O2/CO2气氛下甲烷火焰中NO均相反应机理研究

氧燃烧方式下由于高浓度CO2介质的存在对煤中氮的析出以及氮氧化物的多相转化有重要影响。该文基于化学动力学分析软件CHEMKIN对O2/CO2及O2/N2气氛下甲烷燃烧均相反应体系中NO的转化行为进行模拟计算，探讨了温度、过氧系数 、CO2浓度、O2浓度、初始含N污染物组分等因素对NO形成及其还原的影响规律，采用生成率分析和敏感性分析工具分析了不同气氛富燃及贫燃条件下NO的反应机理。结果表明，2种气氛富燃及贫燃条件下NO的还原率变化规律相反，与空气气氛相比，富燃条件下O2/CO2气氛不利于NO的还原，而贫燃条件下O2/CO2气氛有利于NO还原。生成率分析表明高浓度CO2气氛能够促进NO还原并对NO的生成具有一定的抑制作用。敏感性分析表明2种不同气氛下NO的反应历程区别不大，但所发生的重要反应有明显差别；在富燃及贫燃条件下，NO反应历程有明显区别，富燃条件下NO的主要反应历程为NO->HNO->NH->N2，贫燃条件下NO的主要反应历程为NO->N->N2。

Homogeneous Reaction Mechanism Research on NO in CH4 Flame Under O2/CO2 Atmosphere

Oxy-fuel combustion is one of several promising new technologies associated with mitigating the CO2 rise in the atmosphere. NO reduction chemistry in methane flame under O2/CO2 atmosphere was studied using detailed kinetic modeling. A suitable reaction mechanism was chosen based on comparison of the calculations to experimental data. The influence of various parameters (temperature, equivalence ratio, fuel-N concentration) on NO reduction was investigated. Further, rate-of-production analysis was employed to study NOx reduction mechanisms in different atmospheres. The sensitivity of the results to the major reactions was analyzed. According to this study, NO reduction under fuel-rich condition by methane mainly proceeds via reaction: NO->HNO->NH->N2, while conversion of NO to N2 under fuel-lean condition: NO->N->N2.