Determination and thermodynamic evaluation of isobaric VLE of methyl acetate or ethyl acetate with 2-propanol at 0.3 and 0.6 MPa

Accepted Manuscript Title: Determination and Thermodynamic evaluation of Isobaric VLE of Methyl Acetate or Ethyl Acetate with 2-Propanol at 0.3 and 0.6 MPa Author: Pedro Susial Rodrigo Susial Esteban J. Estupi˜nan Victor D. Castillo Jos´e J. Rodr´ıguez-Henr´ıquez Jos´e C. Apolinario PII: DOI: Reference:

S0378-3812(14)00253-2 http://dx.doi.org/doi:10.1016/j.fluid.2014.04.033 FLUID 10094

To appear in:

Fluid Phase Equilibria

Received date: Revised date: Accepted date:

6-2-2014 3-4-2014 27-4-2014

Please cite this article as: P. Susial, R. Susial, E.J. Estupi˜nan, V.D. Castillo, J.J. Rodr´iguez-Henr´iquez, J.C. Apolinario, Determination and Thermodynamic evaluation of Isobaric VLE of Methyl Acetate or Ethyl Acetate with 2¨ ¨/>MPa, Fluid Phase Equilibria (2014), Propanol at 0.3 and 0.6
1

Determination and Thermodynamic evaluation of Isobaric VLE of Methyl

2

Acetate or Ethyl Acetate with 2-Propanol at 0.3 and 0.6 MPa

3 4 5 6 7

Pedro SUSIAL*, Rodrigo SUSIAL, Esteban J. ESTUPIÑAN, Victor D. CASTILLO, José J. RODRÍGUEZ-

8

Keywords: VLE isobaric data, Binary System, Methyl Acetate, Ethyl Acetate, 2-Propanol

HENRÍQUEZ and José C. APOLINARIO Gran Canaria. 35017 Campus de Tafira, Tafira Baja, Las Palmas de Gran Canaria., Spain.

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Escuela de Ingenierias Industriales y Civiles. Departamento de Ingeniería de Procesos. Universidad de Las Palmas de

ABSTRACT: Isobaric vapor-liquid equilibria for the binary system methyl acetate+2-

11

propanol at 0.3 and 0.6 MPa and ethyl acetate+2-propanol at 0.3 and 0.6 MPa have been

12

determined. Thermodynamic consistency was checked applying the Redlich-Kister and

13

Herington area tests. In addition, the PAI test of Kojima et al. and the point-to-point test of

14

Van Ness were applied. Validation criteria were considered for the different tests and all

15

systems showed to be consistent. The global and individual deviations of experimental data

16

were obtained from the Fredenslund routine. Azeotropes in these systems have been

17

determined. It was verified that the singular points move towards lower ester mole fractions

18

with pressure increase. The different versions of the UNIFAC and ASOG predictive group

19

contribution models were applied.

20 21

1. Introduction

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Vapor-Liquid equilibrium (VLE) data are important for the development of chemical processes.

23

For this purpose, VLE data have to be evaluated by the different thermodynamic consistency tests,

24

because reliable VLE data are essential for the design of different processes, such as purification of

25

solvents, where the presence of azeotropes is common in the mixtures.

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Azeotropes can be removed using various procedures. Some of them are: extractive distillation,

27

azeotropic distillation, membrane pervaporation and hybrid separation techniques. However, the

28

pressure swing distillation is a simple and economically attractive alternative which can be applied

29

when the composition of the azeotrope is sensitive to changes in distillation pressure. If the

30

azeotrope composition varies enough (between 4 to 5%) to modify the distillation pressure, then it

31

is possible to use two rectification columns [1].

32

Binary systems consisting of methyl acetate and ethyl acetate with primary alcohols have been

33

studied in previous works [2-5]. The presence of azeotropes and their pressure dependence was

34

verified for these systems. In this work we have studied mixtures of these solvents with a secondary

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alcohol in order to verify the existence of the azeotrope in the binary mixtures and the pressure

36

effect on the singular point. For this, the VLE data corresponding to the systems methyl acetate (1)

37

+ 2-propanol (2) (MA2P) and ethyl acetate (1) + 2-propanol (2) (EA2P) have been determined both

38

at 0.3 and 0.6 MPa. MA2P system has been studied isothermally [6] and isobarically at 101.3 kPa [7] and also at

40

different pressures: 74.66, 101.32 and 127.99 kPa [8]. EA2P system has been studied isothermally

41

at different conditions by Van Winkle and Murti [9], Nagata et al. [10] and Hong et al. [10] and

42

isobarically at 101.3 kPa by Murti and Van Winkle [9], Nishi [9], Rajendran et al. [10] and by

43

Hernandez and Ortega [10]. The azeotrope of the EA2P system is also described in the literature

44

[11] for different operating conditions.

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The thermodynamic consistency of the experimental VLE data reported in this study was

46

checked out by means of the area test of Redlich-Kister [12] and Herington [13] and by using the

47

point-to-point test of Van Ness [14]. The Fredenslund et al. [15] routine was employed. The point

48

test, area test and infinite dilution test (PAI test) of Kojima et al. [16] were also used for VLE data

49

assessment.

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Several thermodynamic models (Wilson, NRTL and UNIQUAC) were used for fitting the

51

activity coefficients and also to verify the VLE data. In addition, the ASOG [17] and different

52

versions of the UNIFAC [18-20] group contribution models were employed for prediction of the

53

VLE data of this work.

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2. Experimental section

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2.1. Chemicals and apparatus

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The physical properties, normal boiling point (Tbp), density (ii) at 298.15 K, and refractive index

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(nD) at 298.15 K, determined for methyl acetate (purity of 99%), ethyl acetate (purity of 99.5%) and

58

2-propanol (purity of 99.8%) from Panreac Química S.A., are not different from those previously

59

published [4,5,21]. These products were used as received. The normal boiling point at 0.1 MPa was

60

determined with a stainless steel ebulliometer and an experimental facility described in previous

61

works [2-4]. A Kyoto Electronics DA-300 vibrating tube density meter with an uncertainty of ± 0.1

62

kg·m-3 was used for density determinations. For the refractive index determinations of pure

63

components a Zusi 315RS Abbe refractometer with an uncertainty of ±0.0002 units was used.

64

2.2. Equipment and procedure

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The experimental work in this paper was performed with a stainless steel dynamic ebulliometer

66

equipped with a Cottrell pump, previously described [2], in which the recirculation of both phases

67

was verified. Dostmann Electronic GmbH Pt100 probes, to which a nut and welded ring were

68

included, were placed in the experimental equipment [2]. The electrical system was later assembled

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69

inside the sheath, allowing to screw the probe to the stainless-steel ebulliometer. The digital

70

Dostmann Electronic GmbH p655 probes allowed temperature measures with a ±0.03 K

71

uncertainty. The NPL and NIST standards were applied during the calibration of the device by

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Dostmann Electronic GmbH. After the probes had been installed, their correct operation was

73

verified by measuring the boiling point of distilled water. In order to determine work pressure, a digital display pressure transmitter type 8311 from

75

Burket Fluid Control Systems (0.0–4.0 MPa range, ±0.004 MPa uncertainty) was included in the

76

experimental installation [3,4]. A controller valve (Binks MFG Co.) was included in the

77

experimental setup in order to adjust the dry nitrogen flow into the equipment during continuous

78

operation and for the determination of the experimental VLE data. However, for the determination

79

of vapor pressure, a controller valve with a 0.6–2.4 MPa range from Truflo International and a

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discharge pressure regulator with a 0.035–2.8 MPa range from Fairchild Ind. Prod. Co., were

81

employed. The experimental installation [4] is also provided with a silica gel vessel of 15 cm outer

82

diameter and 100 cm length to prevent or reduce the entry of possible traces of humidity into the

83

ebulliometer through the nitrogen flow. In addition, a Baumer Bourdon-type manometer with a -

84

0.1–0.0 MPa range and ±0.0005 MPa uncertainty was included.

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The equilibrium still was loaded with one of the pure products (A) and then the heating was

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connected. After the product (A) reached the boiling point, the ebulliometer was completely closed

87

and pressure was established by introducing dry nitrogen. The still remained in operation about 4

88

hours to homogenize the temperature in the equipment. Subsequently, 15 cm3 of another product

89

(B) was charged and the mixture was allowed to recirculate for 90 min to ensure an approximately

90

stationary state. After the concurrent flow in the Cottrell pump and the recirculation of both phases,

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liquid and vapor condensate samples were extracted from the ebulliometer into external sealed

92

recipients. Once the samples were extracted, the equipment was recharged with a new amount

93

(about 15 cm3) of the same compound (B) in order to modify the composition of the mixture inside

94

the ebulliometer in a continuous operation.

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The composition of the liquid (x1) and vapor phases (y1) in the collected samples was

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determined by density method at 298.15 K. A calibration curve of composition vs. density had been

97

previously obtained. The greatest uncertainty found for these systems using this composition

98

analysis procedure was better than 0.002 units in mole fraction (vapor phase).

99

3. Results and discussion

100

3.1. Densities and Excess Volumes

101

Mixtures were prepared by mass and the densities (ρij) for the binary mixtures ester+alcohol

102

studied in this work were measured at 298.15±0.01 K. The ρij vs. x1 data as ester mole fraction are

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presented in Table 1 together with the values obtained for the excess volumes (vE). The deviation of

104

the experimental data was checked by using data from literature [22-24]. The inaccuracy in the vE

105

calculations was verified by the correlation of vE vs. x1 pairs using the following equation:

A Z m

v E  x1( 1  x1 )

106

k k 0

k T

(1)

Ocón [25] defines active fraction (ZT) as a function of molar volumes (vi0) of the pure

108

substances. The RT  v 20 v10  parameter of Ocón [26] was used as the calculation method for VLE

