Pressure Effect on NO Formation in H₂/CO Premixed Flames

Abstract

The purpose of the present study is to better understand the pressure effect on NO formation in H2/CO/air premixed flames. A recently developed detailed chemical kinetic model by merging AramcoMech 3.0 and a comprehensive nitrogen chemistry is first compared against experimental data of H2/CO mixtures including NO formation in premixed flames. Freely propagating H2/CO/air premixed flames are then simulated over a pressure range 1-20 atm and temperatures of 1886 and 1986K. NO formation via N2O becomes important between reaction zone and postflame region with increasing pressure, but NO concentrations in the reaction zone is not sensitive to increasing pressure. Thermal NO production pathways lead to the total NO formation in the postflame zone and the total NO formation rate increases with increasing pressure.