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Extraction of Phytosterols from Tall Soap Using a Selected Organic Solvents
Rousková, Milena ; Heyberger, Aleš ; Volaufová, Eva ; Tříska, Jan ; Krtička, M.
The contribution is focused on the extraction separation of the neutral part from tall soap from the paper mill Mondi Business Paper SCP, s.c. Ružomberok (Slovak republic). Dependences of the total amount of extracted phytosterols and ß-sitosterol on the applied extraction agent were studied. Hexanol, isobutanol, methyl isobutyl ketone, butyl acetate, limonene and hexane were tested. Yields of sterols with the regard to the type of deemulsifier used in the extracted system were compared as well. Acidity of the feeded tall soap-water-deemulsifier, modified by sulphuric acid addition before neutral components extraction, was analyzed as a further parameter. Study of the influence of elevated temperature on the extraction efficiency, was also one part of the work.
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Liquid Holdup in Hydrogenation Trickle Bed Reactor
Stavárek, Petr ; Jiřičný, Vladimír ; Staněk, Vladimír ; Hanika, Jiří ; Lederer, J. ; Tukač, V.
Experimental study of liquid holdup in trickle bed reactor with organic liquid is presented. On-line column weighting method was employed for liquid holdup measurements. Liquid holdup was measured in wide range of gas and liquid flow rates covering film and pulse flow regime. Porous and nonporous bed packing was used. Measured liquid holdup values were in good agreement with the predictions of empirical correlation from literature. Presented results are a part of the project New operational methods of trickle bed reactors – intensification and safe control supported by Ministry of Industry and Trade of the Czech Republic (grant no. MPO FT-TA/039).
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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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Supercritical Extraction and Fractionation of Sea Buckthorn Oil: Beta-Sitosterol Selectivity to Oil
Rochová, Kristina ; Sovová, Helena
Sea buckthorn (Hippophae rhamnoides L.) contains large amounts of compounds important in the human diet and used in medicine, among others phytosterols, whose anticancer, anti-inflammatory and antibacterial effects have been proved. Phytosterols, particularly beta-sitosterol, occur in sea buckthorn oil. The oil was extracted from ground seeds with supercritical carbon dioxide at the temperatures 40 and 60 oC and pressures 15-28 MPa. Using HPLC analysis for beta-sitosterol, its selectivity to the oil was evaluated. The results enable us to increase the concentration of beta-sitosterol in the extract.
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Changes in the Fatty Acid Composition during Enzymatic Hydrolysis of Vegetable Oil
Sovová, Helena ; Zarevúcka, Marie
Hydrolysis of oil in a continuous-flow reactor packed with immobilised enzyme was integrated with oil extraction from blackcurrant seeds, using as solvent supercritical carbon dioxide at 40 oC and 15-28 MPa. The hydrolysate was fractionated into free fatty acids, combined fraction of di- and monoacylglycerols, and the unreacted oil (tricylglycerols). As a result of non-homogeneous distribution of some fatty acids at sn-positions in triacylglycerols and the action of 1,3-specific lipase Lipozyme, free fatty acids were enriched in palmitic, stearic, and alpha-linolenic acids, while gamma-linolenic and stearidonic acids were more concentrated in di- and monoacylglycerols.
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Shape of So-Called Ellipsoidal Bubbles Rising in a Liquid
Wichterle, K. ; Smutná, K. ; Večeř, Marek
Small bubbles have a spherical shape. Big bubbles are of an unstable shape. The shape of a big bubble resembles that of pulsating hemisphere with a flat or concave base. Relatively stable medium-sized bubbles are interesting in view of technical applications. The medium-sized bubbles have approximately a shape of an oblate ellipsoid. Shape of smaller bubbles in low viscosity liquids is determined by gravitational force and surface tension force. Eötvös number comprises of the gravitational and surface tension forces. Ellipsoidal shape is expected for 0,2 < Eo < 30. This corresponds to bubbles in water with bubble size 1 - 2000 mm3. Longstanding records of bubble motion made possible to evaluate bubble shape and shape oscillations. Volume of recorded bubbles was 10 to 800 mm3, water and glycerol solutions were used as liquids. A ratio of horizontal and vertical bubble size, given in literature, is correct in principle.
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