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Photocatalytic water splitting by oxide semiconductors modified with graphen/graphenoxide
Marek, Jiří ; Čáslavský, Josef (referee) ; Cihlář, Jaroslav (advisor)
This master thesis deals with the topic of alternative production of hydrogen as the energy carrier of the future. The primary focus is on the production of hydrogen based on photocatalytical water splitting in the presence of semiconductor materials (especially modified and unmodified TiO2). The aim of the thesis is a synthesis of nanostructured oxide, graphene/graphene oxide particles and its composites, and a study of its structures and photocatalytical properties regarding photolysis of water. Products of the syntheses are described from the point of view of phase composition, surface area and photocatalytical activity. The main output of the thesis is a discussion of the influence of alkaline complex forming reagents on the hydrothermal low-temperature synthesis of biphasic TiO2, and a study of the influence of graphene/graphene oxide modification on photocatalytical activity of biphasic TiO2.
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The hydrogen bus
Kopecký, Petr ; Březina, Michal (referee) ; Štětina, Josef (advisor)
This bachelor's thesis deals with the topic of hydrogen buses, their concept, properties, practical application and economics of operation. It also discusses safety and hydrogen infrastructure, in particular hydrogen production, storage and use, while mentioning future options. Various technical solutions are evaluated with regard to the specifics of buses. It thus offers a general overview of the topic of hydrogen buses and related infrastructure.
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Design of Energy Systems Using Hydrogen as Fuel
Slováček, Adam ; Kermes, Vít (referee) ; Houdková, Lucie (advisor)
The subject of diploma thesis is to gather knowledge in the production and use of hydrogen. This work is devoted to a comparison of the previously existing processes for producing hydrogen, where the vast majority is filled of fossil fuel. Another section is devoted to new materials for the study based on a number of selected patents and the experiment promising new method for decomposition of water. Based on available data will be carried out energy balance and consequently will be drafted energy system using hydrogen as fuel. In conclusion will be future possibilities evaluated in the field of hydrogen energy.
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Possibilities of nuclear energy in the field of energy and media production
Svoboda, Filip ; Lisý, Martin (referee) ; Milčák, Pavel (advisor)
The main objective of this thesis is the possibility of combining nuclear power plants with energy storage technologies (specifically hydrogen production) and the subsequent balance of electricity and hydrogen production when combining these hybrid systems with photovoltaic power plants. With large installed capacities of renewable energy sources, it is necessary that other sources in the energy portfolio are flexible and then it is possible to regulate the supply of electricity from these sources to the electricity grid (for example, reducing the output of a steam power plant for natural gas on sunny and windy days). The regulation of a nuclear power plant is limited and therefore it is advantageous to start using it, for example, in a hybrid system with a PEM electrolyser. Then the nuclear power plant can produce electricity at a constant rate and only regulate the amount of electricity that goes to the grid or to the electrolyser.
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Hydrogen fuels
Umlauf, Martin ; Bébar, Ladislav (referee) ; Jícha, Jaroslav (advisor)
Paper presents a basic review and comparison of energy-conservation made of renewable sources. Principal question of paper concerns evaluation of hydrogen-use made of electrolysis of water. First part of the thesis focuses on the production of energy from renewable sources and the possibility of energy-accumulation. The next section describes methods of hydrogen production and utilization of hydrogen as a fuel for combustion engines. Attention is paid to various aspects dealing with construction of combustion engines using hydrogen. Final part of the study presents comparison between combustion engines using known sorts of fuels as to their pollution and emission-level. Next comparison deals with economic cost per kilometer, when different sort of fuels are taken into account. Conclusion concerns approximate calculation of the production of hydrogen from water by electrolysis using photovoltaic power plants.
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Hydrogen production by bacteria of genus Clostridium
Sedláček, Zbyněk ; Turková, Kristýna (referee) ; Rittich, Bohuslav (advisor)
The bachelor thesis deals hydrogen production by bacteria of the genus Clostridium. Thesis gives an overview about hydrogen production mentioned microoganism, characterized further biotechnological methods and show examples of industrial production of hydrogen. Also there are describes the quantitative characteristic and metabolism of bacteria genus Clostridium and examples of usable substrates. Polymerase chain reaction (PCR) is used to the detection and identification by species and specific primers. DNA isolated by fenol extraction from bacterial culture Clostridium tyrobutyricum DSM 2637 was amplified using genus-specific PCR to form PCR products size 619 bp.
