New insights in the low-temperature oxidation of acetylene

Abstract This work presents new experimental data of C 2 H 2 low-temperature oxidation for equivalence ratios Φ =  0.5–3.0 in a newly designed jet-stirred reactor over a temperature range of 600–1100 K at atmospheric pressure with residence time corresponding from 1.94 to 1.06 s. Mole fraction profiles of 17 intermediates including aromatic compounds such as toluene, styrene and ethylbenzene were quantified. A detailed kinetic mechanism involving 295 species and 1830 reactions was established to predict the oxidation of C 2 H 2 and formation of PAH. In developing the mechanism, particular attention was paid to reactions of the vinyl radical and to steps involved in the sequence C 2 H 2 →iC 4 H 5 →fulvene→C 5 H 5 CH 2 →C 6 H 6 . In general, the peak concentrations of intermediates gradually increase and peak locations tend to shift toward high temperatures with Φ increasing. Flux analysis indicates that the addition of H and the reaction with O are the two major channels governing C 2 H 2 consumption. At temperatures below 1000 K, benzene is mainly formed through the C 2 +C 4 channels:C 2 H 2 +iC 4 H 5 →fulvene→C 5 H 5 CH 2 isomers→C 6 H 6 .The C 1 +C 5 pathway: CH 3 +C 5 H 5 →C 5 H 5 CH 3 →(fulvene and C 5 H 5 CH 2 radicals)→C 6 H 6 tends to be the dominant route for benzene formation at temperatures above 1000 K. In addition to the present data, the model predicts well ignition delay times reported in literature.