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Businesses who need bulk oxygen often start by purchasing tanks from other companies who fill those tanks using an industrial oxygen generator. If the need is large and ongoing, it may be cost-effective for the business to purchase their own oxygen generator and produce oxygen on site. While the up-front cost of the machinery is significant, the cost per cubic foot of oxygen generated is 1/3 to 1/2 that of purchasing bulk oxygen, so over time the oxygen concentrator can pay for itself.

One example of this is hospitals that pipe oxygen into patient rooms. Instead of bottled oxygen, most hospitals have one or more industrial oxygen generators in the building.

Types of Oxygen Generators

Pressure Swing Adsorption Oxygen Generator

Pressure Swing Adsorption (PSA) is the most common method of producing oxygen at an industrial scale. PSA generators separate nitrogen from ambient air inside a pressurized tank filled with Zeolite. Zeolite is a natural or man-made mineral that acts as a “molecular sieve.” It is this ability to “sort” molecules by size that makes zeolite so useful. The larger nitrogen molecules are adsorbed by the sieve material while the smaller oxygen molecules drift past and are collected. Pressure is then released, the nitrogen molecules are vented to the atmosphere, and the tank is pressurized again.

Using PSA will result in 90-95% oxygenated gas. Further refinement can be achieved by repeating the process until over 99% “pure” oxygen is generated.

As a side note, the PSA process can also be used to generate nitrogen by collecting the nitrogen molecules and venting the oxygen. PSA is also used in the large-scale commercial synthesis of hydrogen used in oil refineries and in the production of ammonia for fertilizer.

One special kind of oxygen generator is more commonly known as an oxygen concentrator which is used as an alternative to oxygen bottles for home health care. While the up-front cost of the machine is more expensive than oxygen cylinders, they are safer than bottled oxygen and over time less expensive than having oxygen tanks delivered to the home.

Oxygen concentrators are normally sold through medical supply houses and can be purchased with a prescription from a physician.