Liquid–Liquid Equilibria for Ternary Systems of (Ethyl Methyl

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Liquid−Liquid Equilibria for Ternary Systems of (Ethyl Methyl Carbonate + Methanol or Ethanol + Water) at 293.15, 303.15, and 308.15 K Wenfeng Peng, Quanzhou Zhang, Wanxia Feng, and Yao Chen*

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Department of Chemistry, Jinan University, Guangzhou 510632, China ABSTRACT: Liquid-phase composition values for {water + methanol + ethyl methyl carbonate (EMC)} and (water + ethanol + EMC) were determined at temperatures of 293.15, 303.15, and 308.15 K at 101 kPa. Thermodynamic modified UNIQUAC and extended UNIQUAC models were used in regression of the experimental values, with average rootmean-square deviations of 0.96 and 1.45% in mole fraction, respectively. Moreover, optimum binary interaction parameters of (methanol or ethanol + EMC) were obtained by regression analysis of the phase composition values. The experimental data consistency was further ascertained by applying the Bachman equation. Distribution coefficients and separation factors were used to assess the extraction performance of EMC in the separation of methanol and ethanol from water.

1. INTRODUCTION

Ethyl methyl carbonate (EMC), which is an environmentally benign and asymmetric carbonic acid ester, is widely used as a cosolvent for a nonaqueous electrolyte in lithium batteries.9 It is also a potential extracting agent owing to its lower water solubility, lower volatility, and toxicity. In the traditional synthesis of EMC, the byproducts often contain water, methanol, and ethanol. Thus, for the ternary (water + methanol or ethanol + EMC) mixtures, further study of the phase behavior and thermodynamic properties is of great significance in process engineering. In recent years, the LLE data of the ternary systems (water + methanol or ethanol + EMC) have been reported only at T = 298.15 K.10,11 However, the temperature can influence the solubility of EMC in water and the phase behavior. In this study, we measured the LLE values of (water + methanol + EMC) and (water + ethanol + EMC) at temperatures of 293.15, 303.15, and 308.15 K and at 101 kPa. This work covers the influence of temperature on two-phase regions. An efficient model is necessary for describing the involved liquid−liquid equilibria for the simulation and design of extraction processes. In this study, correlation analysis of the experimental values relied on the thermodynamic modified and extended UNIQUAC models.12,13 Phase diagrams of the experimental LLE data were drawn with tie lines combined with the correlation results of the modified UNIQUAC model. The reliability of the experimental values was determined by using the Bachman equation.14 The distribution coefficients and separation factors calculated from the obtained LLE data were used to establish the extraction capability of EMC and the possibility of EMC as an extractant for the separation of (water + methanol or ethanol) mixtures.

Alcohols such as methanol and ethanol are very valuable intermediates in many synthesis processes. They are widely used in the chemical industry as organic solvents and gasoline additives. For extensive applications, it is necessary and costeffective to reduce the water content in alcohols to obtain higher-purity methanol or ethanol for repeated use. However, (ethanol + water) mixtures have positive azeotropes, which have a maximum in the pressure−composition diagram. Traditional energy-intensive distillation is impossible and uneconomical because of the difficulty in obtaining ethanol from (ethanol + water) azeotropic mixtures. Liquid−liquid extraction, which has mild processing conditions including moderate temperature and pressure, provides an alternative method for separating the azeotropic mixtures. In liquid− liquid extraction, liquid−liquid equilibria (LLE) data are fundamental and important to the select use of extracting agents and the improvement of separation processes. For the design of extraction devices and simulation and optimization of chemical production, reliable LLE data are usually required. For this reason, many investigations of LLE have been found in the literature.1−6 LLE data for {water + methanol or ethanol + dichloromethane (DCM)} and {water + methanol or ethanol + diethyl ether (DEE)} systems at 293.15 K have been reported by Merzougui et al.7 LLE data for {water + ethanol or 2-propanol +1,1′-oxybis(butane) (DBE)} systems at several temperatures have been determined by Wang et al.8 In the literature, DCM, DEE, and DBE have been investigated as extracting agents in the extraction of methanol and ethanol from aqueous solutions. However, DEE and DCM are not perfect extractants due to their lower boiling point and higher volatility. In previous work, we showed that DBE has been suggested as a suitable solvent in the separation of ethanol from (water + ethanol) mixtures.8 © XXXX American Chemical Society

