Anaerobic Digestion Patents: Top Companies & Filing Trends 2026
- Filing has plateaued, not grown. Annual filings rose from 21 in 2017 to a peak of 48 in 2024, but the 2022 midpoint of 35 shows the growth curve has flattened rather than compounded.
- Water treatment IPC codes dominate the corpus. C02F (water & wastewater treatment) appears in 483 of 607 families, nearly double the next most common code, C12M bioreactor apparatus at 219.
- China and the US anchor filing activity. China leads receiving offices with 161 filings, ahead of the United States at 126, with WIPO PCT filings (78) signalling cross-border ambition from a subset of applicants.
Filing growth compares 2021 (45 records) with 2024 (48) — 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 607 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape tracks 607 patent families published between 2015 and mid-2026 that combine anaerobic digestion or biogas upgrading process claims with specific technical elements: digestate handling, methane yield optimisation, H2S removal, co-digestion, or grid injection specification. The search is scoped by IPC classes C12M (bioreactors), C10L (fuels) and C02F (water treatment), which places this dataset at the intersection of waste processing and fuel production rather than pure microbiology.
Because publication typically lags filing by around 18 months, the 2025 and 2026 figures in the trend chart understate real filing activity; treat the most recent two years as a floor, not a ceiling.
Filing trends and technology composition
The numbers below describe where activity concentrates by year, by IPC subclass, and by receiving office. Read family counts, not raw document counts, as the fairer measure of underlying invention volume.
A plateau after a 2024 peak
Filings climbed from 21 in 2017 to a peak of 48 in 2024, but with 2022 sitting at 35 roughly midway through that climb, the growth has been closer to flat than sustained. Expect the 2025-2026 counts to revise upward as publications catch up.
Water treatment codes dominate
C02F carries 483 of 607 families, far ahead of C12M (219) and C12P (201). Smaller but non-trivial activity sits in B01D separation (83), C10L fuels (81), B09B solid waste (70), C05F fertilisers (62) and A01C planting equipment (32) — codes that mark adjacent, less-crowded claim territory.
Shares are the percentage of the 607 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Anaerobic Digestion and Biogas Upgrading with Eureka
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Try EurekaThe most-cited prior art in this space
Device and Method for Improving Methane Production in Anaerobic Digestion Through Magnetic Field of Current-Carrying Coil
A device for improving methane production in anaerobic digestion through a magnetic field of a current-carrying coil is provided, relating to microbial anaerobic digestion. It combines a feed system, digester, stirring system, magnetic field generation system, magnetic field measurement system and gas flow measurement system, with a corresponding method covering feedstock and inoculum pretreatment and coil-assisted digestion.Filed by Shanghai Jiao Tong University, published 2025-07-17 — illustrates a physical-stimulus approach to yield enhancement rather than a chemical or biological one.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20040025715A1 | Concept for slurry separation and biogas production | 161 |
| 2 | US4289625A | Hybrid bio-thermal gasification | 148 |
| 3 | US6254775B1 | Anaerobic digester system and method | 114 |
| 4 | US20090206028A1 | Combined nutrient recovery and biogas scrubbing system integrated in series with animal manure anaerobic dige… | 100 |
| 5 | US4213857A | Anaerobic digestion process | 88 |
| 6 | US20100021979A1 | Apparatus and Process for Production of Biogas | 79 |
| 7 | JP1988088099A | Pretreatment in methane fermenting method | 67 |
| 8 | US20180112142A1 | Method and system for providing upgraded biogas | 58 |
| 9 | WO2002015945A1 | Concept for slurry separation and biogas production | 55 |
| 10 | US20130029394A1 | Apparatus and process for treating waste | 47 |
Citation counts favour older records simply because they have had more time to accumulate citations within the searched corpus; treat this as a signal of influence on the field's vocabulary, not of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once the raw counts are read together: where claim density sits, how citation concentrates in older foundational filings, and how thin cross-assignee collaboration is.
Wastewater framing dominates the claim language
Nearly 80% of families sit in the C02F water-treatment subclass, meaning most applicants frame anaerobic digestion as a treatment process rather than a fuel-production process. That framing choice affects both examiner art units and where prior art searches should start.
Growth has plateaued since the early 2020s
The climb from 21 filings in 2017 to 35 by 2022 and 48 by 2024 shows deceleration rather than acceleration in the growth rate, even before accounting for publication lag on the final two years.
