Dithionite impregnation combined with mild steam explosion of spruce wood – an improved version of kraft pulping
(English)Manuscript (preprint) (Other (popular science, discussion, etc.))
Norway spruce (Picea abies) wood chips were impregnated with water or sodium dithionite (Na2S2O4) and were subsequently subjected to a mild steam explosion (STEX) treatment at four or seven bar for ten minutes. In order to evaluate the combined effect of Na2S2O4 and STEX, kraft cooking was performed on samples pre-treated with different combinations of impregnation and STEX. Carbohydrate composition, Klason lignin content, kappa number, intrinsic viscosity, pulp yield, brightness and tensile strength (on pulp sheets) were tested and compared. The results showed that an impregnation with Na2S2O4 combined with mild STEX had a good effect on the delignification during kraft pulping, shown by lower kappa numbers and lower Klason lignin content. The viscosity of the pulp samples of Na2S2O4 plus STEX was lower than the water impregnated and non-STEX pulps. However, the lower viscosity did not influence the strength of the pulp since the tensile index was still high. The Na2S2O4 plus STEX pulp sheets also showed the highest brightness value.
sodium dithionite, mild steam explosion, kraft pulping, peeling, enhanced delignification
Research subject Fibre and Polymer Science
IdentifiersURN: urn:nbn:se:kth:diva-150394OAI: oai:DiVA.org:kth-150394DiVA: diva2:742769
FunderKnut and Alice Wallenberg Foundation, 8102
QS 20142014-09-022014-09-022014-09-03Bibliographically approved