Dissertation/ Thesis
Χρήση στερεών ιοντικών αγωγών σε καταλυτικές αντιδράσεις και εφαρμογή ηλεκτροχημικών μεθόδων και τεχνικών στη διερεύνηση του μηχανισμού τους: κυψέλες καυσίμου στερεού άνθρακα ; Application of solid ionic conductors in catalytic reactions, electrochemical and mechanistic studies: direct carbon fuel cells
| العنوان: | Χρήση στερεών ιοντικών αγωγών σε καταλυτικές αντιδράσεις και εφαρμογή ηλεκτροχημικών μεθόδων και τεχνικών στη διερεύνηση του μηχανισμού τους: κυψέλες καυσίμου στερεού άνθρακα ; Application of solid ionic conductors in catalytic reactions, electrochemical and mechanistic studies: direct carbon fuel cells |
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| المؤلفون: | Ioannis, Garagounis, Γκαραγκούνης, Ιωάννης |
| بيانات النشر: | Aristotle University Of Thessaloniki (AUTH) Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ) |
| سنة النشر: | 2016 |
| المجموعة: | National Archive of PhD Theses (National Documentation Centre Greece) |
| مصطلحات موضوعية: | Carbon fuel cells, In situ gasification, Ceria-supported catalysts, Ceria-based electrodes, Oxygen-conducting electrolytes, Κυψέλες καυσίμου άνθρακα, Αεριοποίηση άνθρακα, Καταλύτες δημητρίας, Ηλεκτρόδια με βάση τη δημητρία, Αγωγοί ιόντων οξυγόνου, Επιστήμες Μηχανικού και Τεχνολογία, Επιστήμη Χημικού Μηχανικού, Engineering and Technology, Chemical Engineering |
| الوصف: | Direct carbon fuel cells (DCFCs) are electrochemical devices which can convert the chemical energy of a solid carbonaceous fuel, e.g. lignite, to electrical energy in a single process step. There exist many types of DCFCs, with slightly varying oxidation mechanisms, covering various ranges of operating temperatures and accommodating a variety of solid fuels. In this thesis, several strategies for enhancing the performance of DCFCs based on solid oxide electrolytes are explored in the temperature range of 700-800 oC. These include, the addition of a gasification catalyst to the fuel, using CO2 or steam as gasification aids and adding a molten carbonate eutectic to the fuel mixture. The common point of all these strategies is their aim to increase in situ gasification of the solid fuel, the products of which can be easily oxidized at the anode, thereby increasing power output. The first set of experiments was conducted using a carbon black as fuel. Initial experiments were conducted in order to optimize some operating parameters, such as the amount of carbon loaded in each experiment and the weight ratios of carbon to the various additives. Promising results were obtained, including power densities as high as 20.6 mW∙cm-2 in the presence of carbonates and a Co/CeO2 gasification catalyst under CO2 feed, so the same strategies were then applied to commercial coals. Three fossil coals (anthracite, bituminous and lignite) and a charcoal (derived from pine) were examined. It was found that various chemical (ash, sulfur and volatile matter content) and physical (porosity, structural order) characteristics play a very important role in determining the reactivity of the coal with CO2, and consequently on cell performance. Demineralization of the bituminous coal was also tested, demonstrating a positive effect on reactivity and power output. Finally, the use of a thinner electrolyte (0.3 mm) with a cathode suitable for the reduction of oxygen (LSM) and more sophisticated electrode deposition techniques (screen printing), ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | English |
| Relation: | http://hdl.handle.net/10442/hedi/39027 |
| DOI: | 10.12681/eadd/39027 |
| الاتاحة: | http://hdl.handle.net/10442/hedi/39027 https://doi.org/10.12681/eadd/39027 |
| Rights: | BY_NC |
| رقم الانضمام: | edsbas.EE2C783D |
| قاعدة البيانات: | BASE |
| DOI: | 10.12681/eadd/39027 |
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