微细腔内甲烷湿空气低温重整积炭特性的热力学分析  

Thermodynamic analysis of carbon deposition for methane reforming at low temperature in micro-combustor

作　　者：冉景煜[1] 赵柳洁[1] 

机构地区：[1]重庆大学动力工程学院,重庆400044

出　　处：《燃料化学学报》2011年第10期759-765,共7页Journal of Fuel Chemistry and Technology

基　　金：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);中央高校基本科研业务费资助项目(CDJXS11142231)

摘　　要：微细腔内重整积炭会引起催化剂失活和孔道堵塞,甲烷低温自热重整技术的提出,既有利于实现微燃烧器中甲烷的持续稳定燃烧,又能有效降低热点和减少积炭。通过热力学分析,探讨常压下反应温度低于973 K时微细腔内自热重整积炭的影响因素及重整特性。结果表明,温度、空碳比及水碳比对积炭生成有重要影响。微细腔内积炭含量随温度升高先增大后减小;贫氧环境下,空碳比和水碳比的增加不仅对减少积炭有效,对氢气产生也有利;同时,甲烷自热重整系统与无水系统相比减碳性能优越。甲烷质量流量为6.6 g/h、空碳比和水碳比分别为2和1时,积炭产生的温度为680 K～850 K,并在785 K达到积炭质量分数的最大值为0.66%,此时甲烷转化率和氢气质量含量分别为53.43%和2.37%;且消碳对应的空碳比和水碳比分别约为2.4和1.1。Carbon deposition caused by reforming in micro-combustor brings catalyst deactivation and channel snarl-up.The technology of methane wet-air autothermal reforming is presented to realize methane last,steady-state combustion and to reduce carbon deposition.The effects for carbon deposition below 973 K are discussed by thermodynamic analysis at 0.1 MPa in this paper.Results show that temperature,air-methane ratio and steam-methane ratio contribute a lot to the carbon deposition.In micro-combustor,carbon deposition increases with temperature increasing first,then decreases;it is beneficial to reduce carbon deposition as well as to produce hydrogen with air and steam increase under lean oxygen;at the same time,autothermal reforming compared with non-steam system is superior on reducing carbon deposition in micro-combustor.When methane mass flow is 6.6 g/h,air-methane ratio and steam-methane ratio are respectively 2 and 1 in micro-combustor,the carbon deposition temperature range is at 680 K^850 K.The largest mass fraction of carbon deposition is 0.66% and occurred at 785 K,also the methane conversion rate and the mass fraction of hydrogen are approximately 53.43% and 2.37%;and that,requirements of air-methane ratio and steam-methane ratio to eliminate the carbon deposition are about 2.4 and 1.1 respectively.

关 键 词：微细腔 自热重整 积炭 无水系统 热力学分析 

分 类 号：TK123[动力工程及工程热物理—工程热物理]