Evolution of surface functional groups of coal char during coal combustion under O2/CO2 atmospheres

Abstract In this study, quantitative analysis was conducted to study the changes in characteristics of surface functional groups of coal char under O 2 /CO 2 atmospheres using Fourier transform infrared analysis. A drop tube furnace was explored. Besides, the effect of the oxygen‐containing functional group on the generation characteristics of NO emission was also investigated. The results showed that CH 2 /CH 3 is highly influenced by the process and atmosphere of coal combustion. The burning of coal increases the contents of aromatic hydrogen and aromaticity on the surface of coal char particles, and it decreases the content of lipid hydrogen. The oxygen concentration exhibits a significant effect on the oxygen‐containing functional groups in coal char, which promotes the reduction reaction of NO. There is an optimum oxygen concentration of 30% that creates the best NO reduction effect caused by the oxygen‐containing functional groups.