VERFAHREN UND SYSTEM ZUR ZERSETZUNG WASSERHALTIGER BRENNSTOFFE ODER ANDERER KOHLENSTOFFHALTIGER MATERIALIEN

摘要

A staged gasification process and system for thermal gasification of special waste fractions and biomass, e.g. wood comprises a drier (1), in which the fuel is dried by contact with superheated steam. The dried fuel is fed into a pyrolysis unit (4) to which superheated steam is also supplied. The volatile tar containing components produced in the pyrolysis unit (4) is passed to an oxidation zone (5) in which an oxidation agent is added so as to cause a partial oxidation, whereby the content of tar is substantially reduced. The solid fuel components from the pyrolysis unit (4) may be fed into a gasification unit (6) to which hot gases from the oxidation zone (5) are supplied. In the gasification unit (6) the solid fuel components are gasified or converted to carbon. The gas produced in the gasification unit (6) may be burnt in a combustion unit (7), such as a combustion engine. Thus, a gasification process is obtained for gasification of biomass and waste with a high energy efficiency, low tar content of the gasification gas, with moderate risk of slagging for a wide spectrum of fuels, including fuels with a large content of moisture.