. 40. FINAL REMARK W1th a contribution of almost 41 millions toe/year, no one can deny the important role that biomass energy is playing in the Brazilian econo mic struggle. Although Brazil's privileged endowment for energy fram biomass pro grams much of the Brazilian experience may be useful/sultable for other developing countries. 41. REFERENCES (1) - MME - Balanço Energêtıco Nacianal - 1984 (2) - Eduarda Celestino Rodrigues - Unpublished Paper (3) - MIC - CENAL: Relatörio JUL/AGO/84 [4] - FGV: Conjuntura Econômica (5) - Y.Nakano: Inflação e Recessāo TABLE I - BRAZILIAN ENERGY DEMAND EVOLUTIDN PER CARRIER (103 tOe) (1) 1092 TABLE II - EVOLUTION OF THE BRAZILIAN PETROLEUM NET ACEOUNT (2) YEAR NET PETROLEUM IMPORTATION (1000 boe/day) NET-EXPENSES CIF https://www.w3.org/1998/Math/MathML"> 10 6 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> US $ 1972 514 538 1974 668 3,137 1979 1004 6,639 1980 872 9,811 1981 844 10,335 1982 737 9,301 1983 622 7,246 1984 467 5,400 TABLE III - BRAZIL'S BIOMASS PROGRAM RATIONALE RAW-MATERIAL CARRIERS DISPLACES SUGAR-CANE ETHANOL BAGASSE METHANE GASOLINE FUEL OIL LPG/DIESEL WOOD FIREWOOD CHARCOAL TAR WOOD GASES ETHANOL METHANDL FUEL DIL FUEL OIL DISEL/FUEL OIL LPG/DISEL/FUEL OIL GASOLINE DIESEL PALM TREE RAPESEED SUNFLOWER VEGETABLE OILS DISEL RESIDUES PELLETS CHARCDAL METHANE FUEL DIL FUEL OIL LPG/OIESEL TABLE IV - EVOLUTION OF THE BRAZILIAN ETHANOL AND GASOLINE CONSUMPTIDN (2) CONSUMPTION https://www.w3.org/1998/Math/MathML"> 10 6 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> OIL YEAR ETHANOL % AS DISPLACEMENT GASOLINE ANHYDROUS HYDRATED EXTENDER 1000 bep/day 1979 13.426 2.217 18 14,2 33,5 1980 11.438 2.253 429 16,5 39,2 1981 10.943 1.146 1.392 9,5 34,6 1982 10.439 2.017 1.674 16,2 51,2 1983 8.694 2.174 2.940 20,0 69,4 1984 7.734 2.061 4.391 21,0 87,0 SMALL STEAM SYSTEMS FOR THE THIRD WORLD 42. BACKGROUND. 43. Summary 44. INTRODUCTION Some improved techniques to produce energy from biomass are regarded as having potential for employment in rural development (1). An assessment was made as to which techniques were suitable for introduction in coastal was made as to which technlques were suttable for introduction in cuastal Ecuador against a background of existing usage of biomass energy. Particular attention was paid to: Improvements in wood supply, from existing foregto by management, the establishment of community woodlots and the introduction of fast growing tree species; improved wood stoves; charcoal production and supply improvements. A central aim of the study was to ldentify the constraints in the social and economic context and political framework which inhibit the introduction of technical changes. This approach has particular relevance in view of the lack of a national biomass energy policy and the absence of a coherent programme of action and support for biomass energy technical 1nnovations. The project was established as a locally-based case study. Two study areas were selected in Los Rios and Manabi provinces in Ecuador, in moist forest and thorn woodland/dry forest ecologioal life zones respectively (which span the range of conditions found in coastal Ecuador) (2). An examination was made of: the existing role, use and users, producers and distributors of biomass energy. It can be noted that this investigation principally related to the use of wood and charcoal for cooking. The investigation was undertaken in selected urban and rural communities and in different crop systems. In addition, an analysis was undertaken of agricultural, forestry and energy policy as it affected biomass energy supply. 2. ROLE AND SIGNIFICANCE OF BIOMASS ENERGY It is possible to ldentify the following main features of significance which need to be considered in relation to existing and future use of biomass energy:- a. Limited role of biomass energy In the early stages of the study it was found that the limited industrial and agro-industrial processing sectors of the study areas inhibited the introduction of new biomass fuels and the small-scale decentralised industrial plant for which they have been considered particularly suitable The economic structure of Ecuador has led to an industrial pattern which is concentrated in the metropolitan centres of Quito and Guayaquil. Moreover the subsidised prices of fossil fuels has meant that their use has penetrated through the economy, including certain crop production systems. b. Variations in the use of biomass energy It was found that considerable variations existed in biomass energy patterns of use for cooking. The proportion of households which used wood ranged from https://www.w3.org/1998/Math/MathML"> 12 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 93 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in different communities. For charcoal the range was 0% to 63%. Variations were found not only between urban and rural areas but within urban and rural areas. Various factors were examined to see which affected use and it was found that the situation was complex. Use and non-use of blomass energy was related to place of residence, socio economic group and the exercise of personal cholce. The residential factor was closely associated with supply problems. There are supply problems not only of wood in urban and some rural locations, but charcoal and also gas in some rural locations. Future biomass energy use will clearly be related to changes in residential patterns, demographic structure and income, in addition to wood and charcoal production. c. Inefficient use of biomass energy On average, wood-using households used 11.4 GJ person fyear compared to 1.7 GJ person/year for gas. Whilst it might seem that there is considerable potential for improvements in wood stove efficiency, this requires careful examination as those still using wood or charcoal are generally unable or unwilling to invest in a stove for kerosene or gas. An improved wood stove which involved expenditure and an unfamiliar technology could not be expected to be readily acceptable. d. Changing role of blomass energy It has been indicated that communities vary in their patterns of usage of blomass energy. These variations result from changes that many households, principally in urban locations, had made in fuel use, in the previous 5 years. The changes are mainly from biomass energy to fossil fuels although biomass energy may continue to be used as a supplement. Households have changed to gas or kerosene because they are more conventent fuels and /or because of wood supply difficulties. . Significance of biomass energy Despite the changes noted above, for the majority of households in rural areas, and a significant minority in urbar areas, change to fossil fuels is not necessarily possible when biomass supply problems are faced. The households which comprise this majority group in rural areas are the small landowners, agricultural labourers and unskilled workers. It can be noted that in the Manabi study area over https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of these household groups are still exclusively dependent on the use of wood and/or charcoal. Households In all Income groups expressed positive reasons for using wood and charcoal which relate to their qualities for food preparation and the ease with which they can be used on a simple home constructed stove. DISSEMINATION OF ENERGY TECHNOLOGIES: STOVE AND FORESTRY PROJECTS IN GUJARAT M.M. SKUTSCH rechnology and Developente rechnology and Development Group Enschede, Netherlands 45. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> This paper presents preliminary findings from a survey of improved woodstove and social. forestry programmes which was undertaken in Gu- jarat in January and February 1985. The purpose of the research, which was financed by the Indo-Dutch Programme for Alternatives in Development, was to analyse programmes in terms of their strategio management, and by a series of comparisons between programmes, arrive at general conclusions about success and failure in programme manage- ment. In this, the intent was particularly to distinguish strategies which were effective in reaching the poorest https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the population. The major findings were that different dissemination strategies used buted, numbers surviving after a period of time, and proportion taken up by the poorest https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This was partly due to differences in the design of the stoves, itself resulting from the requirements of par- ticular organisational set-ups and dissemination strategies; and nartly due to differences in training supervision and incentives for the stove builders. The range of social forestry programmes is much more limited as the field is dominated by Forestry Department activities; in this case, success in terms of numbers of trees planted was found but it seems unlikely that this will result in the expected solution to the rural firewood problem, since this shortage is not a general one but restricted to the landless and very poor. STOVE PROGRAMMES IN GUJARAT In Gujarat there are at least 15 programmes on-going for atssemination of "improved woodstoves", many of them financed from government sources but implemented through NGOs. Space does not permit a description of each of these programmes individually but their goals do differ. Early program- mes were set up to reduce smoke in houses, a health precaution against lung, throat and eye diseases. Cleanliness of the dwelling was often also a key point. It is only since "the other energy crisis" has been recog- nised that fuel efficiency has also been adopted as a goal. Some agencies have taken up stove programmes for still other reasons, e. g. because sto- ves offer a reasonably simple technology with which to involve village people, so that they may later have confidence to participate in other ruxal development programmes, or alternatively for political expediency in a situation in which the energy crisis is seen as the problem of the day by government and sponsors. For yet others, stoves offer one of the few technologies with chance of positive impact on women. Inpractice however almost all agencies measure their success in terms of numbers of stoves built and not in terms of these underlying objectives. Further the stove programmes differ in their strategic management with respect to (1) choice of stove (2) participation of the user in the stove design (3) type of stove builders, their training and system of reward (4) quality control. (1) type of stove. All stoves were of the two hole smokeless chula type (with chimney), but they varied with respect to materials of construction, from solid cement to a pre-fabricated concrete slab supported on bricks, to several all-mud models. Many diffexences in detail such as dimensions, dampers, baffle, pot hole size etc. were taken into account. (2) participation of user. In some programmes the participation of the user consisted of a small payment for the stove (all were subsidised to a greater or lesser extent). Other programmes offered stoves gratis however with no user participation expected at all in any sense. A few programmes committed the users through requiring them to bring materials to the construction site or to bring their own cooking pots to allow exact size of pot holes to be established. None offered the adopter a choice of stoves. (3) type of stove builders, their training and reward system. Four basic strategies were identified among the 15 programmes: (1) The camp system. 30 volunteer students from universities and colleges camp for two weeks in a village, march, sing and build demonstration stoves under guidance of a fieldworker. People "motivated" by this come and ask for stoves to be built for them immediately. Training is on the spot and apart from food & lodging which is provided by the village as a whole, no payment is received by the studentso (2) The departmental quota system. Stove building is taken on as part of normal work and distributed by quota among officers who train subordinates often by a pyra- midical series of training camps. Usually the number of stoves each Einal trainee is supposed to build is small https://www.w3.org/1998/Math/MathML"> ( 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to 5 https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and no reward is given for this. (3) The integrated artisan system. Artisans are trained by the organization and hired to build stoves when required on a piecework basis. Relationships between artisan & organisation are cordial and long term. (4) The salaried stove builder system. Stove builders are trained by the organisation and pala both on a piecework basis and a nominal salary for continued work in main- taining and repairing stoves in a certain area, thus becoming in effect staff members themselves. (4) quality control. Most programmes had some monitoring system but action on this was not always forthcoming. In a few cases however follow up was institutionalised. MEASURING SUCCESS AND FAILURE Success of a programme could be measured in a variety of ways but here three methods are used: (1) the number of stoves built This criterion reflects the viewpoint and self-evaluation in practice of the implementing agencies (2) the number of stoves surviving after some period of time Abstract This criterion reflects the difference between the agency's view of what stoves should be like and the user"s, assuming that dissatisfied users will abandon their stoves. (3) proportion taken up by the poorest https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the population. This criterion reflects the view of the research sponsor that this group is the most in need of access to technology for basic needs. RESULTS OF THE DIFFERENT KINDS OF PROGRAMMES Success in terms of numbers built was best achieved in procrammes Success in terms of numbers built was best achieved interogranines using the camp and department system for recruiting, training and re-warding the stove builders. About 60.000 stoves were so constructed since 1973 .Jsually aseociated with this, was a stove built of pre-fabricated parts (concrete pre-cast slab and bricks), which is structurally unsound and often breaks. This choice was necessitated by the choice of inexperienced builders with no long texm committment to the programmes, and by the scale on which the programmes are intended to run. Participation of users is virtually nil although in some cases a small payment is made (5 rupees). Monitoring was carried out in these programues but did not result in changes (e.g. in the cholce of the materials), and qualit control was impossible because of the pyramidical structure of the dissemination process. Succeses in terms of survival rates was found to occur most in programmes implemented using the trajned artisan and salaried stove builder systems where survival was about https://www.w3.org/1998/Math/MathML"> 85 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on average. These were also generally the programmes in which locally available materials (mud and aung) were the chief construction materials. Here builders were malnly selected from the village themselves, and were often of low caste; they were able to involve the users in the design at least as far as prefered pot hole size is concerned. They also required a small fee for every stove built, said to promote the value of the stove in the eyes of the user. These stove builders were able to monitor, and to repair stoves when necessary. Related to this good communication system however is the very small scale on which such programmes necessarily operate. Success in terms of proportion of stoves going to the poorest people was not always more in the case of small scale, intimate procrammes, as one might have expected. Some of the camp system programmes were linked by their financial sources to low income housing areas (e.g. the House Improvement scheme) and built https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of their stoves there, finding a good acceptance rate among the landless labourers for a no-cost stove. Lack of participation in this dissemination progress did not seem to hinder the programme. The small artisan and salaried stove builder programmes had mixed success in reaching this group of poorest people, and on average distributed stoves to all strata in the villages in approximate proportion to their size. 46. GENERAL OBSERVATIONS

The strategic elements in programme management are not independent but mutually bound together; the choice of a particular dissemination strategy necessitates a certain type of stove and a certaln approach to training and supervision, and results in a certain attitude to quality control.

47. SOCIAL FORESTRY.

There is a very limited market at present for firewood which is purchased only by a few very wealthy people in rural areas. The poor cannot afford to buy even the small margin of social forestry wood that might be offered as firewood.

Some NGOs have cooperated in the programme in a few small areas, often with the intention of involving the marginal farmers to a greater extent but theix net impact in this respect has been small. FUELWOOD SCARCITY IN RURAL INDIA: PERCEPTIONS AND POLICIES

Department of Chemjcal Engineer ing, Imper ial college, London Fuelwood scarcity in rural India is severe and worsening with increasing deforestation. India's forest land is https://www.w3.org/1998/Math/MathML"> 22.8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of its land area (CFC 1981 ) but only about half is under tree cover. Deforestation rate is probably over 1 m ha/year (CSE 1982): there is acute firewood scarcity in the Indian mountains and deficits in the Indo-Gangetic plain and in S. India. This paper examines perceptions of fuelwood shortage and jts causes. It discusses the implications, for rural fuelwood supply. of population pressures, rural and urban firewood demand, commercial pressures, large development schenes and the Governinent-backed social forestry programme. Methodology. of 13 case-studies and an extensive ifterature review. (Mathrani 1983). Perceptions of fue Twood scarcity The case-studies reveal interesting perceptions of fuelwood scarcity, The Director, ATDA, Lucknow, U.P., notes that while firewood is crucial to over https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the 100 million population in the Indo-Gangetic plain, there is no perceived overall shortage because people can substitute wood with crop residues and do not yet go without food for Tack of cooking fuef. The forest bept. of Goar chatms there is ho overall shortage of firewood in Goas despite estimating that collecting firewood takes, on average 2-4 h/day/nousehold and up to 6 h/day. Similarly, Mr. Panwalkar (TISS) feels that villagers in the Shirotaarea, Maharashtra, are not specially aware of firewood shortages. The area, Maharashtra, are not specially aware of firewood shortages. The time needed for firewood collection is only one factor in the struggle to provide for basic needs which becomes more difficult with worsening poverty. In other words, rural people do not generally separate energy from other problems, rooted in poverty and unemployment: e.g. for them firewood is scarce because they cannot afford kerosene (Barnett, 1982 ). People in poverty may suffer great hardship and inconvenience before perceiving an overall fuelwood shortage. Definitions vary with quality of life, and locally accepted conditions. In the Atmakur taluk (kurnool A.P. for example the population depends on firewood, and over https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> obtain that those most severely affected by shortages are low paid workers with that those most severely affecno time to smugale firewood. no time to smuggle firewood. Causes of rural firewood scarcityRespondents to the writeen questionnaire were asked to identify the cause(s) of fuelwood scarcity in their area. In many instances multiple causes were important, as seen by the summary below: Causes of Rural Fuelwood Scarcity No. of Respondents Subsistence agriculture/population pressuresInability to afford fuelIndustrial expansionUrban expansionDambuildingFelling for urban demandRestricted access to forestsCorruption and illegal fellingUnscientific forest managementUnsuitable tree species Subsistence agr iculture and rural population pressures Rural and Urban Fuelwood demand was emphasised by officials that officials often saw the planting of any tree as a step forward. Farm forestry should not use good agricultural land, but the forest. beparthent cannot prevent it. he conchude that often they worsen the situation of the poorest. Government Policies and Involvement 0fficial policy statements bthe ive year plan (Govt. of India, 1981)) disapprove of clear felling, of diverting forests to other uses, look for focal involvement and the elimination of exploitation of tribals. The plan, however, also looks to develop the Hydro (HEP) programme and open up regions for paper and pulp. The draft. Indian Forest Bill (1980) has been criticised for assuming that the rural and tribal poor are mainly responsible for deforestation and that its https://www.w3.org/1998/Math/MathML">   t r i b a r , p o o r   a r e   m a t n l y   r e s p o n s i b i e   f o r   d e f o r e s t a t i o n ,   a n d   t h a t   i t s a r e s e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> become virtually prohibited; punishments are very harsh, and Forest officials are qiven almost unlimited powers of arrest Although the Government notes the importance of conservation, the massive Tehri Dam (U.P.) Was over halfway completed in 1982, but watershed management had still not begun (Sharma, 1982 ) There are many other examples of conflicts with conservation policy, (e.g. Times of India, July 1983). In February 1983 , restrictions on paper exports were Iffed, although India produces under https://www.w3.org/1998/Math/MathML"> 15 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of its needs (Cardozo I983). Packing case manufacturers obtain concessional timber. With UNDP/F.A.O. providing for the rural poor who formerly used them. Some negative official aspects of schemes were demonstrated on a visit to an aerial seeding and eco-development project in Maharashtra, which aimed to seed 3000 ha with mixed local tree species. The local people doubted its value, resented the ir lack of involvement, the fallure to include their needs for fresh water and atoad, and the obstructive bureaucracy. In contrast, the Bharatiya Agro industries foundation (BAIF) at established rural development centre. BAIF started to popularise the planting of subabul (Leucaena Leucocephala) a good fodder fuel and https://www.w3.org/1998/Math/MathML">   p l a n t i n g s o r   s u b a b u l   ( L e u c a e n a r e b u c o c e p h a l a ) ,   a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> schoolchildren and parents responded enthusiastically. The wasteland that surrounded the Institute https://www.w3.org/1998/Math/MathML"> 1   s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> now densely forested. Headloads of wood are provided preferentially to the poor, at a quarter of the market rate; seedlings are free. Conclusion Pollcy contradictions can worsen rural fuelwood scarcity and deforestation. Clear policies needed include: establishing co-operative control of parts of forests by forest dwellers; afforestation of areas felled for industries and for catchments developing micro and mint hyde sources: using barren rather than agricultural lands for social forestry; involving local institutions in afforestation; developing oranised fue? supplies to urban areas: subsidising wood and charcoal for the rural poor. Rural fuelwood scarcity is one manifestation of poverty and rural unemployment. The rural poor have to compete for fue? with powerful pressures on forests, and are losing the struggle. Until these factors are recognised and understood at the highest level, and unless explicit steps are taken to protect the weakest sections of society, the severe fuelwood crisis in rural India will worsen rather than improve. Anklesaria, S. 1983 , "Cololonfal POTICTes Leave us Denuded", Imprint, Bandyopadhyagia J 1979 , Economic and Political Week https://www.w3.org/1998/Math/MathML"> 1 y , 13 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> oct. 1979 has been installed, tested and improved. The two installed fixed bed gasifiers convert wood into burnable gas. This gas is used to generate electric energy by means of a combustion engine coupled to an electric generator. Each gasifier has an electric power output of approximately https://www.w3.org/1998/Math/MathML"> 44   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and is operating independently from the other. The generated electricity is used to drive 10 irrigation pumps with a total water-delivery capacity of about 600 m https://www.w3.org/1998/Math/MathML">   3 / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hour and facilities for wood processing, rice processing and a small workshop (see Figure 1). Two gasifiers have been installed in order to find out which kind of cooling and cleaning system is the best one, because the purity of the burnable gas and the reduction of condensate production with phem nole is important for a sufficient operation of the gas engines. The two installed systems consist of: Eigure: 1 Energy Flow Diagram of Picon 1. Results Both gasifier systems have been operated with an average operating time of https://www.w3.org/1998/Math/MathML"> 7   h / d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and a specific wood consumption of https://www.w3.org/1998/Math/MathML"> 1.47   k g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> under the same technical and environmental conditions. Due to the use of the general electric energy pumps it was possible to have a second harvest of rice in 1984. To reduce the production of condensate and hence the formation of phenoles modifications were made to a gastffer The gasifier so modified (Figure 2) was provided with a hot gas hose filter instead of a cyclone separator and a cork filter. In addition to this the gas temm perature was maintained at https://www.w3.org/1998/Math/MathML"> 55   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by means of a speed regulated air cooler. The result brought about by this temperature control was that the production of condensate and equally the formation of phenole could be reduced from https://www.w3.org/1998/Math/MathML"> 995 m l / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at a gas temperature of https://www.w3.org/1998/Math/MathML"> 45 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 50 m l / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at https://www.w3.org/1998/Math/MathML"> 55   ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (2). (1) Gasifier(2) Hot gas hose fllter (3) Gas cooler with temperature (4) Settler

