Relationship between the N2O decomposition and NO formation in H2O/CO2/NH3/NO atmosphere under the conditions of simulated air-staged combustion in the temperature interval of 900–1600 °C

Abstract

A fixed bed reactor is adopted to study the N2O decomposition and NO formation in simulated atmosphere to reveal the conversion mechanisms of N2O to NO in the air-staged combustion. It is found that NO is produced during the decomposition process of N2O, which can be explained by the resonance theory. The N2O decomposition can be significantly promoted while the NO generation is hindered by the water vapor, due to the H and OH-radicals produced by H2O decomposition. The O-radicals generated in the CO/O2 atmosphere are critical for the conversion of N2O to NO. CO2 can boost N2O decomposition, and significantly inhibits NO formation. The O-radicals generated by CO/O2 can be conducive to convert N2O to NO, and promote the conversion of NH3 to NO. HNO produced by the reaction of N2O with water is the main source of NO. N2O and O-radicals can exert a consumption effect on NO. The NO formation can be induced by the O-radicals produced in CO/O2 atmosphere and the H-radicals produced by H2O decomposition. The existence of OH-radical is the main contributor to the reduced production of NO. The results can be helpful to provide theoretical support for achieving low NOx emissions.