EP 0441113 B1 19940928 - Process for the chlorine-free bleaching of cellulosic pulp.
Title (en)
Process for the chlorine-free bleaching of cellulosic pulp.
Title (de)
Verfahren zum chlorfreien Bleichen von Zellstoff.
Title (fr)
Procédé exempt de chlore pour le blanchiment de pâte cellulosique.
Publication
Application
Priority
AT 26190 A 19900207
Abstract (en)
[origin: EP0441113A1] The process comprises three stages, namely an oxygen bleach which is optionally combined with a hydrogen peroxide bleach (EOP stage), an ozone bleach (Z stage) and a peroxide bleach (P stage). According to the invention, the residual oxygen content of the exit air from the Z stage is completely reacted in the EOP stage, and the effluent of the Z stage is used for dilution between the EOP and Z stages and/or for ash removal from the pulp after bleaching. It is advantageous in this case to control the temperature, the NaOH supply and the O2/H2O2 ratio in the EOP stage, so that the oxygen consumption at a constant conversion is adjusted to the residual oxygen content of the exit air from the Z stage.
IPC 1-7
IPC 8 full level
D06L 3/02 (2006.01); D06L 4/70 (2017.01); D21C 9/10 (2006.01); D21C 9/147 (2006.01); D21C 9/153 (2006.01); D21C 9/16 (2006.01)
CPC (source: EP US)
D21C 9/1057 (2013.01 - EP US); D21C 9/147 (2013.01 - EP US); D21C 9/153 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
EP 0441113 A1 19910814; EP 0441113 B1 19940928; AT 395028 B 19920825; AT A26190 A 19920115; AT E112338 T1 19941015; BR 9100516 A 19911029; CA 2035698 A1 19910808; CA 2035698 C 20030325; CS 9100280 A2 19910915; CZ 280077 B6 19951018; DE 59007341 D1 19941103; DK 0441113 T3 19941024; ES 2061008 T3 19941201; FI 910601 A0 19910207; FI 910601 A 19910808; FI 98077 B 19961231; FI 98077 C 19970410; HR P930456 A2 19951231; IN 174833 B 19950318; JP H04300380 A 19921023; LT 3392 B 19950825; LT IP753 A 19950131; LV 10514 A 19950220; LV 10514 B 19951020; NO 178079 B 19951009; NO 178079 C 19960117; NO 910455 D0 19910206; NO 910455 L 19910808; PL 169421 B1 19960731; PL 288978 A1 19920113; RU 2040616 C1 19950725; SI 9110206 A 19980228; SI 9110206 B 20000430; SK 278326 B6 19961106; US 5145557 A 19920908; YU 20691 A 19940510; YU 47388 B 19950131; ZA 91840 B 19920129
DOCDB simple family (application)
EP 90890348 A 19901220; AT 26190 A 19900207; AT 90890348 T 19901220; BR 9100516 A 19910207; CA 2035698 A 19910205; CS 28091 A 19910206; DE 59007341 T 19901220; DK 90890348 T 19901220; ES 90890348 T 19901220; FI 910601 A 19910207; HR P930456 A 19930323; IN 85CA1991D A 19910128; JP 1657591 A 19910207; LT IP753 A 19930702; LV 930021 A 19930112; NO 910455 A 19910206; PL 28897891 A 19910206; SI 9110206 A 19910206; SK 28091 A 19910206; SU 4894510 A 19910206; US 65202791 A 19910207; YU 20691 A 19910206; ZA 91840 A 19910205