Single-pulse shock tube studies of hydrocarbon pyrolysis. Part 7.—Pyrolysis of propane

Abstract

The pyrolysis of 1% mixtures of propane in argon has been studied in a single-pulse shock tube over the temperature range 1210–1680 K for reaction times between 0.7 and 1.65 ms and pressures of 0.6–1.0 atm. The overall rates of decomposition and the product distributions are in satisfactory agreement with earlier investigations. The ratio of products arising from C₁ fragments to those from C₂ fragments is not equal to unity as earlier mechanisms have predicted. Computer modelling of the pyrolysis shows that the results can only be matched with reasonable rate constants by incorporating the reaction CH₃+ C₃H₆→ C₂H₄+ C₂H₅. Rate constants for the rate-determining steps in the mechanism are obtained by computer optimization. The sensitivity of these results to the various assumptions involved is also evaluated.