D21C 3/26
Multistage processes
D21C3/26 (Multistage processes) appears on 99 US grants and 102 published applications in this corpus.
Search patents in D21C- Granted patents
- 99
- Published applications
- 102
- Assignees
- 76
- Inventors
- 210
- Latest grant
- 4 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 0 | 0 |
| 1978 | 3 | 0 |
| 1979 | 1 | 0 |
| 1980 | 0 | 0 |
| 1981 | 2 | 0 |
| 1982 | 0 | 0 |
| 1983 | 1 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 1 | 0 |
| 1987 | 2 | 0 |
| 1988 | 1 | 0 |
| 1989 | 3 | 0 |
| 1990 | 1 | 0 |
| 1991 | 0 | 0 |
| 1992 | 1 | 0 |
| 1993 | 3 | 0 |
| 1994 | 1 | 0 |
| 1995 | 0 | 0 |
| 1996 | 3 | 0 |
| 1997 | 3 | 0 |
| 1998 | 1 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 2 | 1 |
| 2002 | 4 | 3 |
| 2003 | 3 | 0 |
| 2004 | 1 | 2 |
| 2005 | 0 | 1 |
| 2006 | 0 | 3 |
| 2007 | 0 | 1 |
| 2008 | 0 | 2 |
| 2009 | 1 | 1 |
| 2010 | 0 | 5 |
| 2011 | 1 | 2 |
| 2012 | 1 | 6 |
| 2013 | 2 | 4 |
| 2014 | 3 | 8 |
| 2015 | 4 | 6 |
| 2016 | 4 | 5 |
| 2017 | 6 | 8 |
| 2018 | 7 | 5 |
| 2019 | 3 | 6 |
| 2020 | 4 | 7 |
| 2021 | 6 | 6 |
| 2022 | 3 | 6 |
| 2023 | 4 | 3 |
| 2024 | 2 | 5 |
| 2025 | 4 | 3 |
| 2026 | 4 | 3 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Optimization of chemical consumption in biomass delignification4 Aug 2026US 12,698,589 B2Sixring Inc.
- Process for treatment of biomass for pulping and biorefinery applications19 May 2026US 12,630,975 B2Fuma Labs Private Limited
- Extraction of delignified, cellulose-based fibers from natural plant material, and materials incorporating such fibers12 May 2026US 12,624,500 B2University of Maryland, College Park
- Optimization of chemical consumption in biomass delignification17 Feb 2026US 12,553,180 B2Sixring Inc.
- Evaporative devices having delignified plant materials, and systems and methods for fabrication and use thereof30 Dec 2025US 12,509,822 B2University of Maryland, College Park
- Method of Preparing High-Strength, High-Toughness, and Recyclable Fiberboard with Bionic Structure3 Sep 2026US 2026/0258602 A1Northeast Forestry University
- Two-step impregnation in ht-ctmp production23 Jul 2026US 2026/0210040 A1Billerud Aktiebolag (publ)
- Extraction of delignified, cellulose-based fibers from natural plant material, and materials incorporating such fibers26 Feb 2026US 2026/0055552 A1University of Maryland, College Park
- Use of cellulase to improve viscosity control of kraft dissolving pulp9 Oct 2025US 2025/0314012 A1Novozymes A/S
- Low temperature and low pressure process for agricultural feedstock preparation27 Mar 2025US 2025/0101683 A1Kanbol, Inc.
Most cited
By later US patents
- Method of treating lignocellulosic biomass to produce cellulose109US 6,419,788 B1PureVision Technology, Inc. · 2002
- Process for oxygen pulping of lignocellulosic material and recorvery of pulping chemicals96US 6,770,168 B1Kiram AB · 2004
- Cellulose production from lignocellulosic biomass93US 6,620,292 B2PureVision Technology, Inc. · 2003
- System and method for preextraction of hemicellulose through using a continuous prehydrolysis and steam explosion pretreatment process51US 8,057,639 B2Andritz Inc. · 2011
- Process to produce a high quality paper product and an ethanol product from bamboo40US 5,198,074 ACompanhia Industreas Brasileiras Portela · 1993