The interaction between soot and NO formation in a laminar axisymmetric coflow ethylene/air diffusion flame
- Institute for Chemical Process and Environmental Technology, National Research Council Canada, 1200 Montreal Road, Ottawa, ON, K1A 0R6 (Canada)
The interaction between soot and NO formation in a laminar axisymmetric coflow ethylene/air diffusion flame was investigated by numerical simulation. A detailed gas-phase reaction scheme and a simplified soot model were employed. The results show that the formation of NO has little effect on that of soot. However, the formation of soot in the flame significantly suppresses the formation of NO. The peak NO concentration and NO emission index are reduced by 28 and 46%, respectively, due to the formation of soot. The influence of soot on NO formation is caused by not only the radiation-induced thermal effect, but also the reaction-induced chemical effect. Relatively the thermal effect is more significant, causing 25 and 38% reduction, respectively, in peak NO concentration and NO emission index. The chemical effect is caused by the competition for acetylene (C{sub 2}H{sub 2}) between soot and NO formation. The formation of soot consumes acetylene in the flame and thus lowers the formation rate of radical CH. This reduces the reaction rate of CH + N{sub 2} = HCN + N, which is the rate-limiting step of the prompt NO formation route, the dominant route in the studied flame. (author)
- OSTI ID:
- 20880651
- Journal Information:
- Combustion and Flame, Vol. 149, Issue 1-2; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
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