The Kinetics of the Thermal Decomposition of Propylene

Abstract

The thermal decomposition of propylene was investigated for temperatures ranging from 680°C up to 870°C and with percentages of decomposition from 0.01 percent up to about 2 percent. The reaction was shown to be a homogenous gas reaction of the first order, the first‐order constant being given by an expression 1.1·10¹³ exp—(72,000/RT). Two mechanisms are discussed, both of which account for the observed kinetics and products of decomposition. It is demonstrated that the first step in the thermal decomposition of propylene is the splitting of the C–H bond leading to the formation of H atoms and allyl radicals. The problem of the value of D(C–H) in propylene is discussed in the light of the two suggested mechanisms. An attempt is made to account for the variety of the reactions between H atoms and propylene molecules as observed by various investigators.