Introduction to Industrial Gases
 Sources, Properties, Uses, Applications

The term "Industrial Gases" refers to gases which are produced in relatively large quantities by industrial gases companies for use in a variety of industrial manufacturing processes.  They are produced and supplied in both gas and liquid form.  They are transported to customers in cylinders, as bulk liquid, or as pipeline gases. 

• Common atmospheric gases:             Nitrogen,  Oxygen  and  Argon

• Air-derived "rare gases":                      Neon,  Krypton  and  Xenon

• Natural gas-derived gases:                  Methane  and  Helium

• Products from methane reforming:   Hydrogen, Carbon monoxide, Carbon dioxide

Industrial Gases Are Valued for Their Physical and Chemical Properties:

Applications and Uses of Common Industrial Gases:

Gases Which Are Valued for Reactivity:

Oxygen (O2):  Oxygen is valued, above all, for its reactivity.  Oxygen enrichment of air is used to increase the amount of oxygen available for combustion or biological activity. Biological activity enhancement includes medical applications and environmental applications such as industrial waste water and sanitary sewage treatment systems.

Oxygen enrichment of air in industrial processes increases reaction rates, which may permit greater throughput in existing equipment or the ability to reduce the physical size of equivalent capacity new equipment. 

Another benefit of oxygen enrichment versus use of plain air is energy savings and due to a reduction in the amount of nitrogen and other gases passing through a furnace or through a chemical process.  Reducing inert gases which would otherwise have to be compressed or heated, can reduce energy consumption due to a decrease in gas compression requirements or a reduction in the amount of fuel required to make a given amount of product.  Reducing the amount of hot gases vented to the atmosphere from combustion processes may also decrease the size and cleanup costs associated with stack gas cleanup systems.

Oxygen’s reactivity is commonly used in metals processing (steel, copper, lead, zinc), glass furnaces, cement kilns, chemical manufacture, sewage treatment, pulp and paper manufacture, welding and cutting of metals, and medical oxygen. 

Hydrogen (H2), methane (CH4), and carbon monoxide (CO):  These gases react with oxygen and other materials in combustion processes and in various chemical production processes.  These gases are often produced for use as raw materials for chemical manufacturing processes. 

Hydrogen is used in refineries to remove sulfur and to chemically restructure (reform) hydrocarbons.  It is used to hydrogenate unstable, unsaturated hydrocarbons and fatty acids in animal and vegetable oils.  It is also used as a reducing agent in steel and zinc manufacture – removing oxygen that would react with and degrade the product. 

Methane (CH4):  Methane is naturally produced by biological activity.  It is the primary component of “natural gas”, which is used as both a fuel and as a chemical raw material.

Carbon monoxide (CO) is co-produced with hydrogen by steam reforming plants using methane or other hydrocarbons as feedstock.  It is a raw material for making monomers and other chemical products.

Carbon Dioxide (CO2) does not react with oxygen, but will combine with other elements and compounds. Thus its commercial uses include raw material for various chemical processes and as a neutralizing agent for alkaline materials. 

Gases Which Are Valued for Inertness:

Inertness is a somewhat relative term and concept. Some industrial gases (helium, neon, argon, krypton and xenon) are almost totally inert. Helium and argon are commercially available in relatively large quantities.  The more expensive inert gases such as neon, krypton and xenon have much more limited availability.

Many applications requiring an "inert gas" use nitrogen or carbon dioxide for that purpose.  While not truly inert, they have very little reactivity under normal pressure and temperature conditions and are much less expensive than the other "inert" gases. 

The naturally inert or "noble" gases are members of "Group 18" of the Periodic Table.  They have their outermost, or valence, electron shell complete (with two electrons for helium and eight for the other gases).  The "noble" gases are all monatomic.  

Nitrogen (N2) and Argon (Ar) are commonly used in the gaseous form to shield potentially reactive materials from contact with oxygen.  Nitrogen will react with oxygen at very high temperatures, as in furnaces, but it is inert under most other circumstances.  Argon, helium, neon, krypton and xenon are "noble gases" that are extremely inert under all conditions.

Carbon Dioxide (CO2) is also used as an inert gas in some applications, in particular for fire fighting.  Both portable fire extinguishers and total room fire extinguisher systems use carbon dioxide to extinguish flames without damage to materials and without the risk of short circuiting electrical systems or damaging electronic components.

Applications which require the property of inertness include blanketing of storage tanks and vessels that contain flammable liquids or powders; blanketing of materials that would degrade in air, such as vegetable oil, spices, and fragrances; maintaining controlled atmospheres for industrial activities such as growing silicon and germanium crystals, manufacturing precision electronic devices, welding and soldering; preventing light bulb filaments from burning; retarding evaporation of filaments with high molecular weight inert gases; sparging (bubbling a gas through  liquids) to reduce the amount of oxygen or other gases dissolved in a liquid; filling insulating spaces between multi-pane windows; and creating non-flammable lighter-than-air devices such as balloons and dirigibles (using helium instead of hydrogen). 

Liquefied Gases Which Are Valued as a Source of Intense Cold:

Liquid Nitrogen (LIN, LN) and Liquid Carbon Dioxide (LCO2) are valued because they combine intense coldness with inertness.  This combination is employed to rapidly chill and freeze food items (meat, fruit, vegetables, baked goods, and dairy products).  Rapid freezing results in very small ice crystals, less cellular damage, and better-quality products after thawing. 

The intense cold produced by these products can also be used to make normally soft and flexible materials hard and rigid, allowing them to be ground, machined or fractured.

Physical Properties Tables for Industrial Gases:

Material Safety Data Sheets - MSDS - for Industrial Gas Products: