Separations Technology最新文献

Liquid-Liquid Equilibria (LLE) were measured at atmospheric pressure for the binary acetonitrile-water system at temperatures ranging from −1.3 to −18.6°C. Data points were taken using two methods, the cloud point method and the analysis of phase compositions using gas chromatography. Both methods show excellent agreement in their representation of the phase envelope. Temperature dependent NRTL (non-random two liquid) parameters were calculated from the binary data. The parameters calculated were τ₁₂ = 355.7−31.49_T(°C) and τ₂₁ = 967.2−26.59T(°C) with the a value held constant 0.3.

A dynamic model has been developed for the size fractionation process of gas-filled microspheres by flotation. The aim of this dynamic model is to control the fractionation process in an Nycomed Imaging AS Infoson^™ production plant. A general population balance is established for the dispersed phase that is later simplified for the specific particle suspension and process equipment used. This dynamic model has been tested against experimental data and shows a good correlation between the predicted and measured values. This paper describes both the physical phenomena and the modeling method.

Chemisorption of SO₂ from smelting plant exhaust gases in a single sieve plate column was investigated. Main parameters were SO₂ and O₂ gas and H₂SO₄, FeSO₄ and Al₂(SO₄)₃ liquid concentrations on reaction rate and equilibrium in FeII-EDTA solutions. Absence of inhibitors with this kind of flue gases promote fast kinetics. Optimal process conditions with 3% wt. FeSO₄ catalyst up to 2000 PPM SO₂. Maximum yield of 16% H₂SO₄ could be achieved considering optimal liquid/vapor ratio, oxygen surplus and insert salt concentrations.

A simple and rapid method for the extraction is described for the separation of beryllium (II) and aluminium (111) from aqueous sulphate solution with Bis-2 ethylhexyl phosphoric acid (HDEHP) in toluene. A systematic study of the solvent extraction of chemically similar elements, beryllium (II) and aluminium (III) was carried out separately and it has been observed that under certain specific conditions beryllium (II) and aluminium (III) can be separated in a short period from their mixture using HDEHP as an extractant.

A method for determining the optimum zone length for maximum separation in multi-pass zone-refining processes is described. Numerical values of the optimum zone lengths and their corresponding maximum separations for up to ten passes are presented. The optimum zone length is found to increase with the distribution coefficient but decreases when the pass number increases. Considerable improvement in separation may be obtained if zone refining is operated at the optimum zone length, except for higher distribution coefficients.

In this paper the analysis of the effects of model uncertainties on predictions is reported for a multi-component gas-solid TSA fixed-bed adsorber. Owing to the complexity of the system the study was carried out by means of a simplifiedmethod. Despite its simplicity this method allowed the evaluation of the effectiveness of predictions and the identification of the most critical aspects of the model, which require improvement in order to obtain reliable model outputs. The advantages of such an analysis are that the results can be used to improve the reliability of the model and make the model useful for good design and safety considerations.

Electroosmotic dewatering was enhanced by periodically interrupting the power (the off-time) and simultaneously short circuiting the electrodes. Noting that continuous application of power corresponds to an off-time of zero, the final amount of water removed increases with off-time, goes through a maximum and then decreases. For Hydrocol clay, the experimental optimum off-time was 0.1 s for an on-time of 30s.