Patent ID: 7132043
Filing Date: 2006-11-07
Classification: C10G

Abstract:
1. Process to prepare a lubricating base oil having a saturates content of more than 90 wt %, a sulphur content of less than 0.03 wt % and a viscosity index of between 80–120 starting from a lubricating base oil product having a saturates content of below 90 wt % and a sulphur content of between 300 ppmw and 2 wt %, which lubricating base oil product is obtained by first removing part of the aromatic compounds from a petroleum fraction boiling in the lubricating oil range by means of solvent extraction resulting in a solvent extracted product and subsequently dewaxing the solvent extracted product, wherein the following steps are performed, (a) contacting the lubricating base oil product with a suitable sulphided hydrotreating catalyst in the presence of hydrogen in a first hydrotreating step at a temperature of between 250 and 350° C.; (b) separating the effluent of step (a) into a gaseous fraction and a liquid fraction, wherein the liquid fraction has a sulphur content of between 50 and 1000 ppmw and a nitrogen content of less than 50 ppmw; (c) contacting the liquid fraction of step (b) with a catalyst comprising a noble metal component supported on an amorphous refractory oxide carrier, including amorphous silica-alumina but having an absence of a cracking effective amount of zeolite-Y in the presence of hydrogen in a second hydrotreating step; and (d) recovering the lubricating base oil having the specified properties.