The reduction of NO by ethylene in a jet-stirred reactor at 1 atm: experimental and kinetic modelling
The reduction of NO by ethylene in a jet-stirred reactor at 1 atm: experimental and kinetic modelling
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DOI：
10.1016/s0010-2180(99)00075-9
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发表时间：
1999-12
影响因子：
4.4
通讯作者：
P. Dagaut;F. Lecomte;S. Chevailler;M. Cathonnet
中科院分区：
文献类型：
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作者：
P. Dagaut;F. Lecomte;S. Chevailler;M. Cathonnet
在熔融石英射流搅拌反应器中，在1个大气压和900 ~ 1400 K的温度下，模拟再燃区的条件，研究了乙烯还原一氧化氮（NO）的动力学。NO的初始摩尔分数为1000 ppm，乙烯的初始摩尔分数为4400 ppm。当量比在0.75至2之间变化。结果发现，NO的还原随温度而变化，并且对于给定的温度，NO的最大还原发生在稍微富燃料的化学计量条件下。因此，在最佳NO再燃条件下操作对于当量比和温度的特定组合是可能的。研究结果与以往的简单碳氢化合物或天然气作为再燃燃料的研究结果基本一致。使用更新和改进的动力学方案（877个可逆反应和122个物种）进行详细的化学动力学模型的实验。总体而言，合理的协议，目前的测量和建模，虽然模型的改进仍然是必要的。此外，建议的动力学机制可以成功地用于模拟还原NO乙烷，乙炔，天然气混合物（甲烷-乙烷10：1）和HCN，以及低温NO和简单烷烃之间的相互作用。根据这项研究，乙烯还原NO的主要途径涉及烯酮自由基，HCCO。该模型表明NO的还原过程为：C2 H4 → C2 H3 → HCCO; HCCO + NO → HCNO + CO和HCN + CO2; HCNO + H → HCN + OH; HCN + O → NCO → HNCO → NH 2; NCO + H→ NH; NHi（i = 1，2）+ NO → N2; NH + NO → N2 O，然后N2 O + H → N2。
The kinetics of the reduction of nitric oxide (NO) by ethylene have been studied in a fused silica jet-stirred reactor at 1 atm and at temperatures from 900 to 1400 K to simulate conditions in a reburning zone. The initial mole fraction of NO was 1000 ppm, that of ethylene was 4400 ppm. The equivalence ratio was varied from 0.75 to 2. It was found that the reduction of NO varies with temperature and that for a given temperature, the maximum reduction of NO occurs slightly fuel-rich of stoichiometric conditions. Thus, operating under optimal NO-reburning conditions is possible for particular combinations of equivalence ratio and temperature. The results generally agree with previous studies involving simple hydrocarbons or natural gas as reburn fuel. Detailed chemical kinetic modeling of the experiments was performed using an updated and improved kinetic scheme (877 reversible reactions and 122 species). Overall, reasonable agreement was obtained between the present measurements and the modeling although improvements of the model are still necessary. Also, the proposed kinetic mechanism can be successfully used to model the reduction of NO by ethane, acetylene, a natural gas blend (methane-ethane 10:1) and HCN, as well as the low temperature interactions between NO and simple alkanes. According to this study, the main way of reducing NO by ethylene involves the ketenyl radical, HCCO. The model indicates that the reduction of NO proceeds through the reactions: C2H4→ C2H3→ HCCO; HCCO + NO → HCNO + CO and HCN + CO2; HCNO + H → HCN + OH; HCN + O → NCO → HNCO → NH2; NCO + H→ NH; NHi(i = 1,2)+ NO → N2; NH + NO → N2O followed by N2O + H → N2.