含湿量对微细腔内甲烷低温重整影响的热力学研究
为了实现微燃烧器内甲烷持续稳定燃烧,要求进一步深入研究原料气中含湿量变化对微细腔甲烷湿空气低温(小于973K)重整反应的影响.于此,本文通过热力学方法分析了0.1MPa下一定温度时,恒定原料气流量和恒定空碳比两种工况中,含湿量在欠氧和低温环境中对微细腔甲烷自热重整反应中积炭、甲烷转化、产氢特性及反应过程的影响.结果表明:微细腔内甲烷质量流量一定时,随着含湿量增加,积炭逐渐减小,甲烷转化率先减小后增加,氢气则一直随之增加.体系中甲烷的转化以生成CO2为主,CO的选择率随含湿量增加先增加后减小,CO2选择率则一直增加;增加含湿量会使反应后体系中水的含量增加,也会促使反应过程中体系消耗的水量最终大于...
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Published in | 物理化学学报 Vol. 27; no. 9; pp. 2027 - 2034 |
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Main Author | |
Format | Journal Article |
Language | Chinese |
Published |
重庆大学动力工程学院,重庆,400044
2011
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Subjects | |
Online Access | Get full text |
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Summary: | 为了实现微燃烧器内甲烷持续稳定燃烧,要求进一步深入研究原料气中含湿量变化对微细腔甲烷湿空气低温(小于973K)重整反应的影响.于此,本文通过热力学方法分析了0.1MPa下一定温度时,恒定原料气流量和恒定空碳比两种工况中,含湿量在欠氧和低温环境中对微细腔甲烷自热重整反应中积炭、甲烷转化、产氢特性及反应过程的影响.结果表明:微细腔内甲烷质量流量一定时,随着含湿量增加,积炭逐渐减小,甲烷转化率先减小后增加,氢气则一直随之增加.体系中甲烷的转化以生成CO2为主,CO的选择率随含湿量增加先增加后减小,CO2选择率则一直增加;增加含湿量会使反应后体系中水的含量增加,也会促使反应过程中体系消耗的水量最终大于生成的水量.在含湿量不超过空气量的反应条件下,两种工况中反应前后水质量分数的变化量均在含湿量达280g·kg^-1后显示出体系以消耗水为主,且原料气中湿空气的含湿量均应满足最低为350g·kg^-1,才有利于反应过程中减少积炭产生和促进重整反应,当达到这一条件时,恒定的空碳比在获得较高的甲烷转化率和氢气产率上更具优势. |
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Bibliography: | 11-1892/06 ZHAO Liu-Jie RAN Jing-Yu WU Sheng (College of Power Engineering, Chongqing University, Chongqing 400044, P. R. China) Humidity ratio; Micro-combustor; Methane; Autothermal reforming; Thermodynamicanalysis To realize the stable combustion of methane in a micro-combustor it is necessary to investigate the influence of the humidity ratio on the reforming system for methane-wet air reforming. Thus, we studied the effects of the humidity ratio on carbon deposition, methane conversion, H2 production, and the reaction process under lean oxygen below 973 K and at 0.1 MPa theoretically with a constant air-methane ratio or feed gas flux using thermodynamic analysis. Results show that carbon deposition always decreases with a humidity ratio increase at a certain methane mass flow in the micro-combustor. In contrast, the methane conversion ratio decreased initially and then increased while the H2 yield always increased. The main product of methane conversion is CO2. The CO selectivity increases initially and then |
ISSN: | 1000-6818 |