Gas - air mixing unit

(6) Bulding - up blower (7) Torch flare (8) Regulator for pre-heating alr 19 Gas engine (11) Generator (12) Ouick start pipeline withBullding - up throttle Figure: 2 Scneme of the modified wood gasifier From the technical point of view we could now say that the cleaning and cooling principle of the modified system is working successfully and reduces the maintenance time to a minimum. From the economical point of view we have made several calculations to compare a wood gasifier system with a diesel generator. The calculation was carried out on the price basis of Indonesia (3). 2. Electric Energy Generation Break Even Curves of Electric Energy Generation with Wood Gasifter 0.891 prowh 0 0.85 0.63 0.42 https://www.w3.org/1998/Math/MathML"> 0.30 0.18 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 0.06 0.06 100 3. Figure: 3 Profitability of wood Gasifiers as a Function of the Iocation (Late OI Interest 148/ a; rates Of price increase: electric energy https://www.w3.org/1998/Math/MathML"> 10 % / a ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wood https://www.w3.org/1998/Math/MathML"> 5 z / a ; https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Iuel https://www.w3.org/1998/Math/MathML"> 14.5 % / a ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Ffaure 3 shows the break-even curves comparing a wood gasification system with a diesel generator In general we could say that an economic use of such a system is a function of the place of installation and the availabtlity of wood and its price. In this case the wood gasifiers will have a good prospect for developing countries, where so many remote areas and isfands have huge amounts of wood waste available. 4. References (1) Agreement on Cooperation in Scientific Research and Technological Development Concluded in Jakarta, March 20th, 1979 (2) Status Report of BPP-Teknologi, Jakarta, December 7 th, 1984 (3) Indonesian Market Price given by BPP-Teknologi, Jakarta, January 20th, 1985 4.1. AND 4.8 MW WOODGAS POWER PLANTS IN OPERATION R. SONNENBERG, W.O. ZERBIN, T, KRISPIN IMBERT Energietechnik GmbH & Co. KG Bonner str. 42 5354 Weilerswist Federal Rep. of Germany 5. Summary In Loma Plata, the Chacco of Paraguay, IMBERT, Germany installed in 1983 an 1.4 MW power plant based on wood gasification. The plant con- sists of two down-draft gas if iers with https://www.w3.org/1998/Math/MathML"> 1,800 N m 3 / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> woodgas production each. The gas if iers feed three Waukesha L 7042 G gasengine-alternator sets with appr. https://www.w3.org/1998/Math/MathML"> 465   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of electricity each. This energy is sufficient to satisfy the requirements of a private agricultural cooperative. Up to now the plant has run more than 15,000 hours. In the Sawmill Mabura Hi11, Guyana, IMBERT instaTled in autumn 1984 the world's largest wood gas if ication plant: a woodgas power plant with https://www.w3.org/1998/Math/MathML"> 4,800   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> electricity generation. The plant consists of https://www.w3.org/1998/Math/MathML"> 7 g a si - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> fierlines https://www.w3.org/1998/Math/MathML"> 1,800 N m 3 / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> woodgas each and 7 gasengine-alternator-sets with https://www.w3.org/1998/Math/MathML"> 685 k W e https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> each. 6. 1. 1.4 MW POWER PLANT IN PARAGUAY 6.1. FEEDSTOCK PREPARATION It is necessary for the gasification process to use clean wood-fue without stones and clay, otherwise the ash in the gasifier becomes slag and disturbe the gasification process. Therefore for the feedstock prepa- ration an area with a hard floor near the gasification plant is arranged. It is recommended that trunks of wood are first cut to lenghts from https://www.w3.org/1998/Math/MathML"> 50   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> up to https://www.w3.org/1998/Math/MathML"> 2.50   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for easier preparing and hand ing in the wood fuel comminution system. To accelerate the drying process it is an advanta- geous to solit the stems at the open air. A simole hydraulic solitter has been delivered. The wood residues must then be reduced in sizes to less than 7 cm lengths and https://www.w3.org/1998/Math/MathML"> 150   c m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> volume per piece. A drum chioper driven by a woodgas engine is used. The drum chipper runs appr. 3 hours per day producing the required wood fuel for 24 hours gasifier operation. From the chipper the wood chips are transported to a feedstock buffer with conveyor. The wood chips are loaded from the buffer into the feed hopper of the gasifiers. The feed hoppers are equiped to use the exhaust gas from the gas engines to reduce the moisture content of the wood. Connecting pipes from the engines to the feed hoppers are installed. 6.2. PLANT LAYOUT The IMBERT Power Plant in Loma Plata, the Chacco of Paraduay, consists of two down-draft gasifiers witn https://www.w3.org/1998/Math/MathML"> 1,800 N m 3 / n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> woodgas production each. The gasifiers are fed by means of hoppers with conveyors, which are installed at the front of the gasifiers in an underfloor oit. The fuel is transported from the hopper to the gastfier automatically to match the gasifiers consumption to balance the gas requirement of the engines. The IMBERT Wood Gasifiers thus operates at negative pressure which results from the suction of efther the gas engine or a gas blower. The total height of the https://www.w3.org/1998/Math/MathML"> 1,800 N m 3 / h - G a s i f i e r https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is https://www.w3.org/1998/Math/MathML"> 7.5   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and the outer diameter appr. https://www.w3.org/1998/Math/MathML"> 2.1   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The special construction of the IMBERT Gasifiers with gasifier hearth includes an automatic and rapid adjustment of gas production to the operating conditions so that only that gas required by the engine is produced. The wood descends through the gasitiers by gravity. At start-up, charcoal is loaded in and below the hearth with wood on top. Lighting is very simple: it is done by hand with some straw or some paper and a match. After start-up it only takes about five minutes for gas production to begin, because the charcoal reacts very quickly with the ar in the hearth. The total time of appr. 40 minutes is needed to achieve gas production capacity. The air intake is provided by a system of pipes and nozzles, with preheating of the air by the heat in the gas produced. Heat conservation is aided by insulation on the outer jacket. In the continuous gasification process, the solid fuel dries, carbonizes to charcoal and is gasified with air without external heat. In the gasification process the charcoal partly oxidises with the incoming air to carbon monoxide - co-a combustible gas and also partiy to incombustible carbon dioxide - CO2 - However, some carbon dioxide is reduced in the high temperature charcoal bed to co which increases the amount of the combustible gas, because during the down-draft gasification process the c0? the steam from the drying zone and the products from the pyrolysis zone must pass through the high temperature charcoal bed. The gasifier is designed such that even https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of design throughput, sufficiently high temneratures are produced that cracking of the most of heavy hydrocarbons is essentially complete, giving a gas practical free of tar. At such high temperatures the steam partly reduces to hydrogen - H2 - and oxygen - 02 - The released oxygen combines with carbon c to CO. In addition a small part of methane - CH4 - is released. The resulting hydrogen, the carbon monoxyde and the methane are the combustible components of the woodgas. The gas components CO2 and nitrogen - N2 also the ash are incombustible products. For the start-up of the gasifiers, starting blowers with flares and automatic electric ignitors are used and only a short time is needed to get product gas. The time varies with the size of the gasifier. If operation of the gasifiers is interrupted or terminated, the engines has to be turned off. If an appropriate temperature has already developed inside the gasifier, gasification re-starts immediately after restarting the suction blower, even after long breaks. The gas composition varies according to fuel wood and the load of the IMBERT Gasifiers and consists approx. of the following volume percent on a basis: The lower calorific value of the gas when using air-dried wood is between https://www.w3.org/1998/Math/MathML"> 4,830 - 5,460   k J / N m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> 1,150 - 1,300 k c a I / N m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , depending on the moisture content of the wood and the load on the gasifiers. The ash content of wood is approx. https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by weight, according to the dry substance. In the gasification process a part of the ash is discharged with the gas flow. Most of the ash and also some fine charcoal fall down into the ash collection chamber. through the lower grate of the gasifier. Normally the grate is moved from time to time by mechanical means to faciTitate the removal of the ash. The ash is readily removed through a gastight service opening with an automatic ash removal system After the gasification process the product gas flows through a dust separator. The pre-cleaned gas passes through a washer and the temperature falls below the dew point. Most of the constituents which might pollute the environment have been removed during the gasification process. Only a small quantity of condensate and ash have to be discharged. An electrostatic filter provides final cleaning of the gas. In this equipment all tiny water drops and any fine dust entrained by the gas flow are nearly completely removed. The reduction of the moisture content in the gas increases the calorific value and the removal of fine dust has an advantageous effect on the life of the combustion engine. Suitable instrumentation and control devices guarantee a continuous and mainly automatic operation. To achieve satisfactory operation, correct carburetion is important. With the usual quality of gas from IMBERT Gasifier, a pressure of 5.6 bars is generated over the piston in the engine under European conditions of operation, i.e. up to https://www.w3.org/1998/Math/MathML"> 500   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> above sea level, ambient temperature https://www.w3.org/1998/Math/MathML"> 20 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and With IMBERT Gasifiers the power of engines can be calculated with the information in the following table: HP performance kW output pe in bar 1 bar HP performance per 1,000 cm https://www.w3.org/1998/Math/MathML"> = 14.5 b s / m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stroke volume stroke volume 5.40 6.0 5⋅25 5.35 8.85 5⋅25 5.25 https://www.w3.org/1998/Math/MathML"> 8.85 10.0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 7.35 urbocharged with intercooler: 10.00 11.34 8.33 10.00 10.00 10.00 17.00 15.00 20.40 n Paraguay IMBERT installed three Waukesha L 7042 G gasengine-alternator sets (12 cylinders, 115.4 Liter/7,040 cu. in. cylinder displacement, 1 , 000 rpm). IMBERT adapted these gasengines on woodgas: Construction of woodgas/air mixer, installation of special spark plugs, adaption of engine control on woodgas etc: The engine power output with natural gas is 554 kWe, with woodgas appr. 6.3. WOODGAS-ENGINES Engine speed suction engine https://www.w3.org/1998/Math/MathML"> 1,000 r p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> https://www.w3.org/1998/Math/MathML"> 1.000 r p m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 465 kWe. Abstract 1.4 PLANT EXPANSION Up to now (March 1985) the IMBERT Woodgas Power PTant in Loma Plata, Paraguay runs more than 15,000 hours. Because the produced electricity is on https://www.w3.org/1998/Math/MathML"> 1 y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> part https://www.w3.org/1998/Math/MathML"> 1 y https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sufficient to satisfy the requirements of the customer, the extension of the plant is planed: with a further installation of one gasification line and the installation of turbochargers with intercoolers for the 3 existing engines. 2. 4.8 MW POWER PLANT IN MABURA HILL, GUYANA 7. 2.1 PLANT LAYOUT In the Sawmill Mabura Hill, Guyana, IMBERT installed in autumn 1984 the world's largest wood gasification plant. The plant starts operation in April 1985. The sawmill is located appr. https://www.w3.org/1998/Math/MathML"> 100   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> south from Georgetown in the tropic forest region. There is no electricity connection to the grid and diem sel transportation to the sawmill will be expensive. Due to lack of water with good qualitiy steam production burning wood waste is impossible. The sawmill will log https://www.w3.org/1998/Math/MathML"> 94,000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lumber per year. The output of the sawmill (sawn lumber walaba and Greenhart) will be https://www.w3.org/1998/Math/MathML"> 42,000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> yearly. Tosatisfy the power requirements of the sawmill and the township. IMBERT delivered a woodgas power plant with https://www.w3.org/1998/Math/MathML"> 4,800   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> electricity generation. The plant consists of 7 gas if ier-1ines https://www.w3.org/1998/Math/MathML"> 1,800 N m 3 / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> woodgas each with the same lavout as the Paraguay Plant (see pictures 2-1 and 2-2). But IMBERT installed in Guyana MWM (Motorenwerk Mannheim, Germany) engines G 441 BV 16 with appr. 685 kWe each (speed 900 rpm, 16 cylinders, bore https://www.w3.org/1998/Math/MathML"> 230   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> stroke https://www.w3.org/1998/Math/MathML"> 270   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , cylinder displacement 179.481, compression ratio https://www.w3.org/1998/Math/MathML"> 10 : 1 ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Two gasification lines and two gasengine-alternator-sets had been tested in the IMBERT works in Weilerswist and reached the required performance. The yearly fuel wood consumption will be 17,000 tons. This wood waste is equivalent via gasification to appr. 10,000 tons of diesel oil or 7,000,000 DM foreign currency. The plants in Paraguay and Guyana show that local available wood waste can be turned into necessary energy and the valuable crude oil is saved. Energy from biomasses is both economical and reliable. Pict.2-1: IMBERT Gasifier Pict.2-2: 7 MWM Gasengine A1ternator Sets THE BAMBOO : RAW MATERIAL FOR PAPER INDUSTRIES OR FER MENTATION INDUSTRIES T. TSHIAMALA, A. MOTTET, L. FRAIPONT, P. THONART, M. PAQUOT Département de Technologie FACULTE DES SCIENCES AGRONOMIQUES DE L'ETAT B 5800 GEMBLOUX, BELGIUM 8. Summary In opposition to softwoods which are important raw materials in paper industries, bamboo sylviculture and needs in tropics are well known for a long time. Bamboo can provide rapidly a good homogeneous ligno-cellulosic stock. Different bamboes species have been characterized and treated in order to obtain differents types of pulp. These pulps have been used for par per making or sugars production. Pretreatment such as sulfate or sulfite cooking are very convenient for both applications. At the opposite sight, 1ime and thermomechanical processes can not be used for such application. 9. PURPOSE OF THE WORK In opposition to softwoods which are important raw materials for paper industries, bamboo sylviculture and needs in tropics are well known for a long time. Bamboo can provide rapidly a good homogeneous ligno-cellulosic stock. The work aims testing the bamboo aptitude for the development of two major industries : paper industries by using bamboo's fibres or fermentation industries after cellulose hydrolysis. 10. METHOD OF APPROACH Different bamboes species have been characterized at an anatomical point of view. The bamboes have been treated in order to obtain different kinds of pulp. The main difference of these pulps results from their chemical composition, especially lignin content. The different pulps have been used for paper making and sugars production by cellulose hydrolysis. Materials and methods have been published previously (Thonart et al, 1979; Tshiamala et a1, 1984 a; Tshiama1a et a1, 1984 b). 11. SIGNIFICANT RESULTS Different analysis has been done to characterize the pulp: chemical composition, fiber length, .. (Table 1) Lime and thermomechanical processes give pulp with a high iignin content (more than https://www.w3.org/1998/Math/MathML"> 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). The pulp are difficult to test and not well hydrated. They can not really be used for paper making or cellulose hydrolysis. The situation is different with sulfate pulp and sulfite pulp (figures 1,2 and 3 https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Good quality papers, especially mechanical strengh are obtained with these pulps (eg. Breaking length : https://www.w3.org/1998/Math/MathML"> 6000   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , tear : 120, bursting strengh https://www.w3.org/1998/Math/MathML"> 4,0 K g / c m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Moreover, these cellulosics substrates are easily hydrolysed by enzymes. Using Trichoderma reesei QM 9414 ( 0,2 U.I.) cellulase complemented by Aspergillus niger https://www.w3.org/1998/Math/MathML"> β - glucosidase ( 6 U . I . ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , one can obtain hydrolysis yields about https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , with regard to the whole bamboo (Table 2). These results show that the dissociation of the lignin carbohydrates complex is sufficent to obtain important hydrolysis yields. 12. CONCLUSION Bamboo may be a raw material for paper industries or fer mentation industries. Sulfate or sulfite cooking are very convenient for both applications. PULPS Table 1 : Bamboo pulps characterization. https://www.w3.org/1998/Math/MathML">   TIME OF HYDROLYSIS     SULFATE     SULFITE     LIME   ( h ) 7,3 8,8 2,9 1 15,0 17,0 5,1 3 17,9 21,8 6,5 5 35,4 31,3 10,9 24 42,7 38,1 13,1 48 49,0 46,9 13,8 72 1,6 3,1 3,9 3,9 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Table 2 : Hydrolysis yield for different bamboo's pulps (hydrolysis percentage with respect to the whole bamboo). 13. REFERENCES THONART, Ph. PAQUOT, M., MOTTET, A. (1979). Hydrolyse enzymatique de pâtes de papeterie - Influence des traitements mécaniques de préparation. Holzforschung, 33,197-202 TSHIAMALA, T., THONART, Ph., PAQUOT, M., FRATPONT, L. et A. MOTTET. (1984a) Hydrolyse enzymatique des pâtes de Bambou : Influence des modes de cuisson et des traitements mécaniques. Holzforschung, 38,343-351. TSHIAMALA, T., FRAIPONT, L., PAQUOT, M., THONART, Ph. et A. MOTTET. (1984b) Etude comparative des pâtes de Bambou. Holzforschung, 38, 281-288. ISSUES RELATED TO INTRODUCTION OF ENERGY-CANE TO LATIN-AMERICA P. JAWETZ and G. SAMUELS Consultants on Agriculture and Energy Policy https://www.w3.org/1998/Math/MathML"> 235 E . 54 S t . N e w Y O I k , N . Y . 10022 , U S A https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Abstract Summ ary Energy-cane is sugar cane managed for high biomass yield - fermentable juice for fuel alcohol and combustible solids for electricity - Latin America grows sugar for domestic consump- tion and for export to favorably priced sugar quota markets; the excess is sola to a depressed world narket. Switching from excess sugar production to energy-cane will enable the use of alcohol for domestic fuel needs and for exports of ethanol octane boosting additive to gasoline needed because of Lead plase-out in the United states and in Europe. Quantities of ethanol produced on these "excess" 1 ands, that is without expanding cane agriculture, could reach 3.6 billion liter of fuel ethanol in Brazil alone. The fiber or woody residue of the energy-cane (the bagasse) can be used for boiler fuel for domestic electrical production eliminating imports of Eluel oil. 14. INTRODUCTION Columbus broucht sugar cane to Hispaniola. Eventually cane became a source of food and a major export crop for most of Latin America. Now, increased population and higher living standard requirements cause increasing pressure on governments and on the land calling to provide more food, clothing, shel- ter and energy: energy being supplied now mostly by importa- tion of oil. Energy-cane is sugar cane managed for high biomass yield - total fermentable juice for fuel alcohol and combustible som 1ids for electricity rather than for crystallizable sucrose. Rolicy problems at government planning levels, in the fiela and in the sugar factory surface when introducing energy-cane management of sugar cane in traditional sugar cane growing areas. phe problems vary with location but certain common Eea tures exist. The object of this paper is to present issues re- lated to the introduction of energy-cane to Latin America and to suggest possible solutions.

