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Author:Kalliola, Simo
Title:Kiinteiden katalyyttimateriaalien soveltuvuus lignoselluloosapohjaisten syöttöjen käsittelyyn
Feasibility of solid catalyst materials for lignocellulosic feeds
Publication type:Master's thesis
Publication year:2013
Pages:vi + 109      Language:   fin
Department/School:Kemian laitos
Main subject:Epäorgaaninen kemia   (Kem-35)
Supervisor:Karppinen, Maarit
Instructor:Rautama, Éeva-Leena ; Lindblad, Marina
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
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Location:P1 Ark Aalto  2027   | Archive
Keywords:oxide
catalyst
water
solubility
oksidi
katalyytti
vesi
liukoisuus
Abstract (eng): Conversion of lignocellulosic biomass to liquid hydrocarbon fuels has been studied because of the possible depletion of oil reserves and the climate change.
Lignocellulose can be converted to liquid hydrocarbon fuels by catalytic water-phase-processes.
Lignocellulose consists of cellulose, hemicellulose and lignin.
Cellulose and hemicellulose are hydrolysed to sugars which can be converted to liquid hydrocarbons through catalytic reactions.
Catalysts are required to remain invariant in the reaction conditions.
Different kinds of oxides are used as catalysts in the traditional oil refining but the stability of such oxides are questionable in water phase.

The literature part of this work discusses the water solubility of oxides.
The water solubility of an oxide depends on the acid -base properties and surface properties of the oxide.
The acid -base properties of an oxide can be predicted by evaluating the electronegativity difference between the constituting elements of the oxide.
The basicity of an oxide increases as the electronegativity difference increases.

In the experimental part of this work the water solubility of zeolites ZSM-5 and Y, amorphous SiO2-Al2O3, y-Al2O3, ZrO2, TiO2, CeO2, MgO and activated carbon are studied in conditions that resemble those found in catalytic water-phase-processes.
In this experiment the most stable oxides were ZrO2, TiO2 and CeO2.
The solubility's of these oxides were low and only minor changes in the crystal structures were observed.
Silicon dissolved in basic solutions and aluminum dissolved in acidic solutions from silicon and aluminum oxides.
Severe changes in crystal structure were also observed in silicon and aluminum oxides.
Magnesium oxide dissolved completely in acidic solutions and reacted to form magnesium hydroxide in all water solutions.
Abstract (fin): Öljyvarojen mahdollisen ehtymisen takia ja ilmastonmuutoksen torjumiseksi on tutkittu perinteisiä fossiilisia polttoaineita muistuttavien nestemäisten hiilivetyjen valmistamista lignoselluloosapohjaisesta biomassasta.
Lignoselluloosa voidaan muuntaa nestemäisiksi hiilivedyiksi katalyyttisilla vesi-faasi-prosesseilla, joissa lignoselluloosan sisältämä selluloosa ja hemiselluloosa hydrolysoidaan sokereiksi, jotka voidaan muuttaa erilaisten reaktioiden kautta nestemäisiksi hiilivedyiksi katalyyttien avulla.
Katalyyttien tulee pysyä reaktio-olosuhteissa mahdollisimman muuttumattomina.
Perinteisessä öljynjalostuksessa on katalyyttien kantamateriaaleina käytössä oksideja, jotka ovat stabiileja poolittomissa liuottimissa, mutta oksidien stabiilisuus vesiliuoksissa on kyseenalainen.

Tämän työn kirjallisuusosassa perehdytään oksidien vesiliukoisuuteen.
Oksidien liukoisuus vesiliuoksiin riippuu niiden happo-, emäs- ja pintaominaisuuksista.
Oksidien happo-emäsominaisuuksia voidaan ennustaa oksidin muodostavan alkuaineen ja hapen välisen elektronegatiivisuuseron avulla niin, että oksidin emäksisyys kasvaa elektronegatiivisuuseron kasvaessa.

Kokeellisessa osassa tutkitaan ZSM-5-ja Y-zeoliittien, amorfisen SiO2 -Al2O3-seoksen, y-Al2O3:n, ZrO2:n, TiO2:n, CeO2:n, MgO:n ja aktivoidun hiilen liukenemista olosuhteissa, joiden kaltaisia voi esiintyä lignoselluloosan prosessoinnissa nestemäisiksi hiilivedyiksi.
Stabiileimmiksi oksideiksi osoittautuivat ZrO2, TiO2 ja CeO2.
Naiden oksidien liukoisuus oli vahaisinta ja niiden kiderakenteessa havaittiin ainoastaan pieniä muutoksia.
PH- ja alumiinioksideista liukeni huomattavasti piitä emäksisiin liuoksiin ja alumiinia happamiin liuoksiin ja niissä havaittiin radikaaleja kiderakenteen muutoksia.
Magnesiumoksidi liukeni täysin happamiin liuoksiin ja reagoi magnesiumhydroksidiksi kaikissa vesiliuoksissa.
ED:2013-05-20
INSSI record number: 46155
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