An Air Separation Unit (ASU), or otherwise known as an air separation plant, separates atmospheric air into its primary components — typically nitrogen, oxygen, and argon.
To put it simply, an ASU works like this:
Step 1: Filtration
Air is drawn in through an intake filter to remove any dust or debris.
Step 2: Pressurization
Air is moderately compressed and moved into a pre-cooling chamber at 40°F where H 2O and CO 2 are removed.
Step 3: Separation
Air is moved into air separators at -297°F where the oxygen turns into a liquid, then argon and nitrogen gases are separated. Argon turns into liquid at -302°F and nitrogen turns into liquid at -320°F.
Step 4: Storage
The gases are piped in their liquid state to storage tanks for later shipment to partners and customers.