ROLE OF CATALYST IN HYDROCRACKING OF RESIDUES FROM ALBERTA BITUMENS

Vacuum residues (424-degrees-C+) from Cold Lake and Lloydminster bitumens were hydrocracked at 430-degrees-C, 13.9 MPa, over five materials: fresh and spent commercial Ni/Mo on gamma-alumina, Mo supported on gamma-alumina, a commercial demetallization catalyst, and gamma-alumina. Athabasca residue was tested using fresh and spent Ni/Mo on gamma-alumina catalyst and was coked at atmospheric pressure in a batch apparatus. The product distributions from thermal (i.e., gamma-Al3O3 or coker) experiments were similar to those from catalytic experiments; therefore, the catalysts served mainly to promote hydrogen transfer to the oil and hydrogenation of aromatic compounds. The activity of the catalysts for residue conversion, heteroatom removal, and hydrogenation of Cold Lake and Lloydminster residue was Ni/Mo on gamma-alumina > Mo on gamma-alumina > demetallization much greater than gamma-alumina. The sulfur in the naphtha and middle distillate fractions was most affected by the hydrogenation activity of the catalysts, based on a comparison to the products from thermal reactions only. The largest effect of the catalyst on conversion of aromatics was in the middle distillate fractions.