Experimental and modeling study of NO emission under high CO2 concentration

• Published in: Science China Technological Sciences 2010-12, Vol.53 (12), p.3275-3283
• Main Authors: Zhao, Ran, Liu, Hao, Hu, Han, Zhong, XiaoJiao, Wang, ZiJian, Xu, ZhiYing, Qiu, JianRong
• Format: Article
• Language: English
• Subjects: Engineering
• ISSN: 1674-7321; 1862-281X
• DOI: 10.1007/s11431-010-4080-7

An experimental and numerical study of the NO x formation and reduction process in a designed coal combustion furnace under both traditional air atmosphere and O 2 /CO 2 atmosphere was conducted, in an attempt to explore the chemistry mechanism of the experimentally observed NO x suppression under high CO 2 concentration atmospheres. A simplified’ chemically oriented’ approach, computational fluid dynamics (CFD)-chemical kinetics modeling method, was validated and used to model the experimental process. The high CO 2 concentration’s chemical effect on NO reduction has been studied, and the differences in NO x reaction behaviors between O 2 /CO 2 atmosphere and air atmosphere were analyzed by detailed chemical kinetic model. On the basis of investigations through elementary chemical reactions, it can be concluded that high CO 2 concentration plays an important role on NO x conversion process during oxy-fuel combustion. Moreover, the dominant reaction steps and the most important reactions for NO conversion under different atmospheres were discussed. Under O 2 /CO 2 atmosphere, the main active sequence for NO reaction includes: NO→N→N 2 , and the main active path for NO reaction under air atmosphere is through N 2 →N→NO.