|
| |
|
|
Analysis of catalytic oxidation product mixture using gas chromatography method and controlled evaporation mixer
Haupt, Josef Michael ; Schwarzová, Karolina (advisor) ; Čabala, Radomír (referee)
The goal of this master's thesis was to develop a method for gas chromatography using the Controlled Evaporation Mixer (CEM) for gas mixture sampling. Gas mixture contained chemical substances formed during manufacturing of acrylic acid by two-step oxidation of propylene. The analyzed mixture composed of permanent gases, light hydrocarbons and compounds containing oxygen. During the method development several capillary columns with polar and nonpolar stationary phase were used. After selection of the most suitable column (SPB-1 Sulfur, Supelco, USA) the method was further optimized for the maximal possible separation efficiency. However, it was impossible to separate propane and propene on SPB-1 Sulfur column. These gases were possible to determine on TCD detector and separate on respective columns prior to the detector. For that purpose, the optimization of multiple-port valves switching inside the gas chromatograph was performed. The next step was calibration of gas chromatograph for a purpose of quantitative analysis of selected substances. The calibration solution containing solvent and an analyte was evaporated and diluted with nitrogen by CEM to obtain desired analyte concentration. Formaldehyde and propane had a very low response on detectors, acetaldehyde was undetectable in desired...
|
|
|
Possibility of using EMW radiation for killing biotic pests
Gintar, Jan ; Klečka,, Tomáš (referee) ; Pěnčík, Jan (referee) ; Šuhajda, Karel (advisor)
The remediation of building elements and structures in terms of moisture and sterilization (inactivation) of biotic pests is dealt with quite often in construction practice and in the construction industry itself, and is thus a topical issue. The issue is dealt with by specialized companies that know the use of available technology on the market, or are themselves involved in the development and improvement of these devices. Several methods are known for the removal of moisture and sterilization of biotic pests, with sufficiently high-quality data on the technology used, the suitability of the equipment used, a more detailed description of the application of the methods themselves and the results themselves. The methods themselves, for removing moisture and eliminating (inactivating) biotic pests, must be chosen according to individual requirements, as some methods will be more appropriate (more effective) and some less suitable. For the practice itself, however, it is important that the methods are sufficiently effective and at the same time available to the wider public (their economic side). In my dissertation thesis I focus on the potential of EMW radiation utilization not only for liquidation of biotic pests (fungi, fungi, wood decaying insects), but also elimination or reduction of necessary conditions for survival or development of these biotic pests. Therefore, my work also focuses on the presence of moisture, because moisture is a common factor in the vast majority of problems associated with the occurrence of biotic pests. Due to its intensity, it is one of the less time-consuming method and therefore a more cost-effective (economically) method. The research I conducted at VUT FAST focused on the use of microwave radiation in the control of biotic pests, under conditions that are close to those on real constructions. The use of a microwave method to eliminate biotic pests and at the same time to remove moisture has proved to be advantageous.
|
|
|
Disposal of Biotic Pests by EMW Radiation
Sobotka, Jindřich ; Klečka,, Tomáš (referee) ; Myslín, Jiří (referee) ; Tomíček,, Oldřich (referee) ; Šuhajda, Karel (advisor)
The possibility of using high-frequency electromagnetic radiation in the construction sector is a common knowledge. Various experiments have been carried out to dry construction materials, or even to destroy biotic pests. However, the majority of these experiments have been executed in laboratory conditions. It means they have been carried out under exact limiting conditions, often very far off those conditions in real building practice. Therefore, this dissertation aims at exploring the possibility of utilizing microwave technology in drying and heating of construction materials, in disposing of biotic pests and sterilizing building materials under real conditions in building practice. The thesis will explain that microwaves are a term given to a part of electromagnetic radiation. Electromagnetic radiation is based on the principle that the radiated energy is absorbed by water molecules present in moist building material. In the mass of the irradiated material, the radiated energy is transformed into thermal energy, where a so-called “motion” of water molecules occurs with the energy then being transformed into kinetic energy. The microwave technology itself offers a very wide range of use, which can be easily achieved, thus making the technology available to use in the future. Part of the experiments and the necessary measurements, too, has been carried out on selected types of building materials in the premises of the Faculty of Civil Engineering of Brno University of Technology. They have been executed under conditions which most closely correspond to the conditions in real buildings. Part of the experiments and the necessary measurements were carried out on particular constructions, by the so-called in situ method. As stated in the conclusion of the dissertation, laboratory measurements and the in situ measurements differ considerably in some cases.
|
|
|
Integration of a technology for digestate thickening in a biogas plant
Miklas, Václav ; Touš, Michal (referee) ; Vondra, Marek (advisor)
This diploma thesis is mainly focused on the digestate thickening in a biogas plant. First, overview of the biogas technology in the Czech Republic is presented. Furthermore, problems with waste heat utilization and processing of fermentation residues (digestate) are described in more detail. Based on the research, multi-stage flash (MSF) evaporation was chosen as the technology for the digestate thickening. The main part deals with the integration of the chosen technology into a biogas plant process. The programming language Python was used to simplify the given task. In the preliminary stage, a complex mathematical model of a biogas plant was created, focusing particularly on the mass and energy balances. Subsequently, a computational model of the MSF evaporator was programmed. A procedure for the integration was suggested using the sensitivity analyses. Additionally, the model of a biogas plant was extended with the MSF evaporator. The key outcome of the thesis is a technical-economic analysis in which the impact of digestate transport price and electricity feed-in tariff on payback period is investigated. The results suggest profitability of MSF evaporator for biogas plants without subsidized feed-in tariff. Contrastingly, installation of MSF evaporator in older biogas plants with subsidized feed-in tariff can be economically viable only in cases of significantly longer transport distances.
