Patent ID: 7641789

Claim:
A process to prepare a base oil having a viscosity index of between 80 and 140 starting with a feedstock having at least 200 ppm sulfur and is either a distillate or a de-asphalted oil, wherein said process comprises: (a) contacting the feedstock in the presence of hydrogen with a sulphided, non-fluorided hydrodesulphurisation catalyst, comprising between 2-10 wt % nickel, between 5-30 wt % tungsten, an acid amorphous silica-alumina carrier, between 0.1 and 8 wt % large pore molecular sieve and alumina in an amount in the range of from 5 to 75% by weight calculated on the carrier alone, and wherein the sulphided, non-fluorided hydrodesulphurisation catalyst has a surface area between 200 and 300 m 2 /g, a total pore volume above 0.4 ml/g, and between 5 and 40 volume percent of its total pore volume present as pores having a diameter of more than 350 Å, to thereby provide an effluent; and (b) separating the effluent into a low boiling fraction and a high boiling fraction; and (c) performing a pour point reducing step on the high boiling fraction to obtain the base oil.