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Large Air Seperation Unit

Large Air Separation Unit

Production of large quantities of oxygen and nitrogen

Used in a wide variety of fields, large air separation units (ASU) produce high purity oxygen, nitrogen, argon and rare gases through a combination of adsorption purification, cryogenic distillation and internal compression of high pressure products.

A comprehensive portfolio

Depending on customers' needs, Air Liquide Engineering & Construction provide oxygen, nitrogen, argon and rare gases production plants, ranging from units with a capacity of a few hundred tons per day of oxygen to Mega ASU multi-train complexes capable of producing more than 20 000 tons per day of oxygen. The company's portfolio includes different technical solutions and different prefabrication (packaging) solutions to address customer's optimization criteria.

Typical applications include smelters, basic oxygen furnaces, blast furnaces and electric arc furnaces in metals industry, methanol and gas to liquid projects for natural gas monetization and energy conversion, ethylene oxide & ammonia production in Chemical industry, and integrated gasification combined cycle and oxy-combustion in Clean power.


  • Extensive design and construction experience including Air Liquide best in class safety standards, operating teams feed back ensuring high reliability & secured performances
  • Large portfolio offer adapted to a wide range of industries
  • Optimized plants design depending on specific projects economics, geography, products, specifications, energy costs and customer process integration potentials

Key figures

  • Production: oxygen up to 99.8% purity and 100 bar
  • More than 1200 references among which more than 75 units larger than 2000 tpd
  • Capacity: up to 6 000 tons per day

Large Air Separation Unit