The ranking covers 91 companies, with a clear leader holding 24 records and a steep drop-off to fifth place at 11 and tenth place at 5. The top five assignees together account for 90 of the 162 records in scope (55.6%), and the top ten reach 126 records (77.8%), so a small group of filers defines most of the accessible claim space. Beyond that group the field flattens into a long tail of single- and few-filing entrants, which is typical for a technology area with both large industrial players and university research groups active in it.

Filing peaked at 18 records in 2019 and has since eased, with the most recent complete comparison period, 2021 to 2024, showing an 18% decline from 11 to 9 filings. That is a real but moderate pullback rather than a collapse. Figures for 2025 and 2026 should be read with caution: publication typically lags filing by around 18 months, so the most recent one to two years in any patent dataset understate true filing activity.

The 162 records in this dataset span separation processes (B01D, 19.1% of records), heat-exchanger details (F28F, 13.0%), refrigeration and heat pumps (F25B, 11.7%), gas liquefaction and separation (F25J, 9.9%), and non-metallic inorganic compound processing (C01B, 9.9%), among others. Notably, business and data-processing claims (G06Q) also sit at 13.0%, on par with heat-exchanger hardware, reflecting how much of this field now involves energy-management software layered on top of physical equipment. Because a single record can carry multiple IPC classes, these shares add up to more than 100% of the record total.

US20220258094A1, assigned to Praxair Technology, Inc. and published in 2022, covers a PSA/VPSA plant energy-efficiency method that uses a high-speed direct-drive centrifugal product compressor to reduce energy consumption during turndown, particularly at lower flow and lower adsorption top pressure. It blocks the specific combination of direct-drive centrifugal compression with that turndown control logic for feed, vacuum and product compressors in PSA/VPSA gas separation plants. Work using different compressor architectures, different pressure-swing control strategies, or applications outside PSA/VPSA gas separation would sit outside its literal claim scope, though a full clearance opinion would need to check the granted claim set directly.

The technology composition data shows claim density concentrated in separation (B01D), heat exchange (F28F) and refrigeration (F25B), while cross-class combinations — such as energy-metric data processing paired with process-heat hardware, or radiative cooling structure integration — appear thinner. Several previously active assignees, including university research bodies, show no filings in the latest year, which may open room for new entrants in adjacent control-logic and compressor-turndown claims. Any whitespace read should be paired with a citation check, since the highest-cited records in this set date back a decade or more and may still anchor broad foundational claims.