New Nickel-Based Catalyst for Tar Reforming,with Superior Resistance to Coking and Sulfur Poisoning in Biomass Gasification Processes

摘要

Gasification of tar by catalytic steam reforming was examined in a circulating fluidized-bed (CFB) biomass gasification process.The tar reforming characteristics of the newly-developed Ni/MgO-CaO catalyst (based on dolomite),doped with WO3 as a sulfur-resistant promoter,was investigated using a simulated gas containing naphthalene as tar.Also,we applied this catalyst to the gasification of a biomass of dried sewage sludge and wood chips.The results of these basic experiments have confirmed that the newly-developed catalyst showed a high tar conversion activity,and is stable even in a gas containing hydrogen sulfide.The catalyst also exhibited superior resistance to coking as well as to sulfur poisoning,compared with several commercial steam reforming catalysts.The gasification demonstration plant (15 ton/d sewage sludge capacity) equipped with the present catalytic reformer showed almost complete tar conversion at 800-850°C in the presence of 300 ppm sulfur.