Hydrogen Liquefaction Patents: Who Leads, Where the Gaps Are 2026
- One assignee dominates the ranked leaders. the leader holds 37 records against a fifth-place count of 3 and a tenth-place count of 2, a steep drop-off rather than a gradual one.
- Filing has cooled from its 2022 peak. activity peaked at 10 records in 2022, and the tracked 2021→2024 span shows an 8-to-4 decline, a 50% fall over three years.
- Claims cluster almost entirely in one IPC class. F25J gas liquefaction and separation covers 91.5% of the 71 records in scope, leaving materials and refrigeration classes as comparatively thin secondary filings.
Filing growth compares 2021 (8 records) with 2024 (4) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field.
What this landscape covers
Hydrogen liquefaction patenting spans two connected problems: the thermodynamic cycle that removes heat from hydrogen feed gas down to below 20 K, and the ortho-para conversion step needed to stop the para-hydrogen fraction from re-equilibrating and boiling off liquid product in storage. This dataset tracks 71 published records filed against both problems together, including precooling architecture, expander performance, boil-off management and the catalysts used to accelerate spin-isomer conversion. Family counting is used throughout so that continuation filings and multi-jurisdiction copies of the same invention are not double counted.
Most records sit in gas liquefaction and separation claims, with a much smaller secondary cluster in refrigerant materials and catalyst compositions. The picture is one of concentrated cycle-level IP held by a small number of established engineering firms, alongside a long tail of single- or few-filing entrants from universities and newer process developers.
Filing trend and technology composition
Two views of the same 71-record dataset: how filing volume has moved year over year, and how those records distribute across IPC subclasses. Because a single record can carry several IPC codes, the class shares below sum to more than the record total.
Filing trend, 2017–2026
Filings rose to a peak of 10 records in 2022 before falling back; the tracked 2021-to-2024 window went from 8 to 4 records, a 50% decline. Note that 2025 and 2026 are still incomplete because publication typically lags filing by around 18 months, so the most recent years should not be read as a continued drop.
IPC subclass composition
F25J (gas liquefaction and separation) appears in 91.5% of the 71 records, confirming that cycle-level claims dominate the field. C09K (materials, 31.0%) is the next-largest cluster, covering refrigerant and catalyst compositions, while classes tied to electrolysis, power supply and gas turbines each appear in under 6% of records.
Shares are the percentage of the 71 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Hydrogen Liquefaction and Ortho Para Conversion with Eureka
This page is one run against one query. Ask Eureka your own question about hydrogen liquefaction and ortho para conversion and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
US20240255216A1 — Method and plant for hydrogen liquefaction (ENGIE, filed 2024)
Method for hydrogen liquefaction comprising at least one precooling step, wherein a hydrogen feed flow is cooled by a first refrigerant, a cooling step, wherein the hydrogen feed flow is cooled by a second refrigerant, and a step of expanding the hydrogen feed flow. Each of the first and second refrigerants is successively subjected to at least one compression and to at least one expansion in order to cool it, and a liquid phase of the first refrigerant cools the second refrigerant between at least three stages of said compression so that the second refrigerant does not exceed a temperature of 150 K, optionally 113 K, during said compression of the second refrigerant.The staged-compression temperature ceiling on the second refrigerant is the distinguishing limitation — it constrains cycle designers who need to keep compression duty below that threshold.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20180347897A1 | Large-scale hydrogen liquefaction by means of a high pressure hydrogen refrigeration cycle combined to a nove… | 38 |
| 2 | US20180320957A1 | Low-temperature mixed–refrigerant for hydrogen precooling in large scale | 22 |
| 3 | US20190063824A1 | Novel production equipment and production method of liquefied hydrogen and liquefied natural gas | 21 |
| 4 | US20220221220A1 | Methods and systems for hydrogen liquefaction | 16 |
| 5 | EP3368630A1 | Low-temperature mixed–refrigerant for hydrogen precooling in large scale | 16 |
| 6 | US20100083695A1 | Process for liquefying hydrogen | 16 |
| 7 | US20180313604A1 | Hydrogen-neon mixture refrigeration cycle for large-scale hydrogen cooling and liquefaction | 14 |
| 8 | EP3163236A1 | Large-scale hydrogen liquefaction by means of a high pressure hydrogen refrigeration cycle combined to a nove… | 14 |
| 9 | CN116608644A | 一种采用复叠制冷和分离式连续转化器的氢液化系统 | 10 |
| 10 | US11391511B1 | Methods and systems for hydrogen liquefaction | 10 |
Citation counts reflect influence within this searched corpus and favour earlier-filed records; they are not a measure of current commercial importance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the filing pattern signals
Reading the trend, the class composition and the citation table together points to a field where cycle architecture is well-claimed but several adjacent problems are not.
One filer sits well ahead of the ranked field
The leading assignee holds 37 records, against 3 at fifth place and 2 at tenth place among the 15 companies in the ranking. That drop-off means most of the ranked leaders are single-digit filers, so the field outside the top position is comparatively open.
Gas liquefaction and separation claims are the default filing target
Nearly every record in scope touches F25J, meaning cycle configuration, precooling and expansion-stage claims are the most heavily occupied part of the field. New cycle-level filings should expect dense prior art here.
