Method for the impregnation and cooking of lignocellulosic material by a batch cooking using spent impregnation liquor from a previous batch
US4764251A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 30, 1985 |
| Grant date | Aug 16, 1988 |
| Priority date | — |
| Expiry date | Jul 30, 2005 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C1/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for the production of cellulose by the batch cooking process, wherein the digester is filled with chips and cooking liquor, and the batch is cooked at elevated temperature and pressure in order to obtain a delignified cellulose pulp in the digester. For the impregnation stage a cooking liquor is used which contains a substantially higher amount of active chemicals than is required for the cooking of the batch, and before the actual delignification stage the active-chemical batch for the cooking is adjusted and the excess amount of active chemicals is removed by replacing it by part of the hot spent cooking liquor recovered from a previous cooking.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.