What Are Cryogenic Gases and How Are They Used in Industry?

Cryogenic gases are gases that have been cooled and liquefied at extremely low temperatures, typically below -150°C (-238°F). At those temperatures, gases like nitrogen, oxygen, argon, helium, and hydrogen compress into liquid form, which makes them far easier to store and transport in large volumes. One liter of liquid nitrogen, for example, expands to roughly 700 liters of gas at room temperature. That density is exactly what makes cryogenic supply practical for industries that consume gas at scale.

How They’re Produced

Most industrial cryogenic gases come from air separation. Air is filtered, compressed, cooled to cryogenic temperatures, and fed into a distillation column where nitrogen, oxygen, and argon separate based on their different boiling points. The resulting liquids are stored in insulated tanks and distributed by tanker truck to facilities that use them directly as liquids or vaporize them for use as gas. Helium is the exception, extracted as a byproduct of natural gas processing rather than from air.

Liquid Nitrogen

Nitrogen is the most widely used cryogenic liquid across industry. Its applications span an enormous range precisely because it’s inert, widely available, and cheap to produce relative to other cryogens.

In food processing, liquid nitrogen is the workhorse of rapid freezing. Its boiling point of -196°C produces freezing speeds that mechanical systems can’t match, preserving cellular structure, texture, and moisture content in meat, seafood, baked goods, and prepared foods. In manufacturing, it cools cutting tools during machining operations, extending tool life and improving surface finish on difficult materials. Shrink fitting uses it to contract metal components enough to slide into tight-tolerance assemblies, where they lock permanently as they return to ambient temperature. Semiconductor fabrication depends on nitrogen for purging process chambers and creating inert environments throughout wafer production.

Liquid Oxygen

Liquid oxygen is a powerful oxidizer with applications concentrated in steel production, aerospace, and medical supply. In steelmaking, oxygen blown into molten iron accelerates the conversion to steel by burning off excess carbon rapidly. Liquid oxygen is the most common oxidizer propellant for rockets, where its energy density makes it well suited to the demands of launch vehicles. In medical settings, it feeds oxygen supply systems in hospitals and for home respiratory therapy, stored as liquid for density and vaporized at point of use.

Liquid Argon

Argon’s complete chemical inertness makes it valuable wherever a shielding atmosphere is required. Welding is the most visible application. TIG and MIG welding of aluminum, titanium, and stainless steel use argon to shield the melt pool from atmospheric oxygen and nitrogen, which would introduce defects and weaken the joint. Metal additive manufacturing depends on it for the same reason. Argon is also used in steel refining through the Argon Oxygen Decarburization process, where it’s blown into molten steel to reduce carbon content without over-oxidizing the melt.

Liquid Helium

Helium reaches liquid form only at -269°C, just four degrees above absolute zero, which makes it uniquely suited to applications requiring extreme cold. MRI machines use liquid helium to cool superconducting magnets to operating temperature, a function that no other practical cryogen can perform. Nuclear magnetic resonance instruments, particle accelerators, and other scientific equipment rely on it for the same reason. Helium supply is geographically concentrated and structurally limited, which makes it one of the more strategically sensitive industrial gases in use today.

Handling and Safety

The same properties that make cryogenic liquids useful create handling considerations that require attention. Contact with skin causes rapid frostbite. The expansion ratios from liquid to gas mean that even a small spill in an enclosed space can displace oxygen quickly. Liquid oxygen, as a powerful oxidizer, makes organic materials it contacts highly flammable. Proper PPE, ventilated storage, and oxygen monitoring in areas where cryogens are used are standard requirements across all applications.

Forge Forward with nexAir

nexAir supplies liquid nitrogen, oxygen, argon, helium, and other cryogenic gases across a wide range of industries, with the KnowHow™ to match supply method, storage configuration, and purity grade to what each application requires. Talk to your local nexAir team and Forge Forward with a cryogenic supply program built around your operation.