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Chemical pulping: Localization of xylan (native and added) during cooking

Salmén, Lennart and Filonova, Lada and Olsson, Anne-Marii and Hafrén, Jonas and Daniel, Geoffrey (2013). Chemical pulping: Localization of xylan (native and added) during cooking. Uppsala: (S) > Dept. of Forest Products, Sveriges lantbruksuniversitet. Intern rapport / Centrum för forskning om vedfiberns ultrastruktur ; 11
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Abstract

The aim of this study was to investigate how the xylan content is changed within a wood chip and within the fiber cell walls at different positions of the chip during cooking. It was hoped that such information would give an understanding regarding the critical factors for xylan deposition within the cell wall and possible ways of affecting strength delivery of the pulp.

Two sets of cooking trials were performed; one Ref-pulp and one with beech xylan addition in the impregnation stage (10g/L). The cooks were interrupted at specific times and the chips taken out and analyzed for chemical composition and distribution of wood polymers within the chips as well as within the fiber cell walls. The pulps produced with beech-xylan addition had about 2 % higher xylan content at the end of cooking compared to the Ref-pulp.

Results indicated that the chips already contained an increased amount of xylan after 10 minutes of impregnation when beech xylan was added to the cooking liquor. However, only chips at the end of the cook showed a substantial increase in xylan sorption. During cooking, a large gradient in lignin content was noted between the surface and the inside of the chips which always showed higher lignin content even at the end of the cook. A progressive increase in xylan content was also noted in the chips as cooking proceeded. From the studies made it was not possible however, to determine if the addition of xylan led to any increased xylan content within the fibre walls. In cooks with beech xylan added during early stages, an increase in xylan was noted in the fibre lumen areas. In later stages and with increased delignification, increased xylan content was also noted between fibres in degraded middle lamellae regions.

Authors/Creators:Salmén, Lennart and Filonova, Lada and Olsson, Anne-Marii and Hafrén, Jonas and Daniel, Geoffrey
Title:Chemical pulping: Localization of xylan (native and added) during cooking
Series/Journal:Intern rapport / Centrum för forskning om vedfiberns ultrastruktur (BIB19552896)
Year of publishing :2013
Depositing date:31 August 2016
Number:11
Number of Pages:41
Place of Publication:Uppsala
Publisher:Department of Forest Products, Swedish University of Agricultural Sciences
Language:English
Publication Type:Report
Article category:Other scientific
Full Text Status:Public
Agris subject categories.:K Forestry > K50 Processing of forest products
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Forest Science
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Wood Science
Agrovoc terms:xylans, mechanical pulp, solid fuels, fagus, cooking
Keywords:xylan content, wood chips, beech xylans, fibre walls, cooking
URN:NBN:urn:nbn:se:slu:epsilon-e-3635
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-3635
ID Code:13514
Faculty:S - Faculty of Forest Sciences
Department:(S) > Dept. of Forest Products
Deposited By: SLUpub Connector
Deposited On:31 Aug 2016 08:48
Metadata Last Modified:06 Sep 2016 08:10

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