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New generation of biofuels
Pražák, Vojtěch ; Lisá, Hana (referee) ; Baláš, Marek (advisor)
This bachelor's thesis deals with different generations of biofuels. Their advantages and disadvantages and problems associated with their use in practice. The first part of the theses focuses on legislation and acquaintance with the issue of biofuels as a whole. The second part is focused on acquaintance and description of individual biofuels with examples of use in practice. At the end of the work there is an analysis of individual generations, representation in the fuel market and their efficiency.
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Možnosti využití mikroorganismů pro výrobu tuku z odpadních materiálů
Novotný, Jonáš
The aim of the work was to use special strains of microorganisms to produce lipids and lipophilic substances using wastes and by-products of the food industry. Lipids are a valuable component of food and their increasing consumption has an impact on the growth of input costs of plants. Some strains of yeast and bacteria can accumu-late high concentrations of lipids in the cell. The composition of these lipids has a si-milar character to commercially used fats and oils. The work focuses on the production of both equivalents of e.g. cocoa butter or palm oil, and specific products such as polyunsaturated fatty acids, which are used for example to enrich foods. For the cultivation of oleaginous strains of microorganisms, waste and by-products of the food industry are used as a carbon substrate. Individual substrates, which are often subject to disposal in incinerators, are described as potential low-cost media for microbial production technology. Some of the carbon sources discussed include whey, fruit and vegetable pomace and waste cooking oil. Furthermore, the extraction of microbial lipids by chemical and physical methods is addressed. In particular, microbial lipid production appears to be the future of food industry. The technology is still in its infancy and the biggest problem is the cost of the resul-ting products, mainly related to the treatment of substrates and extraction processes. Until costs are significantly reduced, microbial lipids and their products will not be compe-titive.
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Environmental assessment of the Czech Republic based on Water Footprint
Žlábková, Jana ; Hák, Tomáš (advisor) ; Vačkář, David (referee)
This dissertation sets its goal in application of the water footprint indicator, which is a practical and multi-layered indicator of water sources consumption. Of human activities, agriculture presents the most significant demands on water sources consumption. Therefore I have turned my focus to the widely-discussed issue of biofuels production, because the input materials for production of this kind of energy are agricultural crops (in the Czech republic those are: oilseed rape, sugar beet, Indian corn and winter wheat). The calculated results of water footprints of the selected industrial crops (m3 /t) and of water footprints of the heating value units of that crops (m3 /GJ) offer us a concrete notion of energy requirements of water of that chosen industrial crops in the conditions of the Czech republic. Keywords: water footprint indicator, biofuels, oilseed rape, water consumption, biodiesel, bioethanol, evapotranspiration.
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Green fuels for small combustion engines
Záhorský, Lukáš ; Klimeš, Lubomír (referee) ; Štětina, Josef (advisor)
Tato práce konfrontuje dostupnost a funkci různých alternativních paliv pro malé spalovací zážehové motory, používané ve sportovním vybavení. Kvůli rostoucím emisím skleníkových plynů a nárustu teploty zemského povrchu, se zdají alternativní udržitelná paliva nezbytná pro zlepšení životního prostředí. V práci je vybráno a vyhodnoceno několik paliv dle jejich vlastností a ekologického vlivu. Nejprve jsou alternativní paliva experimentálně otestována na motorové zkušebně a jednotlivé motorové vlastnosti jsou porovnány. Později je vyhotovena simulace tepelného cyklu motoru k potvrzení výsledků experimentu. Ze všech otestovaných paliv, ekologický ethanol se jeví jako nevhodnější palivo z hlediska výkonových charakteristik. Nicméně, i mixované částečně ekologické palivo E40, které dosahuje nižší měrné spotřeby paliva ale i nižšího výkonu než čistý ethanol, by nemělo být opomenuto. Obecně se dá říct, že všechna alkoholová alternativní paliva dosahují v obou analýzách nižších emisí skleníkových plynů než fosilní paliva. Na základě výsledků z měření je tedy možné tvrdit, že použití alternativního paliva v malých spalovacích motorech bez zásadních úprav může zlepšit jejich výkonnost a ekologii. Je ovšem nezbytné, provést více výzkumu v oblasti alternativních paliv, aby bylo možné zahájit jejich sériovou výrobu a snížit tak dopad dopravního sektoru na ekologii Země.
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Production of Biofuels in the Czech Republic and Slovakia
BAGOVÁ, Veronika
This thesis deals with biofuels and the usage of raw materials, the aim of the work is to compare the contents of national legislations of two european states - the Czech republic and the Slovak republic, as well as to compare the efficiency of these legislations in the biofuels' use. In order to reach the goal of this work, it is divided into two parts. The first part consists of the theoretical base which describes European Union law and the legal basis concerning biofuels in EU legislation. The general characteristics of biofuel and its production is also included in this part. The practical part compares the Czech republic and the Slovak republic in their ability to achieve legally binding goals as well as the legal action relating to transportation as set by the directive of European Commission. In other words, it examines how and even if the states are able to achieve these goals at all and what tools they're using in the process. The possible penalty of not being able to meet the criteria is also discussed in this part.
