A theoretical kinetics study on low-temperature reactions of methyl acetate radicals with molecular oxygen

Abstract

Theoratical studies on the chemistry of methyl acetate radicals with molecular oxygen was conducted to get further understanding of biodiesel combustion. Reactions of the first oxygen addition to methyl acetate radicals has been investigated by high level quantum chemical methods, and rate constants were computed by using microcanonical variational transition state theory coupled with Rice–Ramsberger–Kassel–Marcus/Master-Equation theory. The calculated rate constants agree reasonably well with both theoretical and experimental results of chain-like alkoxy radicals. We considered each step in the oxidation process as a class of reaction, including all the possible reactions taking place, only the formation and re-dissociation of initial adducts are critical for the low temperature combustion of methyl acetate. The current study is an extension of kinetic data for such chain propagation reactions for methyl acetate oxidation in a wider pressure and temperature range, which can be used for the modeling study of low temperature oxidation of methyl esters.