Sofc for the combined production of electricity and nitric oxide
US-2026011764-A1 · Jan 8, 2026 · US
Preparation by absorption of oxides of nitrogen {(C01B21/26 takes precedence)}
Preparation by absorption of oxides of nitrogen {(C01B21/26 takes precedence)} · Cooperative Patent Classification (CPC)
Chemical and metallurgical processes, compounds, and materials.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | C01B21/40 |
| Official title | Preparation by absorption of oxides of nitrogen {(C01B21/26 takes precedence)} |
| Display label | Preparation by absorption of oxides of nitrogen {(C01B21/26 takes precedence)} |
| Total patents | 57 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is declining.
| Year | Patents |
|---|---|
| 2015 | 2 |
| 2016 | 1 |
| 2017 | 5 |
| 2018 | 2 |
| 2019 | 4 |
| 2020 | 8 |
| 2021 | 9 |
| 2022 | 4 |
| 2023 | 9 |
| 2024 | 4 |
| 2025 | 7 |
| 2026 | 2 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Nitric acid production with oxygen supply to absorption section
US-2026001762-A1 · Jan 1, 2026 · US
Method for operating an SOFC for the combined production of electricity and nitric oxide
US-12512498-B2 · Dec 30, 2025 · US
Process and reactor for catalytic oxidation of ammonia
US-12459819-B2 · Nov 4, 2025 · US
Nitric acid plant and process with heat recovery system
US-2025250168-A1 · Aug 7, 2025 · US
Nitric acid plant for producing nitric acid
US-2025171303-A1 · May 29, 2025 · US
Mixing system
US-2025144581-A1 · May 8, 2025 · US
Bleaching tower and method for nitric acid production
US-12252399-B2 · Mar 18, 2025 · US
Mono pressure system for producing nitric acid and method of operating thereof
US-2025011171-A1 · Jan 9, 2025 · US
Dual pressure system for producing nitric acid and method of operating thereof
US-2024367976-A1 · Nov 7, 2024 · US
Integrated process for the synthesis of ammonia and nitric acid
US-2024359982-A1 · Oct 31, 2024 · US
High energy recovery nitric acid process using liquid oxygen containing fluid
US-11905172-B2 · Feb 20, 2024 · US
Ammonia burner for nitric acid production
US-2024002231-A1 · Jan 4, 2024 · US
Mono-pressure plant for the production of nitric acid and method for operating same
US-2023382734-A1 · Nov 30, 2023 · US
Method for operating an sofc for the combined production of electricity and nitric oxide
US-2023378507-A1 · Nov 23, 2023 · US
Nitric acid production process and plant with oxygen supply unit
US-11772971-B2 · Oct 3, 2023 · US
Dual pressure plant for the production of nitric acid and method for operating same
US-2023264957-A1 · Aug 24, 2023 · US
Nitric acid production process and plant with oxygen supply unit
US-2023257268-A1 · Aug 17, 2023 · US
Absorption column comprising a feed box having a serrated weir and a structured packing and process for the production of nitric acid
US-2023202845-A1 · Jun 29, 2023 · US
Method for the catalytic oxidation of ammonia gas
US-11643327-B2 · May 9, 2023 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC C01B21/40?
- CPC C01B21/40 is the Cooperative Patent Classification code for “Preparation by absorption of oxides of nitrogen {(C01B21/26 takes precedence)}.”
- How many patents are filed under CPC C01B21/40 (Preparation by absorption of oxides of nitrogen {(C01B21/26 takes precedence)})?
- Our database includes 57 publications tagged with this CPC code.
- Is patent activity under CPC C01B21/40 growing?
- Publication counts under this code: 4 in 2024 vs 7 in 2025 (latest complete years).