HYDROCRACKING VACUUM RESIDUE WITH NI-W BIFUNCTIONAL SLURRY CATALYSTS

An Arabian Heavy vacuum resid (262 ppm Ni + V, 5.3% S and 24% CCR) was hydrocracked over the following bifunctional catalysts: Ni-W on alumina, silica-alumina, US-Y, montmorillonite, sepiolite, and activated carbon at 427 -C and 13.4 MPa hydrogen in a batch reactor. The activity of the sulfided and unsulfided bifunctional catalysts was compared with that of oil soluble mixtures of Ni and W homogeneous organometallics. Sulfided Ni-W/alumina gave about 70% 538-degrees-C+ conversion, 1.1% coke make, 50% desulfurization, 42% CCR removal and a metals reduction in the liquid product from 262 to 59 ppm Ni+V. In contrast, the other bifunctional catalysts at the same conversion generated at least three times more coke while the homogeneous catalyst gave less upgrading at 0.3% coke make. Coke yield is highly dependent on the ability of the metal function to hydrogenate cracked products before they react to form coke. These results indicate that the addition of sulfided Ni-W/alumina to a slurry type hydrocracking process might improve hydrogenation activity and produce more 538-degrees-C+ conversion at a particular severity while generating the low coke make necessary for a continuous upgrading process.