%0 Journal Article
%T Application of COSMO-RS Method for the Prediction of Liquid-Liquid Equilibrium of Water/n-Dodecane/1-Butanol
%A S. Balasubramonian
%A Shekhar Kumar
%A D. Sivakumar
%A U. Kamachi Mudali
%J ISRN Thermodynamics
%D 2014
%R 10.1155/2014/415732
%X The liquid-liquid equilibrium (LLE) for the system water-dodecane-butanol was estimated using the UNIQUAC model. In the UNIQUAC model interaction parameters were estimated from the vapor-liquid equilibrium (VLE) and LLE data of their constituent binary pairs. The water-dodecane-butanol LLE was experimentally measured at 298.15£¿K. Phase stability constraints were taken into account while calculating the binary interaction parameters from the mutual solubility data. The COSMO-RS method was used to estimate the activity coefficient in the miscible binary pair. The ternary LLE composition was predicted using the experimental VLE data as well as using the COSMO-RS calculated activity coefficient data along with the experimental mutual solubility data. In the latter case the root mean square deviation (RMSD) for the distribution of butanol between aqueous and organic phase is 0.24%. The corresponding UNIFAC model prediction is 7.63%. 1. Introduction Extraction of uranium and plutonium from the spent nuclear fuel using PUREX method employs Tri butyl phosphate (TBP) as the extractant and dodecane as the diluent. During solvent extraction TBP and dodecane undergo hydrolytic and radiolytic degradation and form dibuty phosphate, monobutyl phosphate, butanol, and several other organic compounds [1]. In order to understand the distribution of these compounds in the PUREX process stream their liquid-liquid equilibrium (LLE) behavior between the aqueous and organic phase must be known. The accurate prediction of LLE using the limited amount of experimental data was investigated by several researchers [2¨C6]. Anderson and Prausnitz [2] described the application of UNIQUAC model for the prediction of LLE. The type II ternary systems which have two partially miscible binaries can be predicted using the binary parameter quite accurately. Magnussen et al. [3] reported separate parameter table for the prediction of LLE using UNIFAC group contribution model. Recently COSMO-RS model reported by Klamt and Eckert [6, 7] for the prediction of fluid phase thermodynamic properties is gaining importance to predict LLE. Several authors used COSMO-RS method to predict LLE of system containing water, hydrocarbon, alcohols, and ionic liquids [8¨C10]. The various excess Gibbs energy model such as NRTL, UNIQUAC, and UNIFAC can be used to predict the multicomponent LLE. These models contain the interaction parameters which are usually estimated from the binary experimental data. The miscible binary pair interaction parameters were estimated from VLE data. Similarly for partially miscible
%U http://www.hindawi.com/journals/isrn.thermodynamics/2014/415732/