ABSTRACT
Phase equilibrium data of ternary systems are very important for simulation, design, and optimization of separation operations. A large amount of investigation has been carried out in recent years on the liquid-liquid equilibria (LLE) measurements of ternary systems, in order to understand and provide further information about the phase behavior of such systems. Since, the liquid extraction of acetic acid from aqueous solution is industrially and scientifically important, the precise LLE data of a liquid mixture composed of (water + acetic acid + organic solvent) are required for further investigations. Various organic solvents for extraction of dilute acetic acid from water have been investigated and reported in the literature (Abrams and Prausnitz, 1975; Aljimaz et al., 2000; Arce et al., 1995, 2001; Bendova et al., 1994; Fandary et al., 1999; Garcia et al., 1988; Garcia-Flores et al., 2001; Ghanadzadeh and Ghanadzadeh, 2003; Ince and Ismail Kirbaslar, 2003; Jassal et al., 1994; Kollerup and Daugulis, 1985; Magnussen et al., 1981; Othmer and Tobias, 1942; Pesche and Sandler, 1995; Sandler, 1994; Sola et al., 1986; Zhang and Hill, 1991; Zhang et al., 1998). Mainly heavy normal alcohols such as hexanol, 1-heptanol, and 1-octanol have been used for extraction of acetic acid from aqueous solution. The LLE data for the mixtures of (water + acetic acid + 2-pentanol), (water + acetic acid + 1-heptanol), and (water + acetic acid + 1-hexanol) had been reported previously by Fahim et al. (Al-Muhtaseb and Fahim, 1996; Aljimaz et al., 2000; Alkandary et al., 2001; Fahim et al., 1997). In the
present work 2-ethyl-1-hexanol was used as an organic solvent in order to determined LLE data for the ternary system of (water + acetic acid + 2-ethyl-1-hexanol). Due to its low cost, high boiling point and very low solubility in water, 2-ethyl-1-hexanol has several advantages as a good solvent for recovering of acetic acid form water. Moreover, 2-ethyl-1-hexanol has high separation factor value in the ternary mixture of (water + acetic acid + 2-ethyl-1-hexanol). This solvent also been used as an organic solvent to determine of LLE data for some ternary mixtures of (water +tert-butanol + 2-ethyl-1-hexanol), (water + ethanol+ 2-ethyl-1-hexanol) (Aljimaz et al., 2000; Arce et al., 1995, 2001; Bendova et al., 1994; Fandary et al., 1999; Garcia et al., 1988; Garcia-Flores et al., 2001; Ghanadzadeh and Ghanadzadeh, 2003; Ince and Ismail Kirbaslar, 2003; Jassal et al., 1994; Kollerup and Daugulis, 1985; Pesche and Sandler, 1995; Sola et al., 1986; Zhang and Hill, 1991; Zhang et al., 1998), and (water + acetone + 2-ethyl-1-hexanol) .The aim of this work is to present the phase behavior of LLE for (water + acetic acid + 2-ethyl-1-hexanol). The phase compositions were measured at temperature from (298.2 to 313.2) K. (Martin, 1998)
18.2 EXPERIMENTAL
18.2.1 Materials The chemicals acetic acid (99.9%) and 2-ethyl-1-hexanol (99.5%) were obtained from Merck and were used without further purification. The purity of these materials was checked by gas chromatography. Distilled water was prepared in our laboratory and used throughout all experiments.
