Process for dewaxing waxy hydrocarbon oils using ketone dewaxing solvent and a polyvinylpyrrolidone dewaxing aid

摘要

A waxy hydrocarbon oil, such as a bright stock fraction is dewaxed in a ketone dewaxing process at an increased rate, relative to existing processes, by employing polyvinylpyrrolidone (PVP) as a dewaxing aid. Preferably the PVP has a number average molecular weight in the range of from 150,000 to 400,000, e.g. about 360,000, and as little as 100 ppm based on the waxy oil can result in almost a 50% increase in the filter rate of the dewaxed oil from the wax.