An experimental and modeling study of propene oxidation. Part 1: Speciation measurements in jet-stirred and flow reactors

Propene is a significant component of Liquefied Petroleum Gas (LPG) and an intermediate in the combustion of higher order hydrocarbons. To better understand the combustion characteristics of propene, this study and its companion paper present new experimental data from jet-stirred (JSR) and flow reactors (Part I) and ignition delay time and flame speed experiments (Part II). Species profiles from JSR experiments are presented and were obtained at near-atmospheric pressure over a temperature range of 800-1100 K and for equivalence ratios from phi = 0.64 to 2.19. The new JSR data were obtained at lower dilution levels and temperatures than previously published. Also reported are species profiles from two high-pressure flow reactor facilities: the Princeton Variable Pressure Flow Reactor (VPFR) and the High Pressure Laminar Flow Reactor (HPLFR). The VPFR experiments were conducted at pressures of 6-12.5 atm, in the temperature range 843-1020 K and at equivalence ratios of 0.7-1.3. The HPLFR experiments were conducted at 15 atm, at a temperature of 800 K and at equivalence ratios of 0.35-1.25. The flow reactor data is at higher pressures and lower temperatures than existing data in the literature. A detailed chemical kinetic mechanism has been simultaneously developed to describe the combustion of propene under the experimental conditions described above. Important reactions highlighted via flux and sensitivity analyses include: hydrogen atom abstraction from propene by molecular oxygen, hydroxyl, and hydroperoxyl radicals; allyl-allyl radical recombination; the reaction between ally] and hydroperoxyl radicals; and the reactions of 1- and 2-propenyl radicals with molecular oxygen. The current mechanism accurately predicts the combustion characteristics of propene across the range of experimental conditions presented in this study, from jet-stirred and flow reactors and for ignition delay times and flame speed measurements presented in Part II. In comparison to a previous mechanism, AramcoMech 1.3, the current mechanism results in much improved performance, which highlights the importance of the new experimental data in constraining the important reactions. (c) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.