物理化学学报 >> 2011, Vol. 27 >> Issue (09): 2027-2034.doi: 10.3866/PKU.WHXB20110835

热力学,动力学和结构化学 上一篇    下一篇

含湿量对微细腔内甲烷低温重整影响的热力学研究

赵柳洁, 冉景煜, 吴晟   

  1. 重庆大学动力工程学院, 重庆 400044
  • 收稿日期:2011-05-23 修回日期:2011-06-13 发布日期:2011-08-26
  • 通讯作者: 赵柳洁, 冉景煜 E-mail:zhaoliujie1982@sina.com; ranjy@cqu.eud.cn
  • 基金资助:

    国家自然科学基金(50876118), 教育部新世纪优秀人才计划资助项目(NECT-08-0605)和中央高校基本科研业务费(CDJXS11142231)资助

Thermodynamic Study of the Humidity Ratio for Methane Reforming at Low Temperature in a Micro-Combustor

ZHAO Liu-Jie, RAN Jing-Yu, WU Sheng   

  1. College of Power Engineering, Chongqing University, Chongqing 400044, P. R. China
  • Received:2011-05-23 Revised:2011-06-13 Published:2011-08-26
  • Contact: ZHAO Liu-Jie, RAN Jing-Yu E-mail:zhaoliujie1982@sina.com; ranjy@cqu.eud.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50876118), New Century Excellent Talent Project of Ministry of Education of China (NCET-08-0605) and Fundamental Research Funds for the Central Universities, China (CDJXS11142231).

摘要: 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973 K)重整反应的影响. 于此, 本文通过热力学方法分析了0.1 MPa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280 g·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350 g·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.

关键词: 含湿量, 微细腔, 甲烷, 自热重整, 热力学分析

Abstract: 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 decreases while the CO2 selectivity always increases with an increase in the humidity ratio. Furthermore, the amount of consumed steam will finally increase to more than the amount of generated steam during the reaction process with an increase in the humidity ratio, which also leads to an increase for steam after the reaction. When the amount of steam is less than the air in the feed gas, a steam consumption-dominant system is always obtained upon varying the steam mass fraction before and after the reaction when the humidity ratio reaches 280 g·kg-1. Additionally, it is beneficial to reduce the carbon deposition and to promote reforming during the reaction process when the humidity ratio is higher than 350 g·kg-1. By meeting the humidity ratio conditions mentioned above a higher methane conversion ratio and H2 yield can be obtained under a constant air-methane ratio condition.

Key words: Humidity ratio, Micro-combustor, Methane, Autothermal reforming, Thermodynamic analysis

MSC2000: 

  • O642