Application & Uses


Oxygen (O2):

Multi-Industry Uses for Oxygen:

Oxygen is used with fuel gases in gas welding, gas cutting, oxygen scarfing, flame cleaning, flame hardening, and flame straightening.

In gas cutting, the oxygen must be of high quality to ensure a high cutting speed and a clean cut.

Metals Manufacturing Uses for Oxygen:

The largest user of oxygen is the steel industry.  Modern steelmaking relies heavily on the use of oxygen to enrich air and increase combustion temperatures in blast furnaces and open hearth furnaces as well as to replace coke with other combustible materials.  During the steel making process, unwanted carbon combines with oxygen to form carbon oxides, which leave as gases. Oxygen is fed into the steel bath through a special lance.  Oxygen is used to allow greater use of scrap metal in electric arc furnaces.  Large quantities of oxygen are also used to make other metals, such as copper, lead, and zinc.

Oxygen enrichment of combustion air, or oxygen injection through lances, is used to an increasing extent in cupola furnaces, open-hearth furnaces, smelters for glass and mineral wool, and lime and cement kilns, to enhance their capacity and reduce energy requirements.  Smelting times and energy consumption can also be reduced by special oxy-oil or oxy-gas burners in electro-steel furnaces and induction smelters for aluminum.  A high thermal efficiency is achieved by these “oxy-fuel” burners, which mix fuel and oxygen at the tip of the burner.  As a result, rapid combustion occurs at approximately 2800o C (5072oF).

Chemicals, Pharmaceuticals and Petroleum Uses:

Oxygen is used as a raw material in many oxidation processes, including the manufacture of ethylene oxide, propylene oxide,  synthesis gas using partial oxidation of a wide range of hydrocarbons, ethylene dichloride, hydrogen peroxide, nitric acid, vinyl chloride and phthalic acid.

Very large quantities of oxygen are used in coal gasification — to generate a synthesis gas that can be used as a chemical feedstock or precursor for more easily- transported and easily-used fuels. 

Oxygen is used to enrich the air feed to catalytic cracking regenerators, which increases capacity of the units. It is used in sulfur recovery units to achieve similar benefits. Oxygen is also used to regenerate catalysts in refineries.

Oxygen is used to achieve more complete combustion and destruction of hazardous and waste materials in incinerators.

Glass and Ceramics Industry Uses:

Conversion of combustion systems from air-fuel to oxy-fuel (and construction of new furnaces and tanks around this technology) results in better control of heating patterns, higher furnace efficiencies (lower fuel consumption) and reduction in particulate and NOx emissions. 

Pulp and Paper Manufacturing Uses:

Oxygen is increasingly important as a bleaching chemical.  In the manufacture of high-quality bleached pulp, the lignin in the pulp must be removed in a bleaching process.  Chlorine has been used for this purpose but new processes using oxygen reduce water pollution.  Oxygen plus caustic soda can replace hypochlorite and chlorine dioxide in the bleaching process, resulting in lower costs.

In a chemical pulp mill, oxygen added to the combustion air increases the production capacity of the soda recovery boiler and the lime-reburning kiln.  The use of oxygen in black liquor oxidation reduces the discharge of sulfur pollutants into the atmosphere.

Health Care Uses:

In medicine, oxygen is used during surgery, intensive care treatment, inhalation therapy, etc. High standards of purity and handling must be maintained.

Oxygen is typically supplied to hospitals though bulk liquid deliveries, then distributed to usage points.  It assists with respiratory problems, saving lives and increasing patient comfort. 

Small portable air separation units are gaining wide use in homes. Compact non-cryogenic units, typically producing 93% purity medical grade oxygen, are being utilized in small and/or remote hospitals where demand is high enough to make cylinder deliveries a logistical problem but where liquid deliveries are unavailable or very costly. 


In the biological treatment of waste-water, the use of oxygen instead of air permits increased capacity in existing treatment plants.  Injecting oxygen into sewers reduces hydrogen sulfide formation, which results in reduced corrosion and odor.

Ozone is used for drinking water treatment, in particular when alternatives, such as chlorine, are undesirable.

