An intermediate temperature modeling study of the combustion of neopentane

A detailed chemical kinetic model has been used to study experimental results obtained previously on the oxidation of neopentane (2,e-dimethyl propane) in a closed reactor at 500 torr pressure and a temperature of 753 Ii. Small amounts of neopentane were added to slowly reacting mixtures of H-2 + O-2 + N-2 A complete analysis of all products, except H2O and peroxide, was carried out for three mixtures containing 5 torr neopentane: (1) the standard mixture (H-2 = 140, O-2 = 10, N-2 = 285 torr); (2) one of high O-2 content (H-2 = 140, O-2 = 355 torr); and (3) one of high H-2 content (H-2 = 425, O-2 = 70 torr). Experimental results for mixtures 2 and 3 have appeared in prior publications, but the results for mixture 1, although obtained at the same time, have not previously been reported. Analysis showed that the primary products formed in the experiments included isobutene, 3,3-dimethyloxetan, acetone, methane, and formaldehyde. The major secondary products were 2,2-dimethyloxiran, propene, isobuteraldehyde, methacrolein, and 2-methylprop-2-en-1-ol. A detailed kinetic model was used to explain both primary and secondary product formation. Because the experiments were carried out at 753 EC, both low- and high-temperature reaction schemes are important and resulted in a model comprising 310 species and 1570 elementary reactions. This model was able to explain both primary and secondary product formation with a high degree of accuracy: almost all secondary product formation could be explained through the formation of isobutene. In agreement with past kinetic studies, the addition reaction of neopentyl radical with molecular oxygen and the alkylperoxy radical isomerization reaction were found to be ver important. In addition, the importance of the reverse isomerization, from hydroperoxy-neopentyl to neopentylperoxy radical, was established.