Method and pulping composition for the selective delignification of lignocellulosic materials with an aqueous amine-alcohol mixture in the presence of a catalyst
US4597830A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1983 |
| Grant date | Jul 1, 1986 |
| Priority date | — |
| Expiry date | Jun 20, 2003 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C3/20
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A pulping liquor for the delignification of lignocellulosic materials is disclosed which avoids the use of sodium hydroxide and so avoids degradation of substantial portions of the cellulose component, and simultaneously avoids the use of sulphide or other environmental pollutants. The cooking process employing this liquor can advantageously include recycling of the liquor to provide sustained delignification from the same original liquor provided, and distillation of spent liquor to recover the essential components thereof. The liquor is comprised of alcohol, an amine and water, each present in amount of 1-12 parts by volume. The liquor is further used in the presence of a quinone and/or azine catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.