Green Energy and Low-carbon Technology
SHU Tao, SU Sheng, JIA Mengchuan, YU Juan, ZHANG Zhongxiao, WANG Yi, HU Song, XIANG Jun
In order to reveal the effect of CO on the reduction of NO by NH3, experimental and simulation studies were carried out on the NO reduction process by NH3 at different CO concentrations. Results show that the addition of CO has no significant effect on the NO reduction efficiency below 1 400 ℃ under anaerobic conditions, and above 1 400 ℃, the NO reduction efficiency of the NO reduction process by NH3 is improved when CO is present in the atmosphere. Under low O2 conditions, the temperature window of NO reduction by NH3 process is expanded under low oxygen concentration conditions when CO is present in the atmosphere. Thus, it can still maintain a higher NO reduction efficiency at a high temperature above 1 400 ℃. Under the condition of higher O2 concentration, when CO is present in the atmosphere, the optimal NO reduction temperature moves to the low temperature, and the NO reduction temperature window narrows. The simulation results show that, under anaerobic and hypoxic conditions, above 1 400 ℃, CO promotes the reaction of NH2 and CO to generate HNCO, and then HNCO further reacts with OH to generate NCO, and then reduces NO, thereby enhancing the NO reduction process. When the O2 concentration is high, the generation of OH and O is promoted by CO at a lower temperature, thus ensuring the progress of NH2 generation and NO reduction process. The temperature increase will accelerate the process of CO and OH reaction to generate H, then promote the reaction of H and O2, so that a large number of O radicals are generated in the reaction process, and these O radicals are easily oxidized with NH2. As a result, NO generation is promoted, resulting in a rapid decrease of NO reduction efficiency.
