Industrial gases are purified elements or chemical compounds manufactured for use in various industrial processes. These gaseous materials are a foundational part of modern commerce and manufacturing operations worldwide. Produced to meet high standards of purity, they are delivered as compressed gas in cylinders or as cryogenic liquids in specialized tanks. Their applications are extensive, supporting diverse sectors from metal fabrication and food preservation to healthcare and electronics.
Defining and Classifying Industrial Gases
Industrial gases include a core group of seven substances: nitrogen, oxygen, argon, carbon dioxide, hydrogen, helium, and acetylene. They are categorized based on their chemical properties, source, and intended use, which dictates their storage and transport methods. Nitrogen and oxygen are the most widely used, as they are the main components of air, and argon is also derived from the atmosphere.
Oxygen is highly reactive and supports combustion, classifying it as an oxidizer. Conversely, nitrogen and argon are inert, meaning they are chemically unreactive. Carbon dioxide is a compound gas used for its low-temperature properties and role in carbonation, while hydrogen is valued for its high energy content. These substances are often considered “bulk gases” due to the large volumes in which they are produced and sold.
Gases are classified based on purity and mixture, such as “specialty gases” and “medical gases.” Medical oxygen, for example, must meet strict purity standards for healthcare use, distinct from industrial-grade oxygen. Industrial gases are stored as compressed gases or liquefied gases (e.g., LIN or LOX), allowing large volumes to be transported in a smaller physical space.
How Industrial Gases Are Produced
Industrial gas production relies on specialized processes that separate or synthesize gases from raw material sources. Atmospheric gases like nitrogen, oxygen, and argon are commonly obtained through Air Separation Units (ASU). This process involves compressing and cooling atmospheric air until it liquefies, followed by cryogenic distillation.
Cryogenic distillation separates the gases based on their unique boiling points. Nitrogen boils off first at its lower temperature, followed by argon, and finally oxygen. The resulting gases achieve the high purity levels necessary for industrial use.
Hydrogen is typically produced through steam methane reforming, a chemical process using high-temperature steam to separate it from natural gas. Carbon dioxide is often recovered and purified as a byproduct from industrial processes, such as ammonia production or fermentation. These methods ensure a reliable supply of specific gases.
Primary Industrial Applications
Industrial gases are integrated into manufacturing, serving roles from modifying atmospheres to powering high-temperature processes. In metal fabrication, oxygen enhances the heat of oxy-fuel cutting and welding torches; acetylene is often the fuel gas. Inert gases like argon and nitrogen act as shielding gases during welding to prevent atmospheric contaminants.
The food and beverage sector utilizes these gases extensively for preservation and processing. Nitrogen is employed in modified atmosphere packaging (MAP) to displace oxygen, slowing spoilage and extending the shelf life of perishable foods. Carbon dioxide is used for flash-freezing food products and for the carbonation of sodas and beer.
In healthcare, gases are used for patient care and medical procedures. Medical oxygen is administered for respiratory support and in emergency situations. Liquid nitrogen is used in cryopreservation for storing biological materials, such as blood and tissue.
The electronics and energy industries rely on industrial gases for high-tech manufacturing and fuel development. Semiconductor fabrication uses high-purity gases like argon and nitrogen to create inert atmospheres, protecting sensitive materials. Hydrogen is increasingly used as a clean energy carrier and is a component in the production of green ammonia for fertilizers and fuels.