Argon (Ar) is a monatomic, chemically inert gas which constitutes slightly less than 1% of the air. Its gaseous specific gravity is 1.38 and its boiling point is -302.6°F (-185.9°C). Argon is colourless, odourless, tasteless, non-corrosive, non-flammable, and non-toxic. Commercial argon is the product of cryogenic air separation, whereby liquefaction and distillation processes are used to produce a low-purity ‘crude’ argon product which is then purified to produce the commercial product. Argon is used primarily for its properties as an inert gas in applications such as arc welding, steel-making, heat treating, and electronics manufacturing.
Carbon dioxide (CO2) is a colourless, odourless, non-flammable and slightly acidic liquefied gas. CO2
Nitrogen (N2) constitutes 78.03% of the air, has a gaseous specific gravity of 0.967, and a boiling point of -320.5°F (-195.8°C) at atmospheric pressure. It is colourless, odourless, and tasteless. Nitrogen is often used as an ‘inert’ gas due to its non-reactive nature with many materials. However, nitrogen can form certain compounds under the influence of chemicals, catalysts, or high temperature. Commercial nitrogen is produced through a variety of air separation processes, including cryogenic liquefaction and distillation, pressure swing adsorption (PSA), and membrane separation.
Gaseous nitrogen is used in the chemical and petroleum industries for storage tank blanketing and vessel inerting applications. It is also used extensively by the electronics and metals industries for its inert properties. Liquid nitrogen, produced by the cryogenic air separation process, finds wide use as a refrigerant in applications such as cryogenic grinding of plastics and food freezing.
Oxygen (O2) constitutes approximately 21% of the air, has a gaseous specific gravity of 1.1, and has a boiling point of -297.3°F (-183°C). Oxygen is produced by air separation processes that use either cryogenic liquefaction and distillation or vacuum swing adsorption (VSA) separation. Oxygen can be stored and shipped as either a gas or a cryogenic liquid.
The principal uses of oxygen stem from its strong oxidising and life-sustaining properties. It is used in medicine for therapeutic purposes and in the metals industry for steelmaking and metal-cutting applications. In the chemical and petroleum industries, oxygen is used in the production of a wide variety of fuels and chemicals. In the pulp and paper industry, oxygen is used for a variety of applications, including pulp bleaching, black liquor oxidation, and lime kiln enrichment. In the glass industry, oxygen/fuel combustion is used to reduce particulate and NOx emissions in melting operations. Oxygen is also used for gasification applications for producing synethesis gas to make chemicals, fuels, electricity, hydrogen or steam.