Theoretical Revelation of HNCO Formation during Coal Pyrolysis: Mechanism, Formation Pathway and DFT Calculation

Abstract

ABSTRACT Pyridine is one of the main nitrogen-containing compounds that produce NOx precursors (HNCO, HCN, NH3) in coal during pyrolysis, which can be converted into 2-pyridone (2-Py) in the presence of H2O. HNCO is a NOx precursor during coal and coal tar pyrolysis. In this study, the possible paths for the pyrolysis of 2-pyridone to generate HNCO and HCN were studied using density functional theory (DFT). This was the first theoretical revelation of the source of HNCO generation during coal pyrolysis. At the same time, the formation path of HCN was also calculated and compared with the formation of HNCO. Through the transition state theory analysis, the behavior characteristics of NOx precursors produced during the pyrolysis of 2-pyridone were theoretically explained.