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Chemical characterization in the biorefinery of lignocellulose: Formation and management of oxalic acid and analysis of feedstocks for bioethanol production
Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för kemi och biomedicinsk vetenskap.
2008 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
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.

Ort, förlag, år, upplaga, sidor
Karlstad: Karlstads universitet, 2008. , s. 56
Serie
Karlstad University Studies, ISSN 1403-8099 ; 2008:5
Nyckelord [en]
biorefinery, enzymes, ethanol, lignocellulosic feedstocks, oxalic acid, scaling
Nationell ämneskategori
Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci)
Forskningsämne
Kemi
Identifikatorer
URN: urn:nbn:se:kau:diva-1362ISBN: 978-91-7063-162-7 (tryckt)OAI: oai:DiVA.org:kau-1362DiVA, id: diva2:5246
Disputation
2008-02-15, Nyqvistsalen, 9C 203, Karlstad, 13:15
Opponent
Handledare
Tillgänglig från: 2008-02-01 Skapad: 2008-02-01 Senast uppdaterad: 2011-12-21Bibliografiskt granskad
Delarbeten
1. Xylan is more important than lignin as precursor of oxalic acid during peroxide bleaching of mechanical pulp
Öppna denna publikation i ny flik eller fönster >>Xylan is more important than lignin as precursor of oxalic acid during peroxide bleaching of mechanical pulp
(Engelska)Manuskript (Övrigt vetenskapligt)
Identifikatorer
urn:nbn:se:kau:diva-1965 (URN)
Tillgänglig från: 2008-02-01 Skapad: 2008-02-01 Senast uppdaterad: 2011-12-21Bibliografiskt granskad
2. Enzymatic method for rapid determination of oxalic acid in bleaching filtrates from the pulp and paper Industry
Öppna denna publikation i ny flik eller fönster >>Enzymatic method for rapid determination of oxalic acid in bleaching filtrates from the pulp and paper Industry
2005 (Engelska)Ingår i: Journal of Donghua University, Vol. 22, s. 64-68Artikel i tidskrift (Refereegranskat) Published
Identifikatorer
urn:nbn:se:kau:diva-1966 (URN)
Tillgänglig från: 2008-02-01 Skapad: 2008-02-01 Senast uppdaterad: 2010-09-07Bibliografiskt granskad
3. Comparison between oxalate decarboxylase and oxalate oxidase in the degradation of oxalic acid in filtrates from the pulp and paper industry
Öppna denna publikation i ny flik eller fönster >>Comparison between oxalate decarboxylase and oxalate oxidase in the degradation of oxalic acid in filtrates from the pulp and paper industry
Visa övriga...
(Engelska)Manuskript (Övrigt vetenskapligt)
Nationell ämneskategori
Kemi
Forskningsämne
Kemi
Identifikatorer
urn:nbn:se:kau:diva-1967 (URN)
Tillgänglig från: 2008-02-01 Skapad: 2008-02-01 Senast uppdaterad: 2011-11-14Bibliografiskt granskad
4. Enzyme-based control of oxalic acid in the pulp and paper industry
Öppna denna publikation i ny flik eller fönster >>Enzyme-based control of oxalic acid in the pulp and paper industry
2008 (Engelska)Ingår i: Enzyme and microbial technology, ISSN 0141-0229, E-ISSN 1879-0909, Vol. 43, s. 78-83Artikel i tidskrift (Refereegranskat) Published
Nationell ämneskategori
Biomedicinsk laboratorievetenskap/teknologi Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci)
Forskningsämne
Biomedicinsk vetenskap
Identifikatorer
urn:nbn:se:kau:diva-1968 (URN)10.1016/j.enzmictec.2007.11.014 (DOI)
Tillgänglig från: 2008-02-01 Skapad: 2008-02-01 Senast uppdaterad: 2017-12-07Bibliografiskt granskad
5. Dilute sulfuric acid pretreatment of agricultural and agro-industrial residues for ethanol production
Öppna denna publikation i ny flik eller fönster >>Dilute sulfuric acid pretreatment of agricultural and agro-industrial residues for ethanol production
Visa övriga...
2007 (Engelska)Ingår i: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, Vol. 136-140, s. 339-352Artikel i tidskrift (Refereegranskat) Published
Identifikatorer
urn:nbn:se:kau:diva-1969 (URN)10.1007/s12010-007-9063-1 (DOI)
Tillgänglig från: 2008-02-01 Skapad: 2008-02-01 Senast uppdaterad: 2017-12-07Bibliografiskt granskad
6. The potential in bioethanol production from waste fiber sludges in pulp mill-based biorefineries.
Öppna denna publikation i ny flik eller fönster >>The potential in bioethanol production from waste fiber sludges in pulp mill-based biorefineries.
2007 (Engelska)Ingår i: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, Vol. 136-140, s. 327-338Artikel i tidskrift (Refereegranskat) Published
Identifikatorer
urn:nbn:se:kau:diva-1970 (URN)10.1007/s12010-007-9062-2 (DOI)
Tillgänglig från: 2008-02-01 Skapad: 2008-02-01 Senast uppdaterad: 2017-12-07Bibliografiskt granskad

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Avdelningen för kemi och biomedicinsk vetenskap
Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci)

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