The Catalytic Conversion of Methane to Oxygenates and Higher Hydrocarbons

Abstract

Abstract The catalytic conversion of methane has been achieved both in oxidative and nonoxidative processes, although the yields of useful products are only marginal for commercial utilization. Significant advances have been made in the oxidative coupling of methane to ethane and ethylene. The mechanism generally involves a complex set of coupled heterogeneous and homogeneous reactions. Less progress has been made in the conversion of methane to methanol and formaldehyde; however, it appears that the production of methanol also involves a heterogeneous-homogeneous pathway. By contrast, nonoxidative processes, which occur mainly on metals, are dominated by surface reactions. The conversion of methane alone to higher hydrocarbons has been demonstrated in a cyclic mode, but thermodynamic considerations limit the possibilities for a continuous process. A number of alkylation reactions utilizing methane are thermodynamically feasible, and in a few cases the reactions occur with the aid of a catalyst.