IIR document

Large scale commercial liquid hydrogen plants.

Author(s) : NAHMIAS D.


Although hydrogen was liquefied in 1898, the first commercial scale plants were not built until the late 1950s for a secret US Air Force project. Plants exist today in North America, Japan and Europe, producing 172 tonnes/day in the US alone. Two hydrogen sources are in general use, caustic chlorine production and steam-natural gas reforming. Both have natural impurities with associated risks of freeze-up and safety. Liquefaction requires a purity in the final feed of 99.999%. Typical plants combine catalytic and pressure swing adsorption purification methods. Most plants use a nitrogen precooled liquefaction cycle with expansion machines and a Joule-Thomson valve which can be used only below the inversion temperature of 204 K. A further problem is to convert the ortho state of available hydrogen molecules into the para state requiring less liquefaction energy. Details are also given on storage containers, insulation, and equipment for both low and high pressure systems. D.W.H.

Available documents

Format PDF

Pages: 322-330


  • Public price

    20 €

  • Member price*


* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).


  • Original title: Large scale commercial liquid hydrogen plants.
  • Record ID : 1993-0656
  • Languages: English
  • Source: New challenges in refrigeration. Proceedings of the XVIIIth International Congress of Refrigeration, August 10-17, 1991, Montreal, Quebec, Canada.
  • Publication date: 1991/08/10


See other articles from the proceedings (391)
See the conference proceedings