Distillation

Distillation is a method of separating chemical substances based on differences in their volatilities in a boiling liquid mixture. Distillation usually forms part of a larger chemical process, and is thus referred to as a unit operation.

Commercially, distillation has a number of uses. It is used to separate crude oil into more fractions for specific uses such as transport, power generation and heating. Water is distilled to remove impurities, such as salt from sea water. Air is distilled to separate its components notably oxygen, nitrogen and argon for industrial use. The use of distillation on fermented solutions to produce distilled beverages with a higher alcohol content is perhaps the oldest form of distillation, known since ancient times.