Received: June 27, 2018 Accepted: October 30, 2018

A

DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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2. EXPERIMENTAL SECTION The chemicals used in this work are analytical reagents. The mass fractions of methanol, ethanol, and EMC were measured with a gas chromatograph (GC-14C) and are shown in Table 1, together with CAS number and the source. Redistilled water

Table 2, we found that the solubility of EMC in water decreases as the temperature increases, which may be due to the existence of a hydrogen bond. A carbonyl group can form a weak intermolecular hydrogen bond with water,17 while temperature can influence the stability of a hydrogen bond. When the temperature is lower, EMC dissolves easily in water. As the temperature increases, the solubility of EMC in water decreases owing to hydrogen bond breaking. The measured LLE values for (water + methanol + EMC) and (water + ethanol + EMC) at the experimental temperatures (T = 293.15, 303.15, and 308.15 K) at 101 kPa are presented in Tables 3 and 4. The corresponding ternary phase diagrams at the three temperatures are shown in Figures 1 and 2, in which the measured tie lines are compared with those obtained by correlation by the modified UNIQUAC model. Figure 2 shows that ethanol is more soluble in EMC than in water, while Figure 1 shows that methanol is a little more soluble in water than in EMC. The experimental LLE data are compared graphically with the literature values (T = 298.15 K)10,11 in Figure 3. From Figure 3a, the experimental temperatures have no noticeable influence on the two-phase zones for the (water + methanol + EMC) system. For the (water + ethanol + EMC) system, the two-phase regions increase, especially in the aqueous phase as the temperature increases, as drawn in Figure 3b. It may be that ethanol has one more methylene group that is a kind of hydrophobic group, comparing with methanol, so methanol more easily dissolves in the water-rich phase and ethanol more easily dissolves in the ester-rich phase. When the temperature increases, weaker hydrogen bonds formed by EMC and water17 are broken, and then released free water molecules can form hydrogen bonds with ethanol. For this reason, ethanol dissolves more in the aqueous phase with the increase in temperature. As shown in Figure 3b, the two-phase regions on the side of the aqueous phase change a little. The effectiveness of alcohol extraction was given by a separation factor, which was an examination of the extraction ability of the solvent to separate alcohols from water. The distribution coefficient (Di) and separation factor (S) are calculated with the following formulas:

Table 1. Suppliers and Mass Fraction Purity of Chemicals CAS no.

mass fraction purity

EMC

623-53-0

0.994

methanol

67-56-1

0.994

ethanol

64-17-5

0.997

water

7732-18-5

0.999

component

supplier Xiya Reagent Research Center GuangZhou Chemical Reagent Factory GuangZhou Chemical Reagent Factory GuangZhou Jinan University

analysis method GCa GCa GCa GCa

a

Gas chromatography.

was used in this experiment. The LLE data were determined from 293.15 to 308.15 K at atmospheric pressure. In our previous work, the experimental machines15 and operation procedures16 have been described fully. In this experiment, the liquid sample was placed in a water bath equipped with a thermostatic controller (accuracy of ±0.05 K). The prepared samples were stirred for 3 h with a magnetic stirrer and settled for more than 3 h at constant temperature, which was enough to reach complete phase separation. The microinjector (an injection volume of 1 μL) was used to take samples from the upper and lower phases, respectively. The samples were quickly injected into the gas chromatograph (GC-14C) equipped with a thermal conductivity detector for analysis and fully separated with a Porapak QS packed column (2.5 m length, 3 mm inner diameter). The initial and final temperatures of the chromatographic column were set at 423.15 and 483.15 K, respectively. The injector and detector temperatures were set at 493.15 and 513.15 K, respectively. The oven temperature was increased from 423.15 to 483.15 K at a rate of 25 K·min−1. The flow rate of the carrier hydrogen gas passing through the column was kept at 60 mL·min−1. The response peak values of each experimental component were analyzed by Chromatopac (N2000) and converted to mole fraction through the calibration using standard mixtures prepared gravimetrically. Each experimental sample was measured at least three times with an estimated uncertainty of ±0.005 in the mole fraction.

