Advancements in SNCR Denitrification: A Comparative Study on Oxygenated and Non-Oxygenated Additives

Selective Non-Catalytic Reduction (SNCR) is a cost-effective post-combustion treatment technology widely employed for Nitrogen oxides (NO_x) removal in coal-fired power plants. However, its application is limited by narrow effective temperature window, which constrains denitration efficiency. The use of additives has been shown to broaden this temperature window and enhance overall performance. In this study, three organic compounds, namely acetic acid, toluene, and acetone, were evaluated as additives in a Jet-stirred Reactor (JSR) system to determine the most effective additive and investigate the mechanisms behind additive-enhanced denitration. The results indicate that when the additive ratio is 0.2, the effects of toluene and acetone are most pronounced. They significantly broaden the denitration temperature window, extending it down to 750°C. Acetone was able to maintain a denitration efficiency of over 80% at this temperature. In contrast, toluene slightly reduced the denitration efficiency. Compared with these two additives, acetic acid had a smaller enhancement effect on denitration. A denitration pathway primarily involving NH₂ radicals was identified as a key enhancement mechanism. Additionally, the study discussed issues related to ammonia slip, CO emissions, and other nitrogen-containing byproducts generated during SNCR.