Fastest
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 →https://www.patsnap.com/resources/blog/rd-blog/brine-purification-for-electrolysis-patent-landscape/ · Patsnap · data cut-off 2026-07-31 · downloaded from the live page
Patent Landscape · Chemical Process EngineeringBrine purification patents for electrolysis: who holds the ground and where it opens up
- Concentrated at the top. The five most active filers account for 43.8% of all 96 records in scope, and the top ten hold 61.5% — a shallow field with a long tail of single-filing entrants.
- Filing has cooled from its 2020 peak. Output reached 4 records in 2020 and fell from 3 in 2021 to 2 in 2024, a 33% decline over that span, though 2025-26 counts are still incomplete due to publication lag.
- Almost all activity sits in one IPC subclass. C01D (alkali-metal compounds) touches 74.0% of the 96 records, while adjacent classes like C01F and B01J each cover barely a tenth — a sign of where claim space is thin.
96
Published Records
44%
Top-5 Share of All Records
-33%
Filing Growth 2021→2024
CN
Leading Jurisdiction
Filing growth compares 2021 (3 records) with 2024 (2) — 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 96 records in scope (CR5), not by the ranked leaders only.
Published byPatsnap Research··8 min readSourced from Patsnap Eureka
Overview
What this landscape covers
Brine purification sits upstream of chlor-alkali electrolysis: before saturated sodium chloride brine reaches a membrane cell, calcium, magnesium, sulfate and other impurities have to come out, or they foul the membrane and shorten its working life. This landscape covers 96 published records filed or published between 2015 and mid-2026 that describe purification chemistry, chelating ion exchange, resin regeneration and related steps ahead of the electrolyzer. Patent families, not raw document counts, are the unit used for ranking and concentration figures, which keeps continuation filings and multi-jurisdiction duplicates from inflating any single assignee's position.
The scope is narrow by design: it excludes general water treatment and downstream cell chemistry, focusing instead on the pretreatment step itself. That narrowness is visible in the technology composition, where one IPC subclass dominates and several plausible adjacent branches barely register.
Filing activity and technology composition, 2015-2026
Source: Patsnap Eureka. Assignee ranking and totals. Derived from a Patsnap search on Brine Purification for Electrolysis covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
The Data
Filing trends and technology composition
Two views of the same 96 records: how filing activity has moved year over year, and which IPC subclasses the claims actually sit in.
Filing trend
Activity peaked at 4 records in 2020. From 2021 (3 records) to 2024 (2 records) — the last year with a reasonably complete publication record — filings fell 33%. Counts for 2025 and 2026 will rise as publications catch up with filing dates, given the roughly 18-month lag between the two.
IPC composition
C01D (alkali-metal compounds) appears in 74.0% of the 96 records, far ahead of C02F (water and wastewater treatment) at 32.3% and B01D (separation processes) at 15.6%. C25B (electrolytic production), B01J (catalysis) and C01F (alkaline-earth compounds) each sit near or just above one in ten records, and C01B and C04B are marginal at 4.2% each. Records can carry more than one class, so these shares sum to well over 100%.
Shares are the percentage of the 96 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Source: Patsnap Eureka. Filing trend and technology composition. Derived from a Patsnap search on Brine Purification for Electrolysis covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.
Go deeper on Brine Purification for Electrolysis with Eureka
This page is one run against one query. Ask Eureka your own question about brine purification for electrolysis and every answer comes back with the patent numbers behind it.
Try EurekaKey Patents
The most-cited records in this field
Representative Filing
CA1083780A — Brine purification process (Allied Chemical Corporation, 1980)
ALLIED CHEMICAL CORPORATION
The process treats raw brine containing dissolved strontium, calcium and magnesium by first precipitating strontium and calcium as carbonate with sodium carbonate, then precipitating magnesium as hydroxide with sodium hydroxide, and removing the combined solids from the sodium chloride brine. The improvement recycles a portion of the removed solids back into the treatment zone.Filed decades before the most recent activity in this dataset, it still anchors the sequential carbonate/hydroxide precipitation approach that later filings build on or design around.
