Distillation processes are widely used for the separation of organic chemicals and for the separation of gases, usually at cryogenic temperatures, as in the production of oxygen and nitrogen from air. It is a process for isolating components from a mixture based on differences in boiling points.

Demulsifiers, or emulsion breakers, are a class of specialty chemicals used to separate emulsions, for example, water in oil. They are commonly used in the processing of crude oil, which is typically produced along with significant quantities of saline water. This water and salt  must be removed from the crude oil prior to refining.