Research of anharmonic effect of reaction related to DEE combustion

Cracking of diethyl ether and reactions of diethyl ether (DEE) with free radicals constitute crucial aspects of research on oxygenated fuels. This paper investigates 17 reactions involved in the combustion process of DEE, calculating harmonic and anharmonic reaction rate constants across a temperature range of 300–4000 K. The Yao-Lin method and transition state theory are employed to determine these kinetic and thermodynamic parameters of the reaction system. Specifically, the Wigner model is employed for the correction of tunneling. Furthermore, pressure-dependent rate constants were respectively calculated by TS and RRKM-ME theory. The results indicate that in the majority of reactions, the disparity between the harmonic rate constants and the anharmonic rate constants widens with increasing temperature, and the anharmonic reaction rates align more closely with the experimental values. Remarkably, certain reactions demonstrate significant negative temperature coefficient (NTC) behavior. Furthermore, the effect of pressure on the DEE decomposition reaction is significant.