A novel interconnected fluidised bed for the combined flash pyrolysis of biomass and combustion of char

A novel system of two adjacent fluidised beds operating in different gas at mospheres and exchanging solids was developed for the combined flash pyroly sis of biomass and combustion of the produced char. Fluidised sand particle s (200 mu m d(p) 400 mu m) are transported from the pyrolysis reactor to th e combustor through an orifice and recycled by a standpipe, riser and cyclo ne. Advantages of the new design are its compactness and the high level of heat integration. The solids circulation rate and holdup distribution betwe en the two compartments could be controlled adequately in experiments at ro om temperature and atmospheric pressure. A model, developed to predict the solids and gas exchange between the two reactor compartments, was validated with experiments in which the three relevant gas flows, the orifice diamet er and the particle diameter were varied. (C) 1999 Elsevier Science S.A. Al l rights reserved.