Effect of olefins on the thermal decomposition of propane part I. The model reaction

Study of the thermal decomposition of propane at very low conversions in the temperature range 760–830 K led to refinement of the mechanism of the reaction. The quotient V / V characterizing the two decomposition routes connected with the 1‐ and 2‐propyl radicals proved to depend linearly on the initial propane concentration. This suggested the occurrence of intermolecular radical isomerization: equation image in competition with decomposition of the 2‐propyl radical: equation image The linearity led to the conclusion that the selectivity of H‐abstraction from the methyl and methylene groups by the methyl radical is practically the same as that by the H atom. The temperature‐dependence of this selectivity ( μ = k CH 3 / k CH 2 ) was given by Further evaluation of the dependence gave the Arrhenius representation for the ratio of the rate coefficients of the above isomerization and decomposition reactions. Steady‐state treatment resulted in the rate equation of the process, comparison of which with measurements gave further Arrhenius dependences.