China and the US lead, but neither dominates outright
China's 161 filings lead the United States' 126, with 78 WIPO PCT filings indicating a smaller group of applicants pursuing multi-jurisdiction protection rather than single-market filing.
Co-filing is rare and concentrated
Only ten co-assignee pairs appear across the corpus, with the strongest link — Her Majesty the Queen in Right of Canada with Bio Terre Systems — appearing 9 times. Most applicants file alone.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to anaerobic digestion and biogas upgrading, with the prior art for and against each one.
Who is filing, and where momentum has stalled
Recent-year momentum data shows several previously active assignees, including Tekniska Verken i Linkoping and Iogen Corporation, recording zero filings in the latest year — a pattern consistent with publication lag but also with slowing programme activity at incumbents.
Established filers have gone quiet
Tekniska Verken i Linkoping AB, a repeat co-filer with individual inventors Holm Stig and Ejlertsson Jorgen, shows no filings in the latest tracked year, alongside Iogen Corporation at -100% YoY.
University filers show the same pause
Tongji University's filing count also drops to zero with -100% YoY, suggesting the slowdown spans both corporate and academic applicants rather than being sector-specific.
Government-industry pairing stands out
The Canadian federal government's co-filing relationship with Bio Terre Systems, at 9 shared filings, is the single strongest collaboration pattern in the dataset, well ahead of the next pairs at 3 each.
| Assignee | Recent year | YoY |
|---|---|---|
| Anaergia Inc. | 0 | — |
| Tongji University | 0 | -100% |
| IOGEN CORPORATION | 0 | -100% |
| BCR Environmental LLC | 0 | — |
| Green Agri Energy Inc. | 0 | — |
| TEKNISKA VERKEN I LINKOPING AB | 0 | — |
| UNCONVENTIONAL GAS SOLUTIONS LLC | 0 | -100% |
| HER MAJESTY THE QUEEN & RIGHT OF CANADA | 0 | — |
Where to take this analysis
The landscape data points to specific next steps depending on whether the goal is freedom-to-operate, portfolio strategy, or identifying acquisition targets.
Check freedom-to-operate against dense C02F claims
With 483 of 607 families sitting in the water-treatment subclass, a freedom-to-operate search for any wastewater-framed digestion process should start there before broadening.
Run a claims search in EurekaWatch for renewed activity from quiet incumbents
Several established filers show zero filings in the latest year; confirm whether this reflects publication lag or an actual pause before assuming the space is open.
Track assignee activity in EurekaExplore under-claimed adjacent codes
B09B, C05F and A01C carry meaningfully lower family counts than the core codes, and may offer more defensible first-filing positions.
Explore white space in EurekaCommon questions on this landscape
This dataset tracks 607 patent families published between 2015 and mid-2026 that combine anaerobic digestion or biogas upgrading with specific technical elements such as H2S removal, co-digestion or digestate handling. Annual filings rose from 21 in 2017 to a peak of 48 in 2024. Because publication lags filing by roughly 18 months, the 2025 and 2026 figures should be read as provisional lower bounds rather than final counts.
The ranking is dominated by a mix of corporate, institutional and government filers, with no single applicant holding a dominant share of the 607 families. Co-filing is rare, with only 10 co-assignee pairs identified across the entire corpus, meaning most patents are filed by a single named applicant. Several previously active filers, including Tekniska Verken i Linkoping and Iogen Corporation, show no filings in the most recent tracked year.
China leads receiving offices with 161 filings, followed by the United States at 126. WIPO PCT filings total 78, and Europe (EPO) accounts for 74, with India at 49 and Canada at 37. The mix of national and PCT filings suggests that while most applicants file domestically, a meaningful subset pursues multi-jurisdiction protection through the PCT route.
C02F (water and wastewater treatment) is by far the most common classification, appearing in 483 of 607 families, followed by C12M bioreactor apparatus at 219 and C12P fermentation processes at 201. Smaller but active codes include B01D separation processes, C10L fuels, B09B solid waste disposal, C05F organic fertilisers and A01C planting equipment. The dominance of C02F indicates that most applicants frame their inventions as wastewater treatment rather than pure fuel production, which matters for prior art searches and examiner assignment.
Filing activity is closer to a plateau than sustained growth. From 21 filings in 2017, the count reached 35 by the 2022 midpoint and peaked at 48 in 2024, a growth rate that is decelerating rather than compounding year over year. Combined with several established filers recording zero activity in the latest tracked year, this suggests the field has moved from an expansion phase into a more mature, consolidation-oriented phase, though publication lag means the very latest data understates true activity.
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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.