The distribution of oxidizable structures in ECF- and TCF- bleached kraft pulps
2002 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 17, no 4, 415-419 p.Article in journal (Refereed) Published
The kappa number in kraft pulp contains contributions from lignin and from other oxidizable structures denoted as false lignin. The latter can be divided in hexenuronic acid groups and "non-lignin" structures. In this paper, the kappa number units due to the various contributing structures have been quantified by fractionation of the kappa number. Bleached spruce and birch kraft industrial pulps taken after each stage in an ECF (ODEQP) and in a TCF (OQOPQPO) bleaching sequence respectively have been assessed. Possible correlations between the content of false lignin, the pulp origin, the bleaching conditions, and brightness and viscosity values have been sought. It is concluded that the false lignin structures are formed predominantly during the cooking and oxygen delignification stages. The false lignin structures were found to give different responses in the various bleaching stages, but to have no influence on either pulp brightness or viscosity.
Place, publisher, year, edition, pages
2002. Vol. 17, no 4, 415-419 p.
Bleaching, Chlorine dioxide, Hexenuronic acid, Hydrogen peroxide, Kappa number, Kraft pulps, Lignin, Oxygen, Permanganate consumption
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-8863DOI: 10.3183/NPPRJ-2002-17-04-p415-419ISI: 000180616600010OAI: oai:DiVA.org:kth-8863DiVA: diva2:14331
QC 201010012005-12-022005-12-022010-10-01Bibliographically approved