Experimental and kinetic modeling study of extinction and ignition of methyl decanoate in laminar non-premixed flows

Abstract

Methyl decanoate is a large methyl ester that can be used as a surrogate for biodiesel. In this experimental and computational study, the combustion of methyl decanoate was investigated in non-premixed, nonuniform flows. Experiments were performed employing the counterflow configuration with a fuel stream made up of vaporized methyl decanoate and nitrogen, and an oxidizer stream of air. The mass fraction of fuel in the fuel stream was measured as a function of the strain rate at extinction, and critical conditions of ignition were measured in terms of the temperature of the oxidizer stream as a function of the strain rate. A detailed mechanism of 8555 elementary reactions and 3036 species has been developed previously to describe combustion of methyl decanoate. Since it is not possible to use this detailed mechanism to simulate the counterflow flames because the number of species and reactions is too large to employ with current flame codes and computer resources, a skeletal mechanism was deduced from this detailed mechanism using the “directed relation graph” method. This skeletal mechanism has only 713 elementary reactions and 125 species. Critical conditions of extinction and critical conditions of ignition were calculated using this skeletal mechanism and they were found to agree well with experimental data. In general, the methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.