Miscellaneous Uses for Oxygen:

Oxygen has many uses in breathing apparatus, such as those for underwater work and refinery and chemical plant self contained breathing apparatus.  Aquaculture, the cultivation of fish in ponds uses oxygenated water to increase yields.  Liquid oxygen is used in liquid-fueled rockets as the oxidizer for liquid hydrogen and liquid methane

Nitrogen (N2):

Multi-Industry Uses for Nitrogen:

The inert properties of nitrogen make it a good blanketing gas in many applications. Nitrogen blanketing is used to protect flammable or explosive solids and liquids from contact with air. Certain chemicals, surfaces of solids, and stored food products have properties that must be protected from degradation by the effects of atmospheric oxygen and moisture.  Protection is achieved by keeping these items in (under) a nitrogen atmosphere. "Inerting" or "padding" are other terms used to describe displacement of air and nitrogen blanketing.

"Sparging" with nitrogen is the bubbling of nitrogen gas through a liquid to remove unwanted volatile components, including volatile organic compounds (VOC) which may be necessary to meet pollution reduction regulations.

Certain substances are difficult to pulverize or shred because they are tough or the materials will be degraded by the heat generated by mechanical processes such as grinding.  Liquid nitrogen can be used to freeze soft or tough substances prior to their entering a size reduction process.  Cold vaporized nitrogen can be used to keep materials cool (and in an inert atmosphere) during grinding.  Cryogenic grinding is used in diverse applications, including production of finely ground pharmaceuticals, plastics and pigments; and for shredding tires in recycling plants. 

Metals Manufacturing Uses for Nitrogen:

Nitrogen is used to treat the melt in the manufacture of steel and other metals and as a shield gas in the heat treatment of iron, steel and other metals.  It is also used as a process gas, together with other gases for reduction of carbonization and nitriding.

 “Flash” or “fins” on cast metal can be removed by cooling with liquid nitrogen, making them brittle, allowing then to be broken off by mechanical action. 

Manufacturing and Construction Uses:

Shrink fitting is an interesting alternative to traditional expansion fitting.  Instead of heating the outer metal part, the inner part is cooled by liquid nitrogen so that the metal shrinks and can be inserted.  When the metal returns to its normal temperature, it expands to its original size, giving a very tight fit.

Liquid nitrogen is used to cool concrete, which leads to better cured properties.

When construction operations must be done in soft, water-soaked ground such as tunnel construction underneath waterways, the ground can be frozen effectively with liquid nitrogen. Pipes are driven into the ground, liquid nitrogen is pumped through the pipes under the earth’s surface. When the nitrogen exits into the soil, it vaporizes, removing heat from the soil and freezing it.

Chemicals, Pharmaceuticals and Petroleum Uses:

Refineries, petrochemical plants and marine tankers use nitrogen to purge equipment, tanks and pipelines of dangerous vapors and gases (for example, after completing a pipeline transfer operation or ending a production run) and to maintain an inert and protective atmosphere in tanks storing flammable liquids.

Cold nitrogen gas is used to cool reactors filled with catalyst during maintenance work. The cooling time can be reduced substantially.

Cooling reactors (and the materials inside) to low temperature allows better control of side-reactions in complex reactions in the pharmaceutical industry. Liquid nitrogen is often used to provide the necessary refrigeration as it can produce rapid temperature reduction and easily maintain the required cold reaction temperatures.  Reactor cooling and temperature control systems usually employ a circulating low-temperature heat transfer fluid to transfer refrigeration produced by vaporizing liquid nitrogen to the shell of the reactor vessel.  The liquid nitrogen is vaporized in specially-designed heat exchangers that transfer refrigeration to the circulating heat transfer fluid.

Liquid nitrogen is used during well completion to "frac" natural gas bearing rock formations, in particular, tight gas formations, including shale gas and natural gas from coal (coal bed methane) where water based methods should be avoided. Nitrogen is also used to maintain pressure in oil and natural gas producing formations.  Unlike carbon dioxide, which is also used for pressurization, nitrogen has little affinity for liquid hydrocarbons, thus it builds up in and remains in the gas cap.

Nitrogen is used an as inert gas to push liquids though lines, to clear lines and to propel "pigs" through pipelines to sweep out one material before using the line to transport another material.  High pressure N2 is used to stimulate dead wells to force steam for geothermal power plants.

