EP 0442806 A1 19910821 - A process for producing pulp from a lignocellulosic-containing material.
Title (en)
A process for producing pulp from a lignocellulosic-containing material.
Title (de)
Verfahren zur Herstellung von Zellstoff aus lignozellulosehaltigen Materialien.
Title (fr)
Procédé pour la fabrication de pâte à partir d'un matériau lignocellulosique.
Publication
Application
Priority
ZA 901031 A 19900212
Abstract (en)
This invention provides a process for producing pulp from a lignocellulosic-containing material. According to one aspect of the invention, there is provided a process for reducing the lignin content (as expressed by the Kappa number) of unbleached pulp intended for dissolving grade pulp manufacture, the process including the step of applying an alkali extraction step to the pulp. According to another aspect of the present invention, there is provided a process for producing dissolving grade pulp, the process including the following steps: a pre-hydrolysing step; a step of dissolving the lignin contained in the pre-hydrolysed material; and carrying out an alkali extraction step. The alkali extraction step may include using about 2% to 5%, preferably about 3%, alkali by mass of pulp; at a temperature of about 50 DEG C to 100 DEG C, preferably about 70 DEG C to 80 DEG C; for a period sufficient to give optimal lignin removal. The alkali used is preferably sodium hydroxide. According to a further aspect of the present invention, there is provided a dissolving grade pulp when produced by a process described above.
IPC 1-7
IPC 8 full level
D21C 1/04 (2006.01); D21C 3/04 (2006.01); D21C 3/22 (2006.01); D21C 3/26 (2006.01)
CPC (source: EP)
D21C 1/04 (2013.01); D21C 3/222 (2013.01); D21C 3/26 (2013.01)
Citation (search report)
- [A] US 2301314 A 19421110 - MONTONNA RALPH E, et al
- [X] ABSTRACT BULLETIN OF THE INSTITUTE OF PAPER CHEMISTRY. vol. 40, no. 4, October 1969, APPLETON US pages 292 - 293; Nepenin,Y.N. and Zhalina: "High-yield viscose-grade pulp."
- [X] ABSTRACT BULLETIN OF THE INSTITUTE OF PAPER CHEMISTRY. vol. 58, no. 1, July 1987, APPLETON US page 83 Petrik,A.W. et al.: "Production of dissolving pulp in a continuous digester using the Kraft process with hydrolysis."
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
EP 0442806 A1 19910821; AU 643746 B2 19931125; AU 7098791 A 19910815; BR 9100565 A 19911029; BR 9100592 A 19911029; CA 2036311 A1 19910813; FI 910655 A0 19910211; FI 910655 A 19910813; MW 191 A1 19910910; NZ 237098 A 19940126; PT 96722 A 19911031; RU 2037594 C1 19950619; ZW 1191 A1 19910828
DOCDB simple family (application)
EP 91400355 A 19910212; AU 7098791 A 19910212; BR 9100565 A 19910208; BR 9100592 A 19910213; CA 2036311 A 19910212; FI 910655 A 19910211; MW 191 A 19910212; NZ 23709891 A 19910212; PT 9672291 A 19910208; SU 4894714 A 19910211; ZW 1191 A 19910211