THE ENERGY-CANE CONCEPT

When sugar cane is grown for crystallizable sugar, high sucrose varieties are used and agronomic efforts include restricting nitrogen fertilizer application, 1 imiting irriga- tion near harvest to enhance maturity, and harvesting when the cane reaches its maximum sucrose content. The fields are usually burnt prior to harvest to reduce cane trash (tops of the cane stalk and leaves). The sugar cane factory is geared to extracting as much sucrose from the cane stalk as econo- mically feasible using all of the bagasse as a boiler fuel. 15. ADOPTING THE ENERGY-CANE CONCEPT (5) ROTSTEIN, J. (1983) Brazilian Alcohol in The American Gasoline. Center for strategic & International studies, (6) JAWETZ, P. (1980), The ECOnOmic Realities of Alcohol Fuels. Sugar Journal Vol. 42(8), pp. 13-16. (7) SAMUELS, G. (I984), Potential production of energy- cane Eor fuel in the Caribbean. Energy progress, Vol. 4(4), 249-51, Decerber. (8) JAWETZ, P. and SAMUEIS, G. (1983). Energy as an agricultural output in the production of fermentable fuel ethanol. Lecture Book, Int. Symposium-norkshop on Renewable Energy Sources, 18 - 22 March, Lahore, Pakistan, Clean (9) SAMUELS, G. and JAWETZ, P. (1984) . POIICY Issues In the transfer of energy cane to the Cartbbean. Southeast Industrial Biomass Energy Exposition, Technical Review Sesstons, Atlanta, GA. Nov 28-29. Table 1 Potential Electric and Ethanol production from Energy-Cane Grown on Land Now Devoted ro Sugarcane For Non Secure Markets. for domestic consumption and U.S. quota, 1983-84 (2).

Based on an assumed whole energy cane (stalk, tops and leaf trash) production of https://www.w3.org/1998/Math/MathML"> 125 M T / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (except Colombia where present production is already double other uatin American countries)

thus energy cane production is assumed at 188 MT/ha where whole energy cane fiber produces https://www.w3.org/1998/Math/MathML"> 364 K W h / M T https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or https://www.w3.org/1998/Math/MathML"> 45,500 K W h / h a . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

From data by Bonnet Jr. J.A., director of CEER, Puerto Rico.

Potential electrical production from energycane divided by domestic electrical production.

One MT whole energy cane produces 52 liters ethanol from cane juice times https://www.w3.org/1998/Math/MathML"> 125 M T / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> whole cane or 6,50011 ters https://www.w3.org/1998/Math/MathML"> / h a https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> THE POTENTIAL FOR ALCOHOL AS A FUEL FOR

SPARK IGNITION ENGINES IN TANZANIA J.S. CLANCY and G. RICE Department of Engineering, University of Reading, Reading, U.K. RG6 2AY and S. KAWAMBWA Institute for Production Innovation, University of Dar-es-Saleem, P.0.Box 35075, Dar-es-Salaam, Tanzania 16. https://www.w3.org/1998/Math/MathML">   Summary   _ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Tanzania experiences restrictions on liquid fuel availability. In the rural areas this has considerable implications for irrigation and for small scale industry. This paper describes work currently in progress on a systems study to assess the potential contribution that locally produced alcohol could make to national fuel self-sufficiency, in particular for stationary spark ignition engines in rural areas and its impact on agricultural production. In an attempt to overcome the problem of competition of fuel crops for agricultural land it is proposed that the raw material for ethanol production should be market Eruit wastes, which at present constitute a disposal problem A 4-stroke single cylinder https://www.w3.org/1998/Math/MathML"> 2.2   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Briggs and stratton spark igni- tion engine is currently being tested with fuel of different ratios of ethanol to water to assess its power output and performance. Sta- tionary engines are generally over-rated for their application so that it is expected that a loss of power-output should not be detrimental to the end-use. The higher the percentage of water the engine is able to run on without too great a loss in performance has considerable significance for the economics of the alcohol production. An optimis- ation of these parameters is being undertaken INTRODUCTION Agriculture is the key sector in the Tanzanian economy providing go* of total employment and https://www.w3.org/1998/Math/MathML"> 80 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of exports (1). The Government is currently placing emphasis on agricultural development to increase food production. When considering suitable strategies for adoption the low level of mechan- isation would make this appear a priority. However, this has considerable implications for imports, particularly equipment and fuels. The University of Reading, in conjunction with the Institutaof Prod- uction Innovation, has been assessing the potential for small scale jrrigation using spark ignition engines with locally produced enthanol as the fuel. Irrigation is not commonly practiced in Tanzania and so a prop- erly implemented scheme should make a major contribution to increased procuctivity. Such a system could have additional benefits. Increased food outputs not only provides more for local consumption, reducing dependency on imports and food a https://www.w3.org/1998/Math/MathML"> 1   d https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> but also increases incomes in the rural areas. Local small scale production of ethanol should also provide jobs which should help to 17. A SYSTEM OF IRRIGATION APRROPRIATE FOR TANZANIA Irrigation projects in Africa do not appear to have been a major success. The main criticisms have been levelled at large scale dam schemes and those notable successes appear to have been primarily with small scale schemes using ground water or lift ircigation (3). Small scale projects would prove to be more compatible with the average Tanzanian land holding https://www.w3.org/1998/Math/MathML"> ( ∼ 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ha). (4). When choosing a power source for lift irrigation the authors believe that small englnes provide amore flexible option since they are more easily transported than some of the other renewable energy options. Their operation is also less subjected to climatic conditions. The choice of engine is usually based on fuel cost, which means diesel (compression ignition or CI) engines are selected in preference to kerosene (spark ignition or SI) engines. However, ST engines are lighter and therefore can be employed for other purposes at other locations within a farm ox village. Although their life time Is less than CI engines they have a lower capital cost. The use of magneto ignition helpe to keep down the system cost. In the past they were originally widely used for stationary purposes and small boat propulsion. Today several countries still employ them for water pumping e.g. Guyana (5). The need is primarily for a much cheaper fuel. SI engines operate as well on ethanol as petrol. The major problem is a loss of power output, which can be compensated for by using high compression ratios. There is some concern about the poor lubrication properties of ethanol. This could be overcome by using a 2 stroke engine, with a suitable vegetable oil (e.g. Castor oil, locally available in Tanzania) as a lubricant. 18. CONSTRAINTS The fear that prime agricultural land may be diverted to fuel production is understandable. To overcome such criticism, the authors therefore are proposing the use of fruit waste from markets and farms as a suitable feedstock for ethanol production. The additional advantages to this source are that its avallability is not restricted by geographical distribution, or seasonal variation, and it provides a solution to a disposal, and a pogsthle health, problem. The potential from cashew apples alone( a non-food source in Tanzania) has been estimated by IPI as 30 to 50 million https://www.w3.org/1998/Math/MathML"> / Q https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per annum. From this it is possible to estimate that 5,000 to 25,000 ha of arable farm plots could be irrigated (using parameters of 2 ha irrigated area at https://www.w3.org/1998/Math/MathML"> 7   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> head requiring https://www.w3.org/1998/Math/MathML"> 60   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per day per ha (6)). (ii) Production Large scale production systems have the advantages of economy of scale. However, in a country like Tanzania, the high cost capital equipment woula place a heavy burden on foreign exchange. Also large systems require a well organised transport system which will use large quantities of diesel o11, and form a significant part of the ethanol production costs. However, if a smaller system is used, based on the quantities of feed stock available at the end of local markets, the problem of transporting the feedstock hare been overcome and the cost can be neglected. There is a need to devel- (5) JORDON, L.A. (1984). Feasibility Study of a Low Lift Pump for Guyana's Costal Agriculture. MSC Thesis, University of Reading. (6) HALCRON, Sir William and Partners, in association with IT Power Ltd. (1983). Small Scale Solar-powered Pumping Systems: the technology, its economics and advancement. UNDP project GLO/80/003. (7) CLANCY, J.S., KAWAMBWA, S.J.M. and RICE, G. (1984). The Potential for Alcohol as a Fuel in SI Engines in Rural Tanzania. Proceedings of Conference on Small Engines and their Fuels, University of Reading, Sept. 1984. Pub. Institute of Energy, Iondon. IV. INDUSTRIAL 1. INTRODUCTION The economic feasibility of an anaerobic digester depends in many instances on the extent that the produced biogas can entirely be used within the farm The easiest way ts to burn the gas for space heating and hot water production. However. in sommer usually excess gas is produced. An attractive alternative to just flare the gas off is to burn it in a engine either to alternative to just flare the gas offis to burn it in a engine either to a generator or to power agricultural machinery such as a ventilator for hay aeration. AT1 of the three posibilities were subject of major or minor projects of our group during the last three years and will be shortly discussed in this paper.

CHANGE OF A TRACTOR DIESEL ENGINE TO DUAL FUEL OPERATION

Adaption of the tractor: The major problem of using biogas as a tractor fuel is its low energy density In order to carry an adequat amount of gas on the tractor. it has to be compressed to https://www.w3.org/1998/Math/MathML"> 200 bar https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> which corresponds to the upper limit allowed by law in Switzerland. The space for gas bottles is Timited. The best solution found for our Deutz D6507 test tractor was the fixation of four bottles of 401 each along both sides of the hood and a fifth bottle at the side below the drivers cabin https://www.w3.org/1998/Math/MathML"> ( Fig . 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This set-up allowed an equal distribution of the weight and an optimal protection of the bottles without impeding the driving. The total amount of gas ( https://www.w3.org/1998/Math/MathML"> 60 % C H 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) of https://www.w3.org/1998/Math/MathML"> 60   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (STP) corresponds to about 401 itre of diesel and allowed an operation of 3.5 hours at full load or about 7 hours at https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> load, an average power output to be expected under Swiss farming conditions. Fig.1: Dual fuel (biogas/diesel) test tractor To fuel the engine, the gas was expanded to https://www.w3.org/1998/Math/MathML"> 2 m i 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ibar underpressure by the aid of a reduction valve developped in Italy (iartarini) for cars running on natural gas. The valve is thought to be heated by the engine s cooling water circuit. With the test tractor beeing air cooled. the valve had to be placed in the hot air stream in order to avoid freezing of the coz white the gas was expanded. Adaption of the diesel engine: Biogas is an excellent fuel for engines with spark ignition, thanks to its high knock resistance quality. Today however, the predominant part of the agicultural tractors are powered by diesel engines. For their use with biogas the dual fuel system is a very acceptable solution because it has the capability of running entirely on diesel oil if the gas supply fails. The major problem we have been concerned with when we converted the motor. was the control of the amount of diesel injected to ignite the air/gas mixture which should preferably remain constant over the whole range of engine speed. A simple blocking of the control rod at a fixed position was not possible. because with a fuel pump in row the oil delivery increases with increasing rpm's. For an engine speed correlated adjustment of the control rod, a pneumatic reset device was installed which was regulated by the underpressure of the air intake manifold. In a first set-up this same reset device was also used for starting the dosage of the oil injection when the engine operation was changed from diesel to dual fuel (Fig. 3 ). This purely mechanical regulation worked fine however. it was very difficult to install due to the limited space available and the adjustment of the control rod was rather delicate. A simpler, but slightly more expensive solution was found with an electric relay allowing to place the pneumatic device closer to the fuel pump (Fig.2 and 3).

Diesel Tank

Injection pump

Nozzle

Pressure bottle (max. 200 bar)

Reduction valve

Regulation valve

Gas inlet

Throttle

pneumatic regulator

Switch-board for dual fuel operation

The power regulation of the engine in the dual fuel mode i.e. the regulation of the gas inlet valve was in a first construction electrically controlled. In the final design however, the mechanical speed regulator of the tractor was used to control the gas valve, as it was recommanded by Tartarini (Fig.3). Fig.3: Modifications with the "Tartarini-Kit" changing the diesel into a dual fuel engine. A. Mechanical regulator Bosch EP/RSV B. Pneumatic regulator C. Gas regulation valve d. Control rod e. Arc lever to guide control rod: switched on and of electromagnetically x. Gasline from reduction valve y. to Venturi z. to intake manifold Test resuTts: On the test stand the engine was adjusted in such a way, Abstract that during diesel and dual fuel operation the same torque respectively brake power characteristics were obtained (Fig.4). Except for a short power brake. the engine could easily be switched from one mode of operation into the other. At full load the same efficiencies were achieved in dual fuel Fig.4: Torque and brake power characteristics during diesel and dual-fuel operation. operation as with diesel alone, whereas at partial load. diesel alone was superior. While at nominal performance the diesel consumption amounted to https://www.w3.org/1998/Math/MathML"> 220   g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in full diesel operation, https://www.w3.org/1998/Math/MathML"> 30   g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of diesel was required in dual fuel operation in addition to the https://www.w3.org/1998/Math/MathML"> 4001 / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of biogas. The savings of diese fuel thus amounted to about https://www.w3.org/1998/Math/MathML"> 86 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . At a https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> load and an engine speed of https://www.w3.org/1998/Math/MathML"> 1 ' 400 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> rpm (the average load condition of agricultural tractors in Switzerland), the consumption of the diesel operation amounted to https://www.w3.org/1998/Math/MathML"> 250   g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and for the pilot spray operation to https://www.w3.org/1998/Math/MathML"> 80   g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at a gas consumption of https://www.w3.org/1998/Math/MathML"> 6001 / k W h   ( F i g . 5 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The saving of the diesel fuel thus amounted barely to https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Fig.5: Specific diese 1 oil https://www.w3.org/1998/Math/MathML"> ( A ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and biogas consumption ( B ) during dual fuel operation in https://www.w3.org/1998/Math/MathML"> g / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> respectively https://www.w3.org/1998/Math/MathML"> 1 / k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> .

A SMALL SPARK IGNITION ENGINE OPERATED ON BIOGAS

test, the original efficiency of the engine running on petrol at a generator power of https://www.w3.org/1998/Math/MathML"> 3.25   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was improved from https://www.w3.org/1998/Math/MathML"> 16.6 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 24.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by reducing the size of the carburator nozzlen During the operation with biogas (63% methane) the efficiency of the system was by 1% to https://www.w3.org/1998/Math/MathML"> 3 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> lower than with petrol over the whole power range (Fig.6). At https://www.w3.org/1998/Math/MathML"> 3.25   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> the engine eficiency was https://www.w3.org/1998/Math/MathML"> 23.5 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> hence still better than the original set-up. An even higher efficiency and power output https://www.w3.org/1998/Math/MathML"> ( 25.2 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> resp. https://www.w3.org/1998/Math/MathML"> 3.7   k W ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was achieved when the orifice of the gas regulator was slightly decreased however, the engine speed could not be kept Fig.6: Efficiency and brake power of the spark ignition engine runing either with petrol or biogas. constant anymore. In the upper power range the gas consumption was about https://www.w3.org/1998/Math/MathML"> 1   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per kwh. Because the motor was equipped with a cable starter, the few piston strokes did not allow the formation of an ignitable gas mixture. Hence, the engine was allways started with petrol and switched to gas later on. THE USE OF GAS FROM BIOMASS IN ENGINES - EXPERIENCES E. Nolting, M. Leuchs M.A.N.-Neue Technologie, Munich, Germany 19. Sumary Up to now the only suitable way to get power out of biomass (up to about l MW) is by applying internal combustion engines. In almost all cases the fuel is gaseous being produced in anaerobic digesters or thermal gasification or pyrolysis-systems. Experiences with engiThes running on gaseous Euels EIDI biomass have reached a consideram from sewage water treatment plants, anaerobic digesters of agricultural wastes, landfills and thermal gasification plants. As a result one can state, that a successful performance of gas engines is given in all cases. The essential premise for flawless operation is a gas sufficiently cleaned Erom dust (less than 5 pm and https://www.w3.org/1998/Math/MathML"> 0,6 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) and corrosive, oil spoiling gases like https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , fluoric and chloric hydrocarbides. 20. General remarks Adapting internal combustion engines to different gaseous fuels, several points have to be observed:

The gas heating value and the ignition property of the gas-air-mixture have to be sufficient in the sense, that conventional ignition systems can initiate the combustion.

The knocking quality of the gas has to be determined or interpolated

from experience in order to adjust the compression ratio of the engine.

The gas-air mixing device has to be adjusted to the specific air/gas ratio needed. In some cases the device has to be able to follow changes of gas quality.

The influence of the gas quality on power-output and efficiency of the engine has to be considered (Tab.I and Tab. II).