Rubber and Plastics Industry Uses:

Materials become hard and brittle when cooled by to very low temperatures.  This property permits the removal of “flash” or “fins” on cast plastics and rubber.  The castings are cooled by liquid nitrogen and the flash broken off by mechanical action.   

Food and Beverages:

The intense cold in liquid nitrogen allows very rapid freezing of food items, resulting in minimal cell damage from ice crystals and improved appearance, taste and texture. Well-designed cryogenic tunnel and spiral freezers efficiently capture refrigeration from liquid vaporization and from the cold nitrogen gas as it flows through the freezer.

When substances such as vegetable oil and wines are stored, the inert properties of nitrogen can be used to protect against loss of quality by oxidation by expelling any air entrained in the liquid (“sparging”) and protecting liquids in storage tanks by filling the vapor space (“blanketing”).  

Nitrogen (and nitrogen mixed with CO2 and oxygen) is used in transport trucks and in Modified Atmosphere Packaging (MAP) to extend the shelf life of packaged foods by preventing oxidation, mold, insect infestation and moisture migration.

Health Care Uses:

Nitrogen is used as a shield gas in the packing of some medicines to prevent degradation by oxidation or moisture adsorption.

Nitrogen is used to freeze blood, as well as viruses for vaccination. It is also used to freeze livestock semen, which can then be stored for years. The quick freezing resulting from the intense cold minimizes cell wall damage. Liquid nitrogen is also used in some MRI (Magnetic Resonance Imaging) devices to pre-cool the low temperature magnets prior to using much more expensive liquid helium for final cooling.

Liquid nitrogen is used in cryo-surgery to destroy diseased tissue. 

Miscellaneous Uses for Nitrogen:

Nitrogen is used directly as a coolant for severe environmental testing of many items, or as a refrigeration source for chilling circulating dry air. 

    1.  Used as blanketing gas to preserve the shelf life up the oil in a
          bulk storage tank
    2.  Used as modified atmosphere for food packaging to preserve the
          taste and quality


Carbon dioxide (CO2):

Multi-Industry Uses for Carbon Dioxide (CO2):

Carbon dioxide in solid and in liquid form is used for refrigeration and cooling.  It is used as an inert gas in chemical processes, in the storage of carbon powder and in fire extinguishers. 

Metals Industry:

Carbon dioxide is used in the manufacture of casting molds to enhance their hardness. 

Manufacturing and Construction Uses:

Carbon dioxide is used on a large scale as a shield gas in MIG/MAG welding, where the gas protects the weld puddle against oxidation by the surrounding air.  A mixture of argon and carbon dioxide is commonly used today to achieve a higher welding rate and reduce the need for post weld treatment. 

Dry ice pellets are used to replace sandblasting when removing paint from surfaces.  It aids in reducing the cost of disposal and cleanup.

Chemicals, Pharmaceuticals and Petroleum Industry Uses:

Large quantities are used as a raw material in the chemical process industry, especially for methanol and urea production.

Carbon dioxide is used in oil wells for oil extraction and maintain pressure within a formation.. When CO2 is pumped into an oil well, it is partially dissolved into the oil, rendering it less viscous, allowing the oil to be extracted more easily from the bedrock.  Considerably more oil can be extracted from through this process.

Rubber and Plastics Industry Uses:

Flash is removed from rubber objects by tumbling them with crushed dry ice in a rotating drum.

Food and Beverages Uses for Carbon Dioxide:

Liquid or solid carbon dioxide is used for quick freezing, surface freezing, chilling and refrigeration in the transport of foods. In cryogenic tunnel and spiral freezers, high pressure liquid CO2 is injected through nozzles that convert it to a mixture of CO2 gas and dry ice "snow" that covers the surface of the food product.  As it sublimates (goes directly from solid to gas states) refrigeration is transferred to the product.

Carbon dioxide gas is used to carbonate soft drinks, beers and wine and to prevent fungal and bacterial growth.

Liquid carbon dioxide is a good solvent for many organic compounds.  It is used to de-caffeinate coffee.

It is used as an inert “blanket”, as a product-dispensing propellant and an extraction agent. It can also be used to displace air during canning. 

Supercritical CO2 extraction coupled with a fractional separation technique is used by producers of flavors and fragrances to separate and purify volatile flavor and fragrances concentrates.

