There are two processes used in refineries today to dewax lube oil stocks.  One uses refrigeration to crystallize the wax and then a solvent to dissolve the heavy oil fraction to precipitate the wax out.  Another uses a catalytic hyrocracking process to crack the wax molecules into lighter fractions.

Solvent Dewaxing:

    The two types of solvents used for this process are ketones and propane.  Approximately 85% of current solvent dewaxing processes use ketones.  One method of solvent dewaxing involves adding a solvent to a waxy feed prior to going through a series of coolers.  Following the coolers, the feed goes through a rotary filter with a scraper that scrapes off the crystallized wax.  Then the solvent is recovered and recycled back to the feed stream.  The wax is used to produce products such as candles, cosmetics, and petroleum jelly.  The dewaxed oil is used to make lube oil.

Catalytic cracking to dewaxing