(Liquid+liquid) equilibria of ternary and quaternary systems with two hydrocarbons, an alcohol, and water at 303.15 K. Systems containing cyclohexane, benzene, ethanol, and water

Abstract

Tie-line data for the water, ethanol, and cyclohexane [{w 1 H 2 O + w 2 C 2 H 5 OH + (1 À w 1 À w 2 )C 6 H 12 }] ternary system, where w is the mass fraction, was investigated at T ¼ 303:15 K. A quaternary system containing these three compounds and benzene {w 1 C 2 H 5 OH + w 2 C 6 H 6 + w 3 C 6 H 12 + (1 À w 1 À w 2 À w 3 )H 2 O} was also studied at the same temperature, while data on its other two partially miscible ternary systems were taken from the literature [the fourth {w 1 C 2 H 5 OH + w 2 C 6 H 6 + (1 À w 1 À w 2 )C 6 H 12 } is not partially miscible]. From our experimental results we conclude that this quaternary system presents a very small water tolerance and that phase separation could produce a considerable loss of C 2 H 5 OH drawn into the aqueous phase. On the other hand, the results also show that the aqueous phase generally contains a higher concentration of C 6 H 6 than of C 6 H 12 . A comparison with other similar quaternary systems investigated in our laboratory was also made. The ternary experimental results were correlated with the UNIQUAC equation, and predicted with the UNIFAC group contribution method. As previously, the equilibrium data of the three ternary systems (including those taken from the literature) were used to determine interaction parameters for the UNIQUAC equation. These parameters were then averaged in order to predict equilibrium data of this quaternary system. The UNIFAC method was also used with the same purpose. The UNIQUAC equation appears to be more accurate than the UNIFAC method for this ternary system. However, this last model is slightly better for the quaternary system, as can be seen from the values of both residuals.

Phase equilibria of ethanol fuel blends

“…Volume 69 of the IUPAC Solubility Data Series compiles evaluated ternary LLE data for ethanol-hydrocarbon-water systems through 1992 [17]. Several sets of ternary and quaternary LLE data have been reported since 1992 [18][19][20][21][22][23][24]. Data are available for about 22 hydrocarbons in the typical molecular weight range found in gasoline.…”

Measurements and Correlations of Liquid-liquid-Equilibria of the Mixtures Consisting of Ethanol, Water, Pentane, Hexane, and Cyclohexane

“…4, 5, and 7 were plotted for these three ternary mixtures all at 303.15 K. Among the LLE data of these ternary mixtures, Figs. 2 and 3 are the plots of experimental data and literature data of Gramajo de Doz, Bonatti, and Sólimo [6] of ethanol + water + cyclohexane at 303.15 K already mentioned earlier. Fig.…”

“…The LLE data of ethanol, water, and cyclohexane mixture have been reported by Ju, Xu, Shao, and Ying in 2006 [5]. In 2003 Gramajo de Doz, Bonatti, and Sólimo [6] reported the LLE data of ternary and quaternary of ethanol, water, cyclohexane, and benzene. In 2005, also Gramajo de Doz, Bonatti, and Sólimo [7] reported the LLE data of ethanol, water, benzene, cyclohexane, isooctane, and n-hexane and observed the very small water tolerance and that phase separation could result in a considerable loss of ethanol drawn into aqueous phase.…”

“…The results of this test experiment were compared to the literature data of Gramajo de Doz, Bonatti, and Sólimo [6]. Since there is no match between the present and literature data obtained at the same experimental conditions such that the exact comparison between the present and literature data can be made.…”

(Liquid+liquid) equilibria for the quaternary system water+methyl tert-butyl ether+ethanol+benzene at 303.15K

“…As part of an on going research program, we focus on the investigation of the phase equilibrium of quaternary systems containing hydrocarbons (benzene, isooctane, toluene, or cyclohexane), oxygenated compounds (methanol, ethanol or methyl tert-butyl ether), and water [1][2][3][4][5][6], because this type of systems has gained importance due to the increasing demand of oxygenated compounds to produce lead-free gasoline. The US Environmental Protection Agency recommends the use of alcohols (particularly ethanol) as gasoline additives to provide antiknock properties and to help reduce harmful combustion emissions [7,8].…”