For gases from biomass discussed in this paper (gas from sewage water treatment plants, anaerobic digesters for agricultural wastes, landfills and thermal gasifiers) all of these problems are solved. The gas engine is ready for application in the field of gaseous fuels from biomass. We can state this, because we have gained a lot of experiences in different plants. 21. Specific experiences 2.1 Gas from sewage water treatment plants The gas quality of sewage water treatment plants is in general well stitable for gas engines, because the methane volume is about https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Only the corrosive component https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> has to be considered carefully. For Elawless operation the engine manufacturers 1ike M.A.N. allow 0,15% (volume) of https://www.w3.org/1998/Math/MathML"> H 2   S https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This corresponds to the sulfur content in heavy fuels. The sewage water treatment plant at Groblappen has long term experiences with gas engines being used for heat and power or heat and compressed air. There are eight engines installed with a total capacity of https://www.w3.org/1998/Math/MathML"> 6,200   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . They are in operation since the mid of the sixties with more then 40,000 running hours. At the soest sewage water treatment plant a highspeed gas engine (1500 rom, https://www.w3.org/1998/Math/MathML"> 155   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) is running on sewage gas or natural gas. The switch over is done automatically. The cogeneration modul is used as emergency set as well and running since 1980 more than 20,000 hours. 21.1. Gas Erom anaerobic digesters The gas from anaerobic digesters is basically the same as that from sewage water treatment plants. There are differences, though. The purpose of sewage water treatment plants is to clean waste water and anerobic gas production is only one part, while anaerobic digesters for agricultural wastes are optimized for gas production for the gss engine these differences are of minor importance. Usually the gas from sewage water treatment plants has to be cleaned from H__ more carefully. The plant, of which we can report successful performance, has been installed in 1982 in The anerobic digester - two containers of https://www.w3.org/1998/Math/MathML"> 500   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> each - was built as a testplant with federal money. The biomass is a mixture of cattle and pig manure and vegetable wastes. The engine installed is capable of producing https://www.w3.org/1998/Math/MathML"> 85   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> electric and https://www.w3.org/1998/Math/MathML"> 140   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> thermal power. The farm is separated from the public grid, whenever the engine rune during working hourg (about lo hours every working day). The heat of the engine available at https://www.w3.org/1998/Math/MathML"> 90 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is partly needed for the digester to keep the temperatur at https://www.w3.org/1998/Math/MathML"> 35 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and used for other heating purposes. Bngine related problems have been H_2 corrosion in gas supply components like pressure governers. A H_2 filter had to be installed. A total of 4000 running hours has been reached by today. 21.2. Gas from landfills Gas from landfills originates from anaerobic processes in oxygen free zones within a landfill site. Gasproduction usually starts a few month after the deposit and lasts about 20 years. The gas quality is less steady, because of less specific conditions of the gas production. The range of the methane content is between https://www.w3.org/1998/Math/MathML"> 30 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , because of an important amount of nitrogen and a few percent of oxygen. The nitrogen is the leftover of the air, which was included in the deposited materials and the oxygen of which has been used up by aerobic processes. Air, which is sucked through leaks in the landfill and the gas wells, is responsible Depending on the kind of waste, which has been deposited, traces of further gas components create problems for engines. Besides H_2 which can be handled by filters and by the material, traces of cholorine and Elourine in hydrocarbons up to several hundred mg/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> have been found. It looks like contents up to about https://www.w3.org/1998/Math/MathML"> 50 - 100 m g / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> can be tolerated in gas engines. To handle higher contents of corrosive gas components, research is concentrating on new materials and oil additives for the engine. We can report about two plants, one in Ludwigsburg (stuttgart) and one close to Biberach: Ismaning. for the oxygen. 21.3. Gas from thermal gasifiers c) It is our view, that the remaining technical problems are solvable. The economical problems still seem very big. The costly part beeing on the side of gas production and cleaning, where further progress is necessary, Not much cost reduction can be expected for the power units. d) Application of the technology using gas from biomass will strongly depend on following points:

Biomass must be available cheap or the cost for its deposition should be a credit item.

The cost of conventional energies have to be high. This is the only way, the high capital costs of bio-energy systems can balance the economics against conventional energy supply systems.

ORIGIN OF THE GAS MAJOR GASCOMPONENTS HEATING VALUE RANGE MJ/m https://www.w3.org/1998/Math/MathML">   3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> METHANE NUMBER SEWAGE WATER https://www.w3.org/1998/Math/MathML"> C H 4 , C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 19-21 130 ANAEROBIC DIGESTERS https://www.w3.org/1998/Math/MathML"> C H 4 , C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 19-23 130 LANDFILLS https://www.w3.org/1998/Math/MathML"> C H 4 , C O 2 ,   N 2 , 02 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 12-21 110-130 THERMAL GASIFIERS https://www.w3.org/1998/Math/MathML"> H 2 , C O , C H 4 , C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , https://www.w3.org/1998/Math/MathML"> N 2 , 0 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , 4-6 70 Table I: Some properties of gases from biomass. ORIGIN OF THE GAS STOCHIOMETRIC AIR CONSUMPTION https://www.w3.org/1998/Math/MathML"> m 3   A / m 3 G https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> HEATING VALUE OF STOCHIOMETRIC MIXTURE https://www.w3.org/1998/Math/MathML"> M J / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ENGINE POWER oUTPUT (% OF NATURAL GAS ENGINES) SEWAGE WATER 5,7 3,2 95 ANAEROBIC DIGESTERS 5,7 3,2 95 LANDFILLS 4,7 3,1 91 THERMAL GASIFIERS 1,0 2,5 75 NATURAL GAS 10,0 3,4 100 Table II: Heating value of stochiometric gas-air-mixtures and engine power output (natural gas https://www.w3.org/1998/Math/MathML"> = 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) https://www.w3.org/1998/Math/MathML">   Fig.I:     Engines with a cylinder volume   v H . Schematic drawing of the volume     share of air and fuel. Remember, that about   60 %   of the wood gas     are not burnable.   https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Fig.II: Engine power output for different fuels and varying λ y https://www.w3.org/1998/Math/MathML"> ( = https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> real air volume/stochiometric air volume), setting the diesel engine with https://www.w3.org/1998/Math/MathML"> λ V = 1.35 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> equal to https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . AQUATIC BIOMASS PRODUCTION AND PISCICULTURAL WASTE STABILIZATION PRODUCTION DE BIOMASSE AQUATIQUE, EPURATION D'EFFLUENTS DE PISCICULTURE ET ESSAIS D'AQUACULTURE C. LE FUR, C. SIMEON, M. SILHOL, Ph. BLACHIER Commissariat à https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Energie Atomique, IPSN/DPS/GETA BP 171,30205 Bagnols sur Céze Cedex (France) 22. Résumé Le pressent travail entre dans le cadre des recherches entreprises par le Commissariat à 1 Energie Atomique sur la valorisation des eaux basse temperrature provenant du complexe industriel Eurodif-Cogema de Pierrelatte. La démarche suivie peut se dëcomposer en trois parties

êpuration : évaluation des possibilitês de dépollution des eaux de

rejet d'une anguilliculture par des macrophytes aquatiques (jacinthe d'eau et laitue d'eau). Les abattements observess en 4 jours sont de 1'ordre de: https://www.w3.org/1998/Math/MathML"> N H 3 : 95 % , N O 2 : 94 % , N O 3 : 47 % , P O 4 : 85 % , D C O : 90 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>

biomasse: détermination de la capacité annuelle de production végé-

tale. Les resultats sont respectivement de 46 t/ha/an (M.S.) pour Eichhornia crassipes et 39 t pour Pistia stratiotes.

aquaculture: essai de recyclage d'une fraction de la biomasse pro-

duite dans https://www.w3.org/1998/Math/MathML"> 1 ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> alimentation de poissons macrophytophages (Tilapia Zillii) 23. INTRODUCTION Les premiēres recherches du Centre d'Etudes Nucléaires de la Vallée du Rhône sur les possibilités d'utilisation de 1'eau de refroidissement de 1"usine de sêparation isotopique (Eurodif) ont débouchê en 1976 sur 1 a construction de 4 ha de serres maraichêres pilotes. Depuis 1984,40 ha de serres et 2 ha de pisciculture sont fonctionnels. 24. MATERIEL ET METHODES Les caractêristiques de la station expérimentale utilisëe ainsi que les conditions climatiques de la region de Pierrelatte ont déjá été décrites (1), (2). La pisciculture fonctionne avec 55 bassins. Les eaux rêsiduaires repressentent https://www.w3.org/1998/Math/MathML"> 1000   m 3 / h . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Seule une fraction de https://www.w3.org/1998/Math/MathML"> 1 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> eau brute (eau de surverse + eau de nettoyage des bassins) alimente les 10 canaux du pilote biomasse. L'essai https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> aquaculture https://www.w3.org/1998/Math/MathML"> s ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> est déroulé en deux temps. La reproduction a eu lieu dans un canal en terre á une température moyenne de https://www.w3.org/1998/Math/MathML"> 25 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (système en eau verte). Les fingerlíngs ont êtê transfërês en aquarium de : 60 l, 6001 ou https://www.w3.org/1998/Math/MathML"> 5   m 3 : https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> température régulée a https://www.w3.org/1998/Math/MathML"> 27 ∘ C . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> 25. EPURATION Experriences de lagunage (êtë). Deux essais ont été pratiquês dans un canal clos pendant https://www.w3.org/1998/Math/MathML"> 25 j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (A) puis https://www.w3.org/1998/Math/MathML"> 14 j https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (B). Les conditions climatiques êtailent sensiblement identiques, pH: 7,58 et température de https://www.w3.org/1998/Math/MathML"> 1 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> eau https://www.w3.org/1998/Math/MathML"> 17 , 1 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (A), https://www.w3.org/1998/Math/MathML"> 20 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (B). Les teneurs de dëpart en sels dissous en mg/1 êtaíent: (A) https://www.w3.org/1998/Math/MathML"> N O 2 - N : 0,14 , N O 3 - N : 2,86 , P O 4 - P : 0,49 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Figure 1 (B) https://www.w3.org/1998/Math/MathML"> N O 2 - N : 0,11 , N O 3 - N : 1,9 , P O 4 - P : 0,22 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> FIGURE 1 CONCLUSION La fiabilitê et le dimensionnement https://www.w3.org/1998/Math/MathML"> d * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> un ouvrage https://www.w3.org/1998/Math/MathML"> d ' https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> épuration d https://www.w3.org/1998/Math/MathML">   * https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> eaux résiduaires de pisciculture par un lagunage axe sur l'utilisation de la jacinthe d'eau après dëcantation (traítement Iaire) nëcessite des essais preliminaires dans ies conditions climatiques identiques a celles de son lieu d'utilisation (influence de microclimats : rayonnement solaire, tempêrature de https://www.w3.org/1998/Math/MathML"> 1 † https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> air, vent dominant). Il est nécessaire d'autre part de prêvoir un équipement de traitement phytosanitaire. La production moyente envisageable a Pierrelatte se situe aux alentours de https://www.w3.org/1998/Math/MathML"> 55 t / h a / a n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (M.S.) pour une culture allant du 15 avril au 15 novembre. 26. REFERENCES (1) SIMEON, C., SILHOL, M. and LE FUR, C. (1984). Simultaneous waste water stabilization and macrophyte production for temperate countries. Symposium Energy from biomass and Wastes VIII., https://www.w3.org/1998/Math/MathML"> 30 / 01 - 03 / 02 / 84 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Lake Buena Vista, Florida. Published by I.G.T.. Chicago, I11inois. 163-192 (2) SIMEON, C., LE FUR, C. and SILHOL, M. (1984). Aquatic biomass and waste treatment. Symp. Bio Energy 84, June 18-21, 1984, Gothenburg, Sweden. (3) FLORENTZ, M. (1982). Contribution à 1'élimination du phosphore des eaux usées par voie biologique. Thèse, Univ. Nancy I, France. (4) Mc VEA, C., BOYD, C.E. (1975). Effects of water hyacinth cover on water chemistry, phytoplankton and fish ponds. J. Environ. Qua1, 4(3) : 375-378. UNDERSTANDING REFUSE DECOMPOSITION PROCESSES TO IMPROVE LANDFILL GAS ENERGY POTENTIAL D J V CAMPBELL https://www.w3.org/1998/Math/MathML">   1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , E R PIELDING https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and D B ARCHER https://www.w3.org/1998/Math/MathML">   2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> AERE Harwell, Oxfordshire, https://www.w3.org/1998/Math/MathML"> U K 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> andAFRC Food Research Institute, Norwich, UK Summary Understanding refuse decomposition processes in landfills is an important prereguigite in achtering maximum yields of abstracted Luportant prefequisite in achieving maximun yields of abstracted gas for use as an energy resource. Refuse core samples were taken from a number of different landfill sites and incubated in the laboratory. Gas production rates were measured and the samples were analysed chemically and microbiologically. Techniques for the jaentification and enumeration of methanogenic bacteria in landfill samples are being developea so that, for the first time, data from the field can be compared with information gained in the laboratory on the chemical and microbiological composition of landfill samples. We show that landfill operational methods, particulaxly those which affect temperature and moisture content of the refuse, influence the development of appropriate microbial cottununities which, in turn, control the degradation processes. 27. Introduction Tandfill gas is produced by the microbial deqradation of organic matter present in deposited wastes in landfill sites. The dramatic increase in interest, in harnessing valuable energy resources, over the lagt few rears has regulted in the implementation of uartous gas the last few years, has resulted in the implementation of various gas abstraction and utilisation projects around the world. Ime current number of operational and proposed projects is probably approaching one hundred, representing a substantial commitment, by many different organisations to the realisation of the potential viability of the technolocy. This is most notably so in the United states, where the technology was initially developed and has now become a major growth industry (1). Although many of the engineering aspects of gas production are now well understood, less attention has so far been given to understanding the mechanisms of waste decomposition. This understandiang is essential if control of gas production, and/or maximisation of potential yields of gas are to be achieved. The majority of current projects are operating at large sites but future Table 1. Chemical analyses for site C core samples at various depths Site C primarily received municipal waste where the organic content would commonly represent about https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of all waste. However as the analyses in rable l indicate substantially lower values were obtained (cellulose and lignin content analyses). Similar observations were Found for all gamples from other sites at various denths watues were often below https://www.w3.org/1998/Math/MathML"> 30 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). Such low values are a reflection of refuse sampling techniques in the field where extracted material contains a higher percentage of goilg and tines" then ig contained in municinal waste as deposited. Drilling methods will erequently push solid matter outside the core sampler and only collect small particle sized material. These factors have important implications for the interpretation of gas production rates and yields obtained from the samples incubated in small fars in the laboratory. The number of methanogens present in the same site c samples (qrowing on https://www.w3.org/1998/Math/MathML"> H 2 / C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ) are indicated in Table 1 rhis data when related to measured paxameters of moisture content and refuse temperature indicates that increasing values of both are important in achieving good rates of methanogenesis. It is commonly believed that high moisture contents are required for nigh microbial activity but measured values in site c samples are little different from 'typical waste' (as deposited) mojsture contents rt ig a lao gurpriging that methanogenic activity is significant in a waste environment Containing liquid with pH values ranging from 5.5 to 6.5. A number of methanogenic species have been isolated in monoculture from the waste samples from various sites. Isolates Methanobacterium spp. , pethanococcus spp. and yethanosarcina spe. have been obtained. Numbers of methanogens present in sampleg which grow on Holcoz are apparentay greater than those which grow on acetate, as shown in Table 2. Table 2. Examples of various landfill site conditions and the numbers of methanogens growing on https://www.w3.org/1998/Math/MathML"> H 2 / C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> or acetate,samples https://www.w3.org/1998/Math/MathML"> g - 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> wet weight https://www.w3.org/1998/Math/MathML"> ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> at tepths specified. Table 3. Maximum rates of gas production from Incubated samples at depths and refuse ane as indicated. ENVIRONMENT PROTECTION AND ENERGY RECOVERY DECOMPOSITION GAS FROM THE BERLIN-WANNSEE MUNICIPAL WASTE DISPOSAL SITE J. SCHNEIDER Glienicker Str. 100, D-1000 Berlin 39, FRG 28. Summary Berlin's biggest municipal waste disposal site is located in Berlin-Wannsee, close by the Hahn-Meitner-Institut. From 1954 to 1980 more than 11 million tons of household waste were accumulated there. The site covers an area of about 500 ono squaremeters a former gravel site covers an arra of about 500,000 squaremeters. A former gravel pit has been refilled up to 40 meters above the surrounding ground. The surface of the site is completely covered with a layer of soil. Decomposition gas, a mixture of methane https://www.w3.org/1998/Math/MathML"> ( 58 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , carbondioxide https://www.w3.org/1998/Math/MathML"> ( 40 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and more then three hundred different compounds, is produced in the hill as a product of the chemical and bacteriological decomposition of the organic part of the waste. This combustible gas moves through the surface of the site and into the surrounding soil, causing problems regarding the recultivation of the area, and public safety. A feasibility study, based on data from a pilot gas withdrawal plant, proposes the recovery of the gas by a withdrawal system and it's utilization in a co-generation plant for the production of electicity and heat. Thus the gas flow across the surface will be reduced by about https://www.w3.org/1998/Math/MathML"> 70 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , and a potential energy source will be used. A co-generation plant, based on internal-combustion engines with a total electric power output of 4,000 kilowatts, and a thermal power output of 6,500 kilowatts is planned to be built in 1985/86. 29. INTRODUCTION Disposal in big landfill sites is the common way of handling municipal waste. The greater part of the waste is garbage, a more or less organic material. When dumping the waste, bacteria immediately start decomposing the organic substances. In modern landfill operation, the waste is compressed by heavy maschines to get an maximum of waste into the limited space. Aerobic bacteria reduce the content of oxygen in the porous media, and due to the compression, no further air can get into the waste. With the decrease in oxygen, anaerobic bacteria start decomposition of the organic material. Parallel to the activity of bacteria, different chemical processes take place. After a period of about one year, the processes reach a stable state in the dumped waste, and a major part of the decomposition products are gaseous ones. This gas is a mixture of methane https://www.w3.org/1998/Math/MathML"> ( 58 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , carbondioxide https://www.w3.org/1998/Math/MathML"> ( 40 % ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , hydrogen, nitrogen, and more then three hundred different compounds as impurities. The sum of all impurities is less than https://www.w3.org/1998/Math/MathML"> 0.1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in weight. Nevertheless, attention has to be paid to the impurities, because some of them are dangerous chemicals, such as vinylchloride, hydrogensulphide, chlorobenzene, etc., and some are corrosive ones. Figure: The Berlin-Wannsee site from the north. The basic area depicted is 1,560 meters by 710 meters. 1. GAS WITHDRAWAL PILOT PLANT A IIrst rough calculation of decomposition gas production in the landfill, done in 1980, showed a volume of about 8,000 cubicmeters per hour. This means thermal power of about 40 megawatts, based on 50 % of methane in the gas mixture. The energy potential of the landfill is much greater in the gas mixture. The energy potential of the landfill is much greater than the requirement of HMI. Therefore, in 1982 a gas withdrawal pilot plant was constructed, to acquire data about the recoverable qas volume, and gas quality, about the efficiency of the withdrawal system, and about the optimal depth, and distance of the vertical suction wells. Additional research has been done in identifying and quantifying the impurities in the gas mixture. 10 gas suction wells have been contructed on a 2.5 hectares section of the landflll by drilling vertical holes of 0.6 meter in diameter and 12 meters in depth into the waste. A perforated pipe has been put into the center of each hole, and the upmost 4 meters of the hole have been sealed with clay. Pipes made of hard polyethylene connect each suction well with a common blower. The concentration of methane, carbondioxide and oxygen has been measured in each suction well as well as the gas flow. Measurement of methane concentration in the soil has shown the gas flow reduction through the surface. Partially the gas flow decreases to zero. Modell- calculations have been done to assess the time dependent volume of gas production over the next 15 to 20 years, and the recoverable volume of gas. Figure: Time dependent volume of recoverable gas (47% methane) and the potential co-generation power, regarding internai-combustion engines. A feasibility study, based on the data from the pilot plant, and taking into account the local conditions has shown, that the gas utilization in a co-generation plant of about 4,000 kilowatts electric power output will be energetically the most useful and economically the best solution to the problem of gas treatment. 2. DECOMPOSITION GAS AS AN ENERGY SOURCE Parallel to the construction of the pilot plant, a pipeline was constructed from the pilot plant to the heating center of the HMI. A former oİ-fired boiler was reconstructed with a special burner for landfill gas. Since May 1983 about https://www.w3.org/1998/Math/MathML"> 65 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of HMI's yearly requirement of heatenergy is produced by burning decomposition gas from the landfill. That means a saving of about 850,000 liters of oil per year. The results of the feasibility study, the positive experience with the pilot plant, and the necessary safety of people and vegetation led to the decision to construct a large-scale decomposition gas withdrawal and treatment system. The Hahn-Meitner-Institut and the local electricity company BEWAG made an agreement to construct and to run a large-scale gas recavery and utilization plant. Detailed engineering is now in progress. The decomposition gas will be collected by a system of about 120 tical gas suction wells with single flow-regulation each to optimize the gas recovery in respect of gas quality and gas flow through the surface. A system of underground pipes will connect the suction wells with the comm pressor station on the landfill site. The compressed gas will be transported through the existing pipeline to the HMI site. There, a co-generation power plant will be constructed, based on 3 to 5 internal-combustion engines. The total output of the plant will be 4,000 kilowatts electric and 6,500 kilowatts thermal power. The electric power will be generated by synchronousgenerators at 10,000 volts, and fed into the HMI, and into the public grid. The thermal power will be used as much as possible in the buildings of the HMI and in the apartement-houses in the neighbourhood of the HMI. Regarding to the environment protection aims on the landfill site, restricted levels in noise and flue-gas emission of the power plant have been formulated by HMI and BEWAG. This led e.g. to the necessity of technically reducing the nitrogenmonoxide and the nitrogendioxide in the flue-gas of the co-qeneration plant. Today calculations show a necessary investment of about https://www.w3.org/1998/Math/MathML"> 15 m i l l i o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Deutsch Marks for the construction of the gas recovery system and co-generation plant, The repayment-time for that money will be at least 15 years. The actual timetable is as follows: - construction commencing in autumn of 1985, - start of operation in winter 1986/87. PRODUCT DEVELOPMENT NEEDS OF WASTE MANAGEMENT P. VILPPUNEN Energy Laboratory, University of Oulu, Fintand Summary The objective of the research "Product development needs of the waste management" is to find out R&D needs by which the factors that prevent the energy economical utilization of municipal waste can be diminished. The partial objective is to develope by a separation-handling system producing refuse derived fuel. The system is based on two-phase separation of municipal waste: at source and centralized, as well as on the refining of the separated combustible fraction of the waste into fuel. The research includes:

