Research on NO generation characteristics of ammonia-premixed flame

Qiaoqun Sun; Yukai Li; Yu Zhang; Jianmin Gao; Heming Dong; Dongdong Feng; Zheng Chen; Shaozeng Sun

doi:10.1016/j.scitotenv.2023.162707

Research on NO generation characteristics of ammonia-premixed flame

Sci Total Environ. 2023 Jun 10:876:162707. doi: 10.1016/j.scitotenv.2023.162707. Epub 2023 Mar 9.

Authors

Qiaoqun Sun¹, Yukai Li², Yu Zhang³, Jianmin Gao⁴, Heming Dong², Dongdong Feng², Zheng Chen⁵, Shaozeng Sun⁶

Affiliations

¹ School of Aerospace and Architectural Engineering, Harbin Engineering University, Harbin 150001, China.
² School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
³ School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address: zhang.y@hit.edu.cn.
⁴ School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address: yagjm@hit.edu.cn.
⁵ Shandong Branch of Huadian International Power Co. Ltd, No.14800 Jingshi Road, Jinan, Shandong Province, China.
⁶ School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address: sunsz@hit.edu.cn.

PMID: 36898542
DOI: 10.1016/j.scitotenv.2023.162707

Abstract

Ammonia is a promising fuel with high energy density, accessible storage, and no CO₂ production by combustion, but its combustion produces the pollutant NO. In this study, a Bunsen burner experimental bench was selected to investigate the concentration of NO generated by ammonia combustion at different initial oxygen concentrations. Further, the reaction pathways of NO were analyzed in depth, and sensitivity analysis was performed. The results show that the Konnov mechanism has an excellent predictive effect on NO generated by ammonia combustion. In the ammonia-premixed laminar flame at atmospheric pressure, the NO concentration peaked at an equivalence ratio of 0.9. The high initial oxygen concentration enhanced the combustion of ammonia-premixed flame and increased the conversion of NH₃ to NO. NO was not only a product but a contribution to the combustion of NH₃. As the equivalence ratio increases, NH₂ consumes a large amount of NO and reduces NO production. The high initial oxygen concentration enhanced NO production, and the effect was more pronounced at low equivalents. The study results provide theoretical guidance for the utilization of ammonia combustion and pollutant reduction and help to drive the process of ammonia combustion toward practicality.

Keywords: Ammonia; NO; Numerical simulation; Premixed combustion; Reaction mechanism.