B01D 2259/4006
Less than four
B01D2259/4006 (Less than four) appears on 77 US grants and 31 published applications in this corpus.
Search patents in B01D- Granted patents
- 77
- Published applications
- 31
- Assignees
- 50
- Inventors
- 189
- Latest grant
- 14 Jul 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 1 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 2 | 0 |
| 1981 | 0 | 0 |
| 1982 | 0 | 0 |
| 1983 | 1 | 0 |
| 1984 | 4 | 0 |
| 1985 | 2 | 0 |
| 1986 | 4 | 0 |
| 1987 | 3 | 0 |
| 1988 | 2 | 0 |
| 1989 | 2 | 0 |
| 1990 | 2 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 2 | 0 |
| 1996 | 2 | 0 |
| 1997 | 2 | 0 |
| 1998 | 4 | 0 |
| 1999 | 3 | 0 |
| 2000 | 4 | 0 |
| 2001 | 5 | 0 |
| 2002 | 2 | 0 |
| 2003 | 3 | 2 |
| 2004 | 3 | 1 |
| 2005 | 0 | 1 |
| 2006 | 0 | 3 |
| 2007 | 0 | 2 |
| 2008 | 1 | 3 |
| 2009 | 3 | 0 |
| 2010 | 1 | 2 |
| 2011 | 2 | 1 |
| 2012 | 1 | 2 |
| 2013 | 3 | 0 |
| 2014 | 0 | 1 |
| 2015 | 1 | 2 |
| 2016 | 1 | 0 |
| 2017 | 0 | 2 |
| 2018 | 1 | 3 |
| 2019 | 2 | 0 |
| 2020 | 2 | 1 |
| 2021 | 1 | 0 |
| 2022 | 0 | 0 |
| 2023 | 0 | 0 |
| 2024 | 0 | 4 |
| 2025 | 1 | 1 |
| 2026 | 2 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Direct capture of CO2 from air and point sources14 Jul 2026US 12,678,727 B2ExxonMobil Technology and Engineering Company
- Gas treatment process and process arrangement10 Mar 2026US 12,569,799 B2Linde Aktiengesellschaft
- Method for mobile pressure swing adsorption oxygen production device30 Dec 2025US 12,508,534 B2Chengdu Yingchen Technology Co., Ltd
- Connection of a spontaneous delivery device to a concentrator21 Sep 2021US 11,123,512 B2Inogen, Inc.
- Carbon molecular sieve adsorbent17 Nov 2020US 10,835,856 B2Air Products and Chemicals, Inc.
- Impurity removal system for use in a fuel cell system30 Oct 2025US 2025/0336996 A1Hydrogenics Corporation
- Optimization of a pressure swing adsorption process19 Dec 2024US 2024/0416272 A1Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO
- Gas treatment process and process arrangement13 Jun 2024US 2024/0189758 A1Linde Aktiengesellschaft
- Direct capture of co2 from air and point sources22 Feb 2024US 2024/0058743 A1ExxonMobil Technology and Engineering Company
- Method for Mobile Pressure Swing Adsorption Oxygen Production Device22 Feb 2024US 2024/0058744 A1Chengdu Yingchen Technology Co., Ltd
Most cited
By later US patents
- Rapid cycle pressure swing adsorption oxygen concentration method and apparatus193US 5,827,358 AImpact MST, Incorporation · 1998
- Rapid cycle pressure swing adsorption oxygen concentration method and apparatus81US 6,068,680 AImpact MST Incorporated · 2000
- Enhanced gas separation process78US 4,690,695 AUnion Carbide Corporation · 1987
- Removal of perfluorocarbons from gas streams77US 5,417,742 AThe BOC Group, Inc. · 1995
- Rapid pressure swing adsorption process with high enrichment factor65US 4,194,892 AUnion Carbide Corporation · 1980