Abstract: Self-promoted molybdenum and tungsten sulfide hydrotreating catalysts are prepared by heating one or more water soluble catalyst precursors in a non-oxidizing atmosphere in the presence of sulfur at a temperature of at least about 200.degree. C. The precursors are (Cr.sub.x M.sub.1-x L)[Mo.sub.y W.sub.1-y O.sub.4 ].sub.1+.5x wherein M is a divalent promoter metal selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn and mixtures thereof, x is any value from about 0.2 to 1, y is any value from 0 to 1, and wherein L is a nitrogen-containing, neutral multidentate, chelating ligand. In a preferred embodiment the lligand L will comprise one or more chelating alkyl di- or triamines and the non-oxidizing atmosphere will comprise H.sub.2 S.

Abstract: This invention relates to a method for upgrading heavy oils for use in subsequent hydrocarbon processing. The process is especially suitable for removing metals which are in the form of nickel or vanadium organic compounds and for lowering the Conradson Carbon Residue of the resulting oil. The process includes the steps of diluting the heavy oil with a solvent which completely solvates the oil and subjecting the resulting mixture to an ultrafiltration step using selected membranes.