金属钙对煤焦异相还原NO催化机理的量子化学研究  

Quantum Chemistry Study on Catalytic Mechanism of Ca on NO-Char Heterogeneous Reaction

作　　者：温正城[1,2] 王智化[1] 周俊虎[1] 周志军[1] 刘建忠[1] 岑可法[1] 

机构地区：[1]浙江大学能源清洁利用国家重点实验室,杭州310027 [2]杭州电子科技大学理学院,杭州310018

出　　处：《燃烧科学与技术》2009年第6期505-510,共6页Journal of Combustion Science and Technology

基　　金：国家重点基础研究发展规划(973)资助项目(2006CB200303);国家杰出青年科学基金资助项目(50525620)

摘　　要：从动力学和热力学角度,采用量子化学方法对金属钙催化煤焦异相还原NO的机理进行详细研究.采用QCISD(T)/6-311G(d,p)//UB3LYP/6-31G(d)方法,对煤焦及金属钙还原NO的各个基元反应进行动力学或热力学研究.结果表明,煤焦和金属钙还原NO的活化能分别为245.35 kJ/mol和109.82 kJ/mol,说明金属钙还原NO的活化能大大低于煤焦,金属钙对NO的还原能力显著高于煤焦.而另一方面,采用UB3LYP/6-31G(d)方法对CaO与煤焦的反应进行热力学分析.结果表明,该反应在高温下的相关吉布斯自由能差ΔG约为-1 000 kJ/mol,说明CaO在高温下很容易被煤焦迅速还原成Ca,从而使金属钙循环再生.The catalytic mechanism of Ca on NO-char heterogeneous reaction was investigated by employing quantum chemical calculation in this paper. The kinetics and thermodynamics of all elementary reactions of NO reducing by char and Ca were studied by the QCISD （T） /6-311G （ d, p）//UB3 LYP/6-31G （d） method. The results show that activation energy of NO-Ca reaction is much lower than that of NO-char reaction, which are 109.82 kJ/mol and 245.35 kJ/mol, respectively, which indicates that NO reduction efficiency of Ca is much higher than that of char. On the other hand, the thermodynamics of CaO-C reaction was calculated by the UB3LYP/6-31G （d） method. The results show that AG of CaO-C reaction （reaction of CaO and char） is approximately - 1 000 kJ/mol at high temperature, which indicates that Ca can be refreshed easily and rapidly by char at high temperature.

关 键 词：钙 煤焦 NO 催化机理 量子化学 

分 类 号：TK477[动力工程及工程热物理—动力机械及工程]