Étude chimique et cinétique de l'oxydation homogène en phase gazeuse d'alcanes légers. II. Propane et mécanisme généralisé

Abstract

An experimental study of the homogeneous gas phase oxidation of propane at 350 °C and subatmospheric pressure has been performed in order to identify and to measure the major primary products of the reaction. The experimental results have been interpreted by a chain radical mechanism, deduced from these results and from estimates of the rate constants for the elementary steps obtained by the methods of Thermochemical Kinetics. The proposed elementary steps are discussed and compared with the experimental observations. The results that we have obtained and their interpretation are compared with a similar detailed investigation performed on the oxidation of isobutane. As in the case of isobutane, two parallel reaction pathways appear, a dominant one leading to the conjugated alkene (propylene) and another one leading to the epoxide of this olefin (here propylene oxide). The oxidation of isobutane and that of propane appear to be quite similar, which corroborates the results that we have obtained. Key words: oxidation, kinetics, reaction mechanism, propane, thermochemical kinetics.

Study of the Low Temperature Oxidation of Propane

“…Vogin et al (2) studied the oxidation of propane in a closed vessel at the temperature of 623 K and at subatmospheric pressures (initial pressure of 125 Torr) for equimolar mixtures of propane and oxygen (ɸ = 5). They recorded the evolution of the partial pressures of reaction products as a function of reaction time.…”

“…In contrast to larger n- alkanes, , the low temperature oxidation of propane in the gas phase has been the subject of very few experimental studies, mainly due to its very low reactivity. This C 3 hydrocarbon is not very reactive because of the short size of the alkyl chain which limits the low temperature branching paths.…”