The Characteristic Research On Rice Husk And Sawdust Char High-temperature Gasification Reaction With Steam

As a by-product,the biomass char contains high carbon content,low nitrogen,and sulfur content. It has abundant pore structure,when gasification with steam,gas of high heating value would be gained,which is rich in H2 and CO. The composition of gas production can be controlled by regulating the flow of steam.Rice husk and sawdust char were made by a lift type electric furnace. The results show that the higher the temperature,the slower heating rate,the longer residence time,the smaller yield of biomass char. When temperature increases from 1000℃ to 1400℃,the yield of rice husk and sawdust char decline from 28.5% and 14.4% to 20.2% and 8.2%,so there is still volatile precipitation at high temperatures. The maximum specific surface area of the rice husk and sawdust char were 316m2/g and 590m2/g at 1000℃. The pore size of the rice husk and sawdust char prepared from 1000℃ to 1400℃ is in the range of 2-17 nm.The characteristics of rice husk and sawdust char high-temperature steam gasification was investigated by a fixed bed reactor. The results show that temperature is the main factor affecting the carbon conversion of rice husk and sawdust char,from 600℃ to 1200℃,the carbon conversion rate of rice husk and sawdust char made at 1000℃ increase from 24.51% and 39.33% to 86.07%和 89.71%. When the flow rate of water vapor from 0g/min to 2.61g/min,the carbon conversion rate of rice husk and sawdust char made at 1000℃ increase from 49.56% and 59.17% to 89.42% and 91.2%, the content of H2+CO decreased slightly. The specific surface area of rice husk and sawdust ash is 165 m2/g and 949m2/g at the gasification temperature of 800℃, and the specific surface area of rice husk and sawdust ash declines sharply to 3m2/g and 521m2/g at the gasification temperature of 1200℃.Under the condition of 600 to 1200℃(the conversion rate of 1000℃ and 1200℃were 30-85%),the gas film reaction model,the surface reaction model and homogeneous reaction model can be a better description of rice husk and sawdust char steam gasification, the kinetic parameters of surface reaction model and homogeneous reaction model are obtained,the correlation coefficients are above 0.984,it shows that the two models can describe the rice husk and sawdust char steam gasification reaction,but the surface reaction model has higher correlation coefficient, the surface reaction model is better than homogeneous reaction model.