On the basis of the thermal decomposition of mixtures of propylene and propane with molar ratios of 0.0–0.33 in the temperature range 779–812K, the influencing functions describing the inhibition by propylene of the decomposition of propane were determined. The rate‐reducing effect is explained mainly by the reactions (Formula Presented.) (in which .R = .H, .CH3 and 2‐Ċ3H7) and also by the addition reactions (Formula Presented.) (Formula Presented.) It was established that the bulk of the allyl radicals formed (Formula Presented.) (Formula Presented.) participate in the chain step, but, due to their lower reactivity, they restore the decomposition chain more slowly than the original radicals do. From the characteristic change in the ratio υ CH 4/υ H 2, the rate ratios of hydrogenabstraction reaction by radicals from propylene and propane could be determined. In these reactions there was no significant difference between the selectivities of the radicals. For an interpretation of the changes, the decomposition mechanism must be completed with the reaction (Formula Presented.) Evaluation of the influencing curves revealed that the initiation reactions (Formula Presented.) (Formula Presented.) must be taken into account. By parameter estimation we have determined the rate ratios characterizing the above initiation reactions, the unimolecular decomposition of propane, hydrogen abstraction by radicals from propane and propylene, intermolecular isomerization of the 2‐propyl radical via propane and propylene, and abstraction of propane hydrogens by the ethyl and methyl radicals; these are given in Tables II.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry