Air separation unit
Matheson Tri-Gas
In large industrial air separation plants atmospheric air is filtered, compressed, and cooled. The contaminants (primarily moisture, carbon dioxide and heavy hydrocarbons) are removed and are either frozen out in a reversing heat exchanger or absorbed by a molecular sieve. The air is then separated in a four column system.
The columns are trayed distillation columns with vapor rising through holes in the trays as liquid travels across them, and then down to the next tray. As the vapor rises, it contains a higher percentage nitrogen, which is the lower boiling point constituent. As the liquid descends the column, it becomes richer in the higher boiling point constituents of air: oxygen and argon.
