DEVELOPMENT OF GAS, POWER, TAR CO-GENERATION SYSTEM INTEGRATING CIRCULATING FLUIDIZED BED COMBUSTION WITH COAL PYROLYSIS

摘要

A gas, power and tar co-generation technology, which combines a circulating fluidized bed (CFB) boiler and a fluidized bed gasifier to realize gas, power and tar co-generation in one system, has been developed. Based on the research works on a 1MWe pilot plant test facility in the laboratory, a 12MWe demonstration system fired the bituminous coal has been operated for co-generating gas, tar and power in 2008. In 2011, a 40t/h lignite feed rate industrial scale co-generation system has been constructed as part of an existing 300MWe CFB boiler by retrofitting one of four hot ash recycle systems. The demonstration operation results show that both of 12MWe bituminous coal and 40t/h lignite coal co-generation systems may be operated continuously and steadily in design requirements. The 12MWe co-generation system may produce about 1950Nm~3/h gas with high heating value (HHV) about 23MJ/Nm~3, about 1t/h tar and 70t/h superheated steam with, a bituminous coal feed rate of roughly 11t/h, meanwhile the 40t/h lignite coal co-generation system will produce 8200Nm~3/h gas with HHV about 17MJ/Nm~3 and about 1.1t/h tar. A series of test operation results from 12MWe co-generation plant showed that the operation temperature in the gasifier has great influence on the pyrolysis gas composition and tar yield. Based on the achieved results, the developed gas, power and tar co-generation system may be applied in industry next step.