View full filingHighest-citation records
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4405465A | Process for the removal of chlorate and hypochlorite from spent alkali metal chloride brines | 97 |
| 2 | US20100219372A1 | Brine purification | 70 |
| 3 | WO2002000551A2 | A process and apparatus for brine purification | 69 |
| 4 | CN101289200A | 卤水净化工艺方法 | 59 |
| 5 | WO2009026212A1 | Brine purification | 53 |
| 6 | US4210626A | Manufacture of magnesium carbonate and calcium sulphate from brine mud | 48 |
| 7 | EP0492727A1 | Process for the preparation of sodium chloride | 36 |
| 8 | WO2012025468A1 | Brine purification process | 34 |
| 9 | US5221528A | Process for the preparation of sodium chloride | 28 |
| 10 | US20070189945A1 | Method for the treatment of salt brine | 27 |
Citation counts favour older filings simply because they have had longer to accumulate references within the searched corpus — read them as a signal of influence on later drafting, not as a measure of current commercial relevance.
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.
Source: Patsnap Eureka. Citation counts and representative records. Derived from a Patsnap search on Brine Purification for Electrolysis covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Run it yourself
Put your own technology through the same analysis
Where to run it
For builders
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 →Insights
What the numbers mean for a filing decision
Read together, the concentration, trend and composition data point to a field with a settled core chemistry and a shrinking but still-contested filing rate.
Concentration
43.8% / 61.5%
top 5 / top 10 share of 96 records
A shallow leadership tier
The leader holds 11 records and fifth place holds 5, with tenth place down to 3 — concentration drops off fast after the top few names, and the remainder of the 65 ranked companies file once or twice each. That long tail suggests room for a new entrant with a distinct chemistry, not just a process tweak.
Based on the full 65-company ranking
Momentum
-33%
2021 → 2024 filing change
Activity has pulled back from its peak
Filings peaked at 4 records in 2020 and declined to 2 by 2024, the last year with a largely complete publication record. That is a real slowdown in a niche field, not evidence the underlying problem is solved — brine chemistry keeps evolving with feedstock and membrane specifications.
2025-26 figures will revise upward as publication catches up
Technology mix
74.0% vs 11.5%
C01D share vs C01F share of records
One subclass carries most of the claim density
C01D (alkali-metal compounds) is the dominant classification by a wide margin over every adjacent class. C01F (alkaline-earth, aluminium and rare-earth compounds), B01J (catalysis) and C25B (electrolytic production) each sit near a tenth of records, marking them as comparatively open relative to the core.
Shares sum above 100% because records carry multiple IPC codes
Geography
34 / 16 / 9
China / US / WIPO filings
Filing offices skew toward China and the US
China accounts for the largest single share of receiving-office filings, with the United States second and WIPO PCT filings a distant third ahead of Canada, Europe and India. That split matters for freedom-to-operate work that assumes a US or European-centric prior art base.
Receiving-office counts across the 96-record set
Eureka AI Agent
Looking for what nobody has claimed yet?
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to brine purification for electrolysis, with the prior art for and against each one.
Source: Patsnap Eureka. Co-assignee relationships and derived observations. Derived from a Patsnap search on Brine Purification for Electrolysis covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Players
Who is active, and where they are not
Filing activity clusters among a handful of long-standing chemical and industrial names, with co-filing patterns pointing to a small number of tightly linked inventor groups rather than broad industry-wide collaboration.
Leader position
11 records
top-ranked assignee
A single filer well ahead of the field
The top-ranked assignee holds 11 of the 96 records, roughly double the fifth-place count of 5. That gap, combined with recent-year momentum showing zero filings in the latest year for several of the most active historical names, suggests the leadership position was built earlier in the window rather than sustained by current output.
Recent-year filings flat to zero across several top assignees
Co-filing structure
10 pairs
co-assignee pairs identified
Small, dense inventor clusters
Only 10 co-assignee pairs appear across the dataset, and the strongest three pairs share the same three names in different combinations — a tight inventor group rather than a broad cross-company alliance. That pattern is typical of a niche chemistry field where expertise is concentrated in a few individuals.
