The oxidation of 2-butene: A high pressure ignition delay, kinetic modeling study and reactivity comparison with isobutene and 1-butene

2-Butene oxidation at elevated pressure in a high-pressure shock tube and in a rapid compression machine was studied over a wide range of pressures temperatures and equivalence ratios. The ignition reactivity of the three butene isomers (1- 2- and isobutene) were compared under the same conditions. An increase in reflected shock pressure resulted in shorter ignition delay times (higher reactivity) for all equivalence ratios studied. The effect of equivalence ratio on ignition delay times depended on the temperature of the experiment where all mixtures had similar reactivity at higher temperatures and fuel-rich mixtures were most reactive at lower temperatures. Because of the isomeric structural difference between 1-butene and isobutene 1-butene oxidation facilitated more chain branching reactions than isobutene leading to more rapid chain branching in 1-butene compared to isobutene.