Liquid–liquid equilibria of 1,3-dimethylimidazolium methyl sulfate with ketones, dialkyl carbonates and acetates

https://doi.org/10.1016/j.fluid.2007.02.027Get rights and content

Abstract

The liquid–liquid equilibria of several binary systems of 1,3-dimethylimidazolium methyl sulfate MMIM MeSO4 and dialkyl carbonates (dimethyl carbonate and diethyl carbonate), ketones (acetone, 2-butanone and 2-pentanone) or acetates (methyl acetate and ethyl acetate) were studied from 278.15 K to close to the boiling temperature of the solvent. The liquid–liquid equilibrium of the ternary system of 2-butanone + ethanol + MMIM MeSO4 was carried out at 298.15 K and atmospheric pressure. Experimental liquid–liquid data are compared with the correlated values obtained by means of the NRTL equation. This model satisfactorily correlates the experimental data.

Introduction

The behaviour of ionic liquids (ILs) is very different from conventional molecular liquids when they are used as solvents. The aim of our work is to investigate the possible use of these remarkable liquids as solvents in separation processes since these chemicals are considered beneficial due to their interesting properties that could be applied to replace the conventional organic solvents. In general terms, to design an industrial process it is necessary to know the separation section, in our case an IL is used as solvent and the research is focused on liquid–liquid extraction involving azeotropic mixtures (ketones or acetates with alcohols). Likewise azeotropic data are very common in many chemical engineering processes and azeotropic distillation is the most widely separation technique used to separate the chemicals. In this paper, the azeotropic mixture 2-butanone + ethanol was chosen due to it is hard to separate into each component by conventional distillation. 2-Butanone is a solvent in paints and resin adhesives and it is very common to found it mixed with alcohols.

With the aim of continuing the thermodynamic study of the thermodynamic properties [1], [2], [3] of the ionic liquids (in this case MMIM MeSO4 which has been synthesized in our laboratory) with different organic solvents, the phase composition of the two liquid phases for binary and ternary systems of MMIM MeSO4 and several dialkyl carbonates, ketones and alkyl acetates was measured due to such information is of great value in the study of solution properties to be used in thermodynamic modelling and in the prediction of phase equilibria. The results have been correlated by the NRTL model [4]. LLE data involving MMIM MeSO4 have no been published before.

Section snippets

Materials

The chemicals used in this work (the sources reported and their mass percent purities) were as follow: dimethyl carbonate (Fluka, ≥99%), diethyl carbonate (Fluka, ≥99.5%), ethanol (Merck, ≥99.9%), acetone (Aldrich, ≥99.8%), 2-butanone (Fluka, ≥99.5%), 2-pentanone (Aldrich, ≥99.5%), methyl acetate (Merck, ≥99%), ethyl acetate (Aldrich, ≥99.5%) and MMIM MeSO4 (synthesized in our laboratory [1] and characterized by its NMR spectra and positive FABMS (FISONS VG AUTOSPEC mass spectrometer)). All

Results and discussion

Experimental tie-line data of (MMIM MeSO4 + dimethyl carbonate), (MMIM MeSO4 + diethyl carbonate) and (MMIM MeSO4 + 2-pentanone) from (278.15 to 343.15 K); (MMIM MeSO4 + acetone) and (MMIM MeSO4 + methyl acetate) from (278.15 to 318.15 K); (MMIM MeSO4 + 2-butanone) from (278.15 to 333.15 K) and (MMIM MeSO4 + ethyl acetate) from (278.15 to 338.15 K) are reported in Table 4. Experimental phase diagrams of LLE for these binary mixtures are shown in Fig. 1.

