The Effect of Sodium Ion Concentration and Dissolved Wood Components in the Kraft Cook of Softwood
2004 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 19, no 3, 325-329 p.Article in journal (Refereed) Published
The effect of ionic strength and dissolved wood components (DWC) in form of industrial black liquor on the delignification rate and the brightness of the unbleached softwood kraft pulp has been investigated. A technique with a high liquor-to-wood ratio (75 L/kg) a so-called constant composition cook was used to separate the effects of the different parameters. The study showed that an increase in the ionic strength led to a decrease in the rate of delignification and gave a more coloured pulp, where as the presence of DWC gave a more coloured pulp and an increase in the delignification rate.
The influence of the ionic strength and DWC on the bleachability of the softwood kraft pulp in an ECF-sequence (D(EOP)DD) was also investigated. The results show that the bleachability i.e. consumption of bleaching chemicals to reach a certain brightness, was not affected by the ionic strength during the cook. The addition of DWC, on the other hand, increased the consumption of bleaching chemicals to reach ISO brightness 89%.
Place, publisher, year, edition, pages
2004. Vol. 19, no 3, 325-329 p.
kraft pulping, delignification rate, bleachability, softwood, black liquor
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-5432ISI: 000224636500007ScopusID: 2-s2.0-6344252669OAI: oai:DiVA.org:kth-5432DiVA: diva2:9795
QC 201412052006-03-082006-03-082014-12-05Bibliographically approved