Experimental and kinetic modeling study on the ignition characteristics of methyl acrylate and vinyl acetate: Effect of C=C double bond

The ignition characteristics of methyl acrylate (MA) and vinyl acetate (VA) are investigated in a heated shock tube at 1176-1618 K, 4-16 atm, and equivalence ratios of 0.5-2.0. The ignition delay times of MA and VA decrease with increasing equivalence ratio and decreasing pressure but pressure has a negligible effect on their ignition at low temperatures. Comparison between ignition delay times of MA and VA as well as their corresponding saturated esters indicates that both saturation and position of C=C double bond affect the ignition process. To reveal its chemical kinetics on ignition characteristics of esters, the existing kinetic model of MA is updated and VA model is further constructed based on the updated MA model. The new kinetic models can better reproduce ignition delay times under current experimental conditions. Comparisons and kinetic analyses demonstrate that MA is more active than VA and Haddition and unimolecular decomposition reactions are the major channels consuming fuel molecules. The reactivities of MA and VA are lower than their corresponding saturated esters at 4 = 0.5 and 1. With increasing temperature and equivalence ratio, the saturated esters become less active than MA and VA because of low decomposition rate and stable intermediate formations, respectively. (C) 2022 Elsevier Ltd. All rights reserved.