deepening prestudy

selection of alternative separation-handling methods

technical-economical comparison of the different choices

spesification of the selected method and product development basis.

The method can be used when developing the energy economical utilization of solid municipal waste in the energy and waste management of the community and also when developing the recovery of the raw materials in the refuse at source or in centralized separation plant. 3. BACKROUND The energy economical utilization research of waste in Finland consists mainly of the collection of experiences of municipal waste used in other countries. In addition has been studied the suitability of fluidised bed technology and the research method needed for the quantity and quality study of the waste. The preliminary results show that the separation of the combustible and other fractions from the municipal waste significantly influence in the energy economical possibilities of utilizing the waste. The sorted municipal waste enables the preparation of more homogeneous waste fuel and so it increases the possobilities to use the waste with other combustibles in ordinary burning plants. 4. OBJECTIVE The objective of the researh is the selection of a waste fuel producing separation and handling system based on technical-economical study. The system is founded on two-phase separation of municipal waste: at source and centralized, as well as on the refinig of the separated combustible fraction of the waste into fuel. With the system is achieved the production of waste fuel which could be used as wide as possible in the existing heating centres of the communities and the industry. Picture 1. Separation-handling system as a part of energy economical utilization of the solid municipal waste.

RESEARCH REALIZATION

The research is divided into following partial stages:

deepening prestudy

selection of alternative separation-hand ling methods

technical-economical comparison of the different choices. In the comparison are taken into account:

technical conditions

economical conditions

environmental conditions

public opinion conditions

specification of the selected method and product development basis. 1) Prestudy

In the prestudy is analized the following information:

quantity and quality of the waste (household, office, commercial and similar industrial waste) by considering for example the different structure of the communities, year season and the changes caused by consumption variations

selection of different locations

https://www.w3.org/1998/Math/MathML"> 500000   h . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , enough waste for burning even as unique fuel in a waste combustion plant https://www.w3.org/1998/Math/MathML"> 100000   h . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , central heating plants burning peat and many solid fuel district heating plants in the surrounding communities waste fuel transportation to the vicinity. Dispersed dwellings or small towns where are possibilities for the use of refuse derived fuel. 2) Selection of alternative separation-handling methods For the basic alternatives of coliparison are chosen two systems in which one separates the waste already at source (for example the housenolds) wet food and similar wastes from dry combustible and recoverable waste. The other basic alternative is the existing system without separation at source.

Technical-economical comparison of the different choices The dasic factors are technical, econonical, environinental and the public opinion conditions and demands. The comparison is done for

I-stage i. separation at source

handling the separated-unseparated waste before II-stage

II-stage i.e. centralized separation handling

production and utilization of waste fuel

On the ground of the comparison is chosen a method to be developed for two-phase waste fuel producing separation-handling system.

Specification of the selected method and product development basis

The selected method is specified for example by adjusting the necessary prehandling stages. At the same time are determined those changes needed when using the method in different kind of communities (100 000- https://www.w3.org/1998/Math/MathML"> 500000   h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . dispersed dwellings).

RESULT UTILIZATION

Research result

Anplication area

¿ Energy economical use of solid municipal waste in the energy and waste management of the communtties (waste fuel production).

Raw material recovery from waste at source and with centralized separation.

Applying method

Technical-economical estimation of the method (product proposal) for further development to the manufactures.

Users

The authorities directly or indirectly responsable of the waste and energy management in the communities, designers, manufacturers and industry.

Energy economical signifance

The method increases directly the possibilities to use native solid fuels (wood, peat and municipal waste) in combination.

Indirectly the method increases the energy quantity recovered from organic waste by anaerobic digestion (the separation of organic matter at source improves the base for biogas production).

0ther significances

The method decreases the charge for environmet caused by incineration (more homogeneous fuel - less emissions)

The method increases the recovery degree of the recoverably raw materials (two-phase separation)

The method improves the realization of the long term planning of the waste management (for example decreases the need of landfills).

5. SEWAGE SLUDGE AS FNERGY SOURCE H.P. ZWIEFELHOFER UTB UNWELTTECHNIK BUCHS AG, 9470 Buchs/SG SwitzerIand 6. Summary Practical experiences with newly developed sewage sludge treatment processes like pre-pasteurization or aerobic-thermophilic pre-treatment, followed by anaerobic-mesophilic stabilization were studied at full scale operation. The thermal conditioning effect of pre-pasteurization and, in the case of aerobic-thermophilic pre-treatment, the combined effect of temperature, mechanical and bacteriological hydrolysis have proven to be of great cost-saving on sludge treatment plants. Intensified anaerobicmesophilic digestion and the exothermic thermal energy-production in the case of the aerobic-thermophilic pre-treatment minimized energy costs and allow safe sludge recycling by agricultural use. 7. INIRODUCTION In Switzerland each year over two million cubic meters sewage sludge are disposed of in land application for agriculture. At an average dry solids content of about https://www.w3.org/1998/Math/MathML"> 6.4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , of which about https://www.w3.org/1998/Math/MathML"> 42 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> are volatile solids (VS), a representive digested sludge contains the following fertilizing matter per ton of dry matter: https://www.w3.org/1998/Math/MathML"> 40   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (N) , https://www.w3.org/1998/Math/MathML"> 70   k g P 2 O 5 , 3   k g   K 2 0 , 70   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Ca), https://www.w3.org/1998/Math/MathML"> 7   k g https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Mg) The Swiss Federal Research Institute for Agricultural Chemistry and Environmental Hygiene (Liebefeld/Berne) calculates the sludge's value as fertilizer at an average of SFr. https://www.w3.org/1998/Math/MathML"> 8.40 / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> liquid siudge or about 20 Mi.llion https://www.w3.org/1998/Math/MathML"> S f r . ( 1 $ = 2.8 S F r . ) ( 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . These figures show why the Swiss Authorities encourage development of new technologies and processes to condition and hygientze sewage sludge; thus the land recycling of this product under controlled conditions is a declared aim of Swiss environmental policy. Stringent Swiss laws assure the protection of soil, humans and cattle. The Swiss Ordinanance of 8 April 1981 , concerning the disposaI of sewage sludge for agriculture, dictates conditioning and hygienization technologies, process minimum requirements, limits for hygiene, maximum heavy metal contents, method, quantity and time for using sludge in agriculture.

UIB TWO-STAGE TREATMENT: 1st Stage Aerobic-thermophilic Conditioningand Hygienization, 2nd Stage Anaerobic-Mesophilic Stabilization

This process was developed and first applied at the sewage treatment plant of Wartau / St. Gallen (7'000 population equivalents). The Wartau plant was comissioned in 1978 as a mechanical/biological/chemical (phosphate-precipitation) plant. To stabilize the sewage sludge, a conventional anaerobic digestion was installed. To hygienize digested sludge, a pasteurization plant was built but never used. Consequent1y, farmers were very reluctant to use the waste-sludge since it was not hygienized. Early in 1982 it was decided to install an aerobic-thermophilic sewage sludge conditioning/hygienization plant (AEROMHERM) as a processstage in sludge treatment prior to the existing anaerobic digestion. This decision was taken, after the performance and security of the process had been demonstrated to the responsible authorities in a two year' test run. Description of the AEROTHERM Process. Raw sludge from primary clarifiers and the biological and chemical secondary stage treatment (phosphate-elimination) is thickened statically (1) from https://www.w3.org/1998/Math/MathML"> 98 - 99 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> water content to https://www.w3.org/1998/Math/MathML"> 95 - 97 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and pumped (3) through a comminutor (2), in which textiles, Q-tips, plastic-parts, etc., which have passed the bar-screen at the entry of the sewage treatment plant, are reduced to acceptable particle sizes, into the aerobic-themophilic conditioning/hygienization plant (AEROIHERM). Sludge is mixed very intensively in the AEROTHERM-reactor (7) and air/oxygen is introduced in a specially designed injector (9). In the well insulated reactor, aerobic microorganisms digest organic matter with simultaneous heat generation. This exothermic reaction heats the reactor content un to a temperature of oven 600 C. Temperature rise varies between 0.5 to https://www.w3.org/1998/Math/MathML"> 1.5 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per hour, depending on several parameters such as volatile solids concentration, pH, etc.. The shorter the aeration time, the lower is the elctrical energy consumption. Biogas, produced in the following anaerobic digestor, is used in gasbumers and/or gas-engines to the the aerobic sludge through a heatexchanger (12). Excess heat, not necessary for the operation of the above anaerobic mesophilic stage (working at about https://www.w3.org/1998/Math/MathML"> 32 - 40 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> C) is recovered by means of a sludge/sludge heat exchanger that preheats the raw sludge (4). After 24 hours retention time at https://www.w3.org/1998/Math/MathML"> 60 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in the AEROIHERM-reactor, the sludge is mechanically, thermally and bacteriologically conditioned, sludge is pumped (5) into the anaerobic digestor (13). Anaerobic bacteria in the digestor further digest volatile solids and produce biogas. The sludge is further stabilized: salmonella, worm eggs, enterobacteriacea are destroyed; and the reinfection of sludge with salmonella, much feared with pasteurization plants, is impossible. The hydrolizing effect of the AEROTHERM-stage and the resulting performance of the 2 nd (anaerobic) stage sumarized lead to overall reduction of investment and operating costs (2). 8. SUMIARY OF THE PRACTICAL EXPERIENCES SINCE 1982 Effects on Hygiene. The process above guarantees results within the limits of the Swiss Federal Ordinance on Sewage Sludge of the 8 Apri1 1981 regarding hygiene (max. 100 enterobacteriacea per gram at the point and time of transfer to the transport bringing it to farmer's and no reinfection capacity). Tests (2) have proven the safety of the process with regard to the destruction of enterobacteriacea, salmone1la (3) and worm eggs (4). Effects on energy balance. The biological heat-generation in the aerobic system substantially contributes to a favourable energy balance for the sewage treatment plant as a whole. For every kWh electrica] power input, the heat-output is approx. https://www.w3.org/1998/Math/MathML"> 3 k W h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . Total energy costs being approx. https://www.w3.org/1998/Math/MathML"> 3.5 - 12 k W h / m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> raw sludge at https://www.w3.org/1998/Math/MathML"> 4 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TS, depending on retention time and plant size. For circumstances existing prior 1980 at the Wartau plant, a very unfavourable relation between raw sludge and the quantity to heat lost from the digestors was found, since the whole lower part of the digestor had been placed without insulation in a ground water flow. Themal hygienization of the sludge would have resulted in a massive increase of fuel consumption. However, with the AFROMHERM-process, the total fuel oil consumption including heating for the building and warm water production was reduced from ca. 8 t/year (without hygienization) down to ca. 3 t/year (with hygienization). An additional measure which will be taken soon is the installation of a gas-motor capable of waste heat recovery. Effects on consolidation, dewaterability. Due to the conditioning of the sludge before its anaerobic digestion, consolidation and dewatering properties were significantly improved. Dry substance contents of https://www.w3.org/1998/Math/MathML"> 12 - 20 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , compared with https://www.w3.org/1998/Math/MathML"> 6 - 8 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in earlier years, in the storage tank, are now standard. Current structure is responsible for maintained "pumpability". At Wartau this effect brought a reduction of over https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the volume of sludge to be disposed of. Consequently, there are no more problems with sludge disposal even in winter since the former digestor II now serves as a storage/consolidation tank. Tests on site have also shown that the performance of mechanical dewatering equipment has improved. Relatively high dry solid contents can be reached. Using polyelectrolyte (PE), 35 - https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TS were reached with belt filters and https://www.w3.org/1998/Math/MathML"> 48 - 53 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TS in filter presses. This means an increase in dry solids content of about 5-10 percentage-points compared to average digested sewage sludge and a considerable reduction in polyelectrolyte consumption per ton of dewatered dry solids. 9. FINAL CONCLUSIONS The UTB-AEROTHEPM process is presently used at five sewage treatment works. By the end, of 1985 , twelve plants will be in use with capacities from https://www.w3.org/1998/Math/MathML"> 4 - 140   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> sludge per day. Further plants in Europe are under construction. So far, the positive results on the first plant (Wartau) have been wholly confirmed on the other plants and by a process evaluation on the Unterterzen plant by the Department for Technical Biology of the Swiss Federal Institute for Water Resources and Water Pollution Control, Dübendorf (EAWAG). In most projects for performanceimprovement or adaption of liquid sludge treatment facilities to meet new regulations, the aerobic-thermophilic process is now considered as the most cost/effective alternative. 10. References (1) FURRER, O., Agricultural use of sewage sludge. PHOENIX 2/1983 (2) ZWIEFEI HOFER, H.P., IWTUS-Symposium 1984 at Ittingen/Switzerland (3) Institute for veterinary-Medicine. University of Zurich/Switzerland (4) Institute for Parasitology. University of Zưrich/Switzerland 11. FLAME DEVET OPMENT IN SPARK-IGNTTION R A Johns and A W E Henham University of surrey, GuIldford, England 12. Summary Small diesel engines may be readily converted to spark-lgnition to burn alcohols. The highly turbulent pre-chambers in these engines are 1deally sulted to burning lean mixtures, thereby fmproving fuel economy whilst reductng exhaust emissions. This paper describes the application of a diagnostic englne computer combustion model to the analysis of flame development in such an englne. The results exhibit characteristic features of flame development: a period of heat transfer to the unburnt gas between the spark plug electrodes, Instantaneous self-lgnition and a period of decelerating flame propagation. These characteristicg were modelled for use in engine computer simulations. 13. INTRODU CTION Alcohol fuels, efther methanol, produced from indigenous deposits of natural gas, or ethano1, produced from biomass, offer attractive Of matural gas, or ethanol, produced from biomass, offer atcractive alternative fuels to oil. With RON of 114 and 111 respectively, they are well suited as fuels for high compression spark-ignition engines. Evaluation programmes are already In progress; malnly with captive vehicle fleets which are largely independent of extensive fuel d1stribution systems. On the other hand, both these oxygenates have extremely low cetane numbers and are, therefore, diff1cult to ignite by compression ignition, particularly at loads below https://www.w3.org/1998/Math/MathML"> 25 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the englne rating. The small stationary diesel engines, in common use for power generation and pumplng in remote areas may, however, be easily converted to spark lgnition to burn the localiy produced alcohol fuels. The high compression ratios and highly turbulent combustion chambers in these englnes are 1deal for the combustion of lean alcohol mixtures. Such an englne, a single cylinder https://www.w3.org/1998/Math/MathML"> 7.5   k W https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diesel with a spherical premchamber, was converted to spark-ignttion and performance tests with lean methanol mixtures indlcated that stable operation could be extended further into the lean burning regime than was possible with the baseline fuel, isooctane (1). Analysis of the cylinder pressure readings using a computer engine combustion model showed the existence of four different types of burning cyles (2) which Included cycles with partial burning. The period of initial flame development was found to have a significant Influence on subsequent flame development. Complete combustion with h1gh maximum burn1ng rates resulted from a short period of flame development, whereas the partial burning cycles were a consequence of a long flame development period. The purpose of this work was to apply the engine computer combustion model in a diagnostic manner to analyse the experimentally acquired cylinder pressure data to Identify the characteristic features of flame development in spark-ignited lean methanol mixtures. Fig. 1 Variation in heat transfer period with laminar flame speed. Fig. 3 Comparison of flame establishment definitions. Fig.2 Voriation in instontoneous propagation velocity with laminar flome speed. Fig 4 Voriation in flome estoblishment period with laminar flame speed. Table I: Cyclic dispersion in flame establishment period. 4 . CONGLUSIONS The period of flame establishment in the divided-chamber methanol engine exhibited four characteristic features which were related to the laminar flame speed and could be modelied for use in engine computer simulations. Flame establishment was difficult to ascertain in terms of the onset of a propagation acceleration with lean mlxtures below an equivalence ratio of 0.8 and a definition in terms of a mass fraction burnt of https://www.w3.org/1998/Math/MathML"> 1 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was considered to be more definitive. This technique of employing diagnostic englne combustion models provides an inexpensive method of analysing engine combustion performance with alternative fuels. REFEREN CES (1) Johns RA and Henham AWE, The performance of a divided chamber single cylinder engine with lean methanol mixtures, Conference on small englnes and their fuels for developing countries, University of Reading, September 1984. (2) Johns RA, The analysis of the combustion of methanol in the leanburning reglme using an englne combustion model, VIth International Symposium on Alcohol Fuel Technology, Ottawa, May 1984. (3) Koda S et al, Burning characteristics of methano1 - water - air mixtures in a constant volume combustion vesse1, combustion and Flame 46: 17-28. (4) Chomiak J, Flame development from an ignition kernel laminar and turbulent homogeneous mixtures, 17 th Symposium on Combustion, pp RUBBER SEED OIL FOR DIESEL ENGINES IN SRI LANKA P.D. DUNN and E.D.I.H. PERERA Department of Engineering, University of Reading, U.K. 14. Summary In addition to rubber latex very considerable quantities of rubber seed are also produced in the Sri Lankan rubber estates. A small proportion of the seed is now used in the paint and soap industry, but most of the crop is wasted. This paper considers the possible application of oil, extracted from the seed, for use as an alternative to diesel oil in the rubber industry. The relevant fuel properties are presented and compared with those for diesel oil. The results of some primary engine tests using pure rubber seed oil (RSO) and blends with diesel oil are also given. 15. INTRODUCTION

