木屑在鼓泡流化床和循环流化床中气化特性的对比研究

The performance of sawdust gasification in a 0.3m×0.3m bubbling fluidized bed gasifier (BFBG) is compared to that in the φ0.4m circulating fluidized bed gasifier (CFBG). The effects of fluidization velocity on the biomass gasification in two fluidized beds were analyzed. Due to the higher fluidization velocity and intensive mass and momentum transfer between gas and solids, CFBG has a faster pyrolysis rate than BFBG and can be operated at higher temperature with the same ER, which facilitates the second gasification and cracking of tar to improve the gas quality and reduce the tar content in gas. At low ER(ER≤0.28), the gas yield, carbon conversion and gasification efficiency of CFBG is higher than BFBG′s; however at higher ER(ER＞0.28), there is little difference between CFBG and BFBG.