The ignition and oxidation of allene and propyne: Experiments and kinetic modeling

Abstract

The ignition and oxidation of allene and propyne have been studied in a single-pulse shock tube under reflected shock wave conditions and in a jet-stirred reactor (JSR). These experiments cover a wide range of conditions: 1–10 atm, 0.5≤≤2.0 and 800–2030 K. The ignition delays of allene and propyne measured in a shock tube have been used to propose an overall representation for the dependence of ignition-delay time on the concentrations of the components in gas mixtures: τ(allene)=10−14.6 exp(18,150/T) [allene]0.1 [O2]−1.16 [Ar]0.1 and τ(propyne)=10−14.3 exp(17,910/T) [propyne]0.16 [O2]−1.14 [Ar]0.07 (units; s, mol/dm3, K). These results show that allene and propyne have almost identical ignition characteristics. The power dependencies, preexponential factors, and activation energies are very similar for both fuels. Concentration profiles of reactants, intermediates, and products of the oxidation of allene and propyne were measured in a JSR. A numerical model consisting of a detailed kinetic reaction mechanism with 748 reactions (mostly reversible) involving 121 species describes allene and propyne ignition in shock waves and oxidation in a jet-stirred reactor. Generally, a good agreement between the data and model was observed.