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Selective Enantiomer Separation by Pertraction
Izák, Pavel ; Kačírková, Marie ; Vychodilová, Hana ; Červenková Šťastná, Lucie ; Žitka, Jan ; Brožová, Libuše ; Storch, Jan ; Randová, A. ; Hovorka, Š.
Membrane processes are not commonly used in enantiomer separation due to insufficiency explication of separation mechanisms and because the results of chiral membrane separation are not quite satisfying, especially in comparison with other separation technics, namely HPLC. A new method for selective separation of enantiomers by membrane processes taking advantage of ionic liquids is present. The supported chiral room temperature ionic liquid membrane is used for separation of enantiomers. Volatile enantiomers are separated by pervaporation and non-volatile enantiomers by pertraction.
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Thin Film Composite Membrane for Effective Raw Biogas Upgrading to Pipeline Quality Methane
Kárászová, Magda ; Vejražka, Jiří ; Veselý, Václav ; Friess, K. ; Randová, A. ; Jansen, J. C. ; Izák, Pavel
In this contribution we propose a method to upgrade biogas to the same quality of fuel standard natural gas. The latter contains more than 95 vol. % of methane. Using traditional membranes, such concentration of methane in the retentate could only be achieved using a multistep process. A recently proposed method for raw biogas purification from impurities and carbon dioxide by condensing water on swollen thin film composite membranes was found to be highly effective. The hydrophilic reverse osmosis membrane promotes the formation of a very thin selective water layer under condensing conditions below the dew point of the raw biogas feed. The large difference in permeability of the impurities in raw biogas (carbon dioxide, hydrogen sulfide) and methane through the water layer enables upgrading of raw biogas to biomethane quality in a single stage. Contrary to the classical purification processes, the proposed method does not require any biogas pretreatment, which makes this approach economically attractive. It represents an innovative approach to production of biomethane from biogas.
Fulltext: content.csg - PDF Plný tet: SKMBT_C22012102413470 - PDF
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Forest pedagogy
RANDOVÁ, Anna
The aim of this degrese work is to support the importace of environmental education and forest pedagogy for the development of children´s perceptions. The theoretical part aim at processing information about the implementation of environmental education in kindergarten school educational curricula and at introducing the notion ?forest pedagogy? (in the Czech Republic and worldwide), its aim and purpose. Furthermore the findings of forest kindergartens both in the Czech Republic and abroad are treated. The practical activity itself contain the proposal of forest pedagogy conceived activities according to seasons for a kindergarten class and their realization. In the present work there is interpreted their contribution to the development of children´s perception
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Sorption Characteristics of PDMS in Ternary Systems Benzene (1) + Alcohols (2) + Ionic Liquid (3) and Corresponding Binary Subsystems
Randová, A. ; Bartovská, L. ; Hovorka, Š. ; Friess, K. ; Izák, Pavel
In this work the study of sorption characteristics of PDMS in ternary system benzene (1) + methanol or butanol (2) + ionic liquid (3) and corresponding binary subsystems at the temperature of 20°C is presented. The experimental data on total sorption were determined gravimetrically [3], the experimental data on preferential sorption were evaluated from the concentration change induced by an immersion of the membrane into the liquid mixture [3]. The volume changes of swollen membrane immersed in the studied liquid systems were determined from the dimensional changes of the membrane samples changes in X and Y axis dimensions were monitored directly in liquid by an optical method [1, 3] and membrane sheet thickness was measured by an Inductive Dial Indicator (Mahr, Germany).
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Sorpce kapalné směsi metanol-benzen v polymerních membránách
Randová, A. ; Bartovská, L. ; Izák, Pavel ; Hovorka, Š. ; Friess, K.
The solubility of single mixture components in the membrane is important for the effectivity of membrane separation processes. This information is accessible from the experimental data on the preferential sorption in combination with the experimental data on the total amount of the sorbed liquid. The sorption from binary liquid solutions methanol-benzene in Nafion and low density polyethylene membranes has been studied in the whole concentration range at constant temperature of 25°C.
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