Nitrogen Rejection Unit Patents: Top Companies & Trends 2026
- 55.5% of all 499 records sit with just five assignees, with the leader alone holding 99 records — a field with a narrow group of entrenched holders.
- F25J cryogenic separation covers 60.7% of records, dwarfing membrane and adsorption routes classified under B01D at 20.6% — the claim space is heavily weighted toward distillation.
- Filings dipped -5% from 2021 to 2024 (22 to 21 records) after peaking at 39 in 2019, suggesting a mature core process rather than a fast-moving one.
Filing growth compares 2021 (22 records) with 2024 (21) — 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. Top-5 share is the combined record count of the five largest assignees divided by all 499 records in scope (CR5), not by the ranked leaders only.
What this patent landscape covers
Nitrogen rejection units strip nitrogen from produced natural gas so the remaining stream meets pipeline or LNG feed specifications. This landscape covers 499 published records filed between 2015 and mid-2026 that describe cryogenic double-column distillation, membrane separation, pressure swing adsorption and related methods for separating methane from nitrogen vent streams.
The dataset is drawn from records where the claims or description reference nitrogen rejection, cryogenic nitrogen removal or methane-nitrogen separation alongside a named process route such as double-column distillation, membrane nitrogen removal or pressure swing adsorption. Patent families, rather than raw document counts, are the more reliable unit for judging how much of this space is genuinely claimed, since families neutralise continuation filings and multi-jurisdiction duplicates.
Filing trends and technology composition
Nitrogen rejection unit filings span cryogenic separation, membrane and adsorption routes, tracked here across 499 records published between 2015 and mid-2026.
Filing activity has plateaued since its 2019 peak
Filings rose from 12 in 2017 to a peak of 39 in 2019, then settled into a narrower band; 2021's 22 records fell to 21 by 2024, a -5% change over that span. 2025 and 2026 figures are still incomplete because publication typically lags filing by around 18 months.
F25J dominates; purification and catalysis classes trail well behind
F25J (gas liquefaction & separation) covers 60.7% of the 499 records, more than three times the next-largest class, B01D (separation processes) at 20.6%. C10L, C07C and C01B each sit in the 14-16% range, while C10K (purifying fuel gases) covers just 2.2% — the thinnest slice of documented claim activity in this set.
Shares are the percentage of the 499 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Nitrogen Rejection Units with Eureka
This page is one run against one query. Ask Eureka your own question about nitrogen rejection units and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative filing and most-cited prior art
Hydrogen production with CO2 capture
A steam methane reforming process for producing a hydrogen product while capturing CO2 from the process. Steam and a hydrocarbon are reformed in a catalytic reformer. The reformate is separated by pressure swing adsorption to form the hydrogen product and a PSA tail gas. The tail gas is returned to the reformer as a fuel. The fuel is combusted with synthetic air where the synthetic air is formed by combining a portion of the flue gas with industrial grade oxygen. The flue gas consists essentially of CO2 and H2O. The H2O is condensed out of another portion of the flue gas to form an essentially pure CO2 product.Filed by Air Products and Chemicals; granted 2013-07-30.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5462583A | Absorption process without external solvent | 141 |
| 2 | US20060249020A1 | Separation process using microchannel technology | 137 |
| 3 | US4717407A | Process for recovering helium from a multi-component gas stream | 131 |
| 4 | US4690690A | Steam reforming hydrocarbons | 125 |
| 5 | US5089034A | Process for purifying natural gas | 119 |
| 6 | US5224350A | Process for recovering helium from a gas stream | 114 |
| 7 | US7250074B2 | Process for separating nitrogen from methane using microchannel process technology | 106 |
| 8 | US20050045030A1 | Process for separating nitrogen from methane using microchannel process technology | 101 |
| 9 | US20050217479A1 | Helium recovery from gas streams | 93 |
| 10 | US4451275A | Nitrogen rejection from natural gas with CO2 and variable N2 content | 93 |
Citation counts favour older filings within this corpus and should be read as a signal of influence, not current relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Beyond the raw counts, a few patterns stand out for anyone deciding where to file, litigate or license around nitrogen rejection technology.
A narrow group holds the core process
The leading assignee alone accounts for 99 records, and the top five combined for 55.5% of the 499 records in scope. That level of concentration means freedom-to-operate reviews should start with a small set of holders rather than a broad field scan.
Cryogenic distillation still anchors the field
F25J claims outweigh every alternative route combined among the classes tracked here. Membrane (B01D, 20.6%) and fuel-gas purification (C10K, 2.2%) routes exist but are documented far less densely, which is where design-around opportunities tend to concentrate.
