Process for preparing basestocks having high VI

摘要

A process for preparing high VI lubricating oil basestocks comprising hydrotreating, hydrodewaxing and optionally hydrofinishing. The hydrotreating step is under conditions such that the amount of conversion to 343° C. minus is less than 5 wt. % of the feedstock and the VI increase is less than 4 VI over the feedstock. Hydrodewaxing uses a low alpha catalyst and hydrofinishing is accomplished with a catalyst based on the M41S family.