| 摘要 |
Full-range shale oils or fractions thereof, after hydrotreating, are hydrodewaxed and then hydrogenated to produce lubricating oil fractions boiling above 650.degree. F. (343.degree.C.), having a pour point at or below +10.degree. F. (-12.2.degree. C.), and a viscosity index of at least 95. In the preferred operation, the hydrogenation is effected with a noble metal-containing catalyst wherein the noble metal is dispersed by cation exchange into a carrier comprising a silica-alumina cogel or copolymer dispersed in a large pore alumina gel matrix. It has been found with shale oils that the hydrogenation in the preferred embodiment also results in hydrocracking of some of the polynaphthenic compounds. Since polynaphthenic compounds can contribute to or themselves cause low viscosity index in lubricating base oil, the invention is believed particularly applicable to those feedstocks, not necessarily of shale origin, wherein it is desired or necessary to raise the viscosity index by hydrogenation with simultaneous hydrocracking of polynaphthenic compounds. |
