Hydrodesulfurization reactions of residual oils over cobalt-molybdenum/alumina-aluminum phosphate catalysts in a trickle bed reactor

Catalytic hydrodesulfurization (HDS) plays an important role in the conversion of sulfur-laden residual oils. Cobalt molybdate catalysts are commonly used for the process. In the present study, a series of alumina-aluminum phosphates (AAP) was prepared by a precipitation technique. These materials were used as a support of CoMo HDS catalysts. The samples were characterized by X-ray diffraction, BET surface area, and mercury-penetration pore volume measurements. The temperature-programmed reduction method was used to monitor the reducibility of MoO 2 . HDS of Kuwait atmospheric residuum over these catalysts was carried out in a cocurrent down-flow trickle bed reactor at 663 K and 7582 kPa. The reaction data can be fitted very well a pseudo-second-order rate equation