Thermodynamics of isomeric hexynes + MTBE binary mixtures
Introduction
This paper presents a part of our research work on thermodynamic behaviour of mixtures containing acetylenic hydrocarbons such as hexynes (hex-1-yne, hex-2-yne or hex-3-yne). Previously, we have investigated the binary mixtures of isomeric hexynes with alkanes [1], [2], [3], [4] or alcohols [5], [6]. A survey of the open literature revealed that several thermodynamic studies on the binary mixtures containing acetylenic hydrocarbons have been reported [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], but it revealed also a scarcity of VLE and HE data on these binary mixtures.
The purpose of the present paper is to extend the existing previous studies on alkyne containing mixtures to systems with tertiary-alkyl ethers. We report new isothermal vapor–liquid equilibria (VLE) data measured at several temperatures from 263 to 343 K and excess molar enthalpies (HE) data measured at 298.15 K, for two binary systems of methyl 1,1-dimethyl ethyl (MTBE) + hex-1-yne or hex-2-yne. These data were analysed in the framework of the DISQUAC [37], [38] and modified UNIFAC (Do) [39], [40], [41] models. The DISQUAC calculations, reporting interaction parameters for the acetylenic carbon–carbon group in the isomeric hexynes and the oxygen group in the ether, are regarded as a preliminary approach.
Section snippets
Materials
Hex-1-yne and methyl 1,1-dimethylethyl ether (Fluka Chem. AG, Buchs, Switzerland) materials of stated purities ≥99.5%, tested by GLC, were used without further purification. Hex-2-yne (Aldrich Chem., Milwaukee, WI, USA) material of stated purity 99%, tested by GLC, was used as received. GLC analysis revealed the presence of traces of impurities in the sample. No further purification was attempted because of the high price of the material. However, all the substances were thoroughly degassed
Results and data reduction
The primary measurements, obtained by the experimental procedure described above, are isoplethal T–P data, for the pure components and for the binary mixtures at several constant compositions. These vapor pressure data were correlated with the Antoine equation. Interpolated values at several arbitrarily chosen temperatures, for the pure components and for the binary mixtures at constant compositions, were reported in Table 1, Table 2, respectively.
These interpolated isothermal VLE data were
Modified UNIFAC (Dortmund version)
The modified UNIFAC model developed by Weidlich and Gmehling [39], [40], [41], differs from the original UNIFAC [55] by the combinatorial term and the temperature dependence of the group interaction parameters. The equations used to calculate GE and HE are obtained from the fundamental equation for the activity coefficient γi of component i:where is the combinatorial term and is the residual term.
The combinatorial part was changed in an empirical way
Discussion and conclusion
We examined the influence of the position of the carbon–carbon triple bond, in the hexyne, on thermodynamic properties of the investigated binary mixtures. As expected, we found there is a sizeable difference between the VLE, HE and GE values, for hex-1-yne + MTBE, and those corresponding for hex-2-yne + MTBE. A similar behaviour has been encountered in our previous investigated mixtures of isomeric hexynes with alkanes [1], [2], [3], [4] and with alcohols [5], [6]. The present measurements confirm
References (62)
- et al.
Thermochim. Acta
(1993) - et al.
J. Chem. Thermodyn.
(1987) - et al.
Fluid Phase Equilib.
(1990) - et al.
J. Chem. Thermodyn.
(1988) - et al.
Fluid Phase Equilib.
(1993) - et al.
J. Chem. Thermodyn.
(1999) - et al.
J. Chem. Thermodyn.
(1999) - et al.
J. Chem. Thermodyn.
(2004) - et al.
J. Chem. Thermodyn.
(2003) - et al.
J. Chem. Thermodyn.
(2000)
J. Chem. Thermodyn.
J. Chem. Thermodyn.
Thermochim. Acta
Fluid Phase Equilib.
Fluid Phase Equilib.
Fluid Phase Equilib.
J. Chem. Thermodyn.
Fluid Phase Equilib.
Fluid Phase Equilib.
Fluid Phase Equilib.
Fluid Phase Equilib.
Int. Data Ser., Sel. Data Mixtures, Ser. A
Int. Data Ser., Sel. Data Mixtures, Ser. A
Int. Data Ser., Sel. Data Mixtures, Ser. A
Fluid Phase Equilib.
Int. Electron. J. Phys. Chem. Data
Int. Electron. J. Phys. Chem. Data
Monatsch. Chem.
Monatsch. Chem.
Monatsh. Chem.
Eesti Nsv Tead Akad. Toim. Keem. Geol.
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