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Activation of dissolving pulps prior to viscose preparation
Karlstad University, Faculty of Technology and Science.
2007 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

The conventional viscose manufacturing process is a mature process that needs to be improved with respect to its environmental impact and its production cost structure. Therefore a research study has been done with the aim to improve the reactivity of the dissolving pulp used, in order to reduce the chemical demand in the viscose process and thus reduce the cost and indirectly the environmental impact.

The work described in this thesis has shown that it is possible to enhance the pulp reactivity and to use less carbon disulphide in the production of viscose, while maintaining a good quality viscose dope, by two entirely different pretreatment methods, one chemical and one enzymatic.

The chemical method used pressurized oxygen after the mercerisation step, which increased the reactivity of the alkali cellulose. The viscose dopes produced from the pressurized oxygen treated alkali cellulose had lower filter clogging values, Kw, compared to conventionally produced viscoses. The temperature and the oxygen treatment time of the alkali cellulose were however crucial for the viscose quality.

The best performing enzyme of several tested was a cellulase of the mono component endoglucanase preparation Carezyme®. This enzymatic treatment was optimized with respect to viscose dope preparation. The study showed that the enzyme treatment could be carried out under industrially interesting conditions with respect to temperature, enzyme dose and reaction time. A re-circulation study of the enzyme showed that it was possible to re-use the spent press water from the enzymatic treatment step several times, and thus lower the production cost. Some of the viscose process stages were modified to properly fit the enzymatically treated dissolving pulp and a comparison between viscose made from enzyme-treated pulp and viscose made from conventional pulp, showed that the enzyme-treated samples had a lower filter clogging value, Kw. This indirectly indicates that the enzyme pretreatment could reduce the carbon disulphide charge in the viscose manufacturing process. An initial study of how the Carezyme® influenced different cellulosic sources was also performed.

Place, publisher, year, edition, pages
Fakulteten för teknik- och naturvetenskap , 2007.
Series
Karlstad University Studies, ISSN 1403-8099 ; 2007:46
Keywords [en]
dissolving pulp, enzyme, reactivity, viscose
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
URN: urn:nbn:se:kau:diva-1276ISBN: 978-91-7063-150-4 (print)OAI: oai:DiVA.org:kau-1276DiVA, id: diva2:5128
Public defence
2007-12-14, Ericssonsalen, 9, Universitetsgatan 1, Karlstad, 13:00
Opponent
Supervisors
Available from: 2007-12-17 Created: 2007-12-17
List of papers
1. The effect of modifying the oxidative pre-aging conditions in the manufacture of viscose from wood pulp
Open this publication in new window or tab >>The effect of modifying the oxidative pre-aging conditions in the manufacture of viscose from wood pulp
2006 (English)In: Paperi ja puu, ISSN 0031-1243, Vol. 88, no 3, p. 175-180Article in journal (Refereed) Published
Identifiers
urn:nbn:se:kau:diva-1943 (URN)
Available from: 2007-12-17 Created: 2007-12-17 Last updated: 2017-12-07Bibliographically approved
2. Enzymatic treatment to increase the reactivity of a dissolving pulp for viscose preparation
Open this publication in new window or tab >>Enzymatic treatment to increase the reactivity of a dissolving pulp for viscose preparation
2006 (English)In: Appita journal, ISSN 1038-6807, Vol. 59, no 3, p. 242-246Article in journal (Refereed) Published
Identifiers
urn:nbn:se:kau:diva-1944 (URN)
Available from: 2007-12-17 Created: 2007-12-17 Last updated: 2017-12-07Bibliographically approved
3. Optimization of the enzymatic activation of a dissolving pulp before viscose manufacture
Open this publication in new window or tab >>Optimization of the enzymatic activation of a dissolving pulp before viscose manufacture
2007 (English)In: TAPPI Journal, ISSN 0734-1415, Vol. 6, no 6, p. 14-19Article in journal (Refereed) Published
Identifiers
urn:nbn:se:kau:diva-1945 (URN)
Available from: 2007-12-17 Created: 2007-12-17 Last updated: 2017-12-07Bibliographically approved
4. Pressurized oxygen treatment of alkali cellulose prior to the preparation of viscose dope
Open this publication in new window or tab >>Pressurized oxygen treatment of alkali cellulose prior to the preparation of viscose dope
2007 (English)In: Paperi ja puu, ISSN 0031-1243, Vol. 89, no 7-8, p. 431-435Article in journal (Refereed) Published
Identifiers
urn:nbn:se:kau:diva-1946 (URN)
Available from: 2007-12-17 Created: 2007-12-17 Last updated: 2017-12-07Bibliographically approved
5. Modification of the viscose process for enzymatically pre-treated dissolving pulps
Open this publication in new window or tab >>Modification of the viscose process for enzymatically pre-treated dissolving pulps
(English)In: Paperi ja puu, ISSN 0031-1243Article in journal (Refereed) Submitted
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-1947 (URN)
Available from: 2007-12-17 Created: 2007-12-17 Last updated: 2017-12-07Bibliographically approved

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Citation style
  • apa
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