Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C1–C4) and dimethyl carbonate

https://doi.org/10.1016/j.jct.2011.08.006Get rights and content

Abstract

(Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {methanol + propan-1-ol + dimethyl carbonate (DMC)}, and four binary mixtures, namely an {alcohol (C3 or C4) + DMC}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich–Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor–liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.

Highlights

► The VLE behavior of systems containing dimethyl carbonate (DMC) was investigated. ► VLE data for ternary and binary mixtures containing alcohol and DMC were measured. ► Several activity coefficient models were used for data reduction or prediction. ► Valley line, i.e., distillation boundary, was observed for the ternary mixture. ► Residue curves were calculated to investigate composition profile for distillation.

Introduction

Dimethyl carbonate (DMC) is a non-toxic substance and it is attractive as an environmentally benign solvent because of its negligible eco-toxicity, low bioaccumulation, low persistence, and high activity [1], [2]. DMC has therefore been used in many applications in the chemical industry, for example as a replacement for dimethyl sulfate, methyl halides, and phosgene in methylation and carbonylation reactions [1], [2], as an excellent co-solvent for non-aqueous electrolytes in lithium batteries [3], as an important intermediate material in an environmentally benign process for polycarbonate production [4], [5], [6], [7], and as a suitable candidate for an oxygen-containing fuel additive to replace methyl tert-butyl ether (MTBE) [8].

Recently, several authors have reported (vapor + liquid) equilibrium (VLE) data for binary or ternary mixtures containing DMC, mainly with alcohols [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], with ethylene glycol [15], [19], and with alkanes or aromatic compounds [19], [21], [22]. However, to our knowledge, VLE data for ternary mixtures are scarce. Previously, our group reported experimental VLE data, measured using a modified Swietoslawski-type ebulliometer, for the ternary mixture (methanol + ethanol + DMC) and its constituent binary mixtures [23].

As an extension of that work, we investigated a ternary mixture containing DMC, namely (methanol + propan-1-ol + DMC), to clarify the VLE behavior of ternary mixtures containing DMC and an alcohol. In this study, boiling point data were measured for this ternary system. In addition, the constituent binary mixtures of this ternary mixture, i.e., (methanol + propan-1-ol), (propan-1-ol + DMC), and three binary mixtures containing DMC, i.e., (propan-2-ol + DMC), (butan-1-ol + DMC), and (butan-2-ol + DMC) at p = (40.00, 53.33, 66.66, 79.99, and 93.32) kPa were studied using a modified Swietoslawski-type ebulliometer. To our knowledge, VLE data for this ternary mixture are not available in the literature. In the binary mixtures with an azeotropic point, binary azeotropic data were also determined from the experimental boiling point data. The experimental boiling point data for the five binary systems were represented using the Wilson model [24]. Predictions for the ternary mixture were also tested using parameters for the binary mixtures. In addition, predictions for these binary or ternary mixtures were tested using the modified UNIFAC (Dortmund) model [25], [26], [27], [28], [29].

In our previous paper [23], a valley was observed from the progression of the predicted tie lines at p = (40.00 to 93.32) kPa for the system (methanol + ethanol + DMC). In this study, a valley was also observed from the results predicted by the Wilson and the modified UNIFAC (Dortmund) model for (methanol + propan-1-ol + DMC). According to Naka et al., the term “valley” is defined as the curves which divide the pattern of the (vapor + liquid) equilibrium tie lines [30], [31]. To separate such a mixture into the desired products by distillation, it is important to identify the exact valley in the vapor–liquid composition diagram because it limits the change in product compositions for a batch distillation. However, as Kurihara et al. pointed out [32], the calculated results for valleys obtained using their method are poor since the azeotropic point calculated using the Wilson equation does not agree perfectly with the experimental data for both the binary and the ternary system. The extended Redlich–Kister (ERK) model [32], [33], [34], which can exactly reproduce the binary and ternary azeotropic point, was used to represent the binary and ternary experimental VLE data and to calculate the valley for (methanol + propan-1-ol + DMC). Finally, the residue curves of this ternary mixture were constructed using the Wilson parameters of the constituent binary mixtures to verify whether this valley would become a simple distillation boundary.

