National Repository of Grey Literature 143 records found  1 - 10nextend  jump to record: Search took 0.03 seconds. 
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...
Measurement and toxicity of combustion generated nanoparticles
Sikorová, Jitka ; Topinka, Jan (advisor) ; Klusoň, Petr (referee) ; Bláha, Luděk (referee)
This thesis is focused on nanoparticles produced by internal combustion engines utilized in vehicles. It deals with spatial distribution of nanoparticles within urban areas, impact of alternative fuels usage on particle production and toxicity, and a particle toxicological testing methodology. Monitoring of airborne nanoparticles identified traffic as the main source of airborne nanoparticles in places with heavy traffic load (Prague), as well as in a small city with only local traffic (Čelákovice). Most particles were likely emitted during short episodes of high emissions (e.g. uphill acceleration). During the measurements, high-emission vehicles responsible for a large fraction of the air pollution were also identified. On the other hand, small non-road internal combustion engines, which are not subject to any limit on particle emissions, such as a lawn mower, were operated during the measurement and generated a large number of nanoparticles. The amount and characteristics of the particles produced by combustion depend on the combustion technology and the fuel composition. A large part of the thesis deals with alternative fuels and their effects on the quantity of produced particles and toxicity of organic matter adsorbed on the particles. Hydrotreated vegetable oil (HVO) exhibited the lowest...
The Dynamic CGE Model and Analysis of Impacts of Environmental Policy
Píša, Vítězslav ; Brůha, Jan (advisor) ; Tonner, Jaromir (referee) ; Smeets Křístková, Zuzana (referee)
The thesis evaluates three revenue neutral mixes of political measures aimed at the support of utilization of biofuels in the Czech Republic. The dynamic computable general equilibrium model with three aggregated sectors and two types of households is applied for evaluation of relevant environmental and economic impacts. The hypothetic price subsidy of utilization of energy biomass in production of the first generation biofuels fulfilling sustainability criteria is chosen as the basic supportive tool. The revenue neutrality is satisfied via adequate increase in tax rates in three different alternative scenarios (via labor tax, motor fuel tax, and standard value added tax). The results indicate that at the current price level of crude oil even relatively high level of price subsidy is not sufficient in fulfilling the emission and biofuel share targets presumed by European Commission. Therefore, for attaining the biofuel share target high percentage first generation biofuels and second and third generation biofuels have to be utilized. Furthermore, for the fulfilling of emission targets other alternative fuels have to be utilized as well. The results finally reveal that environmentally most efficient mix is the price subsidy compensated via an increase in the motor fuel tax, economically most...
Water footprint of crops for biofuel production
Straka, Štěpán ; Hrkal, Zbyněk (advisor) ; Rozman, David (referee)
The aim of the bachelor's thesis is to apply a research study for the assessment of often- overlooked effects of growing crops used for the production of biofuels, according to their so- called water footprint. In the theoretical part, the thesis focuses on the definition of the concept of the water footprint, its history and the gradual development of people understanding the impact. Furthermore, the thesis deals with the issue of definitions and determination of water scarcity. The theoretical part concludes with basic information about biofuels, their division and a presentation of the most commonly used biofuels. The following chapters summarize the current state of biofuel production in the world and familiarize the reader with the issues this production causes. The main part of the thesis is the synthesis and processing of data regarding the water footprint of selected crops grown as a source of biofuels, comparison of the values with climate zones and evaluation of the suitability of the production of these crops concerning water resources. Keywords: water footprint, biofuels, maize, canola, sugarcane, oil palm
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.
CO2 reduction with algae
Naider, Jakub ; Rebej, Miroslav (referee) ; Vondál, Jiří (advisor)
The aim of this final thesis is the process of algae cultivation their use for carbon dioxid reduction. The main objective of this work is the mass and heat balance of the photobioreactor and the design of a temperature control system. Within the research work, an overview of certain types of bioreactors and photobioreactors, the current situation around the climate and the impact of the cultivation of algae on carbon dioxide emissions. The model for temperature control and mass transfer of a plate photobioreactor is created in this work.
Hodnocení paliv pro spalovací motory ve vztahu k životnímu prostředí
Vančatová, Šárka
The name of this diploma thesis is „Evaluation of combustion engine fuel and its influence on the environment”. At the beginning there is a brief history of fuels. After that there is a chapter which divides fuels according to their state thus they are separate to three main types (solid state, gaseous state and liquid state). There are described main characteristics in the next part of this thesis which are heat of combustion, bulk density, dosage, volatility, resistance to detonation burning and mainly octane and cetane number. There are described currently used fuels for combustion engines right after the characteristic of fuels. These fuels are divided to fuels made of petroleum (gasoline, diesel, and LPG), fuels made of natural gas (CNG, and LNG), biofuels (bioethanol, biomethanol, vegetable oils – FAME and synthetic diesel fuel) and there is also an independent group of hydrogen. Thereafter are described European emission standards. The practical part of the thesis is focused on an analysis of previously mentioned fuels and there is a biggest focus on production of carbon dioxide. Other emissions are evaluated as well such as carbon monoxide, hydrocarbons and NOx gases. The analysis is done on classical fuels like gasoline and diesel and also on alternative fuels such as CNG, LPG, E85, FAME and hydrogen. In the end there are tables and graphs which contains production of flue gases.
Hodnocení účinnosti spalovacího motoru při spalování biopaliv
Hřebíček, Marek
This thesis is built on evaluating efficiencies of internal combustion engines fueled with bio-fuels. The ways of incorporating bio-fuels into practice are described in the theoretical section of this thesis, and are divided in categories. Physical and chemical properties of selected bio-fuels are described as well as manufacturing processes. There is also a view on current legislation dealing with bio-fuels in Czech Republic and European Union. Thesis offers an energy losses and effects on selected efficiencies are described. Thesis also includes description of engine operating parameters and their combustion cycles. Practical part of diploma thesis is dealing with measuring and evaluating operating parameters of four chosen automobiles fueled with bio-fuels. Measured data are in tables, statistics and graphics are commented and part of thesis. Based on evaluation of operating parameters it was figured out that effective efficiency increased for all measured cases while running on bio-fuels.
Biopaliva pro osobní automobily
Dubšík, Martin
This bachelor thesis deals with the topic Biofuels for passenger cars. It describes the use of biofuels for passenger cars. Furthermore, it focuses on the types of biofuels and their characteristic properties both chemical and physical. It deals with the issue of impacts on economic and ecological aspects of biofuel operation. Finally, there is an overall assessment and use of fuels in the coming years.
Ekonomické aspekty biopaliv
Arestarkhov, Yaroslav
The first part of this work “Economical aspects of biofuels“ is devoted to the legislative framework of biofuels. This part includes a description of the main European law regulations and Czech law connected with biofuels. In the second part briefly described the structure of biofuels according to the state and generation and in more detail described sellected biofuels, the way of their production and use. Next part of the work is devoted to economic aspects, such as the world production of certain types of biofuels and the prices of biofuels or their influence on the price of the end product. End part is devoted to advantages and disadvntages of certain types of biofuels, their problem and the suggestions for their solution.

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