D21C 11/0035
Introduction of compounds
Official title: {Introduction of compounds, e.g. sodium sulfate, into the cycle in order to compensate for the losses of pulping agents}
D21C11/0035 (Introduction of compounds) appears on 16 US grants and 13 published applications in this corpus.
Search patents in D21C- Granted patents
- 16
- Published applications
- 13
- Assignees
- 16
- Inventors
- 39
- Latest grant
- 12 Aug 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1978 | 1 | 0 |
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| 1982 | 1 | 0 |
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| 2004 | 1 | 0 |
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| 2010 | 0 | 1 |
| 2011 | 0 | 1 |
| 2012 | 1 | 0 |
| 2013 | 0 | 0 |
| 2014 | 1 | 0 |
| 2015 | 0 | 0 |
| 2016 | 1 | 2 |
| 2017 | 0 | 1 |
| 2018 | 1 | 1 |
| 2019 | 1 | 0 |
| 2020 | 0 | 1 |
| 2021 | 0 | 1 |
| 2022 | 0 | 3 |
| 2023 | 2 | 1 |
| 2024 | 0 | 1 |
| 2025 | 3 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Method for recovering water and chemicals from plants for treating effluents from pulp and paper factories12 Aug 2025US 12,384,708 B2Investigaciones Forestales Bioforest S.A.
- Method of replacing sodium losses in a pulp mill, a method of producing bleached cellulosic pulp, and a system17 Jun 2025US 12,331,460 B2Metsa Fibre Oy
- Method for preparing fluff pulp from bamboos and fluff pulp prepared thereby29 Apr 2025US 12,286,750 B2South China University of Technology
- Multi-step process for the isolation of components from Miscanthus14 Nov 2023US 11,814,790 B2Exegi IP Management B.V.
- Method of treating fly ash of a recovery boiler15 Aug 2023US 11,725,341 B2Andritz Inc.
- Method for preparing fluff pulp from bamboos and fluff pulp prepared thereby3 Oct 2024US 2024/0328083 A1South China University of Technology
- Methods of treating a kraft process recovery cycle to reduce metal levels at the kraft process31 Aug 2023US 2023/0272581 A1Suzano S.A.
- Processes for extracting lignin from black liquor13 Oct 2022US 2022/0324894 A1Suzano S.A.
- Method for recovering water and chemicals from plants for treating effluents from pulp and paper factories30 Jun 2022US 2022/0204377 A1Investigaciones Forestales Bioforest S.A.
- A method of replacing sodium losses in a pulp mill, a method of producing bleached cellulosic pulp, and a system7 Apr 2022US 2022/0106737 A1Andritz Inc.
Most cited
By later US patents
- Kraft overload recovery process25US 4,470,876 A1984
- Method for fixing a mineral filler on cellulosic fibers and method for making a sheet of paper12US 6,706,148 B1Georgia-Pacific France · 2004
- Process for digesting and bleaching cellulosic material with reduced emissions7US 4,329,199 ASCA Development Aktiebolag · 1982
- Process for cooking and bleaching pulp5US 4,799,994 AOy Tampella AB · 1989
- Method for separating lignin from black liquor, a lignin product, and use of a lignin product for the production of fuels or materials5US 9,382,389 B2Valmet Aktiebolag · 2016