Numerical investigation and experimental verification for dynamic denitration through mixed ammonia/methane combustion: Comparative case study of typical scenarios

To enhance environmental and energy efficiency, ammonia–methane co-combustion is considered one of the efficient and clean energy supply methods. However, the greatest challenge with the combustion of NH${}_3$ is NO${}_x$ emissions. In this work, computational fluid dynamics (CFD) technology was employed to simulate combustion in a burner chamber. Additionally, a user-defined function (UDF) was used to construct the working condition fluctuation model and the species concentration coupling model. And experiments focused on detecting the composition of flue gas after combustion were carried out. To this end, a dynamic and precise denitrification method was proposed, and its performance was systematically compared with two other scenarios, namely non-denitrification and conventional fixed injection denitrification. The combustion and denitrification models employed in this work were verified by comparison with previous studies. The results showed that tail denitrification treatment effectively reduces NO emissions. Furthermore, the average NO concentration at the outlet decreased by 2,378 ppm through ordinary fixed value denitrification. However, this method demonstrated poor denitrification performance under fluctuating operating conditions. In contrast, the dynamic denitrification method can accurately control the average outlet NO concentration to about 73 ppm, reduced nitrogen oxides by 97%. In the end, the result was experimentally validated with an error within 5%.