Di =

S=

Table 2. Solubility Data for {Water (1) + EMC (2)} System at Four Temperatures a

293.15 298.15b 303.15a 308.15a

xII1

xII2

xI1

xI2

0.100 0.0912 0.086 0.081

0.900 0.9088 0.914 0.919

0.995 0.9959 0.996 0.997

0.005 0.0041 0.004 0.003

xiI

(1)

D2 D1

(2)

Here, xi indicates the mole fraction of component i. Superscripts I and II denote the water-rich phase and the ester-rich phase, respectively. Subscript 1 represents water, and subscript 2 represents alcohols. The distribution coefficients and separation factors are presented in Tables 3 and 4. The separation factors range from 2.44 to 5.50 for the (water + methanol + EMC) system and from 2.83 to 15.77 for the (water + ethanol + EMC) system. The distribution coefficients of ethanol and the separation factors are both higher than for methanol at same temperature because ethanol has one more hydrophobic alkyl group than methanol, which means that the extraction of ethanol using EMC is more feasible than for methanol. Table 5 lists the comparisons of the separation factors between the experiments and the literature by the use of extracting solvents EMC, DEE, DCM, and DBE. From Table

3. RESULTS AND DISCUSSION 3.1. Experimental LLE Data. Table 2 lists the solubility data for the (EMC + water) system at four temperatures. From

T/K

xiII

a

Carried out under pressure p = 101 kPa, with standard uncertainties u of u(T) = 0.05 K, u(x) = 0.005, and u(p) = 1 kPa. x, mole fraction; I, aqueous phase; and II, organic phase. bFrom ref 10. B

DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Table 3. Experimental LLE Data for the {Water (1) + Methanol (2) + EMC (3)} System at 293.15, 303.15, and 308.15 K at 101 kPaa xII1

xII2

xII3

xI1

0.108 0.125 0.139 0.171 0.183 0.204 0.227 0.258

0.013 0.021 0.029 0.036 0.042 0.052 0.056 0.068

0.879 0.854 0.832 0.793 0.775 0.744 0.717 0.674

0.967 0.954 0.943 0.931 0.919 0.904 0.892 0.881

0.100 0.134 0.173 0.195 0.232 0.254 0.274

0.016 0.027 0.041 0.049 0.060 0.069 0.077

0.884 0.839 0.786 0.756 0.708 0.677 0.649

0.962 0.949 0.932 0.916 0.904 0.887 0.865

0.101 0.137 0.156 0.169 0.197 0.217 0.249 0.278

0.017 0.033 0.041 0.047 0.055 0.063 0.074 0.080

0.882 0.830 0.803 0.784 0.748 0.720 0.677 0.642

0.962 0.942 0.925 0.915 0.906 0.896 0.879 0.861

xI2 T = 293.15 K 0.023 0.033 0.043 0.051 0.059 0.070 0.078 0.084 T = 303.15 K 0.030 0.040 0.054 0.065 0.073 0.082 0.095 T = 308.15 K 0.031 0.047 0.060 0.066 0.073 0.080 0.089 0.103

xI3

D1

D2

S

0.010 0.013 0.014 0.018 0.022 0.026 0.030 0.035

0.11 0.13 0.15 0.18 0.20 0.23 0.25 0.29

0.57 0.64 0.67 0.71 0.71 0.74 0.72 0.81

5.18 4.92 4.47 3.94 3.55 3.22 2.88 2.79

0.008 0.011 0.014 0.019 0.023 0.031 0.040

0.10 0.14 0.19 0.21 0.26 0.29 0.32

0.53 0.68 0.76 0.75 0.82 0.84 0.81

5.30 4.86 4.00 3.57 3.15 2.90 2.53

0.007 0.011 0.015 0.019 0.021 0.024 0.032 0.036

0.10 0.15 0.17 0.18 0.22 0.24 0.28 0.32

0.55 0.70 0.68 0.71 0.75 0.79 0.83 0.78

5.50 4.67 4.00 3.94 3.41 3.29 2.96 2.44

a

Standard uncertainties u are u(T) = 0.05 K, u(x) = 0.005, and u(p) = 1 kPa. x, mole fraction; I, aqueous phase; and II, organic phase.

