Desirable by-products are ones that come from lube oil base stocks such as waxes that consist of long chain paraffins. There are two ways of “dewaxing” which removes wax from the feedstocks. These methods are solvent dewaxing and catalytic dewaxing.  They are physical and chemical methods respectively. Solvent dewaxing separates waxes using freezing points. Freezing is done in stages after being mixed with the solvent.  This process then forms wax crystals which is then further modified to produce slack wax. Slack wax is found in many everyday common objects such as candles. This method is done in a deasphalting process separates vacuum distillation residue. After placing the residue into an aromatic solvent, an alkane solvent is added which has the effect of some of the compounds to become insoluble. When this happens they precipitate out.

Catalytic dewaxing ultimately increases the ratio of i-paraffins to n-praffins. It does this through the chemical reactions of long chain n-alkanes which will lower the pour point of the wax. When comparing catalytic dewaxing to solvent dewaxing, catalytic waxing is the better method. It gets more lube oil stock because of the variance in pour point as well as its ability to produce both lube oil base stock and light distillates.