Mechanistic insights into the interaction of NO, char‑nitrogen and NH3 during ammonia-coal combustion

Abstract

Ammonia-coal co-combustion effectively reduces carbon dioxide and nitrogen oxide emissions. In this process, nitrogen in char is converted to N₂ in the NH₃ atmosphere. Using density functional theory, the researchers have explored the role of oxygen, which not only increases the energy barrier of the final product, but also facilitates the rapid conversion of char nitrogen to N₂. In the NH₃/O₂ environment, hydroxyl groups play a crucial role in the formation of water molecules. In addition, according to the theoretical calculation and experimental results, it is found that the desorption rate of CO is slightly higher than that of NO.