EP 0720676 A4 19980304 - IMPROVED METHOD FOR BLEACHING LIGNOCELLULOSIC PULP
Title (en)
IMPROVED METHOD FOR BLEACHING LIGNOCELLULOSIC PULP
Title (de)
VERBESSERTES VERFAHREN ZUM BLEICHEN VON LIGNOCELLULOSISCHEM ZELLSTOFF
Title (fr)
PROCEDE AMELIORE DE BLANCHIMENT DE PATE LIGNOCELLULOSIQUE
Publication
Application
Priority
- US 9409951 W 19940902
- US 11604093 A 19930902
- US 26809994 A 19940629
Abstract (en)
[origin: WO9506772A1] The present invention is directed to a method for treating lignocellulosic pulp prior to a bleaching step to minimize consumption of bleaching agent during the bleaching step which comprises the steps of (a) contacting the lignocellulosic pulp with an aqueous solution having a pH of at least about 5 and less than about 11 for a time sufficient to dissolve lignin from the pulp to form a reduced-lignin pulp and a lignin-rich solution, (b) separating the reduced-lignin pulp from the lignin-rich solution, and (c) bleaching the reduced-lignin pulp with the bleaching agent; wherein the time sufficient to dissolve lignin from the pulp to form a reduced-lignin pulp and a lignin-rich solution in step (a) is an amount of time which results in a decrease in bleaching agent consumption in step (c) in the range from about 10 % to about 20 %.
IPC 1-7
IPC 8 full level
D21C 9/10 (2006.01); D21C 9/147 (2006.01); D21C 9/153 (2006.01); D21C 11/00 (2006.01)
CPC (source: EP)
D21C 9/1005 (2013.01); D21C 9/153 (2013.01); D21C 11/0042 (2013.01)
Citation (search report)
- [Y] WO 8604938 A1 19860828 - ELTON EDWARD FRANCIS
- [Y] US 5085734 A 19920204 - GRIGGS BRUCE F [US]
- [Y] WO 9314262 A1 19930722 - SUNDS DEFIBRATOR IND AB [SE]
- See references of WO 9506772A1
Designated contracting state (EPC)
AT SE
DOCDB simple family (publication)
WO 9506772 A1 19950309; AU 7720094 A 19950322; BR 9407409 A 19961112; CA 2170398 A1 19950309; EP 0720676 A1 19960710; EP 0720676 A4 19980304; FI 960972 A0 19960301; FI 960972 A 19960429; JP H09502229 A 19970304
DOCDB simple family (application)
US 9409951 W 19940902; AU 7720094 A 19940902; BR 9407409 A 19940902; CA 2170398 A 19940902; EP 94928001 A 19940902; FI 960972 A 19960301; JP 50829095 A 19940902