Patent ID: 6264826
Filing Date: 2001-07-24
Classification: C10G

Abstract:
A lubricating oil base stock containing less than 0.03% sulfur, greater than or equal to 90% saturates and having a viscosity index of at least 80, which lubricating oil base stock is prepared from a lube oil feedstock containing at least 0.1% sulfur by a process comprising:a) hydrotreating a petroleum feedstock having a viscosity index of at least about 75 in a hydrotreating reaction zone with a hydrotreating catalyst at a hydrogen partial pressure of less than about 1600 psig (11.1 MPa) and a temperature between about 500.degree. F. (260.degree. C.) and about 800.degree. F. (427.degree. C.) to produce a hydrotreated oil having a viscosity index which is at least about 5 greater than the viscosity index of the petroleum feedstock and a viscosity measured at 100.degree. C. of at least about 2 cSt;b) contacting the hydrotreated oil at hydrodewaxing conditions with an intermediate pore size molecular sieve catalyst to produce a dewaxed oil having a pour point which is lower than the pour point of the hydrotreated oil; andc) contacting the dewaxed oil at hydrogenation conditions in a hydrofinishing reaction zone with a hydrogenation catalyst comprising a platinum/palladium alloy to produce a lubricating oil base stock, wherein the platinum/palladium molar ratio of the platinum/palladium alloy is between about 2.5:1 and about 1:2.