Air Separation

An air separation plant separates atmospheric air into its primary components, typically nitrogen and oxygen and sometimes also argon and other rare inert gases, most commonly through fractional distillation in cryogenic air separation units that can also co-produce argon. Other methods, including membrane separation, pressure swing adsorption and vacuum pressure swing adsorption, are used commercially to separate a single component from ordinary air, though high-purity oxygen, nitrogen and argon for uses such as semiconductor fabrication still require cryogenic distillation. The distillation of air using at least two distillation columns is also the only viable industrial source of the rare gases neon, krypton and xenon, and helium can be recovered from advanced air separation processes as well.