Dewaxing is process carried out in oil refineries that takes in deasphalted oil as well as heavy gas oil and attempts to produce a lubricating oil base stock. Lubricating oil is desired to have low pour points, low volatility, moderate viscosity, a high viscosity index, and a high thermal stability however to produce such a substance oils must have long chain paraffinic compounds removed through one of two processes: solvent dewaxing or catalytic dewaxing.

Solvent dewaxing is a physical process where solvents such as methyl ethyl ketone or propane are added to the oil mixture and then the oil mixture is cooled in a refrigeration unit. The temperature of this refrigeration unit will be based on the amount of waxes that need to be removed to reach the desired qualities of the lubricating oil. Once the solvent is mixed in and the solution is cooled, the wax will begin to form crystals and solidify. The solid wax will build up on a cloth within the separation unit then cut off and removed via a solvent stream. As a last step this wax is run through a steam stripper where the solvent can be taken back out and recycled. The lubricating oil is run through a steam stripper to remove and recycle the solvent as well.

Catalytic dewaxing is a chemical process where the long chain paraffins are cracked through the use of a selective catalyst. This catalyst is a molecular sieve with small specifically sized pore openings which allow n-paraffins to enter and be cracked while keeping i-paraffins out of the cracking process. By having a catalyst of this nature it allows the number of n-paraffins to increase while keeping the number of i-paraffins close to the same which increases the n-paraffin to i-paraffin ratio. This is beneficial to the desired lubricating oil product because as the ratio increases the pour point decreases and thus creates a better oil. Due to the selectivity of the catalyst, catalytic dewaxing has a higher yield of more consistent products when compared to solvent dewaxing. Catalytic dewaxing often costs less to install in a refinery system than solvent dewaxing.