A kinetic model for methyl decanoate combustion

A detailed kinetic model for the oxidation of the biodiesel surrogate, methyl decanoate, has been developed and tested against a broad range of experimental data. The methyl decanoate model consists of both low and high temperature oxidation chemistry. It has been constructed strictly through the extension of the chemical kinetic and thermochemical parameters used to describe the oxidation of the better-understood small methyl ester, methyl butanoate. The constructed model is tested in an a priori manner by the computation of all of the appropriate experimental data available for methyl decanoate oxidation. The results show a generally improved performance of the present model relative to that of literature models which have generally been constructed based on similarity to alkane oxidation reaction kinetics. Chemical path flux analyses of all available methyl decanoate models are analyzed and the results reveal that the fuel oxidation pathways exhibit completely different chemical mechanisms depending on the modeling prescriptions of the kinetic and thermochemical parameters. In particular, there is a wide degree of variability in the fate prescribed to the methyl ester functionality. In addition, experimental analysis of diffusion flame extinctions for methyl butanoate and methyl decanoate reveals that the high temperature reactivity of methyl butanoate is similar to that of methyl decanoate by introducing a concept of transport-weighted enthalpy. Consequently, the present modeling work and experimental analysis suggest that further studies of small methyl ester systems, such as methyl butanoate are required in order to improve the model fidelity of large biodiesel like methyl esters.