热管式生物质气化炉的研究

将高温热管技术引入生物质气化中,开发了一种间接供热的热管式生物质气化炉,对高温热管的传热性能和4种生物质原料(木屑、玉米秆、稻壳和稻草)的水蒸气气化特性进行了研究。实验结果表明,气化炉内床层轴向和径向温度的变化趋势与高温热管启动温度的变化趋势基本一致。反应温度和原料种类影响气体产物的组成。在反应温度为650～950℃时,4种原料的气体产物中H2体积分数均为50%～60%,且随反应温度的升高而增加,H2含量增长率的大小顺序为:木屑>玉米秆>稻壳>稻草;CO2体积分数为15%～30%,且随反应温度的升高而减少,木屑和玉米秆的气体产物中CO2含量高于稻壳和稻草;CO和CH4含量随反应温度的升高变化较小,原料种类对CH4含量影响较小,稻壳和稻草的气体产物中CO含量比木屑和玉米秆高。

Study on Heat Pipe Biomass Gasifier

A novel type of indirectly heating gasifier—heat pipe biomass gasifier was developed,where a high temperature heat pipe was used to provide heat for biomass gasification. Heat transfer features of the high temperature heat pipe and steam gasification behavior of four different biomass feeds (wood chips ,cornstalk ,paddy hull ,straw) were investigated. Variation situations of both axial and radial temperatures in gasifier bed are uniform with variation trend of the startup temperatures of heat pipe. Both gasification temperature and biomass feed type are key factors for composition of gaseous products. Volume fractions of hydrogen in gaseous products from four different biomass feeds are about 50%-60% and increase along with gasification temperature raising in range of 650-950 ℃. Increasing rate of hydrogen content for wood chip is the largest,followed by cornstalk,paddy hull and straw in turn. Volume fractions of carbon dioxide in gaseous products from four different biomass feeds are about 15%-30% and reduce with lifting of gasification temperature. Contents of carbon dioxide in gaseous products from wood chip and cornstalk are higher than these from paddy hull and straw. Relevant contents of carbon monoxide and methane in gaseous products from four different biomass feeds change slightly with lifting of gasification temperature. Methane content changes unobviously with biomass feeds,and carbon monoxide content in gaseous products from paddy hull and straw are higher than that from wood chip and cornstalk.