The thermal degradation of n-decane in a plug reactor is studied at about 720-degrees-C. Products not exclusively of primary type were all titrated using a gas phase capillary chromatography method. The major primary products are ethylene, methane, propene and hydrogen. Ethylene selectivity is approximately 35% at lower passage times (40 to 160 ms). A chain radical-based theoretical mechanism has been used to account for all reaction products qualitatively and to represent the associated stoichiometries for the degradation of initial alcane.

A mechanistic model of the thermal decomposition reactions of n-hexane at low conversion ( < 5%) using as a basis a complex free radical chain mechanism and taking into account H abstraction from propene has been adjusted and compared to the observed product distribution. A reasonably good agreement is found between the computed curves and the experimental results obtained at 693 K and 133 mbar.

The chemistry of the thermal reactions of complex hydrocarbons is of fundamental importance in steam-cracking operations. The difference in the product distribution observed when various feeds are cracked could in theory be accounted for by a detailed analysis of the initial feedstock (the distribution of the various hydrocarbons in feedstock can explain the variations of the output of the industrial units, especially from the point of view of the yields of the light olefins), but such a method would be very difficult and would require lengthy and complicated calculations

This paper describes the present knowledge on cyclohexane pyrolysis since the literature on the pyrolysis of cycloalkanes is rather scarce compared to that published on alkane pyrolysis. The present paper summarizes the principal papers published on the subject; we mention, for each analyzed paper, the operating conditions, the type of reactor, and the main results (reaction order, temperature influence, reactions accounting for the reaction products, etc.). After this review of the significant papers, we discuss the corresponding results and their limits; we also give a synthetic view of the effect of additives on cyclohexane cracking, and we propose a synthetic mechanism and a stoichiometric analysis of the thermal decomposition of cyclohexane.

A mechanistic model of the thermal decomposition reactions of 3-methylpentane at low conversion ( < 5%) using as a basis a complex free-radical chain mechanism has been adjusted and compared to the observed product distribution. A reasonably good agreement between the computed curves and the experimental results obtained from an earlier work has been obtained.