As the name suggests, Air Separation plants are meant to separate different constituents of air. When only Oxygen is produced from the plant, it is known as Oxygen Plant, but if other constituents of air are also produced from the plant, the plant is known as the Air Separation Plant. Other products of Air Separation Plant could be Nitrogen, Argon, and Helium etc. Oxygen & Nitrogen are generally produced from the Air Separation plant. With large size plants, Argon is also produced.