The design and testing of an autothermal reactor for the conversion of light hydrocarbons to hydrogen .1. The kinetics of the catalytic oxidation of light hydrocarbons

The catalytic oxidation of methane, ethane and propane on a Pt/delta-Al2O3 catalyst has been studied as part of the design of an autothermal reactor in which exothermic oxidation and endothermic steam reforming are combined. Light-off temperatures and the kinetics of oxidation of the hydrocarbons have been determined. The power rate law kinetics are found to approximate to first order in hydrocarbon and to show a negative order with respect to oxygen. The dependence of rate on oxygen pressure has been shown to be non-monotonic. The kinetics of methane oxidation is best described by a Langmuir-Hinshelwood model in which molecular adsorbed hydrocarbon reacts with adsorbed atomic oxygen. Pt-based catalysts are shown to be more active than Ni-based catalysts for hydrocarbon oxidation.