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Toxic responses in human lung epithelial cells (BEAS-2B) exposed to particulate matter exhaust emissions from gasoline and biogasoline
Závodná, Táňa ; Líbalová, Helena ; Vrbová, Kristýna ; Sikorová, Jitka ; Vojtíšek-Lom, M. ; Beránek, V. ; Pechout, M. ; Kléma, J. ; Cigánek, M. ; Machala, M. ; Neča, J. ; Rössner ml., Pavel ; Topinka, Jan
Motor vehicle emissions substantially contribute to air pollution worldwide and cause serious health problems. While the deleterious effects of diesel exhaust particulate matter (PM) have been widely studied, much less attention is paid to toxicity of PM emitted by gasoline engines although they also produce considerable amount of PM. The primary objective of this research was to assess toxic potencies of exhaust PM released by conventional gasoline engine fueled with neat gasoline (EU) or gasoline-ethanol blend (15% ethanol, v/v, E15). Despite a similar particle mass (mu g PM/kg fuel) produced by both fuels, PM emitted by E15 contained higher amount of harmful polycyclic aromatic hydrocarbons (PAH) as suggested by chemical analysis. To examine the toxicity of organic PM constituents, human lung BEAS-2B cells were exposed for 4h and 24h to a subtoxic dose of E0 and E15 PM organic extracts. We used genome scale transcriptomic analysis to characterize the toxic response and to identify modulated biological process and pathways. Whereas 4h exposure to both PM extracts resulted in modulation of similar genes and pathways related to lipid and steroid metabolism, activation of PPAR alpha, oxidative stress and immune response, 24h exposure was more specific for each extract, although both induced expression of PAH-metabolic enzymes, modulated metabolism of lipids or activated PPAR alpha, E15 additionally deregulated variety of other pathways. Overall, the PM mass produced by both fuels was similar, however, higher PAH content in E15 PM organic extract may have contributed to more extensive toxic response particularly after 24h exposure in BEAS-2B cells.
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Modelling ethanol production in simultaneous equations model of global food demand and supply
Kozák, Miroslav ; Janda, Karel (advisor) ; Macháček, Vít (referee)
This thesis conducts an econometric analysis for the relationship between food price and ethanol production. A system of simultaneous equation models for the demand and supply for food are estimated, paying attention to the effect of ethanol production. The two-stage and three-stage least-squares estimation methods are adopted, which explicitly account for endogeneity in the system. Using annual data from 1981 to 2020, it is found that the ethanol production has little economic impact on food price. This may be closely related with inelastic demand and supply with respect to price that have been found in this study, where exogenous shocks such as an increase of ethanol production may have small effects on price. JEL Classification C12, C13, D12 Keywords Ethanol, Endogeneity, Food Price, Elasticity, Si- multaneous Equations Model Title Modelling ethanol production in simultaneous equations model of global food demand and sup- ply Author's e-mail kozakmiroslav92@gmail.com Supervisor's e-mail karel-janda@seznam.cz
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Synthetic fuels
Pitoňák, Adam ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
The bachelor’s thesis on the topic “Synthetic fuels” aims to introduce the reader to the issue of synthetic fuels and the possibilities of their application for internal combustion engines as alternatives to the conventional fuels derived from fossil sources. The first part of the work is focused on the introduction and division of synthetic fuels according to primary raw material. Subsequently, the properties of the fuels are compared with commonly used fossil fuels. The thesis also deals with the comparison of the equivalents of the emissions of individual synthetic fuels per unit of thermal energy supplied to the engine. Thanks to the model presented in the thesis, it is possible to compare the amount of CO2 equivalent per driven kilometre. The conclusion of this work summarizes the result of the comparison of synthetic fuels with prospects of such fuel in the future.
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Estimating the Relationship between Food, Fuel and Biofuel Prices
Novotný, Matěj ; Janda, Karel (advisor) ; Khymych, Olha (referee)
Although biofuels have drawn the attention of researchers since its boom, which took place 20 years ago, doubts about benefits which their usage brings in the academic debate. This thesis joins the debate that discusses the impact of biofuels on food prices. The prices of 38 commodities and assets that are related to the biofuels are examined under Minimum Spanning Tree and Hierarchical Tree methods over the years between 2003-2019. The time span is divided into 4 periods, that responds to the development of world food prices. The results show that the relationship between biofuels and their feedstock depends on the overall level of food prices. In the case of higher food prices, the link between feedstock and biofuel is stronger and therefore the price transmission is more likely to happen. With lower food prices, this link is significantly weaker. Furthermore, the development of world food prices does not follow the trend of increasing biofuels production as food prices have become stable in recent periods. Therefore, this thesis does not support the claim that biofuels cause higher prices of food. Keywords biofuels, ethanol, biodiesel, transportation, food price transmission, Minimum Spanning Tree, Hierarchical Tree 1
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The Potential Use of the Eustigmatophyceae In the Production of Biofuels
Pilátová, Jana ; Němcová, Yvonne (advisor) ; Pichrtová, Martina (referee)
The eustigmatophytes - yellow-green microalgae - are well known for their high lipid content which is constituted by high amounts of essential polyunsaturated fatty acids (PUFA), such as eicosapentaenoic acid (EPA). This, combined with their high growth rate and an exceptionally high adaptability, makes them very promising feedstock for the biofuels production. In this bachelor thesis the role of eustigmatophytes in the production of biofuels is depicted with consideration of the issue of various cultivation conditions effects on the lipid content and composition. The first review of fatty acid distribution in eustigmatophytes ever reported is provided herein. Thus this work might be tentatively contributing to the strain selection issue - one of the most discussed topics in the biofuels field. The fatty acid distribution is qualitatively and quantitatively changed under various chemical and physical stress conditions. Thus the impact of nitrogen and phosphorous availability alongside with light intensity or temperature on lipid changes are presented. In addition, the process of fatty acid and polyunsaturated fatty acid synthesis is briefly outlined. Recent genetic engineering trends and successes are also mentioned, such as the implementation of high-efficiency homologous recombination to...
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