Steam Generation Patents: Top Companies & Filing Trends 2026
- No dominant filer. the leader holds 85 records and the top 5 combined account for just 11.8% of all 1,882 records in scope — this field has not consolidated.
- Filing has cooled since 2022. activity peaked at 107 records that year and has declined since, with the most recent full year understated by the usual 18-month publication lag.
- Boiler and steam-plant classes dominate composition. F22B (steam generation & boilers) and F01K (steam & thermal power plants) together cover the majority of records, while feedwater control and water treatment remain comparatively thin.
What this landscape covers
This landscape tracks patent activity at the intersection of steam generation and thermal energy storage — filings that combine claims on steam pressure, superheat delivery, ramp rate, feedwater treatment, blowdown handling or integration with storage or industrial steam systems. The scope spans 1,882 published records filed between 2015 and mid-2026, drawn from receiving offices across the United States, China, Europe, Canada, India and the WIPO PCT system.
The technology sits at a crossroads of classical boiler engineering and newer thermal storage integration, which is why records carry classes as varied as earth drilling (E21B, tied to steam-assisted oil recovery) alongside batteries and fuel cells (H01M). Reading the class mix alongside the assignee ranking shows where claim density is heaviest and where it is still open.
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Filing trend and technology composition
Two views of the same 1,882-record dataset: how filing volume has moved year over year, and how records split across IPC subclasses.
Filing trend, 2017–2026
Annual filings rose from 97 in 2017 to a peak of 107 in 2022, then declined toward 14 in 2026 — a partial year given the roughly 18-month lag between filing and publication. The flat-to-declining shape after the midpoint suggests filing appetite has not kept pace with the field's earlier growth.
Technology composition by IPC subclass
F22B (steam generation & boilers) leads at 35.2% of the 1,882 records in scope, followed by F01K (steam & thermal power plants) at 21.4%. Earth/rock drilling (E21B, 9.4%) reflects steam-assisted hydrocarbon recovery use cases, while feedwater control (F22D, 5.3%) and water treatment (C02F, 5.4%) are comparatively thin despite being operationally critical to steam quality and blowdown management.
Shares are the percentage of the 1,882 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Steam Generation from Thermal Storage with Eureka
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Try EurekaMost-cited records and a representative filing
Blowdown recycle for steam generation units (US20160244346A1)
A boiler blowdown recycle method and system for increasing recycle and water recovery percentages for steam generation units used in thermal hydrocarbon recovery processes such as SAGD and CSS methods. Blowdown from a steam generating unit is elevated to supercritical temperatures and pressures, and an oxidizing agent added, thereby oxidizing organic and inorganic compounds in the blowdown and simultaneously reducing solubility of inorganics within the blowdown allowing them to precipitate out or be more easily separated therefrom, leaving a purified stream.Filed by Husky Oil Operations Limited, 2016-08-25.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US6016868A | Production of synthetic crude oil from heavy hydrocarbons recovered by in situ hydrovisbreaking | 478 |
| 2 | US4385661A | Downhole steam generator with improved preheating, combustion and protection features | 256 |
| 3 | US4765142A | Compressed air energy storage turbomachinery cycle with compression heat recovery, storage, steam generation … | 220 |
| 4 | US20090217584A1 | Steam Generation Processes Utilizing Biomass Feedstocks | 200 |
| 5 | US6073448A | Method and apparatus for steam generation from isothermal geothermal reservoirs | 148 |
| 6 | US20060032630A1 | Water treatment method for heavy oil production | 145 |
| 7 | US3971639A | Fluid bed coal gasification | 127 |
| 8 | US7077201B2 | Water treatment method for heavy oil production | 113 |
| 9 | US20090217585A1 | Reduced Carbon Footprint Steam Generation Processes | 112 |
| 10 | US20050279500A1 | Water treatment method for heavy oil production using calcium sulfate seed slurry evaporation | 109 |
Citation counts favour older records simply because they have had more time to accumulate citations within the searched corpus — read them as a signal of influence, not current relevance.
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Three read-throughs from the filing trend, the class mix and the concentration figures.
No single company controls this field
The leader holds 85 records, but the top 5 combined reach only 11.8% of all 1,882 records in scope, and the top 10 reach 18.5%. That leaves a long tail of single- and few-filing entrants working on specific sub-problems rather than a handful of firms setting the agenda.
