Patent ID: 6322692
Filing Date: 2001-11-27
Classification: C10G

Abstract:
A lubricating oil basestock produced by a process which comprises:(a) conducting a lubricating oil feedstock, said feedstock being a distillate fraction, to a solvent extraction zone and under-extracting the feedstock to form an under-extracted raffinate;(b) stripping the under-extracted raffinate of solvent to produce an under-extracted raffinate feed having a dewaxed oil viscosity index from about 85 to about 105 and a final boiling point of no greater than about 650.degree. C.;(c) passing at least a portion of the raffinate feed to a first hydroconversion zone and processing the raffinate feed in the presence of a non-acidic catalyst at a temperature of from 340 to 420.degree. C., a hydrogen partial pressure of from 1000 to 2500 psig (7.0 to 17.3 mPa), space velocity of 0.2 to 3.0 LHSV and a hydrogen to feed ratio of from 500 to 5000 Scf/B (89 to 890 m.sup.3 /m.sup.3) to produce a first hydroconverted raffinate;(d) passing the hydroconverted raffinate from the first hydroconversion zone to a second hydroconversion zone and processing the hydroconverted raffinate in the presence of a non-acidic catalyst at a temperature of from 340 to 420.degree. C. provided that the temperature in the second hydroconversion is not greater than the temperature in the first hydroconversion zone, a hydrogen partial pressure of from 1000 to 2500 psig (7.0 to 17.3 mPa), a space velocity of from 0.2 to 3.0 LHSV and a hydrogen to feed ratio of from 500 to 5000 Scf/B (89 to 890 m.sup.3 /m.sup.3) to produce a second hydroconverted raffinate;(e) passing at least a portion of the second hydroconverted raffinate to a hydrofinishing reaction zone and conducting cold hydrofinishing of the second hydroconverted raffinate in the presence of a hydrofinishing catalyst at a temperature of from 260 to 360.degree. C., a hydrogen partial pressure of from 1000 to 2500 psig (7.0 to 17.3 mPa), a space velocity of from 0.2 to 5 LHSV and hydrogen to feed ratio of from 500 to 5000 Scf/B (89 to 890 m.sup.3 /m.sup.3) to produce a hydrofinished raffinate.