Y02A 50/20
Air quality improvement or preservation
Official title: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Y02A50/20 (Air quality improvement or preservation) appears on 8,759 US grants and 9,055 published applications in this corpus.
Search patents in Y02A- Granted patents
- 8,759
- Published applications
- 9,055
- Assignees
- 3,191
- Inventors
- 17,897
- Latest grant
- 29 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 57 | 0 |
| 1977 | 36 | 0 |
| 1978 | 60 | 0 |
| 1979 | 29 | 0 |
| 1980 | 51 | 0 |
| 1981 | 50 | 0 |
| 1982 | 32 | 0 |
| 1983 | 32 | 0 |
| 1984 | 34 | 0 |
| 1985 | 33 | 0 |
| 1986 | 27 | 0 |
| 1987 | 43 | 0 |
| 1988 | 34 | 0 |
| 1989 | 61 | 0 |
| 1990 | 57 | 0 |
| 1991 | 69 | 0 |
| 1992 | 72 | 0 |
| 1993 | 72 | 0 |
| 1994 | 107 | 0 |
| 1995 | 106 | 0 |
| 1996 | 111 | 0 |
| 1997 | 120 | 0 |
| 1998 | 134 | 0 |
| 1999 | 150 | 0 |
| 2000 | 156 | 0 |
| 2001 | 160 | 58 |
| 2002 | 114 | 157 |
| 2003 | 159 | 218 |
| 2004 | 143 | 276 |
| 2005 | 136 | 234 |
| 2006 | 133 | 272 |
| 2007 | 147 | 269 |
| 2008 | 122 | 299 |
| 2009 | 163 | 320 |
| 2010 | 206 | 419 |
| 2011 | 206 | 447 |
| 2012 | 271 | 366 |
| 2013 | 370 | 418 |
| 2014 | 334 | 440 |
| 2015 | 374 | 533 |
| 2016 | 366 | 478 |
| 2017 | 437 | 534 |
| 2018 | 380 | 552 |
| 2019 | 531 | 512 |
| 2020 | 460 | 525 |
| 2021 | 449 | 504 |
| 2022 | 406 | 435 |
| 2023 | 346 | 395 |
| 2024 | 292 | 226 |
| 2025 | 216 | 100 |
| 2026 | 105 | 68 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Aerosol generating device comprising semiconductor heaters29 Sep 2026US 12,746,349 B2Altria Client Services LLC
- Desulfurization method29 Sep 2026US 12,747,685 B2Subaru Corporation
- Air conditioning apparatus15 Sep 2026US 12,734,472 B2LG Electronics Inc.
- Ozone catalytic elimination device and plasma beauty instrument1 Sep 2026US 12,722,021 B2Shenzhen Leaflife Technology Co., Ltd.
- Composite, zoned oxidation catalyst for a compression ignition internal combustion engine25 Aug 2026US 12,714,990 B2Johnson Matthey Public Limited Company
- Removal of atmospheric pollutants from gas, related apparatus, processes and uses thereof24 Sep 2026US 2026/0284589 A1Intelligent Abatement, LLC
- Supported poly(allyl)amine and derivatives for co2 capture from flue gas or ultra-dilute gas streams such as ambient air or admixtures thereof24 Sep 2026US 2026/0284637 A1Georgia Tech Research Corporation
- Method for manufacturing combustion aid for addition before fossil fuel combustion and desulfurization catalyst27 Aug 2026US 2026/0250590 A1
- Exhaust system and features thereof27 Aug 2026US 2026/0251080 A1ECC TEC MSJ Incorporated
- Online measurement system and method for gas flux of gas-liquid interface13 Aug 2026US 2026/0235484 A1China Three Gorges Corporation
Most cited
By later US patents
- System for detecting base contaminants in air504US 6,096,267 AExtraction Systems, Inc. · 2000
- Method and apparatus for detecting toxic gases499US 5,057,436 AAgMaster, Inc. · 1991
- Apparatus for the monitored metering of no into patients' respiratory air487US 5,531,218 AMesser Griesheim GmbH · 1996
- Device for measuring concentration of nitrogen oxide in combustion gas455US 5,034,112 ANissan Motor Co., Ltd. · 1991
- Photolysis system for fast-response NO2 measurements and method therefor433US 6,346,419 B1The United States of America as represented by the Department of Commerce · 2002