Establishment of the N<sub>2</sub>O and NO Prediction Model and Reveal of the N<sub>2</sub>O Formation Mechanism during Air-Staged Combustion
Songlin Liu, Weidong Fan, Jun Chen, Hao Guo
Abstract
Accurate prediction of NOx formation is of great significance for NOx emission control. The model of NO and N2O in air-staged combustion is established in this study, creatively associates the important reactions involving NO and N2O, and successfully predicts the secondary increase of NO during air-staged combustion and the occurrence of N2O in the high-temperature zone. The model correlates CO with the reduction of NO in the reduction zone and the generation of N2O, successfully predicting the downward trend of NO in the reduction zone. The formation mechanism of NO and N2O was further explored by simulating the combustion atmosphere. The results show that the increase in oxygen concentration can promote the oxidation of NH3 to NO. In the CO/O2 combustible atmosphere, NH3 will be converted into a high ratio of NO and a certain amount of N2O. The addition of NO did not increase N2O formation. N2O can be formed through the direct oxidation of CO(NH2)2 and also can be generated by reaction of NO with NCO; the significant increase in the production of N2O in the second stage indicates the important role of NO in N2O formation.