Filing has cooled from its 2022 peak
Annual filings climbed from 97 in 2017 to 107 in 2022, then declined toward 14 in the most recent year. Because publication lags filing by roughly 18 months, the last one or two years will always look thinner than they eventually turn out to be, but the multi-year decline predates that effect.
Boiler and steam-plant claims dominate the class mix
F22B (steam generation & boilers) and F01K (steam & thermal power plants) together cover the bulk of records, while feedwater control (F22D) and water/wastewater treatment (C02F) sit at 5.3% and 5.4% respectively — thin coverage for functions that directly govern steam purity and blowdown handling.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to steam generation from thermal storage, with the prior art for and against each one.
Who is filing, and where the gaps sit
The assignee ranking spans 100 companies with no single dominant filer. Co-assignment patterns show a small set of collaborative pairs rather than a dense filing network.
A modest lead, not a monopoly
The top-ranked assignee holds 85 records — well ahead of fifth place at 29 and tenth place at 23, but nowhere near the majority of the 1,882 records in scope. That gap between first and fifth place signals a leader with a real portfolio, not a category owner.
Most filing activity sits outside the ranked leaders
With the top 10 combined at just 18.5% of all records, the majority of filings come from assignees outside the ranked group — a pattern consistent with a technology still being worked out by many independent teams rather than converging on a few dominant portfolios.
Collaboration is limited and concentrated
Only 10 co-assignee pairs appear in the dataset, with the strongest pairing filing together 4 times. That is a thin collaboration layer for a field this size, suggesting most development happens inside single organisations rather than through joint filings.
| Assignee | Recent year | YoY |
|---|---|---|
| Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA) | 1 | — |
| Rondo Energy Inc | 0 | -100% |
| Siemens AG | 0 | — |
| Evapco Inc | 0 | — |
| General Electric Co | 0 | — |
| Ionics Inc | 0 | — |
| ConocoPhillips Co | 0 | — |
| Energy Integration Inc | 0 | — |
Where to take this next
The dataset points to specific next steps depending on whether you are scouting freedom-to-operate, tracking a competitor, or drafting new claims.
Check claim density before drafting
Feedwater control, blowdown chemistry and ramp-rate integration show thinner coverage than the core boiler classes — worth a targeted search before locking in claim language in these areas.
Explore white space in Eureka →Watch the leader's next move
With the top filer holding 85 records but no majority share, tracking its recent filings and any joint filings can flag where the category is consolidating, if at all.
Track assignee activity in Eureka →Re-run this search after the lag window closes
The most recent one to two years of filings are understated by publication lag; revisiting this landscape in 12–18 months will sharpen the 2022-peak read.
Set up a monitoring search in Eureka →Common questions on steam generation from thermal storage patents
The assignee ranking in this dataset spans 100 companies, with the leading filer holding 85 records out of 1,882 total. The top 5 combined account for 11.8% of all records and the top 10 for 18.5%, which means no single company controls the field. Most of the filing activity comes from a long tail of assignees outside the ranked leaders, so tracking just the largest portfolios will miss most of the activity.
Filing rose from 97 records in 2017 to a peak of 107 in 2022, then declined toward 14 in the most recent year. Because publication lags filing by roughly 18 months, the last year or two will always look artificially thin, but the decline from the 2022 peak predates that effect. Overall the trend reads as flat to declining rather than accelerating.
Steam generation and boiler engineering (IPC class F22B) covers 35.2% of the 1,882 records in scope, and steam and thermal power plants (F01K) cover 21.4%. Earth and rock drilling (E21B) appears in 9.4% of records, largely reflecting steam-assisted hydrocarbon recovery applications. Feedwater control and water treatment classes are comparatively thin, each around 5%, despite being operationally important to steam quality.
Based on class coverage relative to the core boiler and steam-plant classes, feedwater treatment integration, blowdown chemistry and recovery, and ramp-rate control for storage-coupled steam systems all show thinner claim density. That does not guarantee an area is unclaimed, but it does mean a targeted freedom-to-operate search is worthwhile before drafting in those areas rather than in the crowded F22B/F01K space.
Concentration is low by the numbers available: the top 5 assignees hold 11.8% of the 1,882 records in scope and the top 10 hold 18.5%. Co-assignment is also limited, with only 10 co-assignee pairs identified across the entire dataset and the strongest pair filing together just 4 times. This points to a technology being developed by many independent organisations rather than a small group of dominant players.
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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.