DEACTIVATION OF HYDRODESULFURIZATION CATALYSTS UNDER COAL LIQUIDS .2. LOSS OF HYDROGENATION ACTIVITY DUE TO ADSORPTION OF METALLICS

Minerals identified in coal were investigated as to their poisoning effect on the hydrogenation activity of several HDS catalysts under coal liquefaction conditions. Techniques of impregnation and exposure of catalysts to metal compounds were developed that allow the determination of rates of adsorption, poisoning, and loss of activity. The metals Na, K, Mg, Ca, P, Ti, Fe, and Si were shown to permanently poison catalysts at different rates. Deposition of carbonaceous mineral within the catalyst pores suppresses the adsorption of coal-liquid insoluble constituents. However, organometallics, such as those of titanium, are soluble in coal liquids, gain access to the surfaces, and are adsorbed in high concentrations. © 1978, American Chemical Society. All rights reserved.