On the structure of lignin in kraft pulping
2004 (English)In: 2nd International Symposium on Technologies Of Pulping, Papermaking and Biotechnology on Fiber Plants, Proceedings / [ed] Jin, YC; Xie, HF, NANJING: NANJING FORESTRY UNIV , 2004, 1-5 p.Conference paper (Refereed)
Lignin present in the residual delignification phase is difficult to dissolve and any further pulping leads to an increased loss of pulp strength and yield. In this work, a radical coupling mechanism during kraft pulping is suggested to contribute to the observed incomplete delignification. In such an electron transfer reaction, elemental sulfur may act as an initiator between the residual lignin in the pulp and phenolic structures present in the black liquor. To find support for such a mechanism, lignins from kraft cooks with kappa number of approximate to 30 prepared with and without a reactive phenol, 2,6-xylenol in the cook, were studied. GPC, GS-MS and NMR were the techniques used for analyses of isolated lignins and lignin samples obtained by thioacidolysis to support the suggested mechanism. The analytical data showed that the added phenol was incorporated into the polymeric lignin with a preferential formation of biphenyl structures.
Place, publisher, year, edition, pages
NANJING: NANJING FORESTRY UNIV , 2004. 1-5 p.
IdentifiersURN: urn:nbn:se:kth:diva-44780ISI: 000228663000001ISBN: 988-97887-7-2OAI: oai:DiVA.org:kth-44780DiVA: diva2:451257
2nd International Symposium on Technologies of Pulping, Papermaking and Biotechnology on Fiber Plants Location: Nanjing, PEOPLES R CHINA Date: OCT 13-14, 2004
QC 201110252011-10-252011-10-252011-11-02Bibliographically approved