Distillation is one of the most important processes for separating the components of a solution. The solution is heated to form a vapor of the more volatile components in the system, and the vapor is then cooled, condensed, and collected as drops of liquid. By repeating vaporization and condensation, individual components in the solution can be recovered in a pure state. Whiskey, essences, and many products from the oil refinery industry are processed via distillation.

Distillation has been used widely to separate volatile components from non-volatile compounds. The underlying mechanism of distillation is the differences in volatility between individual components. With sufficient heat applied, a gas phase is formed from the liquid solution. The liquid product is subsequently condensed from the gas phase by transferring heat from the vapor. Therefore, heat is used as the separating agent during distillation. Feed material to the distillation apparatus can be liquid...