ABSTRACT
In chemical engineering, new operating modes as reversed fl ow for reactionregeneration energy effi cient coupling of endothermic and exothermic reactions, countercurrent fl ow and induced pulsing fl ow in trickle beds, unsteady operations, cyclical processes, extreme conditions, low-frequency vibrations to improve gas-liquid contacting in bubble-columns, high temperature and high pressure technologies and supercritical media and use of composite structured packing achieving low pressure drop through vertical stacking of catalyst, are now considered for practical application (Charpentier 2005).
