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THERMAL DECOMPOSITION OF SOLID BIOFUELS AND ASSOCIATED FINE PARTICLE GENERATION
Sitek, Tomáš ; Ličbinský, Roman (referee) ; Svěrák, Tomáš (referee) ; Pospíšil, Jiří (advisor)
Despite otherwise indisputable advantages, biomass burning is associated with significant emissions of fine particles. The different behavior of dissimilar types of biomass during thermal decomposition can be explained to some extent by the different composition, i.e. the different content of cellulose, hemicellulose and lignin. The main aim of this work was to find the emission characteristics of these three components during heating in a thermogravimetric analyzer. The monitored parameters were the heating rate and the oxygen content in the combustion atmosphere. The output is the dependence of the sample mass and also the corresponding distributions of particles on the temperature. The results show considerable differences between the individual samples, but in general the pyrolysis of cellulose produces the highest particle emissions. Higher oxygen content in the combustion atmosphere and lower heating rates cause earlier sample decomposition and reduce particulate emissions. This is followed by an evaluation of the transferability to a sample of a real biomass based on its known composition using a simple weighted arithmetic mean. Useful information on particle sampling and electron microscope visualization, supplemented by images of particles from the pyrolysis of selected samples can also be found in this work.
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Functional carbon layers on fiber structures
Opravil, Petr ; Čech, Ondřej (referee) ; Bača, Petr (advisor)
In this master‘s thesis, we will be informed about creation of carbon coatings on glass fibre structures. Described methods of carbon coating will be compared and we will chose appropriate method for available laboratory in constitution of electronic technologies. Thanks to it’s low price and simplicity, it was firstly chosen to test carbon deposition using dehydration of sugar using concentrated hydrochloric acid. Results of initial experiments helped to develop and propose new methods that were tested using multiple new microfiber samples. Results from these experiments helped choose a correct subtrate on which a function layer of carbon was deposited and later analyzed.
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Preprocessing of sewage sludge for pyrolysis process
Ševčík, Jan ; Rusník,, Igor (referee) ; Bodík,, Igor (referee) ; Hlavínek, Petr (advisor)
The concept of sludge management at the level of sludge treating technology of sewage treatment plants, as well as at national, continental or world level, requires fundamental improvement in the interest of sustainable development. Sewage sludge production is continuously increasing. Sewage sludge contains a number of pollutants but also a significant renewable resource for material transformation and / or energy recovery. Sewage sludge is composed of an inorganic mineral part and organic components. Its organic part is a source of energy and nutrients, but also contains harmful pollutants for exapmple heavy metals. However, there are technologies that offer the possibility of neutralizing pollutants while using other sludge components in terms of recycling energy, nutrients and other attractive sludge components. The mentioned technologies include mainly thermal methods of sewage sludge treatment and one of them is pyrolysis. Thessis focuses on sewage sludge prepartation for pyrolysis process, which includes mixing with additives and peletization of prepared mixture for purposes of agricultural or energetical utilisation. Technology for material transformation and energy utilization of sewage sludge, in particular the mentioned pyrolysis or torrefaction, require an insignificant degree of detailed research in order to expand it in the field of sludge management. Indeed, it is not only research that will enable direct correct use of this technology in practice. The results of such research are the basis for the drafting of the relevant legislation, which will subsequently enable the deployment of pyrolysis technologies in practice.
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Preparation and basic chemical and physical characterization of biochar from wheat bran
Zouharová, Kamila ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
At present, the extraction of biochar and its use is a much-discussed topic in the chemical and research fields. The use of biochar is very often declined in the areas of agriculture, waste management, environmental improvement and the fight against global warming. In addition to these sectors, the topic of biochar is also addressed in the production of bio-diesel and bio-oil. Due to the current use of secondary products during biotechnological processes, the presented theoretical and practical study focused on the issue of obtaining biochar from bran by pyrolysis at different temperatures. Part of the practical part was the extraction of biochar from bran and its subsequent analysis, which could be used to characterize biochar obtained from bran by pyrolysis physically and chemically. The characterization of bran biochar was solved by various analytical methods. These techniques yielded, for example, pH, conductivity, particle distribution, elemental composition of biochar, porosity and content of polycyclic aromatic hydrocarbons. Thanks to this study, the properties of biochar and its possible applications in everyday life were characterized in detail. Given the very promising use of biochar obtained from bran, it can be said that this will be a very desirable topic for the future.
