Distillation is different from deasphalting in the sense that distillation is a separation by boiling points. Deasphalting is a process by which a solvent is used to fractionate feedstock, atmospheric or vacuum distillation with respect to the solubility/insolubility of molecular components in a given solvent. Vacuum Distillation Residue (VDR) is completely dissolved in aromatic solvents such as toluene. VDR is typically a solid at room temperature so the aromatic solvents are used to create a liquid mixture at which point a light paraffin solvent is mixed with the liquid to precipitate the VDR component asphaltene. The light paraffin used will determine the separated asphaltene from the solubilized product based on what portion of the VDR is soluble or not. The VDR component that is soluble in this light paraffin is referred to as a maltene and is classified with a prefix of the paraffin used such as n-heptane maltenes. This separation process can continue by using the product from each step of VDR component mixed with a lighter and lighter solvent to precipitate an insoluble product. This process allows for specific separated products depending on what is needed. This procedure can be carried out to start with a low H/C ratio and eventually make a high H/C ratio by-product, although is not typically high value.

The solubility of the VDR compounds for solvent extraction depends on the strength of the solvent measured by the Hildebrand Solubility Parameters (HSP) for non-polar solvents. There are two parameters that affect this solubility. The first parameter is a relationship between surface tension and molar volume where, increasing surface tension would depend on decreasing molar volume. The second HSP is the relationship of the heat energy required to evaporate a solvent under constant volume conditions and the molar volume. The relation here is a decreasing molar volume will correspond to an increasing energy of vaporization. These two parameters demonstrate why aromatics have a higher solvent power than aliphatic hydrocarbons. An aromatic has a lower molar volume or higher density than an aliphatic hydrocarbon. The molar volume is inversely proportional to the parameter thus the parameter will have a higher value signifying a higher solvent power.