Production of heat and/or fuel gas in multi-stage gasification process comprises circulating pyrolysis gas through fluidized bed until target criterion is attained and then using it as heating medium and/or fuel gas

摘要

The production of heat and/or fuel gas in a multi-stage gasification process in which comminuted solids are pyrolyzed and oxidized and the pyrolysis products are classified while undergoing further reductive gasification in a fluidized bed comprises circulating the pyrolysis gas through the fluidized bed until a target criterion is attained, and then withdrawing a side stream of the gas as a heating medium and/or fuel gas for an engine. An Independent claim is also included for an apparatus for producing heat and/or fuel gas by gasifying solids in a multi-stage gasification process, comprising a feed device (1) for comminuted solids; a pyrolysis and oxidation unit comprising an oxidation zone (2), an aerator (3) and an off-gas channel (13); a fluidized-bed classification/gasification unit comprising a classifier (4), a separating bunker (5), a de-ashing cyclone (6) and a ventilator (7); a pyrolysis gas outlet (10); a heat exchanger (11); and a purification unit (12).