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

Butenes are intermediates ubiquitously formed by decomposition and oxidation of larger hydrocarbons (e.g. alkanes) or alcohols present in conventional or reformulated fuels. In this study, a series of novel igni-tion delay time (IDT) experiments of trans-2-butene were performed in a high-pressure shock tube (HPST) and in a rapid compression machine (RCM) under conditions of relevance to practical combustors. This is the first IDT data of trans-2-butene taken at engine relevant conditions, and the combination of HPST and RCM results greatly expands the range of data available for the oxidation of trans-2-butene to higher pressures (10-50 atm), lower temperatures (670-1350 K) and a wide range of equivalence ratios (0.5-2.0). A comprehensive chemical kinetic mechanism has simultaneously been developed to describe the combustion of trans-2-butene. It has been validated using the IDT data measured here in addition to a large variety of literature data: jet-stirred reactor (JSR) speciation data, premixed flame speciation data, flow reactor speci-ation data and laminar flame speed data. Moreover, the reactivity of trans-2-butene is compared to that of the other two isomers, 1-butene and isobutene, and these comparisons are discussed. Important reactions are highlighted via flux and sensitivity analyses and help explain the differences in reactivity among the butene isomers. (C) 2016 by The Combustion Institute. Published by Elsevier Inc.