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Extraction of hemicelluloses from fiberized spruce wood
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. Chalmers University of Technology, Sweden.
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.ORCID-id: 0000-0002-2900-4713
2015 (Engelska)Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 117, s. 19-24Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A novel mechanical pre-treatment method was used to separate the wood chips into fiber bundles in order to extract high molecular weight wood polymers. The mechanical pre-treatment involved chip compression in a conical plug-screw followed by defibration in a fiberizer. The fiberized wood was treated with hot water at various combinations of time and temperature in order to analyze the extraction yield of hemicelluloses at different conditions. Nearly 6 mg/g wood of galactoglucomannan was obtained at 90◦C/120min which was about three times more than what could be extracted from wood chips. The extracted carbohydrates had molecular weight ranging up to 60 kDa. About 10% of each of the extracted material had a molecular weight above 30 kDa. The extraction liquor could also be reused for consecutive extractions with successive increase in the extraction yield of hemicelluloses. 

Ort, förlag, år, upplaga, sidor
2015. Vol. 117, s. 19-24
Nyckelord [en]
Spruce (Picea abies), Mechanical pre-treatment, Fiberized wood, Hemicelluloses, Galactoglucomannan
Nationell ämneskategori
Polymerteknologi
Identifikatorer
URN: urn:nbn:se:kth:diva-158963DOI: 10.1016/j.carbpol.2014.09.050ISI: 000346263800003Scopus ID: 2-s2.0-84922311559OAI: oai:DiVA.org:kth-158963DiVA, id: diva2:781404
Forskningsfinansiär
Knut och Alice Wallenbergs Stiftelse
Anmärkning

QC 20150116

Tillgänglig från: 2015-01-16 Skapad: 2015-01-16 Senast uppdaterad: 2017-12-05Bibliografiskt granskad
Ingår i avhandling
1. Extraction of Polymeric Hemicelluloses from Spruce Wood
Öppna denna publikation i ny flik eller fönster >>Extraction of Polymeric Hemicelluloses from Spruce Wood
2015 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Hemicelluloses are one of the three main components of spruce wood and constitute about 20% of the wood material. During mechanical pulping, 5–10% of the hemicelluloses are accumulated in waste waters, whereas during chemical pulping 70–80% of the hemicelluloses are lost in process liquors. The concept of integrated forest biorefinery involves the development of methods to extract these hemicelluloses prior to pulping in order to produce value-­added products besides pulp. This thesis describes some of the feasible possibilities of extracting hemicelluloses from wood at a high molecular weight prior to pulping in addition to presenting a deeper understanding of their degradation under mild treatment conditions.

A major obstacle for the efficient extraction of hemicelluloses is the recalcitrance due to the network of lignin and polysaccharides. This network can be loosely opened by the use of enzymes and this improves the extraction of hemicelluloses. A chemical impregnation of the wood chips was performed to enhance the accessibility of the cell wall to enzymes. The ability of different additives to stabilize the hemicelluloses against peeling during the alkaline impregnation stage was also investigated in order to obtain a better yield in subsequent extraction.

Increasing the surface area and decreasing the mass transport length could also improve the yield of hemicelluloses extracted from wood. This was achieved with a mild mechanical pre-­treatment of wood chips using an impressafiner and a fiberizer. Polymers mainly consisting of galactoglucomannan with an average molecular weight of 30 kDa were extracted from fiberized wood with water.

Different pre-­treatment and extraction methods were combined to demonstrate the concept of material biorefinery based on wood.

The kinetics of degradation of spruce galactoglucomannan were studied under alkaline conditions. It was degraded in two phases at two different rates. A kinetic model was developed to fit the experimental data and to estimate the activation energies. 

Ort, förlag, år, upplaga, sidor
Stockholm: KTH Royal Institute of Technology, 2015. s. 50
Serie
TRITA-CHE-Report, ISSN 1654-1081 ; 2015:4
Nationell ämneskategori
Teknik och teknologier
Forskningsämne
Fiber- och polymervetenskap
Identifikatorer
urn:nbn:se:kth:diva-158966 (URN)
Disputation
2015-02-06, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (Engelska)
Opponent
Handledare
Anmärkning

QC 20150119

Tillgänglig från: 2015-01-19 Skapad: 2015-01-16 Senast uppdaterad: 2015-01-19Bibliografiskt granskad

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Lindström, Mikael

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Azhar, ShoaibHenriksson, GunnarTheliander, HansLindström, Mikael
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Träkemi och massateknologiWallenberg Wood Science Center
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Carbohydrate Polymers
Polymerteknologi

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