Table 4. Experimental LLE Data for {Water (1) + Ethanol (2) + EMC (3)} System at 293.15, 303.15, and 308.15 K at 101 kPaa xII1

xII2

xII3

xI1

0.111 0.118 0.166 0.260 0.301 0.332 0.432 0.480

0.026 0.030 0.044 0.068 0.077 0.086 0.099 0.107

0.863 0.852 0.790 0.672 0.622 0.582 0.469 0.413

0.976 0.973 0.963 0.944 0.937 0.930 0.924 0.910

0.132 0.183 0.200 0.285 0.352 0.479 0.520

0.038 0.054 0.058 0.072 0.090 0.109 0.113

0.830 0.763 0.742 0.643 0.558 0.412 0.367

0.977 0.963 0.958 0.949 0.938 0.915 0.897

0.127 0.165 0.214 0.307 0.399 0.469 0.490 0.516

0.043 0.057 0.068 0.086 0.100 0.106 0.112 0.115

0.830 0.778 0.718 0.607 0.501 0.425 0.398 0.369

0.973 0.963 0.956 0.945 0.940 0.931 0.920 0.915

xI2 T = 293.15 K 0.016 0.018 0.026 0.038 0.045 0.048 0.053 0.063 T = 303.15 K 0.019 0.028 0.030 0.038 0.049 0.064 0.069 T = 308.15 K 0.021 0.028 0.035 0.046 0.050 0.056 0.066 0.070

xI3

D1

D2

S

0.008 0.009 0.011 0.018 0.018 0.022 0.023 0.027

0.11 0.12 0.17 0.28 0.32 0.36 0.47 0.53

1.63 1.67 1.69 1.79 1.71 1.79 1.87 1.70

14.82 13.92 9.94 6.39 5.34 4.97 3.98 3.21

0.004 0.009 0.012 0.013 0.013 0.021 0.034

0.14 0.19 0.21 0.30 0.38 0.52 0.58

2.00 1.93 1.93 1.89 1.84 1.70 1.64

14.29 10.16 9.19 6.30 4.84 3.27 2.83

0.006 0.009 0.009 0.009 0.010 0.013 0.014 0.015

0.13 0.17 0.22 0.32 0.42 0.50 0.53 0.56

2.05 2.04 1.94 1.87 2.00 1.89 1.70 1.64

15.77 12.00 8.82 5.84 4.76 3.78 3.21 2.93

a

Standard uncertainties u are u(T) = 0.05 K, u(x) = 0.005, and u(p) = 1 kPa. x, mole fraction; I, aqueous phase; and II, organic phase. C

DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Figure 1. Experimental and calculated LLE for the (water + methanol + EMC) system: black ● and dashed line, experimental tie lines; red ▲ and solid line, correlated results of the modified UNIQUAC model. (a) 293.15, (b) 303.15 K, and (c) 308.15 K.

Figure 2. Experimental and calculated LLE for the (water + ethanol + EMC) system: black ● and dashed line, experimental tie lines; red ▲ and solid line, correlated results of the modified UNIQUAC model. (a) 293.15, (b) 303.15, and (c) 308.15 K.

5, for the (water + methanol + extracting solvents) system, separation factors by using EMC as an extraction agent are similar to those for DEE and DCM, and for the (water + ethanol + extracting solvents) system, the separation factor values by using EMC are similar to those for DEE but lower than those for DCM and DBE. The results indicate that EMC can be employed as an extraction agent to extract methanol or ethanol from alcohol−water mixtures. As shown in Figure 4, the separation factors as a function of mole fraction of methanol or ethanol in the ester-rich phase are represented graphically. The results show that the separation factor values

decrease gradually with the increase in the concentration of methanol or ethanol in the ester-rich phase. 3.2. Consistency of LLE Data. The consistency of the experimental LLE data is verified by the Bachman equation,14 defined by

II ji x zy x3II = a + bjjjj 3I zzzz (3) k x1 { where a and b are parameters of the Bachman equation. The regression coefficient (R2) and parameters of the equation are

D

DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Figure 3. Comparison of the experimental and the literature values for the (a) (water + methanol + EMC) and (b) (water + ethanol + EMC) systems: black ■, 293.15 K; green ◆, 298.15 K;10 pink ★, 298.15 K;11 red ●, 303.15 K; and blue ▼, 308.15 K.

Figure 4. Separation factor (S) as a function of the mole fraction of methanol or ethanol in the organic phase for systems (a) (water + methanol + EMC) and (b) (water + ethanol + EMC) at three temperatures: black ■, 293.15 K; red ●, 303.15 K; and blue ▼, 308.15 K.

listed in Table 6. The regression coefficient values are in close proximity to 1, which indicates a high consistency of experimental values. The linearity of Bachman plots is also shown in Figure 5.