Strongest pairs linked at a count of 4 co-filings each
Recent momentum
0 in latest year
across most top historical filers
Historic leaders have gone quiet recently
Several of the assignees with the deepest filing histories show zero activity in the latest tracked year, including one with a -100% year-on-year change. Combined with the broader -33% three-year decline to 2024, this points to either consolidation of the core chemistry or a shift of R&D effort toward adjacent process steps not captured by this search scope.
Momentum figures cover the most recent full and partial years
Recent-year filing momentum by assignee
| Assignee | Recent year | YoY |
|---|---|---|
| Brunner Mond (UK) Ltd | 0 | — |
| China National Salt Jintan Salt Chemical Co., Ltd. | 0 | -100% |
| Dow Global Technologies LLC | 0 | — |
| Akzo Nobel N.V. | 0 | — |
| Blue Cube IP LLC | 0 | — |
| Solvay SA | 0 | — |
| LORD GLENN | 0 | — |
| HOOK BRUCE | 0 | — |
Source: Patsnap Eureka. Assignee-level momentum. Derived from a Patsnap search on Brine Purification for Electrolysis covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
What's Next
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, competitive tracking or identifying a filing gap.
Run a freedom-to-operate check on the core chemistry
With 74.0% of records sitting in C01D and a leader holding 11 of 96 records, any new sequential precipitation or ion-exchange process needs a claim-by-claim comparison against the most-cited filings before drafting.
Explore claims in EurekaTrack the quiet historical leaders
Several top assignees show zero recent-year filings; a standing watch would flag if any resumes activity or if a new entrant fills the gap left by the -33% decline to 2024.
Set up assignee tracking in EurekaScope the under-claimed branches
Sulfate-resin integration, high-silica resin lifetime and membrane-impact modelling all sit well below the 74.0% core share — each is a candidate for a narrowly targeted first filing.
Map white space in EurekaSource: Patsnap Eureka. Forward-looking reading of the same dataset. Derived from a Patsnap search on Brine Purification for Electrolysis covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
FAQ
Common questions on brine purification patents
Filing activity is concentrated among a small group of long-standing chemical manufacturers, with the top-ranked assignee holding 11 of the 96 records in this dataset and the top five combined accounting for 43.8% of all records. Beyond the top ten, which together hold 61.5% of records, the field has a long tail of 65 ranked companies filing once or twice each. This shape is typical of a mature, narrowly defined process technology rather than an actively expanding one.
Filings peaked at 4 records in 2020 and declined from 3 in 2021 to 2 in 2024, a 33% drop over that span. Because publication lags filing by roughly 18 months, 2025 and 2026 figures are still incomplete and should not be read as confirming a continued decline. The overall pattern through 2024 points to a cooling rather than an expanding field.
CA1083780A, assigned to Allied Chemical Corporation and dated 1980, describes a sequential precipitation process: sodium carbonate first precipitates strontium and calcium carbonate, then sodium hydroxide precipitates magnesium hydroxide, with the resulting solids removed from the brine and a portion recycled back into the treatment zone. Its core contribution is that solids-recycling improvement, not the base carbonate/hydroxide precipitation chemistry itself, which was already established practice. A new filing using a materially different reagent sequence, a different impurity target, or a different recycling mechanism would not necessarily be blocked by it, but any process recycling precipitated solids into an upstream treatment zone should be checked against it directly.
Relative to the dominant C01D alkali-metal compound classification, which touches 74.0% of the 96 records, several adjacent areas are thin: C01F (alkaline-earth and rare-earth compounds) and B01J (catalysis) each sit near 11.5%, and C01B and C04B are marginal at 4.2% each. Specific sub-areas such as sulfate removal integrated with resin regeneration, high-silica resin lifetime, and membrane-lifetime impact modelling appear infrequently in this corpus. These gaps are candidates for new filings, though a full freedom-to-operate search is needed before assuming any of them is genuinely open.
China leads as a receiving office with 34 filings in this dataset, followed by the United States with 16 and WIPO PCT filings at 9. Canada and Europe each show 8 filings, and India shows 4. This distribution means a search or clearance exercise built only around US and European prior art will miss a substantial share of the documented activity in this field.
Answers are grounded in the same dataset. Derived from a Patsnap search on Brine Purification for Electrolysis covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Research Brine Purification for Electrolysis in depth with Eureka
Go past this page: query the whole brine purification for electrolysis 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.