Effect of the blend ratio on the co-gasification of biomass and coal in a bubbling fluidized bed with CFD-DEM

摘要

Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) is employed to describe the co-gasification of biomass and coal in bubbling fluidized bed coupled with chemical reaction kinetic model. Six sets of simulations are set up to study the effect of blend ratio on the amount of gasification products compared with experiments. The calorific value of syngas, carbon conversion efficiency, hydrogen conversion efficiency and cold gas efficiency are calculated. Compared with the separate gasification, the hydrogen efficiency and cold gas efficiency in the co-gasification are enhanced. When biomass accounts for 75, the contents of CO gas and CO_2 gas are the lowest, while the contents of H_2 gas and CH_4 gas are the highest. The high calorific value, carbon conversion efficiency and hydrogen conversion efficiency reach the maximum under this blend ratio. The cold gas efficiency is not obviously affected by the blend ratio, and reaches the maximum when the biomass content is 50.