Table 5. Comparisons of Separation Factors (S) for the Ternary Systems system (1 + 2 + 3)

T/K

water + methanol + EMC

293.15 298.15 303.15 308.15 293.15 298.15 303.15 308.15 293.15 293.15 293.15 293.15 293.15 298.15 303.15 308.15

water + ethanol + EMC

water water water water water

+ + + + +

methanol + DEE methanol + DCM ethanol + DEE ethanol + DCM ethanol + DBE

xII2 0.013 0.014 0.016 0.017 0.026 0.029 0.038 0.043 0.013 0.013 0.044 0.161 0.026 0.029 0.008 0.035 E

to to to to to to to to to to to to to to to to

S 0.068 0.073 0.077 0.080 0.107 0.109 0.113 0.115 0.282 0.322 0.295 0.316 0.273 0.274 0.262 0.294

2.79 2.70 2.53 2.44 3.21 3.09 2.83 2.93 1.14 2.03 2.25 3.31 6.58 7.30 7.40 6.46

to to to to to to to to to to to to to to to to

ref 5.18 4.48 5.30 5.50 14.82 13.72 14.29 15.77 5.91 6.11 16.15 83.26 36.95 31.73 44.25 49.11

this 10 this this this 10 this this 7 7 7 7 8 8 8 8

work work work work work work

DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Table 6. Parameters of the Bachman Equation for the Studied Ternary Systems

Table 7. Structural Parameters for Pure Components substance

system (1 + 2 + 3)

T/K

a

b

R2

water + methanol + EMC

293.15 303.15 308.15 293.15 303.15 308.15

−0.437 −0.362 −0.385 −0.066 −0.057 −0.040

1.441 1.358 1.375 1.045 1.037 1.014

0.994 0.997 0.995 0.999 0.999 0.999

water + ethanol + EMC

EMC methanol ethanol water a

r 3.69 1.43 2.11 0.92

q

q′a

q′b

ref

3.36 1.43 1.97 1.40

0.75

q0.20 1.00 0.89 0.96

19 18 18 18

q 1.48 1.40 1.28

Modified UNIQUAC model. bExtended UNIQUAC model.

UNIQUAC models, respectively.12,13 For a completely miscible binary system, the binary parameters were obtained from the vapor−liquid equilibrium (VLE) data by minimizing the objective function (eq 4) by means of a computer program described by Prausnitz et al.18 ÄÅ ÅÅ (P cal − P exp)2 (Tical − Tiexp)2 Å i F = ∑ ÅÅÅÅ i + Å σP 2 σT 2 i Å ÇÅ ÉÑ (yical − yiexp )2 ÑÑÑÑ (xical − xiexp)2 ÑÑ + + ÑÑ σx 2 σy 2 ÑÑÖ (4) Here, superscripts cal and exp indicated the calculated value and the experimental value, respectively. The standard deviation values, σP, σT, σχ, and σy, were set as 1 mmHg for pressure, 0.05 K for temperature, 0.001 for the mole fraction of liquid phase, and 0.003 for the mole fraction of the vapor phase.18 Table 8 shows the binary parameters for the constituent binary systems. Binary parameters a12 and a21 for completely miscible systems (water + methanol) and (water + ethanol) were obtained from experimental VLE data. 20,21 For immiscible system (water + EMC), the binary parameters were obtained with the experimental solubility data. A regression method, which has been described in detail in our previous research,22 was used to analyze the ternary LLE data and to obtain the binary parameters for systems (methanol + EMC) and (ethanol + EMC). The ternary parameters were obtained by the regression of the experimental LLE data, which uses an iterative computer program that is based on a simplex method.23 The root-meansquare deviation (rmsd) can be taken to be a measure of the precision of the ternary LLE calculations, which is defined by ÄÅ N É ÅÅ ∑ min∑2 ∑3 (x exp − x cal)2 ÑÑÑ1/2 Å ÑÑ ijk ijk k j i Å ÑÑ rmsd = 102ÅÅÅ ÑÑ ÅÅ 6 N ÑÑ ÅÅÇ ÑÖ

(5)

where k = 1, 2, ..., N (tie- lines) and exp and cal indicate experimental and calculated values, respectively. The ternary parameters are presented in Table 9, along with the rmsd values of the experimental and calculated LLE data. Fitting the models with the binary and ternary parameters was done to obtain the correlated results. For the ternary systems at the experimental temperatures, the mean rmsd values of the correlated results are 0.96 mol % for the modified UNIQUAC model and 1.45 mol % for the extended UNIQUAC model. Obviously, the modified UNIQUAC model can correlate the ternary experimental LLE data better than can the extended UNIQUAC model. Figures 1 and 2 show that the experimental and correlated results are in good agreement.