Cold sterilization can be carried out with a mixture of 90% carbon dioxide and 10% ethylene oxide, the carbon dioxide has a stabilizing effect on the ethylene oxide and reduces the risk of explosion.

Health Care Uses:

Carbon dioxide is used as an additive to oxygen for medical use as a respiration stimulant.

Environmental Uses:

Used as a propellant in aerosol cans, it replaces more environmentally troublesome alternatives.

By using dry ice pellets to replace sandblasting when removing paint from surfaces, problems of residue disposal are greatly reduced.

It is used to neutralize alkaline water.

Miscellaneous Uses for Carbon Dioxide (CO2):

Liquid carbon dioxide's solvent potential has been employed in some dry cleaning equipment as a substitute for conventional solvents.  This use is still experimental - some types of soil are more effectively removed with traditional dry cleaning equipment, and the equipment is more expensive. 

Yields of plant products grown in greenhouses can increase by 20% by enriching the air inside the greenhouse with carbon dioxide.  The target level for enrichment is typically a carbon dioxide concentration of 1000 PPM (parts per million) - or about two and a half times the level present in the atmosphere.

Argon (Ar):

Multi-Industry Uses for Argon:

Argon is the most abundant, and least expensive, truly inert gas.  It is used where a completely non-reactive gas is needed. 

Pure argon, and argon mixed with various other gases, is used as a shield gas in TIG welding ("tungsten inert gas" or gas tungsten arc welding) which uses a non-consumable tungsten electrode, and in MIG ("metal inert gas", also called gas metal arc welding, or wire feed welding) which employs a consumable wire feed electrode.  The function of the shielding gas is to protect the electrode and the weld pool against the oxidizing effect of air.  Pure argon is often used with aluminum.  A mixture of argon and carbon dioxide is often used for MIG welding of ordinary structural steel. 

Plasma-arc cutting and plasma-arc welding employ plasma gas (argon and hydrogen) to provide a very high temperature when used with a special torch.

Metals Manufacturing Uses for Argon:

When steel is made in a converter, oxygen and argon are blown into the molten metal.  The addition of argon reduces chromium losses and the desired carbon content is achieved at a lower temperature.

Argon is used as a blowing gas during manufacture of higher quality steels to avoid the formation of nitrides.

Argon is also used as a shield gas in casting and stirring of ladles.

Argon is used in aluminum manufacture to aid degasification and to remove dissolved hydrogen and particulates from molten aluminum. 

Argon is used as an inert gas in the manufacture of titanium to avoid oxidation and reaction with nitrogen (titanium is the only metal that will burn in a 100% nitrogen atmosphere).

Argon is used in the manufacture of  zirconium.

Manufacturing and Construction Uses for Argon:

Argon is used as a filler gas in fluorescent and incandescent light bulbs.  This excludes oxygen and other reactive gases and reduces the evaporation rate (sublimation rate) of the tungsten filament, thereby permitting higher filament temperature.  Most common of the mixtures is 93% argon and 7% nitrogen at a pressure of 70 kPa (10.15 psig).

It is used as a filler gas between the glass panels of high-efficiency thermo pane windows, as it is not only dry and colorless, but a relatively heavy gas that minimizes heat transmission between panels by slower convective movement of the filler gas between the glass panels in the window.

Electronics Uses:

Argon is used with methane as a filler gas, and as a high purity inert shield gas in the manufacture of silicone and germanium crystals used in the semiconductor industry.

Food and Beverages Uses:

Argon is used in winemaking to displace oxygen in barrels and thus prevent the formation of vinegar.  Similarly, it is used in restaurant, bar and home wine dispensing units to allow storage of opened bottles without degradation of the contents.

Health Care Uses:

Argon is used to perform precise cryosurgery, which is the use of extreme cold, to selectively destroy small areas of diseased or abnormal tissue, in particular on the skin.  Very cold argon is created at the site by controlled expansion of argon gas, and directed to the treatment point using a cryoneedle. This provides better control of the process than earlier techniques employing liquid nitrogen.  A similar technique, cryoablation, is used to treat heart arrhythmia by destroying cells which interfere with the normal distribution of electrical impulses.

Miscellaneous Uses:

Argon is used to provide a protective atmosphere for old documents to prevent their degradation in storage and while on display.

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