流化床生物质与煤共气化特性的初步研究

The gasification of the mixture of biomass and coal in a thermogravimetric apparatus (TGA) and a fluidized-bed was investigated. TGA was used to characterize the H2O-char gasification of rice haulm char, broomcorn haulm char, cornstalk haulm char and Shenmu coal char. The results show that the order of reactivity of various chars is as follows: Shenmu coal char < cornstalk haulm char < rice haulm char < broomcorn haulm char. The co-gasification rate of the mixture of biomass char and coal char is found to be higher than the rate sum of single coal char and single biomass char，which suggests that a synergistic effect takes place due to the co-gasification. In fluidized-bed gasification experiments, the carbon conversion and the content of burnable gas of co-gasification are higher than that of coal gasification alone, while the content of CO2 is lower. H2 and CO2 contents varying with the ratio of feeding oxygen to feeding carbon show different tendency between co-gasification and coal gasification. It implies that the co-gasification is affected by not only the reaction rate but also the gas-solid hydrodynamics in fluidized bed gasifier.