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A novel nano cellulose preparation method and size fraction by cross flow ultra- filtration
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
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2012 (English)In: Current organic chemistry, ISSN 1385-2728, Vol. 16, no 16, 1871-1875 p.Article in journal (Refereed) Published
Abstract [en]

A novel energy-efficient method called nanopulping (patent pending) to produce nanocellulose from chemical pulp, and a novel cross-flow ultra-filtration method to separate nanofibrils fractions of different size were applied in this study. Pretreatment with endoglucanase or 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation seems to enhance the nanopulping process. Results were evaluated with atomic force microscope and ultrafiltration. The nanopulping produced a relatively inhomogeneous material with larger particles/ fibers in addition to nanofibers. However, by ultrafiltration of the material it was possible to obtain more homogeneous material in different dimensions with methods industrially acceptable.

Place, publisher, year, edition, pages
2012. Vol. 16, no 16, 1871-1875 p.
Keyword [en]
Cross flow ultra-filtration, Endoglucanase pretreatment, Microfibrillated cellulose, Nanocellulose, Nanopulping, TEMPO pretreatment
National Category
Chemical Engineering
URN: urn:nbn:se:kth:diva-101522DOI: 10.2174/138527212802651197ISI: 000307867800006ScopusID: 2-s2.0-84864563327OAI: diva2:549354

QC 20120904

Available from: 2012-09-04 Created: 2012-08-30 Last updated: 2014-04-04Bibliographically approved
In thesis
1. The Use of Membrane Filtration to Improve the Properties of Extracted Wood Components
Open this publication in new window or tab >>The Use of Membrane Filtration to Improve the Properties of Extracted Wood Components
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The forest is alarge and important natural resourcein Sweden, and approximately 70% of the country’s land area is woodland. Wood is an excellent raw material for the replacement of oil-based products because it is renewable, biodegradable and carbon neutral. Furthermore, the forest industry is searching for new processes and methods to utilise by-product streams in a so-called integrated biorefinery. A key to the success of producing new products from wood could be pure and homogenous raw materials. Because wood contains a large variety of components with different characteristics and sizes, cross-flow filtration (CFF) will be a key separation technique to obtain homogenous and pure raw materials in the biorefinery concept.

Different wood material components have been studied in this thesis. The first part of this work focuses on kraft lignin. Kraft lignin is interesting because approximately 3.5-4 million metric tonnes are produced in Sweden annually (~7million tonnes of kraft pulp/year in 2012), and today it is mainly used as fuel. The second part of this thesis deals with materials in hot water extract (i.e.,  galactoglucomannan, but also other components). These extracted materials are interesting because similar materials are extracted in thermomechanical pulping process by-product streams. Finally, nanocellulose has been studied since it is an interesting raw material for future applications.

Through CFF, kraft lignin from black liquor has been fractionated into raw material samples with more homogeneous characteristics such as molecular weight, aromatic hydroxyl groups and thermal properties. From dynamic mechanical analysis, low molecular weight fractions were found to have the highest degree softening. To precipitate low molecular weight fractions (<1000 Dacut-off) into a convenient solid, lower temperatures than forhigh molecular weight fractions were needed. To produce low molecular weight lignin (<5000 Da cut-off) from re-dissolved LignoBoost lignin, lower lignin concentrations and higher pH and ionic strength were found to increase the permeate fluxat the tested conditions.

Nanocellulose has been producedby a novel process called nanopulping and has subsequently been size fractionated by CFF to obtain more homogenous nanocellulose.

CFF and adsorption chromatography can be used to isolate dissolved wood components, yielding several upgraded products: lignin, lignin-carbohydrate complexes, and galactoglucomannan.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. 59 p.
TRITA-CHE-Report, ISSN 1654-1081 ; 2014.9
National Category
Polymer Technologies
urn:nbn:se:kth:diva-143954 (URN)
Public defence
2014-04-25, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)

QC 20140404

Available from: 2014-04-04 Created: 2014-04-03 Last updated: 2014-04-04Bibliographically approved

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