D21C 3/222
Use of compounds accelerating the pulping processes
Official title: {Use of compounds accelerating the pulping processes}
D21C3/222 (Use of compounds accelerating the pulping processes) appears on 157 US grants and 160 published applications in this corpus.
Search patents in D21C- Granted patents
- 157
- Published applications
- 160
- Assignees
- 116
- Inventors
- 390
- Latest grant
- 4 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 3 | 0 |
| 1978 | 4 | 0 |
| 1979 | 3 | 0 |
| 1980 | 4 | 0 |
| 1981 | 2 | 0 |
| 1982 | 3 | 0 |
| 1983 | 3 | 0 |
| 1984 | 3 | 0 |
| 1985 | 0 | 0 |
| 1986 | 2 | 0 |
| 1987 | 2 | 0 |
| 1988 | 4 | 0 |
| 1989 | 2 | 0 |
| 1990 | 2 | 0 |
| 1991 | 2 | 0 |
| 1992 | 2 | 0 |
| 1993 | 0 | 0 |
| 1994 | 4 | 0 |
| 1995 | 2 | 0 |
| 1996 | 1 | 0 |
| 1997 | 1 | 0 |
| 1998 | 1 | 0 |
| 1999 | 2 | 0 |
| 2000 | 5 | 0 |
| 2001 | 2 | 0 |
| 2002 | 1 | 4 |
| 2003 | 5 | 2 |
| 2004 | 2 | 4 |
| 2005 | 2 | 5 |
| 2006 | 3 | 5 |
| 2007 | 1 | 4 |
| 2008 | 2 | 1 |
| 2009 | 0 | 4 |
| 2010 | 1 | 4 |
| 2011 | 1 | 9 |
| 2012 | 4 | 4 |
| 2013 | 3 | 8 |
| 2014 | 5 | 17 |
| 2015 | 8 | 10 |
| 2016 | 8 | 18 |
| 2017 | 11 | 9 |
| 2018 | 3 | 4 |
| 2019 | 3 | 6 |
| 2020 | 2 | 5 |
| 2021 | 5 | 4 |
| 2022 | 4 | 5 |
| 2023 | 2 | 8 |
| 2024 | 5 | 5 |
| 2025 | 11 | 14 |
| 2026 | 4 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Optimization of chemical consumption in biomass delignification4 Aug 2026US 12,698,589 B2Sixring Inc.
- Processes for fractionation of biomass4 Aug 2026US 12,698,590 B2The Board of Trustees of The University of Alabama
- High yield cooking method14 Apr 2026US 12,601,114 B2AMPPC Finland Oy
- Optimization of chemical consumption in biomass delignification17 Feb 2026US 12,553,180 B2Sixring Inc.
- Lignocellulose refinery23 Dec 2025US 12,503,410 B2Katholieke Universiteit Leuven
- Chemical wood pulp with enhanced tensile strength6 Aug 2026US 2026/0226685 A1SöDra SkogsäGarna Ekonomisk FöRening
- Digestion accelerator and method for producing pulp using same25 Dec 2025US 2025/0389083 A1Nicca Chemical Co., Ltd.
- Method for preparing pulp with relatively high brightness and high-activity lignin25 Dec 2025US 2025/0389084 A1Qilu University of Technology (Shandong Academy of Sciences)
- Use of in-situ ionic liquid (il) and deep eutectic solvent (des) synthesis using chemically synthesized or biomass-derived ions in the pretreatment of biomass4 Dec 2025US 2025/0369183 A1National Technology & Engineering Solutions of Sandia, LLC
- Efficient methods and compositions for recovery of products from organic acid pretreatment of plant materials6 Nov 2025US 2025/0341054 A1Pierson Capital Environmental (Beijing) Limited
Most cited
By later US patents
- Process for oxygen pulping of lignocellulosic material and recorvery of pulping chemicals96US 6,770,168 B1Kiram AB · 2004
- Production of pulp by the soda-anthraquinone process (SAP) with recovery of the cooking chemicals77US 5,595,628 AGrant S.A. · 1997
- Process for extracting lignin from lignocellulosic material using an aqueous organic solvent and an acid neutralizing agent46US 4,746,401 AGeorgia Tech Research Corporation · 1988
- High-yield chemical pulping41US 4,869,783 AThe Mead Corporation · 1989
- Delignification of lignocellulosic material with an alkaline liquor in the presence of a cyclic keto compound40US 4,012,280 ACanadian Industries Limited · 1977