Methane partial oxidation to synthesis gas over bimetallic cobalt/tungsten carbide catalysts and integration with a Mn substituted hexaaluminate combustion catalyst

Abstract

Co0.2W0.8Cx and supported Co0.2W0.8Cx catalysts are shown to be active for the partial oxidation of methane to synthesis gas. The catalyst stability is improved by operating at elevated pressure, or in the presence of excess methane. At atmospheric pressure the Co0.2W0.8Cx catalysts deactivate by oxidation, as seen by X-ray diffraction. Manganese substituted hexaaluminate catalysts with different Mn contents have been tested as catalysts for the total combustion of methane. In particular BaMn2Al10O19 is active and stable for the combustion reaction. The temperature rise observed in the reactor was up to 300K, depending on the reaction conditions, and complete conversion of oxygen in the feed was achieved. A process for stabilising the carbide catalysts is demonstrated, combining the manganese substituted hexaaluminate total oxidation catalyst, in series before the carbide reforming catalyst: this process leads to stable operation, with no carbon formation in the reactor and no carbide catalyst oxidation observed.