High- and low-temperature ignition delay time study and modeling efforts on vinyl acetate

Although esters in general have received much attention over the last decade of combustion research, the combustion of vinyl esters have yet not been studied in detail. Recent studies on ethyl acetate show that vinyl acetate is a major intermediate but its combustion is not well understood. This may be due to the fact that vinyl acetate itself can presumably not be used as a fuel or fuel additive, but both the fundamental understanding of vinyl ester combustion and the improvement of the ethyl ester modeling motivate the present study. Building on the work on ethyl acetate, a first kinetic model for the high- and low-temperature combustion of vinyl acetate is proposed, which includes reactions and intermediates that have not been considered before. These reactions are based on low-level quantum mechanical calculations as well as analogies drawn to mainly ethyl acetate. Seven additional species are considered compared to the ethyl acetate study for which the thermochemical data is derived by ab-initio calculations. The vinyl acetate kinetic model is validated against ignition delay times obtained in a shock tube and a rapid compression machine at pressures of 20 and 40 bar and temperatures ranging from 850 to 1250 K. Overall, a satisfactory agreement between the predictions of the kinetic model and the experimental data was found for all investigated conditions. Rate of production and brute force sensitivity analyses were performed to identify the most relevant reaction pathways, which underline the strong connection between the vinyl acetate and ethyl acetate chemistry.