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Effect of fiber wall chemistry on pulping processes of novel Eucalyptus hybrids

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Ruuttunen, Kyösti, Dr., Aalto University, Department of Forest Products Technology, Finland
dc.contributor.advisor Jääskeläinen, Anna-Stiina, Dr., Aalto University, Department of Forest Products Technology, Finland
dc.contributor.author Muguet Soares, Marcelo Coelho dos Santos
dc.date.accessioned 2013-10-25T09:01:09Z
dc.date.available 2013-10-25T09:01:09Z
dc.date.issued 2013
dc.identifier.isbn 978-952-60-5380-6 (electronic)
dc.identifier.isbn 978-952-60-5379-0 (printed)
dc.identifier.issn 1799-4942 (electronic)
dc.identifier.issn 1799-4934 (printed)
dc.identifier.issn 1799-4934 (ISSN-L)
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/11197
dc.description.abstract This thesis investigates relevant issues regarding the use of Eucalyptus wood: the factors affecting energy consumption during wood defibration, with focus on fiber wall chemistry and the assessment of wood quality from a wide range of novel Brazilian Eucalyptus hybrids. The obtained results are reflected to mechanical and traditional chemical processes. Wood refining experiments were carried out in laboratory scale, with and without chemical pretreatment: alkaline peroxide mechanical pulping (APMP) and thermomechanical pulping (TMP) processes, respectively. The most important finding was the direct influence of the lignin structure on the defibration energy. Especially, the relative contents of the guaiacyl moieties in the wood lignin seem to play a crucial role. The results showed that the higher the amount of guaiacyl structures in the lignin, especially in the middle lamella between the fibers, the higher the specific energy consumption (SEC) in the APMP process. However, for the TMP process the correlation was not as clear. This is most probably due to the fact that in the APMP process the defibration takes place in the middle lamella while in the TMP process other mechanism prevails. However, in the samples with very low amount of guaiacyl structures, SEC decreased substantially also in the TMP process. A different approach was promoting fiber wall deconstruction via autohydrolysis of wood. The autohydrolysis process changed notably the mechanical properties of the Eucalyptus chips, with impressive SEC decrease. Although autohydrolysis was performed under mild temperature (120 oC), lignin structure was changed. This assumption was based on the characterization of the fiber surfaces via x-ray photoelectron spectroscopy (XPS). Results showed high coverage of the fiber surfaces with lignin, indicating that the defibration of autohydrolyzed Eucalyptus wood chips takes place along the middle lamella. This behavior differs from the traditional thermomechanical pulping, where the rupture occurs mostly in the fiber wall (especially in the S1 layer), being similar to chemimechanical processes. As a final step, traditional kraft pulping was performed, alongside with soda-anthraquinone (NaOH-AQ) pulping, with focus on the surface properties of the produced fibers, analyzed by SEM and XPS. The surface lignin content of NaOH-AQ pulp fibers was lower than that of the kraft counterpart. However, kraft pulp handsheets showed better physical and mechanical properties. XPS data (C2/C3 ratio) strongly suggested, together with the pulp bulk chemical composition that xylan is more abundant on the surface of kraft fibers, probably enhancing their mechanical properties. en
dc.format.extent 78 + app. 48
dc.format.mimetype application/pdf
dc.language.iso en en
dc.publisher Aalto University en
dc.publisher Aalto-yliopisto fi
dc.relation.ispartofseries Aalto University publication series DOCTORAL DISSERTATIONS en
dc.relation.ispartofseries 163/2013
dc.relation.haspart [Publication 1]: Muguet, M.C.S., Colodette, J.L., Jääskeläinen, A.-S. (2012) Alkaline peroxide mechanical pulping of novel Brazilian Eucalyptus hybrids. Bioresources 7(3), 3823-3836.
dc.relation.haspart [Publication 2]: Muguet, M.C.S., Ruuttunen, K., Jääskeläinen, A.-S., Colodette, J.L., Vuorinen, T. (2013) Thermomechanical pulping of novel Brazilian Eucalyptus hybrids. Holzforschung 67(5), 489-495.
dc.relation.haspart [Publication 3]: Muguet, M.C.S., Ruuttunen, K., Jääskeläinen, A.-S., Colodette, J.L., Vuorinen, T. (2013) Defibration mechanisms of autohydrolyzed Eucalyptus wood chips. Cellulose 20(5), 2647-2654.
dc.relation.haspart [Publication 4]: Muguet, M.C.S., Gomes, F.J.B., Ruuttunen, K., Johansson, L.-S., Jääskeläinen, A.-S., Colodette, J.L., Vuorinen, T. (2013) Pulping-tailored fiber properties from a novel Brazilian Eucalyptus hybrid. Holzforschung, DOI: 10.1515/hf-2013-0114.
dc.subject.other paper technology en
dc.title Effect of fiber wall chemistry on pulping processes of novel Eucalyptus hybrids en
dc.type G5 Artikkeliväitöskirja fi
dc.contributor.school Kemian tekniikan korkeakoulu fi
dc.contributor.school School of Chemical Technology en
dc.contributor.department Puunjalostustekniikan laitos fi
dc.contributor.department Department of Forest Products Technology en
dc.subject.keyword chemical pulping en
dc.subject.keyword Eucalyptus Hybrids en
dc.subject.keyword fiber wall en
dc.subject.keyword mechanical pulping en
dc.subject.keyword surface properties en
dc.subject.keyword wood deconstruction en
dc.subject.keyword wood chemistry en
dc.subject.keyword wood quality en
dc.identifier.urn URN:ISBN:978-952-60-5380-6
dc.type.dcmitype text en
dc.type.ontasot Doctoral dissertation (article-based) en
dc.type.ontasot Väitöskirja (artikkeli) fi
dc.contributor.supervisor Vuorinen, Tapani, Aalto University, Department of Forest Products Technology, Finland
dc.opn Prof. Pedro Fardim (Åbo Akademi, Finland)
dc.date.dateaccepted 2013-10-08
dc.contributor.lab Forest Products Chemistry en
dc.rev Area, María Cristina, Prof., Universidad Nacional de Misiones, Argentina
dc.rev Ek, Monica, Prof., Royal Institute of Technology, Sweden
dc.date.defence 2013-11-15
local.aalto.digifolder Aalto_64332
local.aalto.digiauth ask

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