How Do OGSI Plants Work?

• OGSI plants produce oxygen by means of an air separation process called pressure swing adsorption (PSA).  The oxygen is only produced upon demand.  Very little oxygen is stored in the system, which is a safety feature.

• The air we breathe generally contains about 78% nitrogen, 21% oxygen, 0.8% argon, with the balance being pollution & other gases.

• A PSA oxygen generator uses a material called molecular sieve, which adsorbs nitrogen much like how a sponge adsorbs water.  Compressed air is passed through a column of sieve, which adsorbs the nitrogen in the air and allows the oxygen to pass on through to a low pressure holding tank.  The nitrogen is later exhausted out of the sieve bed to get it ready for the next stream of air.

• PSA systems have an advantage over Liquid Oxygen (LOX) systems because they do not lose oxygen like LOX tanks, which need to vent at least 1% of their volume per day to limit pressure in the storage vessel.

• The oxygen purity from OGSI plants is typically at 93%, with the balance being even amounts of nitrogen & argon.  This purity meets the medical requirements of the US Pharmacopeial Convention (USFDA), Canadian Standards Association (CSA), & ISO 10083 (European) specifications.

• The low-pressure produced oxygen can then be compressed to fill high-pressure cylinders.