Intrinsic kinetics of the oxidation of methane over an industrial copper(II) oxide catalyst on a γ-alumina support

The kinetic rate of the heterogeneously catalysed methane oxidation reaction was studied at temperatures ranging from 723 to 923 K and atmospheric pressure. A commercially available CuO catalyst supported by thermally stable γ-Al2O3 was used as the catalyst. This kinetic study was carried out in order to evaluate whether this reaction can be suitably handled in a novel type of membrane reactor (J.W. Veldsink et al., Chem. Eng. Sci., 47 (9–11) (1992) 2939–2944).

The equipment in which the experiments were conducted consisted of a differentially operated fixed-bed reactor. For this set-up heat and mass transport limitations have been checked and shown to be absent. The influence of the concentrations of the products and reactants on the reaction rate was studied over a wide range of conditions. Fractions of methane ranged from 1 to 6 vol.%, oxygen between 600 ppm and 21 vol.%, carbon dioxide between 0 and 20 vol.%, and water from 0 to 8 vol.%. All experimentally observed reaction rates could be represented within 30% by an Eley-Rideal type reaction rate expression.