Section snippets

Materials

All chemicals were supplied from Wako Pure Chemical Industries, Ltd., Osaka, Japan. Special grade methanol, propan-1-ol, propan-2-ol, butan-1-ol, and butan-2-ol were dried with 3A molecular sieves, and first grade DMC was dried with 4A molecular sieves. The purities of the materials were checked by gas chromatography and were found to be higher than mole fraction 0.996 for butan-2-ol and mole fraction 0.999 for the other compounds. The purities were further confirmed by measuring the densities (

Binary systems

In this study, the boiling points for five binary mixtures, namely (methanol + propan-1-ol), (propan-1-ol + DMC), (propan-2-ol + DMC), (butan-1-ol + DMC), and (butan-2-ol + DMC), were measured at p = (40.00 to 93.32) kPa. The experimental boiling points for these mixtures are summarized in table 2. In FIGURE 1, FIGURE 2, FIGURE 3, FIGURE 4, FIGURE 5 the experimental results are compared with the literature data [10], [11], [13], [38], [39], [40], [41], [42]. But for all the binary systems only literature

Data reduction and prediction

In this study, the experimental boiling point data were correlated or predicted using three activity coefficient models: Wilson, modified UNIFAC (Dortmund), and ERK. For the correlations, liquid phase activity coefficients were calculated using the following equation assuming ideal gas behavior:γi=pyipisxi,where xi and yi are the equilibrium mole fractions of component i in the liquid and vapor phase, respectively, γi is the liquid phase activity coefficient of component i, p is the total

Conclusions

Isobaric VLE data for the ternary mixture (methanol + propan-1-ol + DMC), two of its constituent binary mixtures, i.e., (methanol + propan-1-ol) and (propan-1-ol + DMC), and three binary mixtures containing an alcohol (C3 or C4) and DMC, i.e., (propan-2-ol + DMC), (butan-1-ol + DMC), and (butan-2-ol + DMC), were determined at p = (40.00 to 93.32) kPa by an ebulliometric method. Binary mixtures containing DMC exhibited a minimum boiling point azeotrope, except for (butan-1-ol + DMC). The Wilson and ERK models were

References (47)

  • J. Gong et al.

    Appl. Catal. A: Gen.

    (2007)
  • A. Rodríguez et al.

    Fluid Phase Equilib.

    (2002)
  • A.B. Pereiro et al.

    J. Chem. Thermodyn.

    (2005)
  • H.-P. Luo et al.

    Fluid Phase Equilib.

    (2000)
  • X.-B. Ma et al.

    Fluid Phase Equilib.

    (2004)
  • J.-H. Oh et al.

    Fluid Phase Equilib.

    (2009)
  • A. Rodríguez et al.

    Fluid Phase Equilib.

    (2002)
  • K. Kurihara et al.

    Fluid Phase Equilib.

    (2007)
  • V. Rodríguez et al.

    Fluid Phase Equilib.

    (1995)
  • R. Bareła et al.

    Fluid Phase Equilib.

    (1995)
  • P. Tundo et al.

    Acc. Chem. Res.

    (2002)
  • P. Tundo et al.

    Green Chemistry: Challenging Perspectives

    (2001)
  • S. Matsuta et al.

    J. Electron. Soc.

    (2001)
  • S. Fukuoka et al.

    Green Chem.

    (2003)
  • J. Haubrock et al.

    Ind. Eng. Chem. Res.

    (2008)
  • J. Haubrock et al.

    Ind. Eng. Chem. Res.

    (2008)
  • M.A. Pacheco et al.

    Energy Fuels

    (1997)
  • R. Francesconi et al.

    J. Chem. Eng. Data

    (1997)
  • A. Sporzynski et al.

    Ind. Eng. Chem. Res.

    (2003)
  • T.E.V. Prasad et al.

    J. Chem. Eng. Data

    (2004)
  • H.-P. Luo et al.

    J. Chem. Eng. Data

    (2001)
  • J.-H. Oh et al.

    J. Chem. Eng. Data

    (2006)
  • Y.-J. Fang et al.

    J. Chem. Eng. Data

    (2005)
  • Cited by (4)

    • Vapor-liquid equilibria of binary and ternary mixtures containing ethyl lactate and effect of ethyl lactate as entrainer

      2016, Fluid Phase Equilibria
      Citation Excerpt :

      A modified Swietoslawski-type ebulliometer was used to measure the boiling points. The equipment and the measurement procedure have been described elsewhere [11,12]. The apparatus consisted of an ebulliometer, a pressure-controlling circuit, and a computer to analyze the data.

    • A modified Patel-Teja cubic equation of state. Part II: Parameters for polar substances and its mixtures

      2014, Fluid Phase Equilibria
      Citation Excerpt :

      In order to assess the predictive power of the generalized expressions presented in the previous section, VLE calculations for pressures above 1 atm are performed for 12 binary mixtures [59,69–80]. Furthermore VLE predictions for 11 low-pressure ternary systems are also conducted [60,62,81–90]. According to the literature [5,13], one of the main advantages of the Wong–Sandler mixing rule is that it allows reliable vapor liquid equilibria predictions at high pressures using binary interaction parameters estimated from low pressure experimental data.

    View full text