Investigations of Effects of Nitric Oxide on Methane Oxidation in a Micro Flow Reactor with a Controlled Temperature Profile

Abstract

The effects of NO on the oxidation and the reactivity of stoichiometric CH4/O2/Ar mixtures were investigated by weak flame responses in a micro flow reactor with a controlled temperature profile (MFR). The oxidation of CH4 was promoted and the reactivity of the CH4/O2/Ar mixture was enhanced as the NO concentration increased up to 948 ppm in both experiments and computations. However, the reactivity of CH4 slightly inhibited when the NO concentration increases from 948 ppm to 9480 ppm. The inhibiting effect was resulted from the competitions for H radicals by the chain-branching reaction (H + O2 = O + OH) and the chain-propagating reaction (NO2 + H = NO + OH).