Catalyst and refrigerant material claims are a distant second
C09K appears in under a third of records, and classes tied to electrolysis (C25B), power supply (H02J) and gas turbines (F02C) each sit under 6%. That leaves ortho-para catalyst formulation and cycle-integration-with-power claims comparatively thin relative to the cycle-level crowding above.
Volume has pulled back from its 2022 peak
Filing peaked at 10 records in 2022 and the tracked 2021-to-2024 window shows a 50% decline. The most recent two years are still filling in given typical publication lag, so this should be read as a pullback from a peak, not a confirmed multi-year decline.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to hydrogen liquefaction and ortho para conversion, with the prior art for and against each one.
Who holds the ground, and where it opens up
The ranked assignee list is dominated by one established cryogenic engineering firm, with universities, national research bodies and newer process-technology companies filling out a long tail of low-volume filers.
A single incumbent dominates cycle-level claims
The top-ranked assignee's record count is more than ten times the fifth-place count, indicating a portfolio built over years of large-scale liquefaction plant engineering rather than a recent filing push.
Most ranked filers hold only a handful of records
From fifth place down, counts sit at single digits, spanning universities, research foundations and process-technology start-ups. This spread suggests active but fragmented experimentation rather than a settled competitive set.
Co-filing is rare and concentrated
Only three co-assignee pairs appear in the dataset, the strongest linking an established engineering firm with a technical university, which points to sponsored academic research feeding directly into an incumbent's filings.
| Assignee | Recent year | YoY |
|---|---|---|
| Linde AG | 0 | — |
| JTURBO ENG & TECH LLC | 0 | — |
| Hangzhou Zhongtai Cryogenic Technology Corp. | 0 | — |
| Technische Universitat Munchen | 0 | — |
| GDF Suez SA (Engie) | 0 | — |
| University of Central Florida Research Foundation Inc. | 0 | — |
| BRISE CHEM PTE LTD | 0 | — |
| JGC Corp | 0 | — |
Where to take this analysis
The dataset points to a field with a dominant cycle-level incumbent and thinner claim density in materials and integration branches. The next steps depend on whether the goal is freedom-to-operate, whitespace identification, or tracking a specific competitor.
Run a freedom-to-operate check on cycle claims
Given how densely F25J is claimed, any new precooling or expansion-stage design should be checked against the most-cited records before development spend commits to a specific configuration.
Explore claims in EurekaMap the catalyst and materials branch separately
C09K's lower filing density suggests ortho-para catalyst formulation claims are worth a dedicated search pass, since they sit outside the crowded cycle-configuration space.
Search materials claims in EurekaTrack the leading assignee's active filings
With one assignee holding the majority of ranked records, monitoring its continuation and new filings gives an early signal of where cycle-level claim boundaries are moving.
Set up assignee tracking in EurekaCommon questions about this landscape
One assignee leads the ranked field with 37 records, well ahead of the rest of the 15 companies in the ranking, where fifth place holds only 3 records and tenth place holds 2. This gap indicates a portfolio built up over sustained large-scale plant engineering work rather than a recent surge of filings. The remaining ranked assignees are a mix of universities, national research bodies and smaller process-technology firms, each with single-digit record counts, so competitive pressure outside the leader is comparatively light.
Filing volume peaked at 10 records in 2022 and the tracked 2021-to-2024 window shows a decline from 8 to 4 records, a 50% drop over three years. However, publication typically lags filing by around 18 months, so the 2025 and 2026 figures in this dataset are still incomplete and should not be read as confirming a continued decline. The safest reading is that filing has pulled back from a 2022 peak, with the most recent trend still unresolved.
Liquid hydrogen naturally contains a mix of ortho and para spin isomers, and if the para fraction is not raised before storage the gas continues converting after liquefaction, releasing heat that causes boil-off losses. Patents in this space cover the catalysts and process stages used to drive that conversion during liquefaction rather than after it. In this dataset, catalyst and materials-related claims (IPC class C09K) appear in 31.0% of the 71 records, a much smaller share than the 91.5% covering the core liquefaction cycle itself, suggesting catalyst-specific claims are less crowded than cycle-configuration claims.
Among receiving offices in this dataset, the United States leads with 16 filings, followed by the European Patent Office with 14 and the WIPO PCT route with 9. Australia, China and India each show smaller counts of 5 to 8 filings. This spread indicates that applicants are pursuing protection across major industrial and energy markets rather than concentrating filings in a single jurisdiction.
The most-cited record in this dataset is US20180347897A1, describing a large-scale hydrogen liquefaction cycle combining a high-pressure hydrogen refrigeration cycle with a single mixed-refrigerant precooling stage, cited 38 times. It is followed by related mixed-refrigerant precooling filings cited 22 and 16 times respectively. High citation counts inside a searched corpus tend to favour older, earlier-filed records, so these figures reflect influence on later filings rather than current commercial significance.
Research Hydrogen Liquefaction and Ortho Para Conversion in depth with Eureka
Go past this page: query the whole hydrogen liquefaction and ortho para conversion corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.