METHOD FOR ISOMERIZING WAX TO LUBE BASE OILS

摘要

Slack waxes and synthetic wax are isomerized and processed into high viscosity index and very low pour point lube base stock oils and blending stocks by the process comprising the steps of hydrotreating the wax, if necessary, to remove heteroatom and polynuclear aromatic compounds and/or deoiling the wax, if necessary, to an oil content between about 5-20% oil, isomerizing the wax over a Group VI-Group VIII on halogenated refractory metal oxide support catalyst, said isomerization being conducted to a level of conversion such that about 40% and less unconverted wax remains in the 330.degree.C+, preferably the 370.degree.C+ fraction sent to the dewaxer. The total isomerate from the isomerization unit is fractionated into a lube oil fraction boiling at 330.degree.C+, preferably 370.degree.C+. This oil fraction is solvent dewaxed preferably using MEK/MIBK at 20/80 ratio and unconverted wax is recycled to the isomerization unit. Operating in this manner permits one to obtain isomerate oil of very high VI (in excess of 130) possessing low pours (-21.degree.C, preferably -24.degree.C, most preferably -27.degree.C).