Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Comparison between oxalate decarboxylase and oxalate oxidase in the degradation of oxalic acid in filtrates from the pulp and paper industry
Applied Microbiology, Lund University/Lund Institute of Technology.
Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
Karlstad University, Faculty of Technology and Science.
Show others and affiliations
(English)Manuscript (Other academic)
National Category
Chemical Sciences
Research subject
Chemistry
Identifiers
URN: urn:nbn:se:kau:diva-1967OAI: oai:DiVA.org:kau-1967DiVA: diva2:5242
Available from: 2008-02-01 Created: 2008-02-01 Last updated: 2011-11-14Bibliographically approved
In thesis
1. Chemical characterization in the biorefinery of lignocellulose: Formation and management of oxalic acid and analysis of feedstocks for bioethanol production
Open this publication in new window or tab >>Chemical characterization in the biorefinery of lignocellulose: Formation and management of oxalic acid and analysis of feedstocks for bioethanol production
2008 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

The pulp and paper industry is entering a new era. Pulp mills will be transformed to biorefineries that produce not only pulp, but also biofuels and novel products from lignocellulose. This thesis addresses problems connected with the industrial transition to environmental-friendly technologies and the implementation of the biorefinery concept.

Peroxide bleaching and enhanced recirculation of process water may lead to increased problems with oxalate scaling. Enzymatic elimination of the oxalate problem could be the ultimate industrial solution. The activities of oxalate oxidase, oxalate decarboxylase and a novel oxalate-degrading enzyme provided by Novozymes have been tested in industrial bleaching filtrates. Chemical characterization of the filtrates was used in combination with multivariate data analysis to identify potential enzyme inhibitors. A method based on oxalate oxidase was developed to determine the levels of oxalic acid in process water.

The precursors of oxalic acid formed during bleaching of pulp have been reassessed. New experimental data indicate that alkaline oxidative degradation of dissolved carbohydrates is the main source of oxalic acid. These findings are contradictory to previous hypotheses, which have been focused on lignin. Xylan was more important than lignin as precursor of oxalic acid under peroxide-bleaching conditions. Hot-water extraction of hemicelluloses from softwood mechanical pulp prior to the peroxide-bleaching stage reduced the formation of oxalic acid by one third.

Lignocellulosic materials were characterized chemically with regard to their suitability as feedstocks in biorefineries producing bioethanol. Four agricultural and agro-industrial residues were investigated; cassava stalks, peanut shells, rice hulls, and sugarcane bagasse. Pretreated sugarcane bagasse was the material that was most susceptible to hydrolysis by cellulolytic enzymes. Waste fiber sludges from three pulp mills were characterized. The waste fiber sludge with the lowest content of lignin was hydrolyzed most efficiently by the enzymes. Oligomeric xylan fragments were isolated as by-products from a waste fiber sludge. Hydrolysis of the waste fiber sludges resulted in solid residues with improved fuel properties. The waste fibers were found to be suitable as a feedstock for the production of biofuels in a pulp mill-based biorefinery.

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2008. 56 p.
Series
Karlstad University Studies, ISSN 1403-8099 ; 2008:5
Keyword
biorefinery, enzymes, ethanol, lignocellulosic feedstocks, oxalic acid, scaling
National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Research subject
Chemistry
Identifiers
urn:nbn:se:kau:diva-1362 (URN)978-91-7063-162-7 (ISBN)
Public defence
2008-02-15, Nyqvistsalen, 9C 203, Karlstad, 13:15
Opponent
Supervisors
Available from: 2008-02-01 Created: 2008-02-01 Last updated: 2011-12-21Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Winestrand, Sandra
By organisation
Department of Chemistry and Biomedical SciencesFaculty of Technology and Science
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

Total: 70 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf