National Repository of Grey Literature 151 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Vegetable oil as a fuel for a diesel engine
Kuběna, Pavel ; Kloss, Ondřej (referee) ; Kaplan, Zdeněk (advisor)
This thesis offers an opportunity to get closely acquainted with ignition engines running on alternative fuels. At the beginning of this work the reader is offered a wide variety of alternative fuels since born automotive industry, their basic information, features, use, and technical issues of each fuel. In the following part of this thesis, the author deals only with vegetable oil and its potential use as a fuel in an ignition internal combustion engine. It focuses on the specific conversion vehicles, their complexity, advantages and disadvantages, the overall economy of operation and risks of using vegetable oil instead of conventional diesel fuel. There is also documented performance characteristics and ecological balance of a particular target vehicle.
Actual State and Potential of Renewable Sources Utilization in the EU
Kubín, David ; Radil, Lukáš (referee) ; Macháček, Jan (advisor)
This bachelor’s thesis named Actual State and potential of renewable sources utilization in the EU offers a detailed summary of the current and future utilization of renewable resources in each member state of the European Union. The opening chapters briefly introduce the term renewable resources and the legislation relating to this issue. The following chapter is devoted to a detailed background research of actual renewable energy utilization in all twenty seven member states of the European Union. The countries are ranked by their dates of accession to the Union in ascending order, in each chapter alphabetically. All information and data are obtained from reliable sources such as annual energy reports of ministries or institutions which are concerned with energy issues. This chapter contains a great amount of charts and tables taken from annual reports and which are revised for the needs of this thesis. The chapter named Potential of renewable energy utilization in the EU offers an insight into the assumed future utilization of renewable resources up to the year 2020. This chapter draws from so-called National renewable energy action plans (NREAP) in which each member state presents its plan leading to higher renewable sources utilization in the near future. The reader is therefore able to familiarize with plans concerning renewable sources in each member state. The chapter named Complex evaluation familiarizes with some pros and cons concerning renewable sources and their utilization. Further the author presents his point of view on renewable sources and some recommendation leading to a better integration of renewable sources into energetics.
Biomass for power plants in the off-grid operation
Roule, Jaroslav ; Radil, Lukáš (referee) ; Baxant, Petr (advisor)
The thesis discusses the use of biomass for electricity island operation. The first chapter explains the concept of biomass and its distribution. It also shows the potential and availability of biomass. The second chapter describes the transformation of biomass into a suitable fuel form. The third to fifth chapter describes the conversion of biomass as a fuel into electrical energy through combustion, Stirling and steam engine. In these chapters there are brought the following parameters and prices of these motors and single-phase and three-phase alternators that can be connected to these engines. Other chapters describe the production of electricity in line with consumption, where the cost per hour to run engines for the various types of fuel and price of the electricity produced in kilowatt hours is calculated. In the last chapter of the thesis there is described the possibility of accumulation of electrical energy.
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.
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.
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.
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.
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
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.
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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