Catalytic hydrogenation and asphaltene conversion of athabasca bitumen

Abstract

Bitumen from the Athabasca Oil Sand deposits was hydrogenated using three MoO₃‐CoO catalysts having markedly different median pore diameters. The results were interpreted in terms of the reaction rates being controlled by the rate of pore diffusion of asphaltene micelles. Catalysts with larger pore diameters produced higher conversions per unit surface area. However, the accessible catalyst surface area per unit volume of reactor decreased as the catalyst pore diameter increased. The decreasing surface area was responsible for the general decrease in conversion with increasing pore diameter. Higher conversions are obtained with higher surface area catalysts having smaller pores, even though pore diffusion controls the rate of reaction.