1 Rubber Seed Oil as a Natural Resource

Sri Lanka is the fourth largest producer of natural rubber (Hevea Braciliensis). Several attempts have been made during the last few decades to exploit the thousands of tonnes of rubber seed which are allowed to go to waste on rubber estates. It is only recently that some measure of success has been achieved. The main commercial product obtainable from the rubber seed is its oil. It has been estimated that about 4,500 tonnes of rubber seed oil https://www.w3.org/1998/Math/MathML"> ( RSO ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and 7,000 tonnes of high protein rubber seed cake may be obtained annually from the 250,000 acres of rubber land from which seed could be readily harvested. The average crop of seed is around one tonne for ten acres and the yield of oil is https://www.w3.org/1998/Math/MathML"> 17 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> by weight. (1) At present the main potential use of RSO in Sri Lanka is in the paint industry. Currently it is used for the production of alkyd resins used in emtlsion paints. RSO has also been considered as a substitute for coconut oil in the soap industry. (2) The largest percentage of the resource however has not been utilized. Since the rubber seed is a by-product of the natural rubber plantation industry, the cost of production of oil seed is negligible. The inedible RSO can easily be extracted from the seeds and this paper considers the possible application of this oil as a fuel for diesel engines. RSO is an oil having a composition somewhat similar to linseed oil (Table I). Table I - Composition of RSO and Linseed Oil Oil is obtained from the rubber seed either by an expeller process or by a solvent extraction process. The yield of oil from rubber seed is somewhat variable and depends mainly on the time factor between seed fall and collection, and drying and expressing. Rubber seed cake, left after the extraction of oil from the rubber seed kernel, could be used as an animal feed or as a nitrogenous fertilizer. (2)

2 Collection, Storage and Milling of Rubber Seeds

One of the most important items that could influence the feasibility of extracting RSO economically is the cost of seed collection. This in turn is controlled by many factors such as seasonal variation in total seed fall, presence of surface vegetation cover making collection difficult, topography of the estate and the type of labour employed for collection. Under the climatic conditions prevailing in Sri Lanka it is desirable to ensure that seed collection takes place on an average of once in four days and at regular intervals throughout the period of seed fa11. (2) Since fresh seeds contain about https://www.w3.org/1998/Math/MathML"> 35 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> moisture, it is not possible to store them in this condition without rapid deterioration. The seeds become mouldy, susceptible to insect attack and permit a rapid increase in free fatty acid content due to an enzymic action. (2) Rubber seeds which cannot be processed immediately should be sun-dried to reduce the moisture content. Another method of treatment is to hest the seeds for over an hour at a temperature of https://www.w3.org/1998/Math/MathML"> 120 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> (2) The rubber producing areas are rather scattered and a mew 1 arge central factory for processing the entire crop of rubber seed would be impracticable in view of the transport difficulties. Therefore any new factories for milling should be in the form of small units sited in the rubber growing areas themselves. RSO may be extracted in existing oil mills, or alternatively in small units attached to pale crepe factories. The use of an expeller or a hydraulic screw press have been recommended for such small operations under estate conditions. The seeds are disintegrated and cooked berore passing through an expeller or a press. The harvest is seasonal, the oreater proportion of the crop falling within a short period usually during the months of July to September. The secondary seed fall which occurs at the commencement of the winter season, January - February, is less important compared with the main crop, Hence storage of the oil or seed will be required. 16. 3 Aim of the Project The main aim of this study is to evaluate the suitability of RSO as a diesel fuel substitute for engines used in the rubber plantation industry. There are a considerable number of diesel engines (both stationary and mobile) used in the rubber plantation industry itself. Large stationary diesel engines are employed in non-electricity grid connected rubber estates to drive a horizontal shaft through which the power for milling coagulated rubber is supplied to different types of rollers. Diesel tractors are used to transport rubber latex and rubber products in and out from the main factory. Therefore a large proportion of the power requirement of the rubber plantation industry is generated from diesel fuel. The present work on RSO concentrates on its potential as a fuel for diesel engines, particularly used in the rubber plantation indtistry in Sri Lanka. An advantage of this application is that any special engine maintenance operation requirement due to the tse of RSO can be ensured since only in-house staff will be involved.

EUEL RELATED PROPERTIES OF RSO

The following fuel properties of RSO were theasured and the results are given in Table II. ASTM specification for No. 2 diesel oil are also given in Table il for comparison. It can be seen that the cetane rating of RSO is close to ASTM minimum of 40 for No. 2 diesel oil. Table II - Fuel Properties of RSO RSO is extremely viscous with viscosity of ten times greater than the viscosity of No. 2 diesel at https://www.w3.org/1998/Math/MathML"> 40 ∘ C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Variations of the viscosity of RSO and blends of RSO with diesel oil with temperature are shown in Eig. 1. When ASTM Test D 86 was used to distil RSO, it cracked into a two-phase distillate, showing its thermal instability. Comparisons with properties of No. 2 diesel oil indicate that RSO meets the ASTM Iimits for total and active sulphur, water and sediment and fails to meet the ASTM limits for ash content, carbon residue. reflecting the crude nature of the sample tested. (Sample was not refined) RSO has higher cloud and pour points than diesel fuel. These low temperature characteristics are not important for tropical countries like Sri Lanka where the ambient temperature hardly drops below https://www.w3.org/1998/Math/MathML"> 20 ∘ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . It can be seen that the heating value of RSO is https://www.w3.org/1998/Math/MathML"> 87 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of diesel oil on a mass basis and https://www.w3.org/1998/Math/MathML"> 94 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on a volume basis at https://www.w3.org/1998/Math/MathML"> 25 C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , since RSO is slightly heavier than diesel oil.

ENGINE TESTS

The engine tested was a single cylinder, four stroke, air cooled, naturally aspirated Petter (Model AC 1) engine giving 4.9 kW (6.5 php) at https://www.w3.org/1998/Math/MathML"> 3600 r e v / m i n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The slightly unusual feature of the engine is its lavona air cell combustion chamber. Tests were carried out at different loads with the engine running on diesel oil, RSO and blends of RSO with diesel oil at constant speed setting of 2600 rev/min. Three blends were used having https://www.w3.org/1998/Math/MathML"> 25 % , 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 75 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of RSO by volume. Fig. 1 Fig. 2 Fig. 3 NEW DIRECT INJECTION DIESEL ENGINE DEVELOPMENT FOR USING VEGETABLE OIL AS A FUEL K. Elsbett, G. Elsbett, L. Elsbett Elsbett-Konstruktion 17. Summary A new engine technology is described for the use of vegetable oil as a fuel. The oil can be used as it is extracted and cleaned without any further processing. Large scale consumption requires large scale production of vegetable oils. An example is shown describing possibilities for the recultivation of desert areas. Under these conditions food production for men and vegetable oil fuel production for the engine are in no way a contradiction. In the contrary the production of vegetable oil fuel can be a basis to in future solve the problems with starvation, environment and unemployment. 18. INTRODUCTION The preprogrammed explosion of human population goes together with three disasters: lack of food, environmental problems, unemployment. If we cannot care for considerable improvements in technology and economy, countless armed conflicts between nations and social classes are unavoidable. The constant trend of the increase in population has only been possible due to the unscrupulous depletion of the earth's resources by technical means. This trend has led to an intercine war against the hydrocarbon resources of the earth, no matter whether fossil fuels or the expansion of the deserts is concerned. The withdrawal of fossil fuels from the earth and oxygen from the air produces 26 billion tons carbon dioxid per year. This decisive interference in the geological development can only be justified if this huge mass of https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is used to create the preconditions for 1 ife in future. This task can only be accomplished if the withdrawal of fossil resources and the production of biomass resources in form of plants and humus are equilibrated. Vertile soil instead of deserts is the most appropriate measure against starvation, unemployment and damaged environment. Humus on the surface of the earth is even better than coal and crude oil below. 19. THE DUOTHERM ENGINE FOR VEGETABLE OIL FUEL Per liter, vegetable oil fuel has almost the same heat value as gasoIine. It has the important advantage to be suitable for d.i. diesel engines which are superior in efficiency to other engines in a ratio of 40 to https://www.w3.org/1998/Math/MathML"> 27 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . This fact results in a lower fuel consumption of 1:1.5 (refer to https://www.w3.org/1998/Math/MathML"> F i g . 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ). If gasoline is supplied by the oil refinery for https://www.w3.org/1998/Math/MathML"> 0.80 D M / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , vegetable oil fuel could even cost https://www.w3.org/1998/Math/MathML"> 1.20 D M / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to keep the fuel cost the same. As all by-products of the vegetable oil fuel production can be sold at a good price, already today the gradual change to the use of vegetable oil as a fuel can be considered as a solution for the present agricultural surpluses of the EC. If for rapeseeds or sunflowers a yield of 3 tons/ha of oil fruits is assumed instead of 5 tons/ha of grain, the oil fruits must yield https://www.w3.org/1998/Math/MathML"> 750 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton instead of https://www.w3.org/1998/Math/MathML"> 450 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton as it is the case for grain. If https://www.w3.org/1998/Math/MathML"> 40 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the yield are used as engine fuel for https://www.w3.org/1998/Math/MathML"> 1.20 D M / L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> and https://www.w3.org/1998/Math/MathML"> 60 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as feeding stuff for https://www.w3.org/1998/Math/MathML"> 800 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton this will bring in https://www.w3.org/1998/Math/MathML"> 440 D M https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> for oil and https://www.w3.org/1998/Math/MathML"> 480 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton for the of 1 cake. These are https://www.w3.org/1998/Math/MathML"> 920 D M / t o n https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , i.e. https://www.w3.org/1998/Math/MathML"> 170 D M / https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ton remain for marketing. Fig. 2 shows the cross section of the vegetable oil fuel engine equip- ped with the Duotherm combustion system according to https://www.w3.org/1998/Math/MathML"> F i g . 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> The most important characteristics are described in the following:

The whole engine is now made in iron and steel. Neither aluminium nor ceramics nor expensive electronics are required. The injection system is integrated in the cylinder head, anyway only three instead of five cylinders have to be operated. Thus the vegetable oil fuel engine is in design not more expensive than the gasoline engine.

As the combustion system is heat insulated, the piston design is so that hardly any heat flows to the cylinder. Therefore the articulated castiron piston has its largest diameter and contact area to the liner already above the piston rings. Consequently the rings are protected from the combustion gases and leftovers.

A single jet injection system is used with a pintle nozzle instead of a hole-type nozzle. This is required for the operation on vegetable oil fuel due to the risk of nozzle clogging.

With the Duotherm combustion the heat remains in the working air and more energy is released to the piston and the turbine so that also small engines can be turbocharged effectively. The harmful products of HC transformation can largely be avoided, even when using vegetable oil as fuel.

The heatflow to the cylinder liner is reduced in a ratio of 2 to 1. Therefore it is possible to change from the external water cooling to the internal cooling by a jet of lubricant oil. Only at the top the liner is cooled by an outer oil coat. From there the oil flows to the cylinder head, where, by means of bores, only the nozzle and the valve bridge are cooled. With this design, the thermal stresses in the cylinder head are much reduced compared to water cooling, and sufficient tempe rature is maintained to avoid lacquer deposits from vegetable oil fuels. This shows that the vegetable oil engine has no disadvantages. Whether it can be as reliable as conventional engines was evaluated by a https://www.w3.org/1998/Math/MathML"> 100,000   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> road test with a Duotherm engine installed in an Audi 100 First only salad oil from the grocery shop filled in bottles was used as fuel, then our own oil press supplied sufficient unrefined rapeseed and sunflower oil. The road test was only carried out with https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> vegetable oil. Also the oil was not chemicaliy treated or esterized but only cleaned by a centrifuge and a settling basin. Also oils from warmer regions such as soybean, castor, physic nuts, peanuts etc. were tested, After every run the combustion chamber was examined and in no case was there any difference to the operation on https://www.w3.org/1998/Math/MathML"> 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> diesel fuel.

LARGE SCALE PRODUCTION OF VEGETABLE OIL The slogan "Bread for the world by vegetable oil for the engine" of course not only touches the problems of the engine development. It touches many matters that today makes man do the most inconsidered things. If the mineral oil industry spends 10 billion DM for erecting one single bore island in the North Sea, they also know, that they can amortize even such high amounts because of the diminishing crude oil reserves. However, the thousands of billion DM spent for armaments to secure the access to all crude oil sources and the financial aid for countries having no foreign exchange to buy crude oil, lastly makes fossil fuel too expensive. Al- ready 10 billion DM suffice to start the recultivation of North Africa as it is shown in Fig. 3 and Fig. 4 .

Europe's climate is influenced by North Africa in so far as the air masses coming from the west to Europe are sucked in by the extreme heat ge- nerated over the Sahara and then blown away westwards. This air current, as shown in Fig. 3, gives us the possibility to enrich the air masses, streaming land-inwards with https://www.w3.org/1998/Math/MathML"> 24,000   m 3 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> water per second ( 10 times the water quantity of the Rhine) by humidification plants installed along https://www.w3.org/1998/Math/MathML"> 3,500   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the Mediterranean coast. One of the 8000 humidification plants having a water output of https://www.w3.org/1998/Math/MathML"> 3   m 3 / s e c https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> is shown in https://www.w3.org/1998/Math/MathML"> F i g . 4 . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> These humidification plants are called fog producers because the water ejected from the rotating self-supporting https://www.w3.org/1998/Math/MathML"> 200   m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> long wings is carried away for a little while as fog, until it is dissolved by the sun rays. The water is evaporated and transported by the sun. The salt left over flows back to the sea. The evaporation performance of such a line of humidification plants can replace a forest of https://www.w3.org/1998/Math/MathML"> 200   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> in width. It is sufficient to provide every year an additional rain quantity of https://www.w3.org/1998/Math/MathML"> 100   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on an area of https://www.w3.org/1998/Math/MathML"> 3 m i 11 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ion https://www.w3.org/1998/Math/MathML"> k m 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . At the latest when the humid air reaches the central Sahara mountains rain will fall during the night. When sufficient vegetation and humidity have been reached the humidification devices can be removed. North Africa, however, could regain the agricultural importance it had in the Roman days, which would not be disadvantageous to Europe. Engine endurance tests have been run with oil from physic nuts (lat.: jatropha curcas). These grow in African regions with far less than https://www.w3.org/1998/Math/MathML"> 100   m m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> rain. https://www.w3.org/1998/Math/MathML"> 50 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of the nuts are oil and although the remaining dry material is slightly poisonous when consumed, it is an excellent natural fertilizer. The high efficiency of this fertilizer is due to the fact that contrary to chemical fertilizers it does not sink into the groundwater but remains ef fective on the surface for years. When calculating the profitability of vegetable oil production the byproducts such as food for men and animals or environmentally safe compound fertilizer have to be considered as a decisive factor in so far as they yield at least as much as can be obtained by the oil production. 20. DRIVING WITH VEGETABLE OIL FUEL The fuel economy of the low emissions' Duotherm engine is such that even more expensive fuels become economically attractive. For instance with the old Audi Quattro and its drag coefficient of 0.42 plus four-wheel drive it was possible to reduce fuel consumption compared to other diesel powered cars as shown in Fig. 5. Cruising at average speeds of https://www.w3.org/1998/Math/MathML"> 150   k m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> was nontheless possible. Future cars with a drag coefficient of 0.3 will thus certainly be within the fuel consumption area 2. A legal fuel consumption limit would thus be the correct way to obtain even better cars combined with even lower pollution of the air. Fig. 5 shows that at https://www.w3.org/1998/Math/MathML"> 120   k m / h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> it is possible to reduce fuel consumption from https://www.w3.org/1998/Math/MathML"> 9   L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> to https://www.w3.org/1998/Math/MathML"> 5   L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> per https://www.w3.org/1998/Math/MathML"> 100   k m https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> . The cost of a year's supply of fuel for the average 13,000 driven km at a liter price of om 1.31 would thus be only DM 850 with a Duotherm engine. Indeed the price of vegetable oil could be as high as DM 2.36 per liter and the yearly fuel cost of the car with a Duotherm engine would be not higher as today's cars using mineral fuel. Apart from that one could save the cost of the catalyst that is reliably estimated at DM 450 per year, when the Duotherm engine is used and at the same time substantially improve on the environmental value of the engine with catalyst. It is also an established fact that the high price of fuel is better accepted by automobilists than such bother and interference as catalysts and speed limits are. If the state wants to effectively protect the environment it should in conformity with the rule that the causer of damage has to pay, eliminate the fuel tax when vegetable oil is used as fuel, instead of eliminating the road tax for cars with catalyst as these cars use the roads as much as others. The fuel tax is called mineral oil tax, and vegetable oil as it happens is no mineral oil. More important vegetable oil does not cause the environmental damages that justify the mineral oil fuel tax. Today, European governments pay to the EC amounts as high as the tax on mineral fuels because the EC has to buy huge quantities of agricultural surpluses that would not exist if the farmer, instead of producing excess quantities of food, would produce the required quantities of fuel. The new situation created with the introduction of the vegetable oil engine has been recognized by governmental agencies. For instance the Bavarian "0berbergamt" has given effective financial support to the further development of this engine. The customs authorities that are responsible for the levy of the mineral oil tax in Germany do not tax vegetable oil as long as it is used without any addition of mineral oil. The Duotherm engine requires no addition of mineral oil, and also runs on vegetable oil without any chemical transformation such as esterification. Developing a combustion system and engine components suitable for the use of vegetable oil as a fuel makes much more sense than adapting all fuels to the needs of today's engines. Chemical transformation of vegetable oil implies organisational and financial difficulties that could block the introduction of vegetable oil as a fuel for engines. Pure vegetable oil can be stocked, the same way as salad oil could be, in a container holding a year's supply of fuel. Such a container could be kept in the garage and filled after each harvest as used to be the case for a family's potato container. Modern cars have a tank of 50 to 90 liters that according to Fig. 5 is sufficient to drive 1,000 to 1,500 km. Thus on that according to Fig. year. Oil esters apart from being environmentally less save would also require production and distribution facilities that would still have to be created. 21. CONCLUSION The consumer is able and willing to do something for the environment, and as the vegetable oil engine is now technically feasible, the consumer can see to it that both the engine and its fuel are produced and made available to the public Also relief and help for developing countries of the third world, for instance in the Sahel, is at least as urgently needed as environmental measures in the developed countries. This help can be supplied with a program that could be entitled "Food production for men by vegetable fuel production for the engine". The produced food would for instance be valuable soybean protein produced as a byproduct of the soybean oil production. The first recultivation of the deserts consumes about as much https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> as is released during one year by the combustion of fossil fuels. With each following year so much humus is produced from the roots and all other parts of the plants not used as fuel or food that gradually new hydrocarbon resources develop on the surface of the deserts which can cover the energy demand of the world even better than fossil resources of coal and crude. Anyway, mining of fossil energies will cease when the regrowing oils become cheaper. The https://www.w3.org/1998/Math/MathML"> C 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> value of the air would again drop to the natural normal basis. More food than ever before would be available for men especially since the crop is harvested and processed by efficient engines and not by herds of cattles. 1181 B. LEDUC, P. LADRIERE tute for Applied Mechanics University of Brus sels 22. Summary The purpose of this study is to develop an electronic system for adapting the spark advance of internal combustion engines Eeeded with biogas. Optimal brake effective power and effi- ciency can be reached when gas composition changes due to the Eermentation process evolution. 23. Introduction All small internal combustion biogas engines are spark ignited. An important regulation parameter of those engines is the spark ignition advance angle. The advance angle is the number of crankshaft degrees between ignition and the top dead center. In fact, if the combustion was instantaneous, the spark Would appear exactly at the top dead center. As the flame front advances with a finite speed, spark must appear earlier in order to release maximum energy around the top dead center. The engine efficiency and its brake effective power are influenced by the choice of ignition timing (fig. l). The optimal ignition point depends on the working condi- tions of the engine:

