|
|
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.
|
|
|
Possibilities of waste glycerol reprocessing
Hýža, Bohumil ; Friedl, Zdeněk (referee) ; Kizlink, Juraj (advisor)
The aim of my bachelor thesis is to describe the possibilities of waste glycerol reprocessing. The thesis is purely theoretical and the information were obtained from various literary sources. Introduction of the study deals with the technological aspects of production of biodiesel by esterification of vegetable oils with methanol. Futhermore, there is described the amount of biodiesel produced in various countries around the world. In the theoretical part of the study are mentioned physical and chemical properties of glycerol and its traditional uses include the manufacture of nitroglycerin, the pharmaceutical use, etc. There are presented different technological methods for processing large quantities of glycerol too, such as steam reforming, which generates syngas which can be used for production of liquid fuels via Fischer-Tropsch synthesis. There is also desribed reduction of glycerol to propylene glycol with hydrogen. Other methods are dehydroxylation of glycerol to 1,3 - propanediol, halogenation of glycerol to produce epichlorohydrin, the catalytic dehydration of glycerol to acrolein and 3-hydroxy-propionic aldehyde, oxydehydration to polyacrylic acid, glycerol butylation over the Amberlyst catalyst and the formation of glycerol-tert-butyl ethers used as additives for fuels , polymerization of glycerol to polyglycerols, glycerol hydrothermal conversion to lactic acid catalyzed by alkali, esterification of carboxylic acids and glycerol to form glycerol esters, selective oxidation of glycerol to glyceric acid, tartronic acid and dihydroxyacetone, and glycerol as an additive for cement.
|
|
|
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.
|
|
|
New Processes of Lactid Acid Polymers Preparation
Figalla, Silvestr ; Svěrák, Tomáš (referee) ; Herink,, Tomáš (referee) ; Petrůj, Jaroslav (advisor)
The work focuses on new processes for the preparation of lactic acid derivatives. The main objective was to verify the feasibility of preparing high molecular weight polylactide using ethyl lactate as a precursor of lactide synthesis. Part of the work is devoted to the new ethyl lactate synthesis method. The experimental part of the thesis is divided into partial key steps on the way from the lactic acid to the high molecular polylactide. The preparation of anhydrous ethyl ester of lactic acid (EtLA) was solved in an innovative way using alcoholysis of the oligomeric lactic acid. A kinetic model for isothermal alcoholysis and equimolar reactants ratio was derived from this method. The ethyl lactate was oligomerized by transesterification into the low and high molecular weight oligomer with the help of newly found catalysts suitable for the reaction medium. Stannous lactate was used as catalyst for oligomerization of the low molecular weight polymer suitable for the preparation of lactide (Mn 1000 g.mol-1). Experimental polymerization of ethyl lactate into high molecular weight product in tens of kDa has been investigated with newly synthesized tetraethyllactoyl titanate, Ti(EtLA)4. The laboratory method was derived for the depolymerization of the oligomer into lactide. Optimal conditions found for lactidation are as follow: temperature 225 ° C, pressure 2 kPa, catalysis 0,05 mol% of stannous lactate (with respect to oligomer lactate units). The prepared lactide was refined to polymer grade purity by distillation and subsequent recrystallization from ethyl acetate and toluene. The method for the preparation of high molecular weight PLA through ROP polymerization of lactide has been optimized. By optimization, suitable catalyst concentration was found in combination with the polymerization temperature and the polymerization length. An equimolar mixture of Tin 2-ethylhexanoate and 1-decanol was used as the catalytic system. The optimal ROP conditions for achieving the maximum molecular weight and suppressed polymer coloration (yellowing) are: catalyst concentration 0,01 mol%, temperature 160 °C, and polymerization length 4 hours. PLA with molecular weight Mw= 447 ± 7,8 kg.mol-1 was prepared at these conditions and good repeatability of the result was achieved. The effect of naturally occurring lactide contaminants and their influence on the course and ROP result was experimentally verified on the optimized polymerization system. The purpose was to explore the effect of lactide contamination with water and ethanol as natural lactide contaminants. The results clearly confirm the orderly lower sensitivity of the polymerization system for the presence of ethanol as compared to water contamination. In the case of the presence of water, the course and the result of the polymerization in terms of both the conversion and achieved molecular weights are negatively affected, even when the water content is in the order of 0,001%. Conversely, the presence of ethanol has a positive effect on lactide conversion and polymer polydispersity. Lactides with an alcohol content of about one-tenth of a percent are suitable to reach molecular weights of PLA similar to commercially available products. This difference shoves a significant advantage in the proposed technology of preparing PLA from ethyl lactate, especially for easier purification of crude lactide into polymer grade purity.
