Distillation is the process of separating the components or substances from a liquid mixture by selective boiling and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components of the mixture. In either case the process exploits differences in the volatility of the mixture’s components. In industrial chemistry, distillation is a unit operation of practically universal importance, but it is a physical separation process and not a chemical reaction.
Distillation has many applications. For example:
Distillation of fermented products produces distilled beverages with a high alcohol content, or separates out other fermentation products of commercial value.
Distillation is an effective and traditional method of desalination.
In the fossil fuel industry, distillation is a major class of operation at oil refineries for transforming crude oil into fuels and chemical feed stocks.
Cryogenic distillation permits separation of air into its components – notably oxygen, nitrogen, and argon – for industrial use.
In the field of industrial chemistry, large amounts of crude liquid products of chemical synthesis are distilled to separate them, either from other products, or from impurities, or from unreacted starting materials.An installation for distillation, especially of distilled beverages, is a distillery. The distillation equipment is a still.