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US 12,181,215 B2Granted
Hydrogen liquefier
AssigneeAir Products and Chemicals, Inc.
InventorsPaul Higginbotham, John H. Petrik, Christopher F. Harris
Life of this patent
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Abstract
Hydrogen is liquefied through a process utilizing refrigeration from hydrogen at one, two, or three different pressures as well as a nitrogen refrigeration cycle. One or more stages of catalyst are used to convert ortho-hydrogen to para-hydrogen as the hydrogen is cooled and liquefied. Subcooled liquid hydrogen feeds the final stage of ortho-hydrogen to para-hydrogen conversion to reduce or eliminate vaporization of the hydrogen during the exothermic ortho-hydrogen to para-hydrogen conversion.
Claims16
A process for liquefying hydrogen, the process comprising:
- cooling a hydrogen feed comprising ortho-hydrogen and para-hydrogen by indirect heat exchange to form a cold hydrogen stream;
- expanding at least a portion of the cold hydrogen stream to produce a partially vaporized intermediate-pressure hydrogen stream;
- separating the partially vaporized intermediate-pressure hydrogen stream to produce an intermediate-pressure hydrogen vapor stream and an intermediate-pressure hydrogen liquid stream;
- expanding at least a portion of the intermediate-pressure hydrogen liquid stream to produce a partially vaporized low-pressure hydrogen stream;
- warming by indirect heat exchange the partially vaporized low-pressure hydrogen stream or a stream derived from the partially vaporized low-pressure hydrogen stream to produce a warmed low-pressure hydrogen stream;
- warming by indirect heat exchange the intermediate-pressure hydrogen vapor stream to produce a warmed intermediate-pressure hydrogen stream;
- compressing and combining the warmed low-pressure hydrogen stream, the warmed intermediate-pressure hydrogen stream, and a warmed medium-pressure hydrogen stream to produce a recycle stream;
- cooling by indirect heat exchange the recycle stream to produce a cooled recycle stream;
- expanding at least a portion of the cooled recycle stream to produce a first cold medium-pressure hydrogen stream;
- and
- warming by indirect heat exchange the first cold medium-pressure hydrogen stream to produce the warmed medium-pressure hydrogen stream;
- wherein a cooling duty for cooling the hydrogen feed by indirect heat exchange is provided at least in part by the intermediate-pressure hydrogen vapor stream;
- wherein the warmed intermediate-pressure hydrogen stream is compressed prior to combining with the warmed medium-pressure hydrogen stream.
10 more elements
Dependencies are inferred from the claim text.