fuel nature

rotation speed

position of the throttle valve

equivalence ratio

ambiant conditions (temperature, pressure, humidity)

For some fuels, if the speed and the load remain constant, typical values of advance angles are given in table I. biogas méthane LPG gazoline 40 30 20 15 table I: typical spark advance trifugal advance weights and vaculum advance mechanism in order to set the advance angle as a function of the engine rotation speed and the throttle valve position (fig. 2). 24. System description (fig. 4). Fig. 1. Influence of the spark advance on the BMEP engine speed (revhmin) Fig. 3. Influence of https://www.w3.org/1998/Math/MathML"> C O 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> on the brake effective power φ COMP : PHASE COMPNRURCR E Fig. 4. IAM electronic system for varying spark advance AUTHOR TKDEX BRIDGWATER A V, 910,915 BROUERS M, 387 BROWNELL H H, 978 BRUNEAU C, 924 BUHS C, 744 BULLY F，489 BUSSMANN P, 814 CALLAGHAN T V, 109,412 CAMPAGNA R, 496 CAMPBELL D J V, 1151 CANTARELLA M, 989 CANTERELLA L, 989 CAPART R, 842 CARRE 3. 809 CASADEVALL E, 717,722,727 CATHALA N, 557 CECCHI F, 572 CESCON P, 572 CHARTIER M, 315, 321 CHASSANY J P, 1049 CHASSANY DE CASABIANCA M-L, 407 CHIUMENTI R, 645 CHORNET E, 933 CHRYSOSTOME G, 889 CLANCY J S, 1131 CLARK A, 288 CLEGG J M, 334 COLACO M I A, 707 COLLARD F, 369 COLLERAN E, 630 COMINETTA G, 594 COMPAGNION D, 589 CORRE B, 722 CORTELLINI L, 599 COUTE A, 727 COX D J, 448 CROATTO U, 158, 577 CUADROS S, 506 CUTAYAR J, 527 DAWSON W M, 264 DE ANGELIS A, 645 DE MENEZES J B, 679 DE POLI F, 625,645 DECLERCK M, 310 DEGLISE X, 822, 920 DEL MEDICO G, 496 DELANNOY B, 547 DELMAS M, 968 DEMUYNCK M, 146 DONNOT A, 822 DORING R, 732 DOS SANTOS C L M, 679 DOUBLE J M, 915 DUBBE D R, 354 DUBOURGUIER H C, 516,542 DUJARDIN E, 369 DUNN P D, 1172 DUVIGNAU M, 557 EBELING J, 804 EGGER K, 453,1136 EL-HOUSSEINI M, 458 ELSBETT G, 1177 ELSBEIT K, 1177 ELSBETT L, 1177 ESNOUF C, 942 EVANS M C W, 117 FAGBENI L, 842 FAIX 0,732,929 FALLOWFIELD H J, 398 FANKHAUSER J, 1136 FAYOLLE F, 692 FDZ-POLANCO F, 464 FELBER J, 1025 FERNANDEZ R, 506 FERNANDEZ J, 330,994 FERRARI D, 617 FIALA M, 869 FIELDING E R, 1151 FINK J D, 5IO FLORENZANO G, 584 FONTES A G, 393 FORISTER G, 804 FORSTER U, 665 FRATPONT L, 1122 FRANK J R, 323,484 FREDERICK D J, 288 FREEL B A, 860 FUJINO D, 804 FUNES L E, 422 GALLIFUOCO A, 989 GARCIA A J, 506 GARCIA P, 464 GARRETT M K, 398 GARVER E G, 354 GASET A, 968 GAST D, 949 GATEAU P, 985 GATTA A, 865 GAUTIER X, 756 GELUS M, 842 GEYER W A, 269 GHERI F, 164 GIANI C, 665 GIRARD H, 651 GIRAUD A, 6 GOCHNARG I, 1088 GOMA G, 458,510 GOSSE G, 66,315,321 GOUDEAU J C, 959, 963 GOUPILLON J F, 783 GRAHAM R G, 860 GRASSI G, 164 GREPINET 0,651 GROS D, 689 GROSZMANN G L, 1088 GUERRERO M G, 393 GUIBET J C, 985 HAARS A, 973 HALL D 0,387 HARKER A P 849 HARTMEIER W, 660,665,684 HAYES T D, 484 HELLWIG M, 793 HELD W, 744 HENHAM A W E, 1167 HENNING K-D, 621 HENRY M, 689 HERBERT J, 809 HILLION G, 985 HIMNEL W, 640 HISLOP D, 1064,1093 HOFFMANN G, 1113 HORTON L, 288 HUMMELL F C, 90 HUTTERMANN A, 973 IBANEZ E, 635 JASTER K W, 879 JAWETZ P, 1126 JAYET P A, 479 JENKINS B, 804 JOHNS R A, 1167 JOSEPH S, 1064,1093 JOYCE R J, 735 JULIEN L, 959, 963 JUNTGEN H, 621 KAFROUNI H, 920 KAHNT G, 339 KANDLER 0,474,609 KaWAMBWA S, 1131 KEKRE M G, 982 KIHUMBA S N, 749 KLOCK G, 374 KNOBLAUCH K, 621 KOGL H, 84 KOUFOPANOS C, 837 KRAUS U, 799 KREULEN H P, 1069 KREUZBERG K, 374 KRISPIN T, 1117 KUNTZEL U, 604 KUUSINEN 0,1006 LA ROVERE E L, 207 LACROSSE L, 809 LADOUSSE A, 920 LADRIERE P, 1182 LAMMERS P S, 874 LARGEAU C, 717, 722 LARIGAUDERIE A, 403 LARIMER D R, 929 LARKIN S B C, 334 LAU C F, 1084 LAWSON G J, 109 LAWSON G J, 412 LE FUR C, 1146 LEDUC B, 1182 LEGROS A, 369,584 LEIBLE L, 339 LEMA J M, 635 LEMASLE J M, 889 LEPRI A, 655 LEPRINCE P, 45 LEQUEUX P, 809 LESCURE J P, 547 LEUCHS M, 1141 LEULLIETTE L, 689 LIINANKI L, 832 LISTER T A, 735 LONGIN R, 651 LOSADA M, 393 LUCCHESI A, 837 LUNNAN A, 1030 MAGNE P, 822 MAINWARING A M, 412 MAJCHERCZYK A, 973 MANERO J, 330 MANURUNG R, 900 MANZANARES P, 330 MARCHAL R, 692 MARCHETTINI N, 702 MARTINDALE L P, 343 MARTIN C, 994 MASCHIO G, 837 MASSON D, 920 Matarasso P, 1010 MATERASSI F, 584 MATHRANI S, 1108 MAZZAGARDI M, 384 MCELROY G H, 264 MCKENZIE HEDGER M, 1098 MCKEOUGH P J, 937 MEGALOS M A, 288 MEHRLING P, 905 MEIER D, 732, 929 MEINHOLD https://www.w3.org/1998/Math/MathML"> K , 84 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> MELICHER M W, 269 MENDIA M, 625 MES-HARTREE M, 982 METZGER P, 727 MICHAELIS L A, 1039 MICHELOT E, 552 MIGLIACCIO N, 625 MILANDE N, 648 MIRANDA U, 164 MISHOE J W, 1020 MISSONI G, 384 MITCHELL C P, 300 MOK L K, 860 MOLETTA R, 510, 516 MOLLER M, 819 MORENO J, 393 MOREL J Y, 594 MOTTET A, 1122 MOULINEY M, 527 MUCKE I, 66 MUKHERJEE C, 768 NATUSCH D F S, 735 NAUGHTON G G, 269 NAVEAU H, 146,369,584,589 NDAYISHIMIYE J, 589 NDITABIRIYE D, 589 NEENAN M, 278 NEGRO M J, 994 NE IBELSCHUTZ H, 675 NEMICHE A, 963 NG' ENY-MENGECH A, 749 NICOLINI S, 614 NIYIMBONA P, 589 NOBLE D H, 334 NOLTING F, 1141 NUTTALL D R, 448 NYNS E-J, 146,369,584,589 O'KELLY N, 630 OELERT H H, 744 OGGIONNI C, 594 OHRT U, 1113 OKKEN P A, 760 ONG K S, 1084 OORTHUYS F M L G, 522 ORSI N, 702, 714 ORSORE H, 999 ORTMAIER E, 348 OSTAN R, 865 OSVIK A, 819 OVEREND R P, 178,860,933 PACI M, 837 PAPADOPOULOS J, 697 PAQUOT M, 1122 PASQUALI G, 865 PEARCE M L, 292 PELKONEN P, 417 PELLIZZI G, 99 PEREIRA H, 707 PERERA E D I H, 1172 PERRIN L, 30 PETERS M, 744 PETRE D, 651 PEZZULLO L, 989 PHILLIPS D R, 288 PICCININI S, 599 PICKEN D J, 493 PIERONI N, 496 PITZER H, 1113 POSTMA H J W, 522 POUET Y, 727 POURQUIE J, 692 PRASAD K K, 814 PRATI D C, 354 PRENSIER G, 542 PRICE R, 214 PULS J, 670,949 PYLE D L, 1074,1108 RADLEY R W, 334 RAMDAHL T, 819 RAYMOND B, 648 RAYNAL J, 552 RAYNAUD 0,651 REBELLER M, 692 REDONDO L J, 464 REIFENSTAHL G, 744 REIMERT R, 905 REQUILLART V, 1015 REYNIEIX M, 847 REYNOLDS P J, 630 REZNICZEK G, 374 RICE G, 1131 RICHARD J R, 894 RICHARDSON D W, 735 RICHTER E, 621 RIETVELD F A J, 579 RIGAL L, 968 RINGBLOM U, 151 ROBERTS D, 804 ROCANCOURT M, 651 ROLOT D, 589 ROMAN J, 310 ROSILLO-CALLE F, 1058 ROSSI C, 702 ROY J, 403 RUDOWSKI M, 1136 SAARIKKO E, 427 SACHS K M, 804 SACHS R M, 804 SADDLER J N, 978 SAEZ F, 994 SAEZ R, 994 SALVI G, 869 SAMAIN E, 542 SAMUELS G, 1126 SANZ I, 464 SAUZE F, 364 SAVOIA G, 441, 865 SCHARF H J, 884 SCHIEFERSTEINER M, 1025 SCHNEIDER J, 1156 SCHORNER G, 1002 SCHRADER L, 884 SCHUTZ P, 640 SCHWALD W, 953 SCOTT R, 109,412 SCULLY J J, 33 SELIGMAN R M, 15 SEMENZA C, 430 SILHOL M, 1146 SIMEON C, 1146 SINGH N P, 1079 SIPILA K, 778 SIRONVAL C, 369 SKUTSCH M M, 1103 SMETS J, 310 SMETS Ph, 310 SMITH D H, 910 SMITH E A, 849 SMITH W H, 222, 323, 484 SOLANTAUSTA Y, 937 SOLANIAUSTA Y, 937 SOUIL F, 963 SOURIE J C, 1054 SOYER N, 924 SPITZER J, 640 SPRUIJT G, 1069 STADLER E, 1136 STAHLBERG P, 778 STEINER A, 474 STEINMULLER H, 1025 STERN B, 985 STREHLER A, 60, 788 STRUB A S, 3 STURMER H, 348 SULILATU F, 814 SUPAJUNYA N, 532 SUTTER K, 453 SVENNINGSSON P J, 832 TABARD P, 283 TABET J P, 1010 TAHA A, 982 TANTICHARDEN M, 532 TATOM J W, 827 TEGGERS https://www.w3.org/1998/Math/MathML"> H , 884 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> TEMPER U, 609 TENORTO J, 422 TESSIER-DU-CROS E, 305 THEANDER 0,1044 THESSEN G, 832 THOMA H, 348 THONART P, 1.122 TIEZZI E, 655 TILCHE A, 599, 645 TORMALA T, 427 TRAMM-WERNER S, 684 TRAVERSO P G, 572 TREDICI M R, 584 TROJANOWSKI J, 973 TROSSERO M A, 296 TSHIAMALA T, 1122 TVETEN G, 819 UGLIATI S, 655 UTITHAM T, 532 VALENTI P, 702,712 VAN BEEK H C A, 1069 VAN DER DRIFT E, 1069 VAN SWAAIJ W P M, 120 VANDECASTEELE J P, 692 VAPAAVUORI E M, 417 VARGAS M A, 393 VENTAS P T, 422 VERRIER D, 537,547 VIGLIA A, 614,617 VILPPUNEN P, 1160 VIMAL O P, 1079 VISCA P, 712 VOVELLE C, 894 VUILLOT M, 379VUORINEN H, 417 WAGNER F, 744 WASHBOURNE J F, 765 WEILAND P, 562 WEISMANN A F，37 WELLINGER A, 453, 1136 WENMAN C M, 172 WIEGEL J, 670 WILDENAUER F X, 469,474,609 WILEN C, 778 WILHELMSEN G, 54 WILKIE A, 630 WILTON B, 765 WINTER J, 469,609 WOHLMEYER A F J, 74 WU WEN, 228 WULFERT K, 562 WUNSCHE U, 359 WURSTER R, 501 YEBOUA AKA F, 458 YU E K C, 978 ZAROR C A, 1074 ZAUNER E, 604 ZERBIN W 0,1117 ZUBR J, 435 ZUFFI 0,648 ZWIEFELHOFER H P, 1163 25. SUBJECT INDEX Acetone butanol fermentation 692 Acid hydrolysis 697 Advanced gasification 120 African termites 999 Agricultural markets 1034 Agricultural residues 832 Agriculture 66,84,350 Agrobioenergy 1065 Air pollution 819 Alcohol 959,1131 Algae 158,369,374,384,393,398, 564,577,614,660,717,727 Alkali treatment 994 Ammonia 387 Anaerobic bacteria 537 Anaerobic digestion 448,474,489, 501,522,537,572,614,617 Anaerobic fermentation 594 Anaerobic filters 630 Anaerobic sludges 516 Anaerobic stabilization 469 Anaerobic treatment 527, 648 Animal feed 369 Animal slurry 398 Animal wastes 522 Anoxal process 527 Aquatic biomass 1146 Aquatic systems 379 Anable onops 315 Austria 73,640,1002 Bamboo 679,1122 Rark 894 Bioconversion 973 Biodegradation 989 Biogas 228,411,453,532,577, 625,640,1.002,1136 Biogas digester 567 Biogas engines 1141,1182 Biogas technologies 506 Biological treatment 496 Biomass valorization 1110 Biomethanation 146,458,479,547, 552,562,564,589 Boilers 819 Botryococcus braunii 717,722,727 Brazil 207, 1058,1088 Briquetting 773,1064 Broom (C. scoparius) 283 Butanol-tolerance 712 Butyrates 516 Canada 178 Cannery wastes 532 Carbonisation 849,865 Cassava residues 501 Catalysis 959,963 CEC 3 Cell immobilization 660,665 Cellulose 860,989 Cellulosic biomass 697 Charcoal 783 Chemicals 978,982 China 228 Chromatography 732 Circulating fluid bed reactor 905 Cloning 651 Clostridium acetobutylicum 702,712 Clostridium thermocellum 651 Coconut shell 849 Combustion 793, 847 Common Agricultural Policy 33 Continuous process 689 Cooking 768 Coppice 264, 269, 274, 292 Corn cobs 756 Corn drying 756 Crop drying 804 Cropping 359 Crude wood oils 732 Cyanobacteria 393 Densified biomass 809 Developing countries 589,827 Diesel engines 1136,1172,1177 Diesel fuel 735 Diesel fuel substitute 1069 Distillery waste waters 552, 562 Domestic firewood burner 768 Downdraft gasifier 832,900 Downflow anaerobic filter 547 EC pilot plants for syngas 120 Economics 484, 493, 937, 1015 1039,1049 Ecuador 1098 Edible oil 1069 EEC 348,350 Eichhornia crassipes 407 Energy balance 920,1088 Energy crops 323,330,435,604 Energy valorisation 1015 Energy-cane 1126 Micropropagation 427,441 Modeling 645,842,1010 Molecular sieves 621 Moving bed gasifier 900 Municipal wastes 572 Mutants 712 Natural vegetation 109 Netherlands 760 Nitrogen 393 Nitrogen fixation 387 NMR 655,702 Nordic countries 54 Northern Ireland 264 Nonway 1030 Nutrients 717 Onopordum nervosum 330,994 Organic chemicals 968 Organosolv lignins 973 Oxygen gasification 889 Paper 1122 Pelletization 778 Pentosans 670 Pentoses 670 Petrol substitution 45 Photobiology 117 Photointerpretation 430 Photosynthesis 403,435 Phragmites 321 Pig manure 489 Pipeline gas 621,625 Piscicultural waste 1146 Plant nutrients 412 Platform tests 847 Producer gas 879 Proprionate 516 Pyrolysis 822, 827, 837, 842, 933,1002 Rape 1034 Refuse 1156 Refuse decomposition 1151 Regional energy 1030 Research information 1020 Residues 99 Rice husk 900 Rubber seed oil 1172 Rural development 1098 SCP production 707 Semi-arid lands 310 Sewage 464 Sewage sludge 1163 Shont rotation forestry 264,278, 953,1034 Slaughterhotise wastes 474 Small steam systems 1093 Social impacts 760 Solia-liquid transfer 968 Solvent delignification 707 Southern US 222 Spark-ignition engines 1131,1136 , 1167 Sri Lanka 1172 Steam explosion 978 Stoves 1.103 Straw 334,343,773,778,788,793, 799,1015 Straw combustion 756 Sugar 978 Sugar industry waste 982 Sugar waste waters 547 Sunflowers 41.7 Sweden 1065 Sweet sorghum 339 Syngas 889,905,959,963 Synthesis 968 System analysis 1,020 Ta.110W 735 Tannery wastes 617 Tanzania 1131 Temperature stress 422 Thailand 1074 Thermal degradation 894 Thermochemical conversion 1039 Thermochemical liquefaction 929,937, 942 Thermochemical processing 1074 Thermophilic digestion 609 Themmophilics 670 Trees 54 Two phase digestion 562 UK 300,334,343 USA 354,484 Vegetable