Industrial gases are the gaseous materials that are manufactured for use in industry. The principal gases provided are nitrogen, oxygen, carbon dioxide, argon, hydrogen, helium and acetylene, although many other gases and mixtures are also available in gas cylinders. The industry producing these gases is also known as industrial gas, which is seen as also encompassing the supply of equipment and technology to produce and use the gases. Their production is a part of the wider chemical Industry (where industrial gases are often seen as “specialty chemicals“).
Industrial gases are used in a wide range of industries, which include oil and gas, petrochemicals, chemicals, power, mining, steelmaking, metals, environmental protection, medicine, pharmaceuticals, biotechnology, food, water, fertilizers, nuclear power, electronics and aerospace. Industrial gas is sold to other industrial enterprises; typically comprising large orders to corporate industrial clients, covering a size range from building a process facility or pipeline down to cylinder gas supply.
Some trade scale business is done, typically through tied local agents who are supplied wholesale. This business covers the sale or hire of gas cylinders and associated equipment to tradesmen and occasionally the general public. This includes products such as balloon helium, dispensing gases for beer kegs, welding gases and welding equipment, LPG and medical oxygen.
Retail sales of small scale gas supply are not confined to just the industrial gas companies or their agents. A wide variety of hand-carried small gas containers, which may be called cylinders, bottles, cartridges, capsules or canisters are available to supply LPG, butane, propane, carbon dioxide or nitrous oxide. Examples are Whipped-cream chargers, powerlets, campingaz and sodastream.
Air separation plants refine air in a separation process and so allow the bulk production of nitrogen and argon in addition to oxygen – these three are often also produced as cryogenic liquid. To achieve the required low distillation temperatures, an Air Separation Unit (ASU) uses a refrigeration cycle that operates by means of the Joule–Thomson effect. In addition to the main air gases, air separation is also the only practical source for production of the rare noble gases neon, krypton and xenon.
Cryogenic technologies also allow the liquefaction of natural gas, hydrogen and helium. In natural-gas processing, cryogenic technologies are used to remove nitrogen from natural gas in a Nitrogen Rejection Unit; a process that can also be used to produce helium from natural gas where natural gas fields contain sufficient helium to make this economic. The larger industrial gas companies have often invested in extensive patent libraries in all fields of their business, but particularly in cryogenics.