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Ammonia Purge Gas Applications

Purification and recovery of hydrogen in ammonia synthesis loops

Built on an extensive history of fiber spinning and polymer technology, Air Liquide Advanced Separations offers some of the most robust membranes for the harshest conditions.


Air Liquide Advanced Separations’ (ALaS) membranes are specially designed to recover high concentrations of hydrogen while rejecting inert gases from ammonia purge gas streams. With superior chemical resistance, high temperature tolerance, and the ability to withstand transmembrane pressures greater than 90bar, ALaS membranes are the most selective commercially available polymeric membranes.

The Technology

Hydrogen (H2) is selectively separated from nitrogen (N2) by permeation through a polymeric hollow fiber membrane. The driving force is the partial pressure difference across the membrane for H2, N2 and other gas components. H2 is the “fast” gas, whereas methane (CH4) and N2 are “slow” gases. The pressurized feed gas enters the bundle from the shell side; the nitrogen, methane and argon stay under pressure while the H2 is collected at a lower pressure from the fiber bore.

Flow Schematic: Hydrogen Recovery in Ammonia Synthesis 


  • Minimized inert gas purge and hydrogen losses
  • Increased ammonia production & decreased natural gas consumption
  • No upstream water wash unit required
  • Low CAPEX, minimal OPEX and no moving parts

01 Reliable

  • ALaS is the only manufacturer of polymeric membranes that can tolerate high concentrations of dry ammonia

02 High Performance

  • Our membranes sustain the highest level of inert rejection paralleled with the highest level of hydrogen recovery

Request information

Paul Terrien, Director, Hydrogen and Helium Membrane Business Units

Contact by phone +1 781-228-3261

Related applications

Air Liquide Advanced Separations’ (ALaS) hollow fiber membranes offer the most robust solution for hydrogen purification needs.

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