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Remediation of former In-Situ uranium mining region.
Kříž, Jakub ; Kalous, Jaroslav (referee) ; Jícha, Jaroslav (advisor)
Remediation process of region, formally exploited for chemical leaching of uranium, is based on pumping water contaminated mostly by residuals of sulfuric acid from the relevant geological horizons. The contaminated water is then treated in a chemical plant. In the treatment process evaporators play the key role. Presently operating evaporators – three units – are of falling film type. Heating service is provided by compressed vapor that is generated by evaporators. For driving the compressors and associated circulating pumps of each unit electric power of 3,4 MW is required. In the evaporators treated solution is distributed into individual tubes by nozzles of cyclone type that are mounted at the top end of tubes. In the evaporators feed solution contains calcium sulfide of low concentration. Once the calcium sulfide concentration in the evaporating process reaches the state of saturation, even locally, fouling is initiated. Thus the solids start to grow on the inner surface of the tube wall and the nozzle’s openings become restricted. The evaporator performance – evaporating rate – gradually declines and when it reaches the bottom limit the evaporator has to be shut down. This is followed by carrying out the cleaning procedure. At the time when the evaporators started operating (1996) the period between shut downs lasted around a half a year. However, gradually, this period has become substantially shorter – presently it may even last one week only. The thesis proposes two ways of approaching the present hardly acceptable state. First, replacement of distributing nozzles by a set of properly perforated sieve trays secures the uniform distribution of solution into each individual tube. Second, evaporators’ duty will be taken over by newly build multi-flash concentrator that will substitute the presently operating evaporators. Configuration of this new equipment is derived from widely used multi-flash distillation of sea water. Heat required by the concentrator’s end heaters is drawn from a gas turbine exhaust gas. Steam provided by Heat Recovery Steam Generator is supplied to the condensing heat exchangers installed on the evaporator’s feed stream. Generator coupled to the gas turbine, fueled by natural gas, provides the electric power of 30 MW for export.
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Different use of the wind energy.
Sukup, Jan ; Houdková, Lucie (referee) ; Jícha, Jaroslav (advisor)
This thesis describe main kinds of wind turbines, principle of their functions and their usage to electricity generation. The second part deals with ways to storing wind energy. There is description of compressed air energy storage technology and their combination with combustion of biomass. Second mentioned energy storage technology is electrolysis of water and possibility of usage hydrogen.
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Nonconventional Utilisation of Wind Energy
Zajíc, Josef ; Turek, Vojtěch (referee) ; Jícha, Jaroslav (advisor)
The thesis considers utilization of the wind energy as source of energy for the production of hydrogen. In the first part, there is described the types of wind engine specialized especially on screw wind engines and their construction. After that follows the description of dilemmas usage of electric energy addicted in time and with it connected problems with accumulation elektricity by the help of various methods. The final part of the thesis is than addicted to statistic evaluation of wind conditions, description and suggestion of the equipment hydrogen management.
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Different use of the wind energy.
Lakva, Petr ; Boráň, Jaroslav (referee) ; Jícha, Jaroslav (advisor)
The target of this bachelor study is describing basic type of renewable sources of energy. Emphasis is put on wind energy. Another part is description of different types of wind generators. In the last part study deals with problem of accumulation of wind energy for later use, thanks to compression of air in the underground mines.
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Recovery of Energy from Municipal Wastes
Šíma, Kamil ; Bébar, Ladislav (referee) ; Jícha, Jaroslav (advisor)
The topic of the diplome thesis is draft of the waste-to-energy plant for municipal waste with cogeneration of heat. Basic specification of project: Waste-to-Energy plant is facilitated by two rotary kilns of type operating in parallel. Further flue gas leaving the post-combustor enters a multicyclone unit to separate substatial portion of fly-ash. Heat of flue gas at the temperature of 1000°C generates superheated steam in a Heat Recovery Steam Generator (HRSG). Dry sorption process is appllied for flue gas treatment. Specifically sodium bi-carbonate is used for it. Products of reactions and remnants of dust are separated by a baghouse. Superheated steam, generated by two HRSG, presents the inlet stream of a condensing steam turbine with steam extraction. The diploma thesis contains calculation of major devices and basic economical and financial statement of project.
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Treatment of Waste Water Treatment Sludge Prior of its Following Utilization
Pěček, Jan ; Klemeš,, Jiří (referee) ; Žaloudík, Petr (referee) ; Jícha, Jaroslav (advisor)
Industrial production of cellulose is an energy intensive process. Businesses aim to utilized as much input energy, materials as possible while minimizing the waste as well. In addition to the main product – cellulose and large amounts of organically polluted water which is subsequently treated in waste water treatment plants. This PhD thesis deals with formation of suitable mixing formula for sludge from cellulose production and available materials (waste) from close neighborhood of Biocel Paskov a.s. so that well balanced cofermentation products are achieved. This mainly involves grass from lawn maintenance, grass ensilage, potato peels, and leftovers from vegetable processing. Fermentation processes (both mesophilic and thermophilic) of prepared fermentation products were conducted in semi-continuous and continuous laboratory fermentation units. Reduction of organic mass depending on residence time was closely observed as well as production and quality of biogas along with quality of output digestate. Course of process behaviour under controlled pH was tested. Results of particular tests were integrated into graphs. Conclusion of the thesis presents balance scheme drawn for selected variants, and design of real fermentation station with individual buildings, operations, basic machinery and equipment description including investment costs. Financial calculation and expected investment return was conducted in two variants – without subsidies and including subsidies from Operational Programme Renewable Sources of Energy.
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Neutralization of acid solutions
Pavlík, Ondřej ; Bébar, Ladislav (referee) ; Jícha, Jaroslav (advisor)
The present thesis is concerned with neutralization of acid groundwater after the hydrochemical uranium mining in the area of Stráž pod Ralskem. In the thesis is briefly described progression of the hydrochemical uranium mining and follow-up negative impacts on the environment. There is described the technology involved in its disposal. This is followed by the design calculation of major apparatus technology associated with neutralization of acid solutions. Output of technology is determined by the mass balance. The results are the main dimensions of the apparatus, mechanical parts and electric power each device.
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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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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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