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Heterogeneous catalytic transformation of organic substances and hydrogen production
Tinoco Navarro, Lizeth Katherine ; Lapčík,, Lubomír (referee) ; Pinkas,, JIří (referee) ; Cihlář, Jaroslav (advisor)
Tato práce zahrnuje čtyři komplexní studie zaměřené na syntézu, strukturu a fotokatalytické vlastnosti materiálů na bázi TiO2, které přispívají k pokroku v udržitelné výrobě energie a sanaci životního prostředí. Výzkumy se ponoří do přizpůsobených syntetických přístupů, tvorby heterofázových spojů a složité souhry mezi vlastnostmi materiálu a fotokatalytickou aktivitou. První studie zkoumá vliv molárních poměrů kyseliny mléčné (LA)/Ti na syntézu komplexu nanočástic TiO2. Řízením poměrů LA/Ti se navrhují fázové složení a mezoporézní struktury, které významně ovlivňují fotokatalytický výkon při výrobě vodíku. Druhý výzkum zkoumá vliv substituovaných octových kyselin (SAA) na "mostovou" syntézu nanočástic TiO2 a odhaluje, jak SAA usnadňují vytváření heterofázových spojení mezi anatasem (A) a brookitem (B). Manipulace s elektronegativními skupinami SAA vytváří krátké můstky, které podporují kondenzaci, což vede ke zvýšené fotokatalytické aktivitě pro produkci vodíku. Na základě toho třetí výzkum analyzuje syntézu nanočástic anatasu/brookitu pomocí kyseliny monochloroctové (MCAA) a zkoumá vliv teploty kalcinace na jejich tvorbu heteropřechodů a fotokatalytické chování přítomnost Ti3+, Ti4+, Ti-O a Ti-OH. hydroxylové skupiny hrály významnou roli v procesu degradace. Komplexní analýzou fázových přechodů (anatas a brookit), velikostí krystalů (5 nm až 11 nm) a specifických povrchových ploch (180 až 70 m2 .g-1) tato studie odhaluje složitou souhru mezi strukturou a fotokatalytickou aktivitou. Čtvrtý výzkum zkoumá dopované aerogely TiO2. Studie syntetizuje aerogely dotované Ni-, Co-, Cu- a Fe a zkoumá jejich struktury a fotokatalytické aktivity během fotodegradace AO7. Přítomnost příměsí ve spojení s řízenými krystalickými fázemi a morfologiemi vede k mezoporézním aerogelům a vysokému specifickému povrchu 130 až 160 m2.g-1, s výjimečným fotokatalytickým výkonem aerogelů Ni-TiO2 a Cu-TiO2 kalcinovaných při 500 ° C. A konečně, tyto studie společně poskytují cenné poznatky o přizpůsobeném designu materiálů na bázi TiO2 pro vylepšené fotokatalytické aplikace. Výzkumy ukazují význam heterofázových spojů, řízených fázových složení a optimalizovaných povrchových struktur při podpoře separace náboje a minimalizaci rychlosti rekombinace. Souhrnné poznatky nejen prohlubují naše chápání fotokatalýzy, ale také přispívají k vývoji udržitelných a účinných materiálů se slibnými aplikacemi při výrobě obnovitelné energie a sanaci životního prostředí.
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Hydrogen as an alternative fuel for internal combustion engines
Hurník, Jakub ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
The object of this bachelor’s thesis is to analyse characteristics of hydrogen and it’s suitability for internal combustion engines used in transportation technologies. The thesis begins with some significant reasons for implementation of alternative fuels, the main part is focused on hydrogen technologies and it finishes with short prediction of the use of hydrogen in the future. The potential of this fuel is analysed from all important points of view, which means its production, storage, ecology and construction of hydrogen powered engines. The thesis also contains summary of current hydrogen technologies, their comparation, and comparation with current conventional engine technologies.
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Hydrogen production by the bacteria of the genus Clostridium
Filová, Dagmar ; Kvasničková, Eva (referee) ; Rittich, Bohuslav (advisor)
Bachelor thesis deals with hydrogen production using bacteria of Clostridium genus - specifically C. butyricum and C. tyrobutyricum. Theoretical part analyzes means of hydrogen production divided into biological and non - biological methods. Thesis is further aimed at practical use of these microorganisms for hydrogen production purposes and introduces cheese whey as one of utilizable growth medias. In experimental part, there was used polymerase chain reaction for identification of bacteria genus Clostridium and species Clostridium butyricum and Clostridium tyrobutyricum. PCR products were reamplified using the same primers for specifity confirmation purposes. Presence of gene producing hydrogenase A enzyme was proved by PCR, too.
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Hydrogen fuels
Tyagunova, Victoria ; Bébar, Ladislav (referee) ; Jícha, Jaroslav (advisor)
This thesis presents a basic review of production and use of hydrogen fuels. The main focus of this paper is the use of hydrogen in industry and power engineering. The first part concerns various industrial production technologies. The next section is dedicated to the description of hydrogen use for energy conservation, fuel cells, power plants and combustion engines. it includes the comparison of hydrogen and classic fuels. The final part focuses on the economy and costs of hydrogen production and use. This paper will evaluate hydrogen as a potencial fuel for future and will estimate it’s advantages and disadvantages in comparison with conventional fuels.
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