Where is the air separation unit used? Air separation unit is a key unit widely used in metallurgy, petroleum and petrochemical industries, providing oxygen, nitrogen and argon for the production process. The main technical difficulties of air separation unit lie in system design and calculation, air separation unit processing technology, new air pre cooling system, overall design of cold box, etc. The technology of air separation unit is also in continuous progress, and is developing towards large-scale production and diversified product gas.