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<div class="csl-entry">Rodríguez, C. (2022). <i>Surface adjustment of biochar via gasification</i> [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2022.102636</div>
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dc.identifier.uri
https://doi.org/10.34726/hss.2022.102636
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dc.identifier.uri
http://hdl.handle.net/20.500.12708/80323
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dc.description
Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprüft
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dc.description
Abweichender Titel nach Übersetzung der Verfasserin/des Verfassers
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dc.description.abstract
Gasification as a method for adjustment of the surface properties of biochar is investigated in this work. Uncontaminated biomass from Pinus sylvestris Scots pine is utilized as the feedstock. This material is later transformed into biochar by submission to the torrefaction process in an inert atmosphere at 300°C for 45 minutes and further activated via gasification. The main goal of the work is to obtain a product with suitable physical characteristics for a post-processing step which consists of passivation by encapsulation within a coke tar layer. Since literature findings suggest higher BET surface areas and porosity production, the thermochemical activation is performed with CO2 as the oxidizing agent. Reaction conditions such as temperature, residence time, and type of reactor are selected considering the state of the art of gasification for the activation of biochar. The parameters are varied to obtain twelve materials with different physical properties. The produced samples from the lab-scale experiments are later characterized via light microscopy, SEM analysis, and physisorption analysis. The results show that an increase in temperature and residence time produces higher burn-off values achieving 87,1% in the fixed bed and 74,2% in the fluidized bed, both experiments performed at 900°C for 25 minutes. This behavior is related to the formation of higher specific surface area and porosity, achieving surface BET area values of 904 m2/g and 516 m2 g, and pore volumes of 0,4897 cm3/g and 0,2632 cm3/g, respectively, which is significantly higher than the 0,6483 m2/g and 0,00092 cm3/g values of the torrefied biochar. SEM analysis demonstrated more significant degradation of the structure, as pores and several fragmentations appeared in the surface layer of the biochar. The main findings from the present thesis are as follows: i) Torrefaction proved to be a suitable process for biochar production; ii) Activation temperature plays a vital role in the gasification of biochar as an increase from 800°C to 900°C produces higher degradation and porosity formation, therefore, increasing the surface area; iii) Temperature, residence time, and type of reactor influences the burn-off and porosity of the activated biochar; iii) Fixed bed shows better results regarding the surface area and porosity in comparison with the fluidized bed in the conditions of 900°C and 25 minutes residence time. These results constitute the basis of further investigations where contaminated biomass can be used as a precursor in different thermochemical processes to obtain high-value-added products and unreactive and stable biochar.
en
dc.language
English
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dc.language.iso
en
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dc.rights.uri
http://rightsstatements.org/vocab/InC/1.0/
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dc.subject
Vergasung
de
dc.subject
Biokoks
de
dc.subject
Oberflächenmodifikation
de
dc.subject
Gasification
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dc.subject
biochar
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dc.subject
surface modification
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dc.title
Surface adjustment of biochar via gasification
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dc.type
Thesis
en
dc.type
Hochschulschrift
de
dc.rights.license
In Copyright
en
dc.rights.license
Urheberrechtsschutz
de
dc.identifier.doi
10.34726/hss.2022.102636
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dc.contributor.affiliation
TU Wien, Österreich
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dc.rights.holder
Camila Rodríguez
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dc.publisher.place
Wien
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tuw.version
vor
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tuw.thesisinformation
Technische Universität Wien
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dc.contributor.assistant
Müller, Florian Johann Franz
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tuw.publication.orgunit
E166 - Institut für Verfahrenstechnik, Umwelttechnik und technische Biowissenschaften