Luftseparering

Luftseparering, also known as air separation, is a process used to separate air into its primary components, most commonly nitrogen and oxygen. This is achieved by cooling air to very low temperatures, causing it to liquefy. The liquid air is then subjected to fractional distillation, a process that exploits the differences in boiling points of its constituent gases. Nitrogen has a lower boiling point (-196 degrees Celsius) than oxygen (-183 degrees Celsius), allowing it to vaporize and be collected separately. Argon, another component of air, is also typically separated in this process.

The most common method for industrial air separation is the cryogenic distillation process. This involves compressing, purifying, and then cooling air to below its liquefaction point. The liquefied air is then fed into a distillation column where the separation occurs. Other methods, such as pressure swing adsorption (PSA) and membrane separation, are also used, particularly for producing gases at lower purities or in smaller quantities. PSA utilizes adsorbent materials that selectively adsorb nitrogen at high pressure, allowing oxygen to pass through. Membrane separation uses semi-permeable membranes that allow oxygen to pass through more readily than nitrogen.

The separated gases have a wide range of industrial, medical, and scientific applications. Oxygen is used in healthcare for respiratory therapy, in industrial processes like welding and steel manufacturing, and in chemical production. Nitrogen finds use as an inert atmosphere in food packaging and electronics manufacturing, as a coolant, and in the production of fertilizers. Argon is used in welding, lighting, and as an inert gas in scientific research. The demand for these separated gases drives the widespread use of air separation technologies globally.