EP 0843757 B1 19991020 - METHOD FOR REPROCESSING AN OZONE-CONTAINING GAS PRESENT IN A PULP BLEACHING PLANT
Title (en)
METHOD FOR REPROCESSING AN OZONE-CONTAINING GAS PRESENT IN A PULP BLEACHING PLANT
Title (de)
VERFAHREN ZUM WIEDERAUFBEREITEN VON EINEM OZONENTHALTENDEN GAS IN EINER ANLAGE ZUM ZELLSTOFFBLEICHEN
Title (fr)
PROCEDE DE RETRAITEMENT D'UN GAZ CONTENANT DE L'OZONE, EXISTANT DANS UNE INSTALLATION DE BLANCHIMENT DE PATE A PAPIER
Publication
Application
Priority
- US 9612776 W 19960806
- US 194595 P 19950807
- US 69391996 A 19960805
Abstract (en)
[origin: WO9706305A1] A method for reprocessing an ozone-containing gas present in a pulp bleaching plant comprising the steps of supplying the ozone-containing gas to a scrubber and reducing the ozone concentration of the gas as the gas flows through the scrubber. The step of reducing comprises the steps of supplying an alkaline medium to the scrubber and flowing the ozone-containing gas in countercurrent relationship with the alkaline medium within the scrubber so as to provide intimate contact between the ozone-containing gas and the alkaline medium, thereby converting the ozone-containing gas into a substantially ozone-free gas. The alkaline medium may comprise one of the following: a sodium hydroxide solution; white liquor; post oxygen stage filtrate; weak black liquor; or filtrate from an Eo stage of the pulp bleaching plant. The method further comprises the step of separately discharging the ozone-containing gas and the alkaline medium from the scrubber. The ozone-containing gas may comprise an off-gas, which has been partially reacted with a pulp within a pulp bleaching stage or alternatively may comprise fresh bleaching gas, having an ozone concentration ranging from about 6 % to about 14 % by weight within a carrier gas, with the fresh bleaching gas being supplied directly from an ozone generator to the scrubber.
IPC 1-7
IPC 8 full level
B01D 53/66 (2006.01); D21C 9/153 (2006.01); D21C 11/06 (2006.01)
CPC (source: EP)
D21C 9/153 (2013.01); D21C 11/06 (2013.01)
Designated contracting state (EPC)
AT DE ES FI PT SE
DOCDB simple family (publication)
WO 9706305 A1 19970220; AT E185857 T1 19991115; BR 9609907 A 19990330; CA 2229046 A1 19970220; CN 1198786 A 19981111; DE 69604809 D1 19991125; DE 69604809 T2 20000511; DE 843757 T1 19981112; EP 0843757 A1 19980527; EP 0843757 B1 19991020; ES 2116952 T1 19980801; ES 2116952 T3 20000201; JP H10510469 A 19981013; PT 843757 E 20000428
DOCDB simple family (application)
US 9612776 W 19960806; AT 96927319 T 19960806; BR 9609907 A 19960806; CA 2229046 A 19960806; CN 96197410 A 19960806; DE 69604809 T 19960806; DE 96927319 T 19960806; EP 96927319 A 19960806; ES 96927319 T 19960806; JP 50860197 A 19960806; PT 96927319 T 19960806