oils 985,1177 Venice lagoon 384,61.4 Volatile fatty acids 516 Waste heat recovery 849 Waste heat recorery 849 Waste management 1.60 Waste treatment 577 Waste water 407,648 Wastes 99,214,469 Water hyacinth 364,403 Water stress 422 Water treatment 364,379 Wetlands 354 Willows 264,417,427 Wood 54,788,793,799,849,865 879,889,894,1039 Nood liquefaction 920,924 Wood stoves 760,814 Wood tar 822 Wood waste 879 Wood-based energy 296 Woodgas power plants 1117 Yeast 660,665,675 Yields 323 Zeolites 959 Zimbabwe 172 Zymomonas mobilis 684 26. LIST OF PARTICIPANTS ALBAGNAC G, INRA, Villeneuve d'Asq, France. ALBERTSSON N, HB Nydo Energi, Stackholm, Sweden. ALEXANDRIAN D, CREMAGREF, AIX-en-Provence, France. ALFANI F, Dept. of Chemical Eng., Univ. Naples, Italy. ALLIRAND J-M, INRA, Thierval Grignon, France. ALTDORFER F, Science Policy Dffice, Brussels, Belgium. AMIRANTE B, Inst. di Meccanica agraria, Bari, Italy. AQUILANI R, Palazzo Uffici, Milano, Italy. APFELBECK R, Bayerische Landesanstalt f. Landtechnik Freising, Germany. ARNOUX M, INRA, Montpellier, France. ARNOUX, Ste.S.G.N. Montigny le Bretonneux, France. ASPLUND D, Tech. Res. Centre, Jyvaskyia, Finland. AUCLAIR D, INRA, Olivet, France. AXELSSON L-E, Pulp & Paper Assoc., Stockholm, Sweden. AYERBE L, INIA, Madrid, Spain. BALDELLI C, CASMEZ, Roma, Italy. BALLONI W, CSMA CNR, Firenze, Italy. BARRETD DE MENEZES T, Ital, Campinas-SP, Brazil. BEAUMONT 0, Elf Aquitaine, St. Symphorien d'Ozon, France. BECKER J J, CEMAGREF, Antony, France. BENNACKERS A A C M, Groningen Univ., Boekelo, The Netherlands. BEETS W C, ICRAF, Nairobi, Kenya. BEGUIN P, Inst. Pasteur, Paris, France. BELLAMY J-J, Assoc. Bois de Feu, Aix-en-Provence, France. BELLETTI A, A. Biotec, Forli, Italy. BENESTAD C, Centre for Industrial Res., Blindern, Norway. BENGTSSON G, Bepolkemi AB, Ornskoldsvik, Sweden. BENN R, UMIST, Manchester, UK. BENTE Jr P, Bio-Energy Council, Arlington, USA. BERGGAMASCHI P, Conphoebus soc. cons., Catania, Italy. BEVAN C, Alsthom Atlantique, La Courneuve, France. BINI SMAGHI B, CEE, Bruxelles, Belgium. BISCEGLIA D, Regione Puglia, Bari, Italy. BODMER R, E. Basler + Partner, Zurich, Switzerland. BODRIA L, Inst. Agr. Eng., Milano, Italy. BDELCKE C, Inst. Fermentation und Brauwesen, Berlin, Germany BOLHAR-NORDENKAMPF H, Inst. f. Pfanzenphysiologie, Wien, Austria. BOILLOT M, Electricite de France, Chaton, France. BOMBELLI V, EIVEA, Roma, Italy. BONAIUTI R, Libeva professioniste, Milano, Italy. BONAMOUR A-M, AFME, Paris, France. BONICEL A, CEN, Grenoble, France. BONOMI E-M, FAC Ingegnema - Roma, Roma, Italy. BORIES A, INRA, Barbonne, France. BOU J, Catalana de gas y electricidad s.a., Barcelona, Spain. BOUISSOU D, AFME, Paris, France. BRANDELS L, Nat. Energy Administration, Stockholm, Sweden. BREAG G R, Tropical Development Res. Inst., Culham, UK. BREEZE P, Modern Power Systems, London, UK. BRENNDORFER M, KTBL, Darmstadt, Germany. BRIDGLATER A V, Univ. of Aston, Birmingham, UK. BROCHIER J, Brochier Agro Cons., Castries, France. BRUGGINK J C, NERF, Le Petten, The Netherlands. BRUNEAU C, ENSCR, Rennes-Beaulieu, France. BULLY F, BIOMAGAZ/Groupe EMC, Cernay, France. BURIAN-HANSEN P, Crone & Koch, Viborg, Denmark. BUSSMANN P, Unive of Tech., Eindhoven, The Netherlands. BUSCH H P, Forschungsinstitut f. schnellwachsende, Hann Munden, Germany. CACERES A, CEMAT, Guatemala City, Guatemala. CAIRE B, VALORGA, St Jean de Vedas, France. CAIREN S, Nat. Energy Aministration, Stockholm, Sweden. CALL H P, Inst. for Biology RuTH, Aachen, Germany. CALLAGHAN T, Inst. of Terrestrial Ecology, Grange - over - sands, UK. VALBIRISSI F, Eniricerche, Monterondo, Italy. CAMPAGNA R, Ist. Guido Donegani, Novara, Italy. CANNAZZA G, European Energy & Environmental Eng. Ltd, Dietikon, Switzerland. CANTARELLA M, Dpto di Ingegneria Chimica, Univ. di Napoli, Italy. CANTARELLA L, Dpto Ing. Chimica Fac. Ing., Univ. di Napoli, Italy. CAPART J, Unive de Compiegne, Compiegne, France. CARBONE D, Conphoebus Soc. Cons., Catania, Sicily. CARRE J, AFME, Paris, France. CARRE J, CRA, Gembloux, Belgium. CARRIERI C, IRSA - CNR, Bari, Italy. CARVALHO NETO C C Fund. de Tec. Ind., Lorena, Brazil. CASADEVALL E, CNRS - ENSCP, Paris, France. CATANZAD G, Cassa per il Mezzogiorno, Roma, Italy. CATHELINAUD Y, OCDE, Paris, France. CELEOTTI S, CAVIRQ, Faenza, Italy. CETINCELIK M, Energy Word, Ankara, Turkey. CHALFONT G, BP Chemicals Ltd, London, UK. CHARTIER P, AFME, Paris, France. CHASSANY de CASABIANCA M L, CNR5, Montpellier, France. CHASSAING, European Energy & Environmental Eng. Ltd, Dietikon, Switzerland. CHESINI R, Verona, Italy. CHIESA G, SpA Castagnetti, Cascine Vica/Rivoli, Italy. CHRISTENSEN J, Inst. of Agr. Econ., Copenhagen, Denmark. CISSE I, CRES, Paris, France. CLANCY J S, Energy Group, Univ. of Reading, UK. COGLIATI G, AGIP, Roma, Italy. COLLERAN E, Dept. of Microbiology, Univ. College, Galway, Ireland. COOMBS J, Bio-Services, London, UK. CORELLA J, Univ. di Zaragoza, Spain. CORTELLINI L, CRPA, Reggio Emilia, Italy. CQX D J, Polytechnic of South Bank, London, UK. CRIME D, INRA, Grignon, France. CUEL J, Beghin - say, Paris, France. CUTAYAR J, L'air Liquide, Les Loges en Josas, France. DAWSON M, DANI, Loughgall, UK. DE BENOIST H, AGPB, Paris, France. DE BOER W, Gist-Brocades nv, Delft, The Netherlands. DECLERCK M, Tractionel, Brussels, Belgium. DE LATOUR P, Univ. of Paris-Dauphine, Paris, France. DEL CAMPD F, Univ. Autonoma de Madrid, Spain. DELTOUR L, INIEX, Liege, Belgium. DENORQY P, INRA, Paris, France. DE PIERREFEU A, IRCHA, Vert-le-Petit, France. DE POLI F, ENRA, Roma, Italy. DE SILGUY C, APCA, Paris, France. D'ESTAIS F, CGB, Paris, France. DEVAUX P, AFME, Paris, France. DE WAART J, CIVD-Analyse-TND, He Zeist, The Netherlands. DINH VAN T, Fichtner Cons. Eng., Stuttgart, W. Germany. DOAT J, CTFT, Nogent sur Marne, France. DOSIK R, World Bank, Washington DC, USA. DOUBLE J, Univ. of Aston, Birmingham, UK. DUBBE D R, Univ. of Minnesota, USA. DUBQURGUIER H-C, INRA, Villeneuve d'Asq, France. DUJARDIN E, Liege Univ., Sart-Tilman, Belgium. DYNESEN C, H Moller Andersen Aps, Frederiksberg, Denmark. EDEN P, Barclays Bank ple, London, UK. EHLE J, Hofspiegelberg, Salzhemmendorf, W. Germany. EL-HOUSSEINI M, INSA, Toulouse, France. ELSBETT K, Elsbett - Konstruktion, Hilpoltstein, W. Germany. EMRICH W, Carbon Int. Ltd, Neu-Isenburg, W. Germany. ENGSTROM S, Dept. of Chem. Tech., Univ. of Stockholm, Sweden. EVANS MC, King's College London, UK. FAIX D, Ist. of wood Chemistry & Chem. Tech. of wood, Hamburg, Germany. FALLDUFIELD H J, West of Scotland Agr. College, Ayr, UK. FANTINI P, Univ. La Sapienza, Roma, Italy. FARINA G L, Foster wheeler Italiana, Milano, Italy. FAUL W, KFA Juelich, Juelich, Germany. FELBER J, Voest Alpine, Linz, Austria. FERRENCZY G, Haustechnik Plannunsgesellschaft, Gmuend, Austria. FERNANDEZ-POLANCO F, Fac. de Ciencias, Valladolid, Spain. FERNANDEZ J, Junta Energia Nuclear, Madrid, Spain. FERRERD G L, CCE, Bruxelles, Belgium. FIEVET B, CESTA, Paris, France. FINCK J D, Elf Bio Recherches, Castanet Tolosan, France. FIORAMONTI S, INRA, Castanet Tolosan, France. FLORENZANO G, CMA-CNR. Firenze, Italy. FLYNN B, Applied Power Technology, Menlo Park, USA. FONTES G, Facultat de Biologia y CSIC, Sevilla, Spain. FOD ENG LEONG, Karolinska Inst., Stockholm, Sweden. FRANK J, Gas Res. Inst., Chicago, USA. FRANZONE V, Consorzio ASI-ENNA, ENNA ( Sicily ), Italy. FUCHS K, Inst. of wood Chemistry & Chem. Tech. of wood, Hamburg, Germany. GAGNAIRE-MICHARD J, CEA, Grenoble, France. GAHAN H, BCTIS, Dublin, Ireland. GALLIFUOCO A, Dipartimento Ingegneria Chimica, Univ. Napoli, Italy. GALVAGNO A, Consorzio ASI-ENNA, ENNA (Sicily), Italy. GARCIA BUENDIA A, ENADIMSA, Madrid, Spain. GARCIA M, GDE, Lisboa, Portugal. WEICKMANS M, CIBE, Paris, France. GARSIA M-G, AGIP SPA, Milano, Italy. GASET A, ENSC, Toulouse, France. GAUTIER E, SES SPA, Rome, Italy. GAUTIER X, AGPM, Serres Castet, France. GELUS, Univ. de Compiegne, France. GEYER W, Kanas State Univ., Kansas, USA. GHERI F, Grassina Firenze, Italy. CHILARDOTTI G, AGIP, Milano, Italy. GIRAUD A, CGE, Paris, France. GLAUSER M, Univ. de Neuchatel, Switzerland. GLYNN P, EEC, Bruxelles, Belgium. GOCHNARGE I, IPT, Sao Paulo, Brazil. GOEBEL https://www.w3.org/1998/Math/MathML"> 0 H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429085949/40d9af03-8043-4805-bf5f-9ed2384b8546/content/eq1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> , Cora Eng., Chur, Switzerland. GOLDSTEIN I S, North Carolina State Univ., Raleigh, USA. GOSSE G, INRA, Grignon, France. GOUDEAU J-C, CNRS Poitiers, St-Julien L'Ars, France. GOUDRIAAN F, Shell, Amsterdam, The Netherlands. GRUPILLON J-F, CEMAGREF, Antony, France. GRAHAM R, Univ. of Western Ontario, Canada. GRASSI G, CEC DG XII, Bruxelles, Belgíum. GRAUBY A, CEA CEN Cadarache, France. GRECCHI M, Settore al problemi Energetici, Milano, Italy. GROOP S, State Power Board, Vallingby, Sweden. GUARELLA P, Ist. di Meccanica agraria, Bari, Italy. GUINARD 0, Agro-Developpement, Paris, France. GURUMURTI K, Forest Res. Inst., Dehravun, India. HAARS A, Inst, f. Forstbotanik, Gattingen, W. Germany. HADZIC M, Projectni Zavod, Beograd, Yugoslavia. HAEFFNER E, Innovation Inst., Stockholm, Sweden. HALL D 0, King's College, London, UK. HARME P V, Min. of Trade & Ind., Helsinki, Finland. HAVE H, Royal Vet. & Agr. Univ., Tasstrup, Denmark. HAYAT G, Foster Wheeler, Paris, France. HEDUIT M, MNE, Paris France. HELD W, Volkswagenwerg AG, wolfsburg, Germany. HELLWIG M, Landesanstalt f. Landtechnik, Freising, Germany. HENHAM A, Unive of Surrey, Guildford, UK. HENNING K D, Bergbau Forschung, Essen, Germany. HILTUNNEN J, Neste Dy, Porvoo, Finland. HISLOP D, ITDG, London, UK. HDBAUS P, NCAR, The Hague, The Netherlands. HOFFMANN G, TUEV Rheinland Inst. ETEP, Koeln, Germany. HOFFMANN J, Office Arid Lands Studies, Tucson, USA. HOLISTER M, UNESCO SC/TER, Paris, France. HORDIJ K, CDP Consultants, Utrecht, The Netherlands. HULSCHER W, Twente University, Enschede, The Netherlands. HUMMEL F, Consultant, Guildford, UK. JAMES R, EDG, Cheltenham, UK. JARGSTORF B, DDE-CI, Bad Homburg, W. Germany. JASTER K, Fritz werhner Industrie GmbH, Geisenheim, w. Germany. JAUNEAUE, AFME, Paris, France. JAWETZ P, Consultant, New York, USA. JDLY J, AFME, Paris, France. JOSEPH S, BEST, Saratoga, Australia. JUNET R, Gaz de France, St. Denis, France. KALAMBLA S, Unive of Reading, UK. KEKRE M, Unive of Gezira, wadmedani, Sudan. KINGSOLVER B, Univ. of Arizona, Tucson, USA. KISGECI J, Inst. Field & Vegetable Crops, Backi Petrovac, Yugoslavia. KI-ZEBO J, Dakar, Senegal. KLEIN M, Kraftwerk Union, Dffenbach, Germany. KOCSIS K, FAD, Roma, Italy. KORFF J, URBK, Wesseling, Germany. KDUFOPANOS C, Dept. of Chem. Eng., Univ. Pisa, Italy. KRAUS U, TUMW, Freising, Germany. KREULEN H P, HUA Int. BV, Amsterdam, The Netherlands. KREUZBERG K, Inst. of Botany, Univ. Bonn, Bonn, Germany. KROLIKIEWICZ M, AMC-STITEUR, Frankfurt, Germany. KUUSINEN 0, Neste Dy, Espoo, Finland. LAFONT S, Technip, Paris, France. LARIGAUDERIE A, CNRS, Montpellier, France. LARKIN S, Silsoe College, Bedford, UK. LATRAVERSE S, Gaucher Pringle Cons. Ltd, Montreal, Canada. LAUFER P, AFME, Paris, France. LEATHER T, Shell Int. Petroleum Co Ltd, London, UK. LEBRE LA ROVERE E, FINEP, Rio de Janeiro, Brazil. LEDUC B, Univ. of Brussels, Brussels, Belgium. LEFEBVRE L, Rhonealpenenergie, Lyon, France. LEIBLE L, Univ. Hohenheim, Stuttgart, Germany. LEINERT S, Leinert-Forest Consult, Dreieich, Germany. LEMA J, Dpto. Quimica Tecnica, Univ. Santiago, Spain. LEMASLE J M, Framatome, Le Creusot, France. LEPRI A, Dipartamento di Chimica, Univ. Siena, Italy. LEPRINCE P, Inst Francais du Petrole, Ruell-Malmaison, France. LEQUEUX P, CEC, Brussels, Belgium. LEROUDIER J P, AIBA, Paris, France. LEROY F, IEGSP, Charleroi, Belgium. LEULIETTE L, SGN, Saint-Quentin Yvelines, France. LINDBLOM A, Vattenfall, Vallingby, Sweden. LINNEBORN J, Wiesbaden, Germany. LJUNBLDM I, Bio Energy, Stockholm, Sweden. LISTER T, LFTB, Wellington, Australia. LONGCHAMP D, Inst. Francais du Petrole - CEDI, Vernaison, France. LUBINSKA A, Journalist, Brussels, Belgium. 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