National Repository of Grey Literature 61 records found  beginprevious49 - 58next  jump to record: Search took 0.00 seconds. 
Membrane Separation of Racemic Mixtures
Kačírková, Marie ; Žitka, Jan ; Sysel, P. ; Storch, Jan ; Izák, Pavel
There were chosen three types of membranes with immobilizing chiral selector (AN-VImEt+L-Lactate40, SNCB6KIL5% and AN-VBCI-TPh(+)+L-Lactate(-)33). With these types is desirable to continue the investigation.
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Purification of Biogas by Means of Membranes
Poloncarzová, Magda ; Vejražka, Jiří ; Izák, Pavel
The aim of this work is to find a way to lower carbon dioxide concentration in biogas and to purify it from undesirable gases by means of membrane. Ideally only one or two steps should be used to make the technology feasible and profitable. Liquid membranes are used because of their high selectivity and good permeability. Successful biogas purification method would open new opportunities in ecological fuels, especially if the methane content in biogas reached more than 95%; biogas could then replace the natural gas. In this work, a new supported ionic liquid has been tested and the first results have been obtained. Sweeping gas permeation was performed with model mixture of CO2 and CH4 1:1.
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).
Pervaporation as a Tool for Higher Effectiveness of Reaction Process
Izák, Pavel ; Kohoutová, Marie ; Afonso, C. A. M. ; Crespo, J.G.
This work is focused on the study of a catalyzed esterification reaction, taking place in the ionic liquid ([bmim] [BF4]), while one of the reaction products (water) is removed by pervaporation.
Sorpční a permeační vlastnosti membrány ze silikonu a iontové kapaliny v butanolových párách
Vopička, O. ; Hynek, V. ; Zgažar, M. ; Friess, K. ; Izák, Pavel
This contribution deals with properties of ionic liquid-silicone blends for butanol vapours.
Vliv obsahu iontových kapalin na vlastnosti neporézních polymerních membrán
Kohoutová, Marie ; Sikora, Antonín ; Hovorka, Š. ; Randová, A. ; Schauer, Jan ; Izák, Pavel
The polydimethylsiloxane membranes containing 0, 10, 20 or 30 wt. % of ionic liquid (benzyl-3-butylimidazolium tetrafluoroborate) were used for separation of butan-1-ol from water. Pervaporation selectivity increased and the butan-1-ol flux through the membrane raised with the increased content of [BBIM][BF4] in the PDMS-[BBIM][BF4] membranes. The PDMS-[BBIM][BF4] membrane showed high stability as well as selectivity (the separation factor raised up to 37, if 30 weight % of ionic liquid was accommodated in PDMS) during all experiments.
Botnání Nafionové membrány a její předpověď skupinově-příspěvkovou metodou
Randová, A. ; Bartovská, L. ; Hovorka, Š. ; Izák, Pavel ; Poloncarzová, M. ; Kolská, Z.
The anisotropic swelling of Nafion 112 membrane in pure organic liquids was monitored by an optical method. The results were used as the input for application of the group contribution method to the relative expansion in equilibrium. Value of plus minus 1.5 % in relative expansions was determined to be the experimental error. Maximum differences between the experimental and calculated relative expansions did not exceed the value of plus minus 3 %.
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.
Influence of Organic Electrolytes Presence on Swelling of Nafion Membrane in Methanol-Water Mixtures
Randová, A. ; Hovorka, Š. ; Izák, Pavel ; Bartovská, L.
The anisotropic swelling of Nafion 112 foil in methanol - water - inorganic salt was examined. Our results show that even small addition of inorganic salt into methanol - water mixture affects kinetics as well as the swelling equilibrium. The effect of inorganic salts LiCl, NaCl, KCl, CsCl, CaCl2, CdCl2, K2CO3, KNO3, NH4Cl, and AgNO3 was studied. Swelling kinetics of Nafion in ternary mixtures including salt show maximum suggesting that effect of methanol-water is faster but effect of inorganic salt is stronger. Theexperimental data, presented in this work allow us to assume that swelling of Nafion decreases with increasing ionic radius of cation.

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