Figure 5. Bachman plot for systems (a) (water + methanol + EMC) and (b) (water + ethanol + EMC) at three temperatures: black ■, 293.15 K; red ●, 303.15 K; and blue ▼, 308.15 K.

3.3. Correlation of LLE Data. The experimental LLE data were correlated through the thermodynamic modified UNIQUAC and extended UNIQUAC models.12,13 The molecular structural volume r and surface area parameter q for pure substances are from the literature,18,19 as shown in Table 7. Correction factor q′ was obtained from the literature for self-associating substances and was set as q0.75 and q0.20 for the nonassociating substance for the modified and extended F

DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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Table 8. Binary-Phase Equilibrium Data Reduction for the Relevant Systems modified UNIQUAC

extended UNIQUAC

system (1 + 2)

T/K

a12/K

a21/K

a12/K

a21/K

water + methanol water + ethanol water + EMC

298.15 298.15 293.15 303.15 308.15 293.15 303.15 308.15 293.15 303.15 308.15

158.59 −46.98 316.84 345.50 316.83 −274.54 −287.10 −271.80 −208.70 −235.66 −247.95

−160.39 212.17 789.75 798.50 831.83 2034.70 2174.00 2086.10 2358.90 2415.20 2487.80

70.15 37.08 352.91 388.09 350.49 178.26 −255.59 −4.06 −283.08 −290.46 −332.27

−71.81 157.12 670.44 681.48 703.95 572.11 805.49 455.31 2029.80 2167.80 2254.80

methanol + EMC

ethanol + EMC

Table 9. LLE Correlated Results for the Studied Ternary Systems modified UNIQUAC system (1 + 2+3)

T/K

τ231

τ132

τ123

rmsd

water + methanol + EMC

293.15 303.15 308.15 293.15 303.15 308.15

−0.36 −1.51 −0.81 −0.50 −0.99 −0.18

0.14 1.16 0.47 −0.37 0.51 −0.83

4.30 4.28 3.01 5.33 4.76 4.96

0.62 0.81 0.57 1.10 1.34 1.32



REFERENCES

water + ethanol + EMC

a

Root-mean-square deviation (mol %).

4. CONCLUSIONS The liquid-phase composition data for the (water + methanol or ethanol + EMC) systems were investigated at 293.15, 303.15, and 308.15 K at 101 kPa. The measurement values were correlated by using the thermodynamic modified UNIQUAC and extended UNIQUAC models, and the interaction arguments of the models are presented. The mean rmsd values (0.96 and 1.45 mol %) of the correlation results are achieved by the models. The calculated values indicate that the models used this study are appropriate for the phase composition calculations for the measured systems, and the modified UNIQUAC model provides more exact results. In addition, the experimental data show high consistency of the Bachman equation. Tie-line phase diagrams for the three temperatures were drawn and compared. It is found that the influence of the experimental temperatures on the two-phase area is not evident for the investigated systems, while the temperature affects the separation factors and the solubility of EMC in water. From this study, the separation factors and distribution coefficients reflect that EMC is an efficient extraction agent for the separation and purification of methanol and ethanol from water.



extended UNIQUAC a

τ231

τ132

τ123

rmsda

−0.47 −0.12 −0.92 −1.12 −1.09 −1.31

1.61 −0.17 1.77 2.77 2.52 4.97

−0.25 0.38 −0.51 1.37 1.47 0.26

1.29 1.56 1.62 1.32 1.26 1.63

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AUTHOR INFORMATION

Corresponding Author

*Fax: +86-20-85221697. E-mail: [email protected]. ORCID

Yao Chen: 0000-0002-3461-388X Funding

The authors are grateful to the National Scientific Research Fund of China for financial support (grant 21271088). Notes

The authors declare no competing financial interest. G

DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

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DOI: 10.1021/acs.jced.8b00543 J. Chem. Eng. Data XXXX, XXX, XXX−XXX