ABSTRACT
Figure 11.1 Views of the city of Güssing. Left: Region around Güssing. Right: Castle of Güssing. The first plant which was built was a biodiesel (rapeseed methyl ester [RME]) plant in the year 1990. This biodiesel plant produced RME until about 2005; afterward the production was stopped due to economic reasons. In 1998 a district heating system based on grate combustion using wood chips as fuel was commissioned which was the largest biomass based district heating system in Austria at that time. In the year 2001 a 2 MWel demonstration plant for combined heat and power (CHP) production based on a novel dual fluidizedbed (DFB) gasification system was realized in Güssing. Later another CHP plant was built on the basis of combustion of wood dust, which was available as residue from parquet factories settled in Güssing at that time. Today, these two CHP plants are able to produce the whole electricity which is consumed by the people living in Güssing, and together with the grate combustor, 95% of the city of Güssing and the industries around Güssing are supplied by district heat from biomass as well. 11.2 Short Description of the Güssing Plant
The innovative DFB-technology for CHP generation has been demonstrated in Güssing for the first time worldwide. Biomass is
gasified in a DFB reactor. The producer gas is cooled, cleaned, and used in a gas engine. The most important data of the demonstration plant are summarized in Table 11.1. A detailed flow sheet of the whole plant is shown in Fig. 11.2. Table 11.1 Characteristic data of the demonstration plant
cannot used for paper production, are chipped on-site (Fig. 11.4) and filled into the daily hopper, which is equipped with a walking floor at its bottom. Biomass chips are transported from a daily hopper to a metering bin and fed into the fluidized-bed reactor via a rotary valve system and a screw feeder (Fig. 11.5, left side). The gasifier consists of two fluidized-bed reactors, a gasification reactor, and a combustion reactor. The gasification reactor is fluidized with steam which is generated by waste heat of the process in order to produce a nitrogen free producer gas. The combustion reactor is fluidized with air and delivers the heat for the gasification process via the circulating bed material. The producer gas is cooled-mainly for steam production-and cleaned by a two-stage cleaning system (Fig. 11.5, right side). A water cooled heat exchanger reduces the temperature from 840°C-860°C to about 160°C-180°C. The first stage of the cleaning system is a
fabric filter to remove the particles and some of the tar from the producer gas. These particles are returned back into the combustion reactor of the gasifier. In the second stage the gas is liberated from tar by a RME scrubber.