The composition of the experimental tie-line ends for the

Conclusions

LLE of binary mixtures involving MMIM MeSO4 with several organic components are determined experimentally from 278.15 K to close to the boiling temperature of the solvent. In general terms, the composition of the MMIM MeSO4 in both phases is constant, except for the systems MMIM MeSO4 + acetone and + methyl acetate where an increase in the IL mole fraction rich phase is observed when the temperature is increased. On the other hand, the immiscibility area of the binary systems increases with an

Acknowledgement

We want to thank the Ministerio de Educación y Ciencia (Spain) for the financial support through Project CTQ 2004-00454.

References (19)

  • A.B. Pereiro et al.

    J. Chem. Thermodyn.

    (2006)
  • G. Marino et al.

    J. Chem. Thermodyn.

    (2000)
  • H. Katayama et al.

    Fluid Phase Equilib.

    (1998)
  • A.B. Pereiro et al.

    J. Chem. Eng. Data

    (2006)
  • A.B. Pereiro et al.

    Green Chem.

    (2006)
  • H. Renon et al.

    AIChE J.

    (1968)
  • I. García de la Fuente et al.

    J. Solution Chem.

    (1995)
  • R. Francesconi et al.

    J. Chem. Eng. Data

    (1996)
  • A. Pal et al.

    J. Chem. Eng. Data

    (1998)
There are more references available in the full text version of this article.

Cited by (36)

  • The molecular nature of the eliminating azeotropy of dimethyl carbonate–ethanol system by ionic liquid entrainer

    2023, Separation and Purification Technology
    Citation Excerpt :

    ILs are excellent entrainers in extractive distillation. At present, they have been applied in the extractive distillation separation of multiple azeotrope systems, such as aqueous systems (water–alcohol/tetrahydrofuran) [7,8], alcoholic systems (alcohol–water/ester/ketonealiphatic hydrocarbons/halogenated) [9–12], aromatic–aliphatic hydrocarbons systems [13] and other azeotropes [14,15]. The macroscopic property changes are from the microstructure change of the mixtures.

  • Extraction of ethanol from mixtures with n-hexane by deep eutectic solvents of choline chloride + levulinic acid, + ethylene glycol, or + malonic acid

    2020, Journal of Molecular Liquids
    Citation Excerpt :

    The thermophysical properties of ILs can also make important contributions to azeotropic breaking by extractive distillation, liquid-liquid extraction, and supported liquid membranes [14]. Azeotrope systems studied using ILs as separating agents cover various mixtures [15–17]. As for ethanol + alkanes, ILs of ethyl sulfate [EtSO4] and other anions combined with imidazolium-based cations have been adopted for ethanol + n-hexane [18–21] and ethanol + n-heptane [18,22,23] to present high separation efficiency.

  • Liquid-liquid equilibria for ternary mixtures of 1-alkyl-3-methyl imidazolium bis{(trifluoromethyl)sulfonyl}imides, n-hexane and organic compounds at 303.15 K and 0.1 MPa

    2016, Journal of Chemical Thermodynamics
    Citation Excerpt :

    Moreover, LLE data provide important information for a variety of processes and their use in chemical engineering is fundamental to widening their industrial applications. LLE data for ternary systems containing ILs have been studied by several authors [7–58], the NRTL model [59] being the most widely used for correlating the experimental data obtained. Because of the lack of pure component volume and area parameters, the UNIQUAC model [60] has not been so widely used with ILs, although, some authors [22,29,38–42,44,48–50,61–64] have correlated LLE data for ternary systems that involve ILs.

  • Phase equilibria of toluene/heptane with tetrabutylphosphonium bromide based deep eutectic solvents for the potential use in the separation of aromatics from naphtha

    2012, Fluid Phase Equilibria
    Citation Excerpt :

    Then binary parameters would be fitted to the ternary data resulting in a good representation of the data. NRTL was also used for systems containing ILs [49,50]. In this work, the different DESs were considered as pseudo-pure components and the model development was achieved within Simulis® thermodynamics environment, a thermo physical properties calculation server provided by ProSim [51] and available as an MS-Excel add-in.

View all citing articles on Scopus
View full text