Extended impregnation in the kraft cook: an approach to improve the overall yield in eucalypt kraft pulping
2010 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 25, no 1, 7-14 p.Article in journal (Refereed) Published
A potential way to improve the overall yield is to terminate the kraft cook at higher kappa number. This method was investigated using Extended Impregnation kraft Cook (EIC). As a reference, kraft pulp manufactured by conventional kraft cooking was used. By utilising the EIC concept, the defibration point in the kraft cook is shifted towards higher kappa numbers, resulting in a lower reject content at a given kappa number. This enables a termination of the ETC cook at higher kappa number. The results show that an overall yield gain of 2.6 percentage units could be achieved using ETC with higher cooking kappa number followed by extended oxygen delignification and bleaching with a D*(OP)D sequence to full brightness. However, the EIC concept at higher cooking kappa number resulted in somewhat higher bleaching chemical requirement. Extended oxygen delignification was shown to be possible to reach as low a kappa number as 10, but a high cooking kappa number is clearly a disadvantage if a high limiting viscosity number after oxygen delignification is required.
Place, publisher, year, edition, pages
2010. Vol. 25, no 1, 7-14 p.
Yield, Kraft pulping, Eucalyptus, Oxygen delignification, Bleaching, Carbohydrate, Xylan, Cellulose
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:kth:diva-27568DOI: 10.3183/NPPRJ-2010-25-01-p007-014ISI: 000278043500001ScopusID: 2-s2.0-84855522574OAI: oai:DiVA.org:kth-27568DiVA: diva2:377923
QC 201012152010-12-152010-12-132012-05-07Bibliographically approved