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Hydrogen, Nitrogen and Argon Recovery

Hydrogen, Nitrogen and Argon Recovery

Ammonia purge gas recovery unit

Air Liquide Engineering & Construction provides effective solutions for recovering hydrogen, nitrogen and argon from purge gas used in ammonia plants. This can deliver significant cost benefits for clients, especially in regions short in Argon.

Two-stage cooling and condensation

Using a proven cryogenic process, Air Liquide Engineering & Construction enables its customers to recover hydrogen, nitrogen, argon and methane from ammonia plant purge gas. The process involves removing water from the purge gas before it enters the cold box. Thanks to a two-stage exchanger, the feedstock is then cooled and partially condensed. During the vapor phase, the main component released is hydrogen. As the condensation phase begins, the feed is sent to separation pots and distillation columns, where nitrogen, argon and methane are further separated.

The solution features a nitrogen cycle compressor and nitrogen turbine, which ensure the necessary cold production and duty for the distillation.


  • More than 97% of hydrogen is recovered from the purge gas
  • Recovery process delivers cost benefits, especially in remote areas where argon can be expensive

Key figures

  • Recovery: > 97% of hydrogen recovered
  • Capacity: up to 50 tons per day of argon

Hydrogen, Nitrogen and Argon Recovery