Removal of metal contaminants from heavy oils by hydrogenation followed by solvent extraction

A process for purifying heavy oils having an initial boiling point of at least 900 DEG F. and containing constituents non-vaporizable at atmospheric pressure comprises hydrogenating the oil at 200 to 2000 p.s.i.; 600 DEG to 950 DEG F.; a space velocity of 0.25 to 4.0 v./v./hr.; and a H2 partial pressure of 100 to 2000 p.s.i., in the presence of a sulphur resistant catalyst to convert non-volatile and non-extractable polymeric metallic contaminants to volatile and extractable monomeric compounds and subsequently extracting the monomeric compounds with butyrolactone, phenol, furfural, pyridine, acetic acid saturated with bromine or dimethylsulhoxide. Heavy oils mentioned are crude petroleums, shale oils, tar sands, asphalts, tars, and their residue. Catalysts mentioned are cobalt and/or molybdenum, nickel, vanadium, their oxides or sulphides, and mixtures thereof. They may be supported, e.g. on alumina, silica or metal hydrides, and promoted, e.g. with fluorine, chlorine, or rare earths. They may be used as fixed, fluidized or gravitating beds or in a suspensoid or slurry process. Preferred solvent extraction conditions are 150 DEG to 300 DEG F. with an oil-solvent ratio between 1 : 1 and 4 : 1. The hydrogenation may be preceded by an additional extraction or asphalt precipitation step.