Development of a kinetic mechanism for NOx fuel interaction

Krishna Prasad Shrestha, Lars Seidel, Fabian Mauß, Thomas Zeuch

Abstract

This work introduces a newly developed reaction mechanism to predict fuel/NOx interaction in freely propagating, burner stabilized premixed flames, shock tubes, jet stirred reactors and plug flow reactors experiments. The study focuses on pure ammonia as fuel as well as H 2 , H2 /CO, CH4 doped with NO, NO 2 and N2O. The kinetic scheme also focuses on the formation and consumption of nitrogen oxides at different experimental conditions. It is found that the doping with N2 O has almost no sensitivity on the H2 chemistry, while small amount of NO2 is enough to change the pressure dependence of H 2 auto ignition. The experiments with N2O
still show the significant influence of the chain breaking reaction H+O 2(+M)⇋HO2 (+M) on the H2 ignition delay times, resulting in the crossing lines for the ignition delay times, which are moved at higher pressure to higher temperature. The concentration of HO2 is decisive for the active reaction pathway in shock tube oxidation as well as in jet stirred and flow reactor. Reaction NO+HO2⇋NO2+OH and NO 2+H⇋NO+OH are very important because they strongly influence the inter conversion process of NO and NO 2 in jet stirred reactor and flow reactor for cases studied herein. The formation of NO in burner stabilized premixed flames is shown to demonstrate the capability of the mechanism to be integrated into mechanisms for hydrocarbon oxidation.