Influences of different diluents on NO emission characteristics of syngas opposed-flow flame
Influences of different diluents on NO emission characteristics of syngas opposed-flow flame
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DOI：
10.1016/j.ijhydene.2017.11.171
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发表时间：
2018-02-01
影响因子：
7.2
通讯作者：
Yan, Weiping
中科院分区：
文献类型：
--
作者：
He, Dong;Yan, Weiping
采用对流火焰模型和GRI 3.0机理分别研究了富氢和贫氢合成气在扩散和预混条件下的NO生成特性，并从热力学和反应动力学角度分析了添加H2O、CO2和N2对NO生成的影响。对于扩散火焰，热反应是NO生成的主要途径，添加N2-、H2O和CO2对NO生成的影响呈递减趋势。对于富氢合成气，由于其火焰温度较高，上述现象更为明显。对于预混火焰，加入CO2比加入H2O导致NO浓度升高，这是因为加入CO2产生更多的O自由基，通过NNH + O = NH + NO、NH + O = NO + H和反向N + NO = N2 + O促进NO的生成。在燃尽气中，热途径是NO生成的主要途径。在本文条件下，添加N2-在降低火焰温度的同时，增加了NO的生成源，总体上减少了NO的生成。另外，对于贫H2和富H2的合成气，以CO2为稀释剂时，N + CO2 = NO + CO在NO生成的热途径中起着重要作用。(C)2017年氢能出版有限责任公司。由爱思唯尔有限公司出版。保留所有权利。
This paper used the opposed-flow flame model and GRI 3.0 mechanism to investigate NO emission characteristics of H-2-rich and H-2-lean syngas under diffusion and premixed conditions, respectively, and analyzed influences of adding H2O, CO2 and N-2 on NO formation from the standpoint of thermodynamics and reaction kinetics. For diffusion flames, thermal route is the dominant pathway to produce NO, and adding N-2, H2O and CO2 shows a decreasing manner in lowering NO emission. The phenomenon above is more obvious for H-2-rich syngas because it has higher flame temperature. For premixed flames, adding CO2 causes higher NO concentration than adding H2O, because adding CO2 produces more O radical, which promotes formation of NO through NNH + O = NH + NO, NH + O = NO + H and reversed N + NO = N-2 + O. And in burnout gas, thermal route is the dominant way for NO formation. Under this paper's conditions, adding N-2 increases the formation source of NO as well as decreases the flame temperature, and it reduces the NO formation as a whole. In addition, for H2-lean syngas and H-2-rich syngas with CO2 as the diluent, N + CO2 = NO + CO plays as an important role in thermal route of NO formation. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.