Cryogenic air separation is a process that cools air to extremely low temperatures to liquefy its components, allowing for the separation of oxygen, nitrogen, argon, and rare gases through distillation.

The process involves compressing and purifying air, cooling it to a liquid state, separating its components by distillation, and then delivering purified gases for industrial use.

The primary gases produced are oxygen, nitrogen, and argon, along with rare gases such as neon, krypton, and xenon.

Industries such as steel, energy, glass, chemicals, mining, and metals depend on cryogenic air separation for a steady and high-purity gas supply.

Cryogenic air separation plants provide an efficient solution for producing large volumes of high-purity industrial gases. Key benefits include continuous oxygen and nitrogen production, the ability to produce gaseous product and backup liquid from a single air separation unit, and customized plant designs that support long-term operating efficiency and reliable gas supply.

Ambient air contains moisture, carbon dioxide, and other impurities that can freeze or interfere with the cooling and separation process. Compression increases air density, while purification removes these contaminants to ensure safe and efficient gas production.

After purification, the air is cooled to cryogenic temperatures—often below -300°F—causing it to condense into a liquid. This step is essential to prepare the air for separation, since different gases liquefy at different temperatures

Using advanced distillation columns, the liquefied air is separated into nitrogen, oxygen, and argon. Each gas has a distinct boiling point, allowing them to be isolated through careful temperature control.

The gases undergo a final purification step to meet industry or customer-specific purity standards. They are then stored in liquid or gaseous form and delivered directly through pipelines or used onsite.

Cryogenic air separation is typically well-suited for facilities requiring large continuous volumes of industrial gases, high purity levels or simultaneous production of oxygen, nitrogen and argon. Non-cryogenic technologies, such as pressure swing adsorption (PSA) and membrane separation, may be better suited for smaller-scale applications, operations with lower purity requirements or facilities that only need oxygen or nitrogen rather than multiple industrial gases. The best choice depends on gas volume, purity, operating costs and facility needs.

Air separation plant capacity depends on several factors, including required gas production volumes, oxygen and nitrogen purity specifications, delivery pressures, demand fluctuations and anticipated future growth. Site conditions, energy availability and whether multiple gases are needed also influence plant design. UIG evaluates these requirements to develop an appropriately sized cryogenic ASU system.

The best solution depends on your volume requirements, operational preferences, and financial strategy. UIG works with you to develop a tailored gas supply plan.

UIG provides custom ASU design, engineering, construction and operational support for industrial facilities across North America. With experience delivering plants ranging from less than 100 to more than 2,000 tons of product per day, UIG develops solutions tailored to each customer’s gas volume, purity and operational requirements.

UIG offers flexible supply options, from turnkey plants to DIY solutions, ensuring that you get a gas supply model that aligns with your business needs – not the supplier’s bottom line.

UIG, a wholly owned subsidiary of Nucor Corporation, designs, builds, and operates air separation plants across North America.

We offer plant design, construction, operation, maintenance, and consulting services to ensure your industrial gas supply is efficient and cost-effective.

Contact us to discuss your gas supply needs, and our team will help you determine the best solution for your business.