The effect of chlorination effluent recycle on chlorate, kappa number, and viscosity in softwood kraft pulp bleaching

1995 ◽  
Vol 10 (4) ◽  
pp. 216-221
Author(s):  
Gary D. Farr ◽  
Kenneth L. Pinder ◽  
Leslie R. Galloway
Keyword(s):  
Kraft Pulp ◽  
Kappa Number ◽  
Pulp Bleaching ◽  
Kraft Pulp Bleaching ◽  
Softwood Kraft Pulp

Optimization of elemental chlorine-free bleaching for a softwood kraft pulp – part 1: impact of oxidative extraction on chlorine dioxide stoichiometry

TAPPI Journal ◽  
2010 ◽  
Vol 9 (8) ◽  
pp. 27-35 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Decision Making ◽  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Alkaline Extraction ◽  
Pulp Bleaching ◽  
Elemental Chlorine ◽  
Kraft Pulp Bleaching ◽  
Softwood Kraft Pulp ◽  
Chemical Usage ◽  
Minimize Costs

The present investigation meticulously analyzes how oxidative alkaline extraction can be augmented through process changes, and how these augmentations can be leveraged to optimize chlorine dioxide usage with elemental chlorine-free (ECF) sequences for a conventional softwood kraft pulp. Bleaching data from Basta and co-workers (1992 TAPPI Pulping Conference) are re-examined and re-interpreted in this study. We determined that ~60% to 65% of the overall ClO2 charge should be applied in the D0-stage. Peroxide addition to an (EOP) can replace 0.6 to 2.5 Kg. ClO2 per Kg H2O2. Boosting the (EO) temperature to 80°C is equivalent to a 70°C (EOP) with 0.25% to 0.30% H2O2,whereas a 90°C (EO) is equivalent to 0.50% – 0.75% H2O2 in a 70°C (EOP). The stoichiometric bleaching data from this study can guide decision-making for lowering chemical usage and minimize costs to reach target brightness levels with three- and five-stage sequences.

Size-exclusion chromatographic study of ECF and TCF softwood kraft pulp bleaching liquors

2011 ◽  
Vol 18 (7) ◽  
pp. 1049-1056 ◽  
Author(s):  
Jukka Kukkola ◽  
Juha Knuutinen ◽  
Jaakko Paasivirta ◽  
Sirpa Herve ◽  
Piia Pessala ◽  
...  
Keyword(s):  
Kraft Pulp ◽  
Size Exclusion ◽  
Chromatographic Study ◽  
Pulp Bleaching ◽  
Kraft Pulp Bleaching ◽  
Size Exclusion Chromatographic ◽  
Softwood Kraft Pulp

Application of a Catalyst in Peroxide Bleaching of Eucalyptus Kraft Pulp

Holzforschung ◽  
2000 ◽  
Vol 54 (4) ◽  
pp. 407-412 ◽  
Author(s):  
L. Kühne ◽  
J. Odermatt ◽  
T. Wachter
Keyword(s):  
Hydrogen Peroxide ◽  
Kraft Pulp ◽  
Pulp Bleaching ◽  
Selective Catalyst ◽  
Peroxide Bleaching ◽  
Softwood Pulp ◽  
Kraft Pulp Bleaching ◽  
Eucalyptus Kraft Pulp ◽  
Softwood Kraft Pulp

Summary A binuclear [Mn(III)Mn(IV)(μ-O)2(μ-CH3COO)L](ClO4−)2 complex with L = 1,2 Bis-(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)-ethane, described as a selective catalyst in hydrogen peroxide bleaching of softwood pulps, was tested in hardwood kraft pulp bleaching. The catalyst application gave rise to a higher consumption of peroxide which resulted in higher pulp brightness. The delignification improvement caused by the catalyst was shown to be much lower compared to catalysed peroxide bleaching of softwood kraft pulp. In contrast to the results of softwood pulp bleaching no selectivity improvements could be found when using the catalyst in bleaching of eucalyptus kraft pulp.

Formation of organochlorine compounds in kraft pulp bleaching processes

Chemosphere ◽  
1996 ◽  
Vol 33 (12) ◽  
pp. 2431-2440 ◽  
Author(s):  
S. Juuti ◽  
T. Vartiainen ◽  
J. Ruuskanen
Keyword(s):  
Kraft Pulp ◽  
Organochlorine Compounds ◽  
Pulp Bleaching ◽  
Kraft Pulp Bleaching
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