温度和水蒸气流量对烟秆高温气化的影响  

Effects of temperature and steam flow rate on gasification of tobacco stem at high temperatures

作　　者：田甜[1] 李清海[1] 李文妮[1] 何榕[1] 张衍国[1] 

机构地区：[1]清华大学热能工程系,热科学与动力工程教育部重点实验室,二氧化碳资源化利用与减排技术北京市重点实验室,北京100084

出　　处：《环境工程学报》2016年第4期1973-1978,共6页Chinese Journal of Environmental Engineering

基　　金：国家科技支撑计划项目(2010BAC66B03);国家自然科学基金资助项目(91434119);北京市重点实验室科技创新基地培育与发展专项(Z151100001615006)

摘　　要：利用上吸式固定床反应器,对烟秆进行了水蒸气气化实验,在617~1 435℃的温度范围内研究了温度及水蒸气流量对气化特性的影响。结果表明,当气化温度低于917℃时,升高温度可同时促进均相和非均相产氢反应的进行,产氢率随着温度升高而迅速上升。当温度上升到917℃时,非均相反应已进行得足够充分,潜在产氢率达到最大值,碳转换率超过0.8。当温度超过917℃后,温度升高对产氢的影响主要体现为促进均相反应进行,产氢率上升变缓。温度达到1 327℃时,均相反应速率足以使气体在反应器内反应完全,因而升高温度不再有助于提高产氢率,产氢率最大值为0.97m^3/kg。水蒸气流量增加能够促进气化产氢反应与水蒸气扩散,同时会缩短气体停留时间、降低局部温度,因此,随着水蒸气流量增加,产氢率先升高后降低,在917℃时烟秆气化的最佳水蒸气流量为15.7 g/min。结果可以为生物质高温气化制氢的研究提供参考。A fixed-bed updraft gasification reactor was used to study the effects of temperature and steam flow rate on the tobacco stem gasification characteristics in the temperature range from 617 to 1 435 ℃. The experimental results showed that both homogeneous and heterogeneous reactions are promoted by increasing the temperature and,as a result,the hydrogen production increases rapidly when the gasification temperature is lower than 917 ℃. When the temperature approaches 917 ℃,the heterogeneous reactions have completed sufficiently so that the potential hydrogen production reaches its maximum value and the carbon conversion rate also exceeds0. 8. At over 917 ℃,the gasification temperature mainly promotes the homogeneous reaction; thus,hydrogen production begins to slowly increase. At 1 327 ℃,the homogeneous reaction rate is rapid enough that the reaction can be completed sufficiently in the reactor within the residence time. The hydrogen production no longer increases as the temperature rises above 1 327 ℃. The maximum hydrogen production rate is 0. 97 m^3/ kg. As the steam flow rate increases,the gasification hydrogen production reaction and water vapor diffusion are promoted. However,gas residence time and local temperature are also reduced owing to the steam flow increase. It can be observed that with increasing steam flow rate,the hydrogen production first increases and then decreases. For a temperature of 917 ℃,the optimum steam flow rate is 15. 7 g / min. The results can be used as a reference for the development of high-temperature gasification technologies of biomass.

关 键 词：生物质 气化 产氢 高温 水蒸气 

分 类 号：X705[环境科学与工程—环境工程]