Patent · US Expired

Method for delignifying lignocellulosic raw materials

US7182836B2 · kind B2 · utility

2Cited by

6References

47Claims

0Family size

Assignee

Voith Paper Fiber Systems GmbH KG · DE

Inventors

Rudolf Patt · Bocholt, DE
Othar Kordsachia · Glinde, DE
Bjorn Rose · Hamburg, DE

Key dates

Filing date	Jul 1, 2002
Grant date	Feb 27, 2007
Priority date	—
Expiry date	Jul 1, 2022

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD21C3/06
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

The invention relates to a method for delignifying lignocellulosic raw materials by using sulfites in the presence of an alkaline component, especially sodium hydroxide or sodium carbonate or a mixture thereof in an aqueous solution at a high temperature and high pressure. The invention is characterized in that a first partial fragment of the alkaline component is added when the aqueous solution starts to decompose and in that at least a second partial fragment of the alkaline component is added only when delignification begins.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.