Photoionization mass spectrometry and modeling study of a low-pressure premixed flame of ethyl pentanoate (ethyl valerate)

A stoichiometric premixed burner-stabilized flame of ethyl pentanoate/O₂/Ar mixture at low pressure (20 Torr) was examined by molecular-beam mass spectrometry combined with single-photon ionization to delineate the decomposition and high-temperature oxidation kinetics of ethyl pentanoate in combustion processes. Mole fraction profiles of 43 species were measured in the flame and compared with those calculated using a detailed chemical kinetic mechanism for ethyl pentanoate oxidation. Substantial discrepancies between the measured and modeled peak mole fractions of many intermediates in the flame were noted. The reaction pathways responsible for consumption of primary radicals formed directly from the fuel molecule as well as of the products of successive β-scission reactions should be revised when developing a next-generation combustion model for ethyl pentanoate.