Activity has plateaued, not collapsed
After peaking in 2019, filings settled into a narrower band; 2021's 22 records became 21 by 2024, a -5% change. That pattern reads as a mature process with occupied claim space rather than one still being actively contested.
Filing is concentrated in US, EPO and Canada
The United States receives the largest share of filings at 152, ahead of Europe at 77 and Canada at 70. WIPO/PCT filings at 43 suggest a meaningful minority of applicants are pursuing multi-jurisdiction protection from the outset.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to nitrogen rejection units, with the prior art for and against each one.
Leaders, momentum and where the gaps sit
Ninety companies appear in the assignee ranking behind these 499 records, but activity is far from evenly spread — a handful of industrial gas and engineering firms hold most of the documented claim space.
One filer anchors the field
The leading assignee's 99 records is more than four times the fifth-place holder's 24, underscoring how much of the core cryogenic separation process is claimed by a single filer rather than spread across the field.
A steep drop-off after the leaders
By tenth place, filing counts have fallen to 13 records, and the top ten combined still only reach 70.9% of the 499 records in scope — meaning nearly 30% of filings are spread across a long tail of smaller and single-filing entrants.
Momentum has shifted to a smaller set of filers
Several of the historically largest assignees show no filings in the latest year, while at least one mid-tier filer posted a 100% year-on-year increase off a small base. That shift suggests the most active filers today are not always the same as the historical leaders.
| Assignee | Recent year | YoY |
|---|---|---|
| ConocoPhillips | 2 | +100% |
| BCCK Holding Co | 1 | — |
| Air Products and Chemicals, Inc. | 0 | — |
| ExxonMobil Upstream Research Company | 0 | — |
| Butts Properties | 0 | — |
| Siluria Technologies | 0 | — |
| Lummus Technology Inc | 0 | — |
| Imperial Chemical Industries | 0 | — |
Turning this landscape into a filing or licensing decision
The dataset points to where the core process is claimed and where a first claim could still stand. Turning that into a defensible filing or a clean freedom-to-operate opinion means going record by record.
Check freedom to operate against the top holders
With 55.5% of the 499 records in scope held by five assignees, a targeted claim chart against those filers is more efficient than a broad field scan.
Run a claim comparison in EurekaTest a design-around in the thinner classes
C10K and C10G together cover a small share of records relative to the F25J core, leaving room to draft claims around fuel-gas purification or catalytic vent treatment.
Draft and stress-test claims in EurekaCommon questions on nitrogen rejection unit patents
Filing activity is concentrated at the top of the ranking: the leading assignee alone accounts for 99 of the 499 records in scope, and the top five combined hold 55.5% of all records. The top ten combined reach 70.9%, which leaves a long tail of single-digit filers among the 90 companies the ranking covers. This concentration reflects decades of process patents around cryogenic double-column distillation held by a small number of industrial gas and engineering firms.
Cryogenic gas liquefaction and separation, classified under F25J, covers 60.7% of the 499 records in scope, making it by far the dominant documented approach. Separation processes such as membranes and adsorption (B01D) trail at 20.6%, and purifying-fuel-gases claims (C10K) are the thinnest slice at 2.2%. Because a single record can carry multiple IPC classes, these shares add up to more than 100%, and they should be read as claim density rather than exclusive categories.
Filings peaked in 2019 at 39 records and have since settled into a lower, fairly stable range: 22 records in 2021 versus 21 in 2024, a -5% change over that three-year span. That is a modest dip rather than a clear slowdown, and it should not be read as declining interest given how the most recent two years are still filling in. Because publication lags filing by roughly 18 months, 2025 and 2026 figures will rise as more records post.
US8496908B1, assigned to Air Products and Chemicals, claims an integrated steam-methane-reforming process that uses pressure swing adsorption to split a hydrogen product from a PSA tail gas, then recycles that tail gas as reformer fuel alongside a synthetic air stream built from flue gas and industrial oxygen to isolate a near-pure CO2 product. The block is the specific combination of these steps rather than any single one in isolation. Teams building a similar hydrogen-with-carbon-capture flow should review this claim set closely, particularly around the flue-gas recycle and CO2 isolation sequence, before finalizing their own process design.
The thinnest documented classes in this dataset are C10K (purifying fuel gases) at 2.2% of the 499 records and C10G (hydrocarbon oils & refining) at 7.8%, both well below the F25J core at 60.7%. That gap suggests downstream fuel-gas purification and catalytic treatment of vent streams are less heavily claimed than the separation columns themselves. A first claim built around a specific catalyst or adsorbent tied to the nitrogen-rich vent stream, rather than the separation mechanism, is one way to approach that open space.
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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.