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Optimisation of fibre-matrix interface in ceramic matrix composite
Halasová, Martina ; Černý,, Martin (referee) ; Chlup, Zdeněk (advisor)
This thesis is concerned to the study of behaviour of fibre composites with ceramics matrix. The composite consists of pyrolysed polysiloxane matrix reinforced by ceramic fibre Nextel 720. Main aim of this work is optimisation of fibre matrix interface through the selection of suitable precursor of the matrix with respect to temperature stability, sufficient strength and reasonable fracture toughness. Samples of matrices were exposed to the long term heat treatment in the range 1100 – 1500 °C. The mechanical properties as hardness and indentation elastic modulus were determined after heat treatment. Selected precursors of matrices were used for composite fabrication. Elastic modulus and fracture toughness at room and elevated temperatures were studied. Discussion is dedicated to the description of changes in mechanical properties with respect to chemical processes taking place during high temperature exposition. Further, reasons of fracture behaviour of composite materials are discussed, and finally, gained knowledge and outlined possibilities of subsequent development are summarised.
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Energy use of biomass
Musilová, Petra ; Brázdil, Marian (referee) ; Baláš, Marek (advisor)
The objective of this bachelor’s thesis is a research study of biomass use in energy industry with main focus on electric energy production. This thesis primarily concerns with biomass properties, biomass processing technologies and the application of such technologies in the Czech Republic. The first part of this work consists of biomass definition and its division. The next part deals with biomass energetic properties and following is a familiarization with cogeneration (the combined use of heat and power to create electricity). Furthermore this thesis analyses individual technologies used in electricity production. The last part focuses on heating plants, power stations and biogas plants, which use biomass and on charting these specific units in the Czech Republic.
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Removal of micropollutants from wastewater by adsorbtion.
Trávníček, Jakub ; Macsek, Tomáš (referee) ; Hlavínek, Petr (advisor)
The aim of the thesis is to create a research on the issue of adsorption of micropolutants with a subsequent focus on biochar. The first part therefore deals with the micropolutants themselves, the origin of their formation in wastewater and their negative impact on the health of organisms. It also deals with adsorption technology, discusses its basic knowledge necessary to grasp the topic and describes known adsorbents and their use. It pays special attention to biochar. The second part of the thesis deals with practical filter tests of adsorption abilities of biochar on wastewater from tunnel maintenance and treatment carried out in the laboratory of the AdMaS centre.
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Energy use of biomass
Bouchner, Michal ; Špiláček, Michal (referee) ; Baláš, Marek (advisor)
The aim of this bachelor thesis is research of technologies for energy usage of biomass with concentration to production of electricity. In the first part of thesis are analyzed and described technologies producting electricity. In the second part are described suitable types of biomass for each aplication. Following part deals with used aplications for production of electricity in the Czech Republic. Last part shows specific technologies used in the Czech Republic.
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Less usual technologies of biomass utilization
Červenáková, Jana ; Brázdil, Marian (referee) ; Baláš, Marek (advisor)
The main aim of the bachelor thesis is to elaborate less usual technologies of biomass utilization. In the first part of thesis are individual technologies described and divided. The second part of the bachelor thesis describes the concept of biomass and its specific featuress. The last part describes selected applications of less traditional technologies in the Czech Republic which produce electric power by using biomass fuel.
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Evaluation of technology for the biomass incineration.
Havelková, Pavla ; Máša, Vítězslav (referee) ; Jícha, Jaroslav (advisor)
This bachelor’s thesis is interested in description of the biomass and its utilization as a renewable energy source. The text is specified in the production of the biomass and also an overview of the technologies used in its processing and utilization, which is both energy and non-energy. Then, this thesis deals with the description of the various devices, in which the biomass is processed.
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