|
|
|
Fermentation remainder treatment in a biogas plant
Budín, Oto ; Touš, Michal (referee) ; Vondra, Marek (advisor)
This diploma thesis deals with dewatering technologies of fermentation residues from biogas plants and aims to design an integration of selected technology into the biogas plant. Fermentation residues (or digestate), which are a by-product of anaerobic biomass fermentation in biogas plants, contain a certain amount of nutrients and are usually used as agricultural fertilizers. However, the high-water content in digestate and the associated low nutrient concentration increase the cost of its storage and transport. Dewatering of fermented material could help reduce these costs. The main part of this work included the design of an integration of the selected dewatering technology into the biogas plant – its placement in a process, an addition of necessary appliances, the influence on material and energy flows. In this case, the fermentation residues are processed in two phases. First, a separation of the solid and the liquid fraction by a screw press. The second step is to thicken the liquid digestate by evaporation in a multistage evaporator. Evaluation of the design of a dewatering technology, including its impact on the economy of the biogas plant, is also part of the diploma thesis.
|
|
|
Industrial evaporators for process water treatment
Cacková, Tereza ; Havlásek, Martin (referee) ; Vondra, Marek (advisor)
Bachelor thesis is focused on industrial process water evaporators. The basic principles of evaporation were described and various types of industrial water evaporators were introduced. The main part of the thesis was a thorough research and creation of a database of industrial water evaporators, which is also a probe into the current situation on the water evaporator and sewage sludge market. Part of the thesis is also comparing evaporators with other thickening technologies.
|
|
|
Assessment of evaporator integration into biogas plant
Peťovský, Patrik ; Touš, Michal (referee) ; Máša, Vítězslav (advisor)
The main waste output of the biogas plant is digested which is used as fertilizer. It can be further process. Digestate cannot be discharged freely into surface waters. This problem is associated with high transportation costs and higher costs of storage tanks in the new biogas plant. The aim of this bachelor thesis is to assess a suitable evaporation system for a particular biogas plant. The evaporation system leads to the concentration of digestate by evaporation water. The system uses heat produced by cogeneration unit. The main consequence of the integration is lower cost for the transport of liquid digestate. The output of the bachelor thesis is a technical and economic evaluation that assesses the payback period depending on the flow of concentrated digestate. The specific costs for adjustment of liquid digestate with regard to the payback period are in the range of 5–15 years. The values do not exceed 210 (Kčyear)/t_fug . The values considering selling heat are even negative. The minimum value guaranteed by the manufacturer is around 260 (Kčyear)/t_fug . The integration of the evaporation system into Žamberk's biogas plant is economically disadvantageous. The thesis brings new knowledge about the potential of multi-stage flash evaporation in biogas plants with short transport distances and high utilization of waste heat.
|
|
|
Foaming of fermentation residues during a vacuum evaporation
Knob, Jan ; Brummer, Vladimír (referee) ; Vondra, Marek (advisor)
The diploma thesis deals with the processing of digestate, which is the remaining material after biogas production. It aims to experimentally prove how chosen operational parameters of antifoaming agents influence digestate foaming associated with the vacuum evaporating technology. Based on the research of available antifoamers and the issue of digestate foaming itself, it was observed how three selected antifoamers (i.e. rapeseed oil, silicone antifoamer Erbslöh Schaum-ex and oleic acid), together with the decrease in the pH factor of the evaporating digestate, influence the final foam production. For the purposes of the research, an apparatus simulating the vacuum evaporating process was set up in which the heated sample was brought to boil by gradual pressure decrease. The process of foaming was observed in a transparent cylinder of a testing culumn. The essential part of the experimental activity is represented by a planned experiment which by means of a DoE (Design of experiments) method proved rapeseed oil to be very efficient. In contrast, other antifoamers, as well as the influence of the pH factor decrease, manifested themselves as insignificant factors, while the oleic acid even supported the foaming. The supplementary measurements led to a more detailed research of the effects of rapeseed oil and to the construction of a mathematical model describing how the concentration of rapeseed oil undermines the amount of generated foam. The main contribution of the thesis is firstly the evidence that rapeseed oil plays an important part in the reduction process of digestate foaming and secondly the determination of minimum substance concentration leading to the foaming reduction of a particular sample which is considered efficient enough to enable functioning of a vacuum evaporator. The thesis has also experimentally demonstrated the influence of some polymer organic flocculants which have been proved to support the foaming.
|
|
|
OPTIMIZATION OF WELLNESS AIR CONDITION
Kysilka, Michal ; Zubíček, Vojtěch (referee) ; Šikula, Ondřej (advisor)
The theme of diploma thesis is a design optimization of air distribution in swimming-pool hall with regard to free water surface evaporation. This problem was solved according to determined criterions with the aid of CFD simulation. Experimental measurement part of the thesis deals with evaporation problems where own formula for this physical phenomenon is determined. This formula is compared with already known algorithms. Author suggests that such formula might be integrated in CFD software.
|
guest ::
