Mechanistic Insights into N 2 O and NO Formation During Single-Particle Coal Combustion

Accurate prediction and control of nitrogen oxide (NOx) emissions from coal combustion critically depend on understanding nitrogen release mechanisms from individual coal particles. This study establishes a model predicting the formation of nitric oxide (NO) and nitrous oxide (N2O) during the combustion of a single pulverized coal particle. The model integrates the chemical percolation devolatilization (CPD) framework with heterogeneous char surface reactions. Crucially, this model represents the first approach incorporating the significant contribution of N2O to nitrogen oxide formation pathways. This capability allows tracking concentration profiles of key species throughout the particle combustion process. The model reasonably predicts N2O formation under high-temperature, low-oxygen conditions and effectively captures dynamic interactions between NO and N2O. Under varying oxygen concentrations and initial NO levels, the model clearly reveals mechanistic influences of O2 and NO on N2O production. These results provide a robust framework for understanding nitrogen oxide formation mechanisms and informing targeted emission control strategies.