APPARATUS AND METHOD FOR MULTI-STAGE PYROLYSIS AND GASIFICATION OF SOLID FUEL

摘要

An apparatus and method for multi-stage pyrolysis and gasification of solid fuel are provided. Said apparatus comprises coal feeder (1), multi-layer fluidized bed reactor (6), slag discharge valve (9), cyclone separator (10) and condensate separator (11). The bottom of the multi-layer fluidized bed reactor (6) is installed with gas inlet. Several layers of fluidized bed (3) are set inside the multi-layer fluidized bed reactor (6) and each layer of fluidized bed (3) is separated by perforated distribution plate (5). The topmost layer of fluidized bed connects with coal feeder (1). The coal fed into the top layer of fluidized bed exchanges heat with pyrolysis semi-coke in this layer and upward-flow of gas produced by high temperature pyrolysis and gasification and is pyrolyzed at low temperature. The obtained solid particles which have been preliminarily pyrolyzed move downwardly into the next layer of fluidized bed through overflow pipe (4)/ distribution plate (5). They sequentially exchange heat with semi-coke and gas produced by pyrolysis and gasification, and then get into the next layer of fluidized bed in turn after being pyrolyzed. Finally the particles get into the bottommost layer of fluidized bed where gasification reaction occurs. Said apparatus and method can produce more light tar components.