Experimental And Simulation Study On The Characteristics Of Gasification Of Typical Biomass

Energy crisis and environmental pollution has become increasingly serious. With theadvantages of rich in resources and zero emissions of carbon dioxide, biomass energyattractsworldwide attention. Currently,gasification technology is one of the most effectivetechnologies for the use of biomass. The main purposes of this thesis are to enhance theyield of syngas and help promote the quality of syngas. Theresearch in this paper is carriedout mainly through two ways-experiment and simulation, to study the mechanism ofbiomass gasification and the effects of operation parameters on gasification characteristics.Firstly, the release characteristics of gaseous products during pyrolysis and gasificationof the three Chinese typical biomass-rice husk, rice straw and sawdust were studied using alab-scale gasificationsystem. The results showed that CO, CH4and CO2were almostreleased simultaneously. Compared with H2and CH4, the yield of CO was the largest inpyrolysis. In gasification, introducingof steam promoted the conversion of biomass,andespecially enhanced the water-gas shift reaction to increase the yield of H2. Comparedwith rice straw and rice husk, the reactivity of sawdust is the highest, and the yield of H2and CH4of sawdust is the largest.A kinetic model of biomass steam gasificationwas built using Aspen Plus andvalidated with the data from experiment.With the model, the effects of operation parameterson thecharacteristics of biomass steam gasification were studied. The results showed thathigher reaction temperature could significantly promote the gasification ofbiomass.Introducing of steamcould enhance the yields of CO2and H2.The influence of O2on biomass gasification could be divided into two parts.Introducing of a lowerconcentration of O2could promote the gasification reaction by enhancing the exothermicoxidation reaction, while introducing of excessiveoxygen could consume the compositionof CO and H2. Introducing of CO2could enhance the production of CO, but reducethe lowerheating value of syngas. Compared with rice husk, the effects of operating parameters onsawdust were more intense, andthe changes in syngas distribution and lower calorific valuecompleted in a shorter time.