Comparisons of the validity of different simplified NH3-Oxidation mechanisms for combustion of biomass

In this work comparisons and validations of several simplified ammonia oxidation mechanisms at conditions relevant for combustion of biomass have been performed. The aim of the investigation was to clarify the weakness and the strength of the available simplified mechanisms for computational fluid dynamics (CFD) based prediction of NOx emissions. The mechanisms have been tested at typical conditions for biomass combustion, considering temperature and gas composition. All the simplified mechanisms have been compared against a validated comprehensive elementary reaction mechanism containing 340 reversible reactions between 56 chemical species. In comparing the simplified mechanisms, the mixing pattern between the species was described by a continuous stirred tank reactor, with typical residence times in eddy dissipation concept fine structure. The results show that, for substoichiometric conditions at low temperatures (<1000 °C), all tested simplified mechanisms have poor agreement with the comprehensive me...