search query: @keyword kinetiikka / total: 9
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Author: | Visuri, Juha |
Title: | Modeling of hot water extraction |
Kuumavesiuuton mallinnus | |
Publication type: | Master's thesis |
Publication year: | 2010 |
Pages: | vi + 111 Language: eng |
Department/School: | Kemian ja materiaalitieteiden tiedekunta |
Main subject: | Kemian laitetekniikka (Kem-42) |
Supervisor: | Alopaeus, Ville |
Instructor: | Kuitunen, Susanna |
OEVS: | Electronic archive copy is available via Aalto Thesis Database.
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Location: | P1 Ark Aalto 1957 | Archive |
Keywords: | hot water extraction depolymerization poputation balance random scission end of the chain scission kinetics kuumavesiuutto polymeeriketjun pilkkoutuminen populaatiotase satunnaispilkkoutuminen päätepilkkoutuminen kinetiikka |
Abstract (eng): | A population balance based model was developed to describe the depolymerisation reactions of hemicelluloses taking place in hot water extraction conditions. Kinetics of the cleavage of glycosidic bonds in hemicellulose was studied and two scission mechanisms were tested. The literature part of this work consisted of exploring the phenomena that need to be taken into account when hot water extraction is modelled. The previous kinetic studies were reviewed and the reactions taking place were identified. The modelling of depolymerisation was studied to get an overview on the topic. Mass transfer and thermodynamic aspects were also considered. In the applied part, kinetic parameters for the two scission mechanisms were optimized for the depolymerisation of galactoglucomannan. The effect of hydrogen ion concentration on the scission rate was also studied. The experimental data for galactoglucomannan reactions was received from Åbo Akademi. The obtained kinetic parameters were compared against the acid hydrolysis data of disaccharides. |
Abstract (fin): | Työssä kehitettiin populaatiotaseisiin perustuva menetelmä hemiselluloosapolymeerin pilkkoutumisen mallintamiseen kuumavesiuuttoprosessin olosuhteissa. Glykosidisidoksen katkeamisen kinetiikkaa tutkittiin Ja kahta polymeeriketjun pilkkoutumismekanismia testattiin. Työn kirjallisuusosassa tutkittiin ilmiöitä, jotka tulee huomioida kuumavesiuuton mallintamisessa. Aikaisempia kineetiikkatutkimuksia tarkastelemalla tunnistettiin oleelliset prosessiin liittyvät reaktiot. Polymeeriketjun hajoamisen mallintamiseen luotiin yleiskatsaus ja myös prosessin aineensiirtoa ja termodynamiikkaa tutkittiin. Työn soveltavassa osassa määritettiin galaktoglukomannaanin pilkkoutumisen kinetiikkaparametrit kummallekin polymeeriketjun pilkkoutumismekanismille. Myös vetyionikonsentraation vaikutusta pilkkoutumisnopeuteen tutkittiin. Kokeelliset tulokset galaktoglukomannaanin reaktioille saatiin Abo Akademista. Määritettyjä kinetiikkaparametreja verrattiin kirjallisuudesta löydettyihin disakkaridien happohydrolyysiparametreihin. |
ED: | 2011-03-18 |
INSSI record number: 41583
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