EVOLUTION OF ALCOHOL SYNTHESIS CATALYSTS UNDER SYNGAS

Methanol-higher alcohols mixtures can be synthesized from natural gas via CO/CO2/H2 mixtures and constitute potential octane boosters for un leaded gasoline. Catalytic formulations have been developed around the world, which allow rather high alcohol selectivities to be reached, b ut these performances are generally attained after an aging period whi ch is necessary for the in situ preparation of the active phase. For t his reason, the evolution of copper-cobalt-based model catalysts has b een studied in different test equipments and operating conditions, suc h as fixed bed, slurry phase, and Berty reactors, as well as autoclave s and differential scanning calorimeters (DSC). The evolution of metal lic cobalt dispersion was followed by magnetic measurements, and carbo n deposits were visualized by temperature-programmed hydrogenation exp eriments. The interest of a slurry reactor for alcohols synthesis is d emonstrated at lab scale. Acetaldehyde thermodesorption and CO disprop ortionation allow the performances of cobalt-based active phases to be predicted.