Ammonia Marine Propulsion Patent Snapshot 2026
The ammonia marine propulsion patent space is sharply concentrated, with Toyota Industries Corp and its affiliated Toyota Motor Corporation together accounting for the majority of filings and Hitachi Zosen the principal third-party challenger. Activity peaked around 2020 and has since eased, leaving meaningful adjacent branches in exhaust treatment, separation processes, and catalysis relatively underserved.
Toyota Industries leads a tightly held field with two other active filers
Toyota Industries Corp holds the top-ranked position among all identified applicants, followed by Toyota Motor Corporation and Hitachi Zosen Corp — each occupying a distinct tier. The top five filers collectively represent 94% of the ranked applicants visible in this query’ combined patent records, signalling an unusually high concentration for an early-stage industrial technology.
The tier gap between the leader and the rest is stark: Toyota Industries Corp’s record count is more than double that of either Toyota Motor Corp or Hitachi Zosen Corp. Below the top three, participation drops to single-figure record counts from Chinese academic institutions, indicating that no well-funded challenger outside the Toyota ecosystem has yet established a credible portfolio.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Toyota Industries Corporation | 15 | |
| 2 | Toyota Motor Corporation | 7 | |
| 3 | Hitachi Zosen Corporation | 7 | |
| 4 | Institute of Energy, Hefei Comprehensive National Science Center (Anhui Energy Laboratory) | 2 | |
| 5 | Shanghai Jiao Tong University | 1 | |
| 6 | Tsinghua University | 1 | |
| 7 | Tianjin University | 1 |
The visible position of two Toyota-group entities suggests that proprietary engine-system know-how accumulated in automotive is being redeployed into marine ammonia applications. Hitachi Zosen’s presence adds an established marine-engineering perspective, but the overall evidence snapshot remains controlled by entities with strong engine and fuel-supply competencies rather than shipbuilders or fuel-logistics specialists.
The most recent filing years are subject to publication lag and likely under-represent current activity; the apparent absence of filings in 2024 and 2026 should not be read as a cessation of R&D. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
A 2020 filing peak, a fuel-supply technology core, and sparse catalytic branches
The annual filing trend and IPC technology composition together reveal a field that surged in 2019–2020, plateaued at a lower level through 2022–2023, and is now past its initial growth peak — while the technology mix points clearly to fuel supply and combustion engineering as the established core.
Annual filing trend
Filings rose from zero in 2017–2018 to a peak of six records in 2020, then pulled back. Activity held at four records in both 2022 and 2023, and three records appear for 2025. The lifecycle stage is consistent with a field that has passed its peak annual intensity; the 2024 and 2026 zeros almost certainly reflect publication lag rather than real cessation.
↗ Hover for values · click a bar to ask EurekaTechnology composition
Fuel supply and carburettors (F02M) and internal-combustion engines (F02B) together are visible in the IPC mix, confirming that ammonia-specific fuel delivery and combustion chamber design are the most-contested technical routes. Engine control (F02D) and inorganic compounds for hydrogen/ammonia chemistry (C01B) form a secondary tier. Exhaust treatment, separation, catalysis, cooling, and plasma-assisted combustion each account for only a small share, marking them as adjacent branches with relatively sparse filings.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Engine system
An engine system includes: an ammonia engine; a reforming device that has a reforming catalyst for cracking ammonia gas into hydrogen and configured to reform ammonia gas to generate reformed gas containing hydrogen; and a control unit. The control unit includes: a purge controller configured to control a reforming injector so as to be closed and control a… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Ammonia-engine system | 45 |
| 2 | Engine system | 29 |
| 3 | 一种基于等离子体辅助氨燃烧及氨催化裂解的发动机系统 | 27 |
| 4 | Ammonia-engine system | 24 |
| 5 | Ammonia combustion system | 22 |
| 6 | アンモニアエンジン | 21 |
| 7 | 一种降低氨发动机未燃氨排放的系统和方法 | 17 |
| 8 | Engine system | 10 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
Assignee snapshot from the current evidence set
The applicants below are visible in this query result. Because the evidence set is relatively small, read this section as a directional snapshot rather than a full competitive ranking.
Toyota Industries Corp
Toyota Industries Corp leads the ranking with 15 patent records focused on fuel supply and carburettors (F02M 21, F02M 27) and engine control (F02D 19) — the core delivery and management system for ammonia combustion. Its momentum trend is classified as a new entrant, indicating that all recent filings fall in the latest window with no comparable prior-period base, suggesting a deliberate and concentrated push rather than a long-running programme.
families: 15Hitachi Zosen Corp
Hitachi Zosen Corp holds 7 patent records, co-filed entirely with Toyota Motor Corporation, with emphasis on internal-combustion engines (F02B 43), gas separation (B01D 53), and catalysis (B01J 23). This profile reflects a systems-engineering approach that integrates combustion, post-combustion gas cleanup, and catalytic conversion — technically distinct from the fuel-supply focus of the Toyota Industries portfolio. No momentum trend data is available for Hitachi Zosen in the recent-window analysis.
families: 7Frequently asked questions
The corpus contains 20 patent families in scope. This is a small corpus reflecting the early and specialised nature of the technology, and the most recent filing years are likely under-counted due to publication lag.
Toyota Industries Corp leads the applicant ranking with 15 patent records, more than double the count of the next-ranked filers, Toyota Motor Corporation and Hitachi Zosen Corp, each with 7 records.
Annual filing volume peaked in 2020 and has eased since then, placing the field in a past-peak lifecycle stage. The multi-year record count remains positive but the annual intensity observed in 2019–2020 has not been sustained. Recent low counts in 2024 and 2026 likely reflect publication lag.
The United States has the highest single-jurisdiction record count among all identified jurisdictions, followed by Australia and China at equal levels. Europe (EPO), India, and Japan also appear in the data, and two WIPO PCT records indicate broader filing intent.
Yes. The only documented co-applicant collaboration involves Hitachi Zosen Corp and Toyota Motor Corporation, who jointly filed 7 patent records. No other co-filing relationships appear in the current evidence.
The sparsest IPC branches relative to the core fuel-supply and combustion classes are plasma and particle accelerators (H05H, 1 record), engine cooling (F01P, 1 record), catalysis (B01J, 4 records), separation processes (B01D, 4 records), and exhaust treatment (F01N, 5 records). These branches represent under-served adjacent areas in the current corpus.
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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.
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