Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The present study focuses on the investigation of 2,2,2-Nitrilotrisethanol (triethanolamine) as entrainer to effect the separation of isopropanol-water mixture. The VLE data were measured for the binary systems isopropanol + triethanolamine and water + triethanolamine using an improved Othmer still at 101.32 kPa. Experimental data for ternary mixture isopropanol + water + triethanolamine were also studied for different entrainer concentrations. Three initial triethanolamine concentrations: 5 mol%, 10 mol% and 15 mol% were examined in the feed solution for VLE experiments. The results demonstrated that the addition of triethanolamine in the isopropanol + water mixture produces considerable increment in the relative volatility, which could eliminate the azeotrope successfully. Hence, triethanolamine was found an effective entrainer for breaking the isopropanol + water azeotrope. Further, the NRTL model was used for fitting the experimental VLE data and the binary interaction parameters were regressed. The estimated values for binary and ternary systems agreed well with the experimental data. The overall average deviation for vapor phase mole fraction and equilibrium temperature between the experiment and correlation were found to be 0.09 and 0.40 K, respectively. Moreover, the thermodynamic consistency check of experimental VLE data were performed by using modified McDermott-Ellis test and Wisniak's L-W test. 1. INTRODUCTION Isopropanol (propan-2-ol), is an important member of the alcohol family and is widely used raw material in many industries such as production of dyestuffs, preparation of pesticide, cellulose synthesis, cosmetics, paints, pharmaceutical manufacturing and as solvent in semiconductor industries.1 Isopropanol (IPA) is generally produced by two techniques: direct hydration and indirect hydration of propylene.2 In many industries it is necessary to use pure isopropanol, for this purpose it is essential to eliminate water from IPA + water mixture. IPA + water mixture forms minimum-boiling azeotrope with water at 67.5 mole% (IPA), at standard atmospheric pressure and 353.45 K temperature.3 Thus it becomes difficult to separate through