Wall-less reactor studies. Part 2.—Propane pyrolysis

Abstract

A wall-less reactor technique has been applied to study the kinetics of the early stages of propane pyrolysis at 891–1079 K and 600 Torr (1 Torr = 133.3 N m^–2) in excess argon. The rates of formation of methane, ethene and propene have been measured. A numerical integration technique that is applicable to complex reactions in two dimensional flow systems was used for interpretation of results. The order for methane formation is close to 1.5, and rate constants of this order, corrected for fall-off and non-steady state effects, were found to be lower than predicted by extrapolation of static studies, but when combined the results give, log₁₀(_1.5k/dm mol^–½ s^–1)= 10.8 ± 0.2–(204 ± 12 kJ mol^–1)/2.303 RT. The results are shown to be consistent with the mechanism proposed from conventional studies. The ratio of rates of primary and secondary H abstraction from propane (α), and the total rate of abstraction by methyl (k₃) deduced agree with earlier studies. The rate of initiation is found to be thirty times smaller than calculated from the equilibrium constant and the room temperature recombination rate.