ilmanerottelussa

Ilmanerottelussa, a Finnish term, translates to "air separation" in English. It refers to a process used to separate gases from a mixture of gases, most commonly from atmospheric air. The primary products obtained from the separation of air are nitrogen, oxygen, and argon, though other trace gases can also be isolated.

The most common industrial method for air separation is cryogenic distillation. This process involves cooling the air to very low temperatures, causing it to liquefy. The liquid air is then fed into a distillation column where the different gases separate based on their boiling points. Nitrogen, with the lowest boiling point, vaporizes first and rises to the top of the column, while oxygen, with a higher boiling point, remains liquid at the bottom. Argon, with a boiling point between nitrogen and oxygen, collects in the middle.

Non-cryogenic methods also exist, such as pressure swing adsorption (PSA) and membrane separation. PSA uses adsorbent materials to selectively retain nitrogen or oxygen under pressure, allowing the other gas to pass through. Membrane separation utilizes semi-permeable membranes that allow certain gases to permeate faster than others. These methods are often used for smaller-scale or specific applications where the purity requirements are not as stringent as those achieved by cryogenic distillation.

The separated gases have numerous industrial applications. Nitrogen is used in food packaging, electronics manufacturing, and as an inert atmosphere. Oxygen is vital for medical purposes, welding, and in steel production. Argon is used in welding, lighting, and as an insulating gas in double-glazed windows.