Thermodynamics of binary mixtures containing N-methyl-2-pyrrolidinone: VLE measurements for systems with ethers—Comparison with the Mod. UNIFAC (Do) and DISQUAC models—Predictions for VLE, , and SLE☆
Introduction
N-Methyl-2-pyrrolidinone (NMP) is an aprotic and dipolar solvent of high selectivity. It has been used to extract aromatic hydrocarbons from aliphatic hydrocarbons. NMP causes the known specific interactions of a large carbonyl group, or nitrogen atom, or the hydrogen atom of methyl group with a solvent. On the other side the monoethers are aprotic and are considered essentially to be non-associating molecules. The interactions between NMP and ethers are believed to occur via complex formation between the two species.
The molecular structure of the N-methyl-2-pyrrolidinone under study is as follows:The interaction of NMP with ethers was studied by us by the measurements of the excess molar volumes and enthalpies of binary mixtures [1] and solid–liquid equilibrium measurements [2]. Recently, we have studied the interaction of NMP with ketones [3] and 2-alkanols [4]. The thermodynamic description using new interaction parameters of the Mod. UNIFAC (Do) or DISQUAC model were presented.
The present work is the continuation of our studies concerning the physicochemical properties of binary mixtures involving NMP. Up to now, we have reported data on vapour–liquid equilibria (VLE) [3], [4], solid–liquid equilibria [2], [5], [6], [7], [8], excess molar volumes, [1], [9], [10], [11], [12], and excess molar enthalpies, [10], [11], [12], of systems formed by NMP and n-alkanes, cycloalkanes, 1-alkenes, 1-alkynes, benzene, toluene, chlorobenzene, 1,1,1-trichloroethane, dichloromethane, 1-alkanols, ketones and ethers. We showed that, in (NMP + alkanol) solutions, the strong polar interactions between NMP and solvent are more important than the self-association of the alcohol. For this reason the ERAS model [13] was used for the description of some mixtures [4], [12]. The purpose of this paper is to investigate the ability of the Mod. UNIFAC (Do) and DISQUAC models to describe the for (NMP + an ether) mixtures. For a more complete study, we also report VLE (P−x) measurements of N-methyl-2-pyrrolidinone with dipropyl ether at T = 353.15 K and T = 373.15 K, or dibutyl ether at T = 373.15 K, or methyl 1,1-dimethylethyl ether, (tert-butyl methyl ether) (MTBE) at T = 333.15 K, or methyl 1,1-dimethylpropyl ether, (tert-amyl methyl ether) (MTAE) at T = 353.15 K, at pressure range from P = 0 kPa to P = 135 kPa by an ebulliometric method. New interaction parameters for (NMP + ether) of the Mod. UNIFAC (Do) and DISQUAC models were determined to describe the thermodynamic properties of these mixtures: VLE, , and SLE.
Section snippets
Materials
The origin of the chemicals (in parentheses are Chemical Abstracts registry numbers, and their mass percent purities) are as follows: NMP (872-50-4, Aldrich Chemical Co., 0.995, anhydrous), dipropyl ether (111-43-3, Aldrich, 99 mol%), dibutyl ether (142-96-1, Aldrich, 99 mol%), dipentyl ether (693-65-2, Fluka AG, 99 mol%), methyl 1,1-dimethylethyl ether (1634-04-46, Aldrich, 99.5 mol%), methyl 1,1-dimethylpropyl ether (994-05-8 Aldrich, 99 mol%). NMP was purified by fractional distillation under low
Results and data reduction
The experimental P−x1 data at different temperatures are listed in Table 3, Table 4 and are plotted in Fig. 1, Fig. 2. No data have been found in the literature for comparison. The P−x1 measurements were reduced using Barker's method [27] to obtain values γi, the activity coefficient of component i in the liquid state. To this end, it was assumed that is represented by an equation of the Redlich–Kister type:where is the molar excess Gibbs energy, x1 the
The Mod. UNIFAC (Do) model
There have been several attempts in the literature to correlate and predict thermodynamic excess functions and phase equilibria using either theoretical lattice-type models or other, more empirical, group contribution models. The Mod. UNIFAC (Do) [29], [30], [31] group contribution model based on the local composition concept with temperature-dependent parameters needs four parameters per contact (two for the Gibbs energy and two for the enthalpy) to reproduce and ; two heat capacity
The DISQUAC model
The molecules under study, i.e. NMP and ethers, are regarded as possessing four types of groups: (1) type a (CH3, CH2 in NMP and ethers), (2) type c (c-CH2 in NMP), (3) type e (O in ethers) and (4) type n (NCO group in NMP, which is different from the group in the Mod. UNIFAC model). The geometrical parameters, relative volumes ri, total relative surfaces qi, and surface fraction αdi for the compounds considered in this work were calculated on the basis of the group volumes and surfaces
Discussion
The results from the Mod. UNIFAC (Do) and DISQUAC models are compared with the experimental data for VLE, , and SLE in Table 11 and for selected mixtures in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7. Generally, in the case of the VLE, the prediction is quite satisfactory (σ < 2 kPa). Using the new and available interaction parameters, the models are more or less successful in predicting the phase equilibria. The prediction of is somewhat worse for the (NMP + MTAE) system by
Conclusions
P−x measurements at different temperatures for (NMP + ether) systems are reported. Mixtures of NMP with ethers were investigated in the framework of the Mod. UNIFAC (Do) and DISQUAC models. The corresponding interaction parameters were developed. The Mod. UNIFAC (Do) model offers an agreement of the usual quality using a limited number of adjusted parameters. The discrepancies were mainly due to the steric effects in the investigated ethers, which especially influence the SLE. The DISQUAC model
Acknowledgement
The authors gratefully acknowledge the Warsaw University of Technology for the financial support.
References (36)
- et al.
J. Chem. Thermodyn.
(2002) - et al.
Fluid Phase Equilib.
(2005) - et al.
J. Chem. Thermodyn.
(2005) - et al.
J. Chem. Thermodyn.
(2000) - et al.
Fluid Phase Equilib.
(2002) - et al.
J. Chem. Thermodyn.
(2003) - et al.
Fluid Phase Equilib.
(1998) - et al.
J. Chem. Thermodyn.
(2001) - et al.
J. Chem. Thermodyn.
(2001) - et al.
J. Chem. Thermodyn.
(2002)
Thermochim. Acta
J. Chem. Thermodyn.
Fluid Phase Equilib.
Fluid Phase Equilib.
Fluid Phase Equilib.
Fluid Phase Equilib.
Pure Appl. Chem.
Ind. Eng. Chem. Res.
Can. J. Chem.
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Presented at CALCON 2003, Laie, Hawaii, USA.