Detailed oxidation kinetics and flame inhibition effects of chloromethane

Abstract

A comprehensive experimental and numerical study has been performed on the detailed oxidation kinetics and the flame inhibition effects of chloromethane, with an emphasis on the isolation of the temperature and chemical effects caused by substitution of methane in the fuel by chloromethane. The experimental efforts involved the determination of laminar burning velocities for a series of fuel mixtures of different ratios of chloromethane to methane, but with a fixed ratio of total fuel to oxygen (and air). The thermal and chemical effects were isolated by comparing the laminar burning velocities obtained with the adiabatic flame temperature uncompensated with the substitution of methane by chloromethane, versus those obtained with fixed adiabatic flame temperature achieved by replacing nitrogen in air with an equal amount of argon. The experimental results indicate that temperature reduction due to increased chloromethane substitution is a significant factor for the reduction in the laminar burning velocity. Furthermore, when the results at a fixed flame temperature were examined on the basis of the mass burning rate, which is the eigenvalue for laminar flame propagation, the response was found to be insensitive to the chloromethane concentration in the mixture. This implies the possibility of a corresponding insensitivity to the chlorine flame chemistry. Concurrently, a detailed reaction mechanism of chloromethane/methane oxidation was compiled and validated against literature data from shock tube to flow reactor studies. Numerical simulation of the present experimental situation was then performed. The numerical results were found to be in close agreement with the current experimental findings.