A Comparative Study on Water and Ethanol Separation Mixture by Different Solvents: New Experimental and Correlation Data

This paper describes our interest in ethanol separation and the enhancement of the obtained interaction parameters. The binodal curves and tie-line data for the ternary systems of water + ethanol + 1-octanol, water + ethanol + 4-methyl-2-pentanone, and water + ethanol + ethyl acetate were investigated at 293.15 K. All these three ternary systems followed a type-1 liquid-liquid equilibrium diagram. Furthermore, the extraction capabilities of these solvents were tested by the separation factor (S), which was found to be greater than 1 in all ternary systems, with the separation factors varying between 3.52 and 18.37. In addition, it was found that the values of the distribution coefficient (D) of ethanol were not constant over the entire composition of the two-phase region (D values varied between 0.777 and 0.928), which confirmed the extraction of ethanol. The ternary system water + ethanol + ethyl acetate was found to be the best option in terms of the distribution coefficient and separation factor. Othmer-Tobias and Hand plots were used to determine the reliability of the experimental tie-line data. In addition, the non-random two-liquid (NRTL) model was used to correlate the experimental data, and the model parameters were obtained using a genetic algorithm (GA). The results showed that there was a strong agreement between the experimental and calculated tie-lines, with root-mean-square deviation (RMSD) values below 1.72%.