Oxygen concentrators typically use pressure swing adsorption (PSA) technology and are used very widely for oxygen provision in healthcare applications, especially where liquid or pressurized oxygen is too dangerous or inconvenient, such as in homes or in remote clinics & hospitals. For other purposes there are also concentrators based on membrane technology.
An oxygen concentrator takes in air and removes nitrogen from it, leaving an oxygen enriched gas for use by people requiring medical oxygen due to low oxygen levels in their blood. Oxygen concentrators are also used to provide an economical source of oxygen in industrial processes, where they are also known as oxygen gas generators or oxygen generating systems. Oxygen concentrators utilize a molecular sieve to adsorb gases and operate on the principle of rapid pressure swing adsorption of atmospheric nitrogen onto zeolite minerals and then venting the nitrogen. This type of adsorption system is therefore functionally a nitrogen scrubber leaving the other atmospheric gases to pass through. This leaves oxygen as the primary gas remaining. PSA technology is an incredibly reliable and economical technique for oxygen production, with cryogenic separation more suitable at higher volumes and external delivery generally more suitable for small volumes.