|
|
|
Energy use of biomass
Holečková, Michaela ; Kracík, Petr (referee) ; Baláš, Marek (advisor)
The aim of this bachelor thesis is the research of different types of biomass, description of the various types of methods and technologies for energy usage of biomass and the mapping of large power plant units in the Czech Republic. The first part of this thesis deals with the definition of biomass, its distribution and the description of basic essential attributes describing its composition. The downstream part of this work is focused on the technologies of gaining energy out of biomass or its possible conversion into other products depending on the currently discussed type of technology. The last part deals with energy balances of biomass in the Czech Republic and focuses on individual companies who use biomass as an energy source, by applying one of the methods mentioned in the previous part.
|
|
|
Energy use of biomass
Budiš, Marek ; Štelcl, Otakar (referee) ; Baláš, Marek (advisor)
This final work, written in the bachelor degree on the Faculty of Mechanical Engineering, Brno University of Technology, is engaged in literary research on the use of biomass energy. The first part deals with biomass, its origin and cultivation. The second part focuses on biomass suitable for energy purposes. Is described in detail adjustment of biomass for energy purposes, and various technologies conversion of biomass to generate energy.
|
|
|
Energy use of biomass
Ošťádal, Michal ; Elbl, Patrik (referee) ; Baláš, Marek (advisor)
The main aim of this bachelor thesis is to search for technologies for biomass conversion with subsequent energy utilization. At the beginning of the work is analyzed the nature of biomass as an energy source. The next part deals with individual technologies. The following section deals with combustion and biogas chains. The penultimate chapter deals with chosen energy sources. The last chapter is statistical processing of emissions, mining, electricity and heat production from renewable sources and biomass.
|
|
|
Preparation of Ethyl 2-acetoxypropanoate
Kučerová, Eliška ; Pospíšilová, Aneta (referee) ; Figalla, Silvestr (advisor)
The bachelor thesis focuses on the preparation of ethyl 2-acetoxypropanoate as a potential nonpolar biosolvent. Selected preparation should provide the highest yield possible. For this purpose, a theoretical review of possible syntheses was developed, with emphasis on syntheses based on acetylation of ethyl lactate. The experimental part of the work then focuses in more detail on the possibility of isolating ethyl 2-acetoxypropanoate from the reaction mixture. Product isolation was verified by fractional distillation and extraction method. In the isolated product, the basic physical properties were determined and the spectrum measured by Fourier transformation infrared spectroscopy. Furthermore, the hydrolytic stability of ethyl 2-acetoxypropanoate was investigated and a series of calorimetric measurements were performed. From these measurements, the effect of reaction temperature on reaction rate and product conversion and the effect of catalyst presence was assessed.
|
|
|
Synthesis and Characterization of PVAl Acrylic Esters
Hynštová, Karolína ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
The diploma thesis deals with a detailed study of he esterification reaction between PVAl and acrylic and methacrylic acids. Tha goal is to prepared PVAl-based macromers bearing (meth)acrylic moieties bound to PVAl macromolecular backbone. Attention will be paid especially to equlibrium establishing times and to the influence of reaction mixture composition on the properties of resulting products.
|
|
|
Chemické modifikace bilinových barviv
VOMÁČKOVÁ, Hana
This thesis deals with isolation of phycocyanobilin from cyanobacteria Thermosynechococcus elongatus and its purification with TLC. Purified phycocyanobilin was esterified using Fischer esterification method. The esterification method in this thesis was modified by using dichlormethan as solvent. The results were analysed by HPLC method. Pilot experiments dealing with insertion of esterified phycobilins into self-organized aggregates of bacteriochlorophyll c were carried out.
|
guest ::
