Low-temperature oxidation of diethyl ether: Reactions of hot radicals across coupled potential energy surfaces

Abstract

Electronic structure calculations and transition state theory are used to compute rate coefficients for the low-temperature oxidation of diethyl ether. Additional rate coefficients are computed to account for rovibrationally excited species that react with O2 prior to thermalization in a process known as non-Boltzmann reactions. A detailed, low-temperature kinetic mechanism for DEE combustion is developed. Ignition delay curves are computed using two mechanisms, one that includes only thermal reactions and a second that also includes 8 non-Boltzmann reactions. Simulations suggest that at an initial pressure of 1 atm and temperatures below 800 K, the inclusion of non-Boltzmann reactions decreases the predicted ignition delay by a factor of 2 or more. As the pressure increases, the effective contribution of these reactions diminishes. These results suggest that non-Boltzmann phenomena can have a significant effect on real-world applications.