Fischer–Tropsch studies with cobalt–manganese oxide catalysts: Synthesis performance in a fixed bed reactor Original Research Article

An investigation was undertaken to establish the performance of a cobalt/manganese oxide catalyst in a fixed bed reactor for the conversion of carbon monoxide with hydrogen under conditions favouring the formation of gaseous, liquid and solid (i.e. wax) hydrocarbons. The cobalt/manganese oxide catalyst in the form of extrudates with a diameter of 3 mm was prepared by a co-precipitation method. The fixed bed reactor consisted of a single tube with a diameter of 21 mm, similar to tubes used in typical industrial scale Fischer–Tropsch reactors. The catalyst requires a fairly long stabilisation period and produced an industrially viable product spectrum. Significant water–gas activity was observed which is not normally expected for cobalt based catalysts under Fischer–Tropsch synthesis conditions. Increased pressure up to 2100 kPa suppressed the water–gas shift reaction and lowered the olefin production.