One assignee holds 56 of the 80 patent families in this dataset, making it by far the largest filer in the field. That same assignee's early filings are also the most-cited records in the set, which means its claim position covers both volume and technical influence. The remaining ten ranked entities each hold far smaller counts, with fifth and tenth place both at 2 families, so the field outside the leader is a long tail rather than a second tier of comparable competitors.

Filing peaked at 7 records in 2017, then fell before recovering to a smaller but real rise from 1 filing in 2021 to 3 in 2024, a 200% increase over that span. Figures for 2025 and 2026 look low but publication typically lags actual filing by around 18 months, so those years are not yet complete and should not be read as a slowdown. The honest read is a small field rebuilding from a low base, not a maturing or declining one.

The large majority of records, 87.5% of the 80 in scope, carry a B01D separation-process classification, and 56.3% also carry a C02F water-and-wastewater-treatment classification, since many filings claim both together. Smaller classes — C01D alkali-metal compounds, C25B electrolytic production and B01F mixing — each appear in 5% or fewer records, marking them as thinly claimed rather than absent. That split shows the field is anchored in filtration and treatment engineering, with salt-recovery and electrochemical valorisation still emerging.

The clearest openings sit in the classes with low record counts relative to the core: C01D alkali-metal salt recovery, C25B electrolytic brine valorisation, and B01F mixing methods tied to draw-solution regeneration each cover 5% or less of the 80 records. These branches sit adjacent to the dense B01D and C02F core rather than outside the field entirely, so a claim there still needs to be drafted carefully around the dominant assignee's existing osmotic-separation filings. A first claim in these areas would likely centre on the chemistry or process control step rather than the membrane or draw-solution architecture itself, which is already heavily claimed.

US20230234869A1 claims a closed-loop chemically-forced precipitation process for producing potable water and salts from seawater or brackish water, including a software-based process control method for managing salt, solvent and water concentrations. It sits outside the dominant assignee's forward-osmosis and draw-solution claim territory, so it does not block membrane-based approaches directly, but anyone using chemical precipitation with computer-controlled concentration management for brine treatment should review its claim scope closely. Because it is a relatively recent filing (2023), its practical blocking effect will depend on how the granted claims are eventually construed.