GASIFICATION OF TORREFIED BIOMASS WITH CARBON DIOXIDE IN A FLUIDIZED BED

摘要

Biomass torrefaction at mild pyrolysis temperature is usually applied to improve the fuel quality ofrnbiomass. However, removal of a large amount of volatiles after torrefaction, torrefied biomass gasification with airrncannot enhance the syngas production. Therefore, applying the Boudouard reaction, gasification of torrefied biomassrnwith CO_2 at higher temperature could improve the syngas quality. In this study, gasification of torrefied biomass withrnCO_2 was carried out in a 30 kWth bubbling fluidized bed gasifier to investigate the effects of the air equivalencernratios (ER) and gasification temperatures on the syngas components, the higher heating value (HHV) and tar content.rnThe preliminary results show that the syngas content of CO_2 increased with increasing the ER, but that of H_2, CO,rnCH_4 shows the contrary results. In addition, at higher temperature above 800℃, gasification with CO_2 can enhancernCO concentration compared with the air-blown gasification process, due to the Boudouard reaction for the higherrncarbon content of torrefied biomass.