D21C 11/04
Regeneration of pulp liquors or effluent waste waters: of alkali lye
Official title: of alkali lye
D21C11/04 (Regeneration of pulp liquors or effluent waste waters: of alkali lye) appears on 101 US grants and 57 published applications in this corpus.
Search patents in D21C- Granted patents
- 101
- Published applications
- 57
- Assignees
- 76
- Inventors
- 210
- Latest grant
- 17 Jun 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 3 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 2 | 0 |
| 1985 | 4 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 2 | 0 |
| 1989 | 1 | 0 |
| 1990 | 1 | 0 |
| 1991 | 2 | 0 |
| 1992 | 1 | 0 |
| 1993 | 1 | 0 |
| 1994 | 3 | 0 |
| 1995 | 2 | 0 |
| 1996 | 8 | 0 |
| 1997 | 9 | 0 |
| 1998 | 5 | 0 |
| 1999 | 2 | 0 |
| 2000 | 6 | 0 |
| 2001 | 6 | 1 |
| 2002 | 1 | 0 |
| 2003 | 1 | 0 |
| 2004 | 1 | 3 |
| 2005 | 0 | 2 |
| 2006 | 0 | 3 |
| 2007 | 2 | 1 |
| 2008 | 0 | 1 |
| 2009 | 1 | 1 |
| 2010 | 2 | 1 |
| 2011 | 1 | 5 |
| 2012 | 0 | 0 |
| 2013 | 1 | 1 |
| 2014 | 3 | 4 |
| 2015 | 5 | 6 |
| 2016 | 1 | 3 |
| 2017 | 2 | 3 |
| 2018 | 2 | 1 |
| 2019 | 3 | 5 |
| 2020 | 2 | 0 |
| 2021 | 2 | 6 |
| 2022 | 2 | 3 |
| 2023 | 2 | 1 |
| 2024 | 5 | 4 |
| 2025 | 2 | 0 |
| 2026 | 0 | 2 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Black liquor viscosity reducing and anti-scale agent17 Jun 2025US 12,331,461 B2Ecolab USA Inc.
- Method for lignin purification14 Jan 2025US 12,195,492 B2Ligneasy Oy
- Method for producing oxidized lignin in kraft pulp mill6 Aug 2024US 12,054,886 B2Andritz Inc.
- Continuous process for production of cellulose pulp from grass-like feedstock7 May 2024US 11,976,416 B2
- Black liquor viscosity reducing and anti-scale agent20 Feb 2024US 11,905,655 B2Ecolab USA Inc.
- Calcination reactor arrangement, calcination system and calcination method20 Aug 2026US 2026/0241355 A1Limearc Process AB
- A method for removing non-process elements in a kraft pulping process9 Jul 2026US 2026/0193840 A1Valmet Corporation
- Treating black liquor with acidic biomass for lignin recovery21 Nov 2024US 2024/0383937 A1SunCarbon AB
- Method and system for producing lignin29 Aug 2024US 2024/0287737 A1Valmet Corporation
- Black liquor viscosity reducing and anti-scale agent9 May 2024US 2024/0150961 A1Ecolab USA Inc.
Most cited
By later US patents
- Process of producing kraft pulping liquor by the oxidation of white liquor in the presence of lime mud32US 5,082,526 APulp and Paper Research Institute of Canada · 1992
- Kraft overload recovery process25US 4,470,876 A1984
- Method for obtaining useful products from green pseudostem, including papermaking pulp plantain22US 4,547,263 A1985
- Method for methylolation of lignin materials22US 4,764,597 AWestvaco Corporation · 1988
- Pulping with low dissolved solids for improved pulp strength21US 5,489,363 AKamyr, Inc. · 1996