109

temperatures [26]. To systematize the calculation procedure of vi0 using the Yen-Woods [27]

110

equation, a modification of RV  RT1 is made, thus ZT is expressed as follows:

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v 

0 1 1 1

0 1 1 1

us

ZT 

111

v 

cr

1

x

 

1

x  v 20

(2)

x2

The x1 and the calculated values of vE presented in Table 1 were adjusted by using Eqs. (1) and

113

(2) and the results were: A0=2911.2; A1=-2010.2; A2=1583.4 with RV=1.03 and (109·vE)=3 m3·mol-

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1

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2494.3; A2=2426.4 with RV=1.30 and (109·vE)=7 m3·mol-1. Fig. 1 shows the data from this work

116

and their respective fitting curves. Fig. 1 also includes the literature data [22-24] for comparison.

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as standard deviation for the system MA2P. For the system EA2P results were: A0=2755.3; A1=-

Regarding the MA2P and EA2P mixtures, in Fig. 1 the expansion effect was observed when the

118

ester chain decreased: this volumetric behavior showed a possible decrease in the association

119

phenomenon via cross-hydrogen bonding with decreasing molecular weights of the ester, which had

120

a positive contribution in vE.

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3.2. Vapor pressures

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Vapor pressures (pi0) of methyl acetate in this work from 0.0 to 1.6 MPa were obtained with the

123

stainless-steel ebulliometer [2] and the new equipment included in the installation [3,4]. The vapor

124

pressures and temperature data (T) from this work and several data that had been obtained

125

previously [28] with a copper ebulliometer are presented in Table 2. The vapor pressures of ethyl

126

acetate and 2-propanol are informed in others papers [4,29]. The T vs. pi0 pairs from this work

127

(using the Nelder and Mead [30] procedure) were correlated to the Antoine equation: o

log10 (pi /kPa)  A 

128

B T/K  C

(3)

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The obtained constants were: A=6.7347; B=1529.38; C=6.59 with ( pi0)=0.002 MPa. The T vs.

130

pi0 data were verified by calculating the enthalpy of vaporization (DHvap) with the Clapeyron

131

equation [31],

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ΔH vap dp o  dT T (viG  viL )

132 133

(4)

and considering the Antoine equation, introduced in Eq. (4), as follows: ΔH vap 

(viG  viL ) pi0 BT (T  C ) 2

(5)

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The constants obtained from Eq. (3) and the vapor pressures from Table 2 were applied in Eq.

136

(5). The critical properties [15] were employed in the determination of the vapor and liquid molar

137

volumes of pure compounds (viG,viL) by using the Hayden and O’Connell [32] method and the

138

equation of Yen and Woods [27], respectively. When considering all data in Table 2 for methyl

139

acetate and the Antoine constants in literature [33,34] as references, results show that the average

140

errors in the enthalpy of vaporization were less than 3.7 and 2.8%, respectively. On the other hand,

141

the application of Eq. (3) using the normal boiling point and the Antoine constants of this work

142

returns deviations lower than 5.7%, when considering DHvap from literature [34] as reference. The

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acentric factor was obtained by using the properties from the literature [15] and from the correlation

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of the experimental data in Table 2 as reduced properties in the Antoine equation. The acentric

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factor showed to be 0.337 with an error less than 3.6%; literature data [34] were taken for

146

comparison.

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3.3. Vapor-Liquid equilibria

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The VLE data T-x1-y1 for MA2P and EA2P at 0.3 and 0.6 MPa are shown in Table 3. The

149

activity coefficients of the liquid phase (i) for each system were determined by using the following

150

equation:

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γi 





 p   p io Bii yi p pio  p viL       exp 2 y B y y B     i ij  i j ij  RT RT xi p io i j  RT  j  

(6)

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The virial state equation truncated at the second term was employed and the second virial

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coefficients (Bii, Bij) were obtained by means of the Hayden and O’Connell [32] method. The liquid

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molar volumes of pure compounds were estimated by the equation of Yen and Woods [27].

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Table 3 includes the i data, calculated from VLE data with the previous procedure by using the

156

literature properties [4,15,29] and the Antoine constants from this work. A moderate positive

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deviation from ideal behavior was observed, probably due to a molecular association via hydrogen

158

bonds.

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The experimental data of this work were verified to evaluate the thermodynamic consistency by

160

using the point-to-point test of Van Ness [14] following the method described by Fredenslund et al.

161

[15] and by using the properties as previously indicated. The Legendre polynomials were used to

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correlate the excess Gibbs free energy (GE/RT). According to the Fredenslund et al. [15] criterion,

163

the experimental data are consistent if the mean absolute deviation between the calculated and

164

measured mole fraction (vapor phase) is less than 0.01. In the present study, the obtained values are

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presented in Table 4. Moreover, Wisniak et al. [35] indicated that it is appropriate to use different tests for

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thermodynamic consistency to verify the VLE data. In their work Wisniak et al. [35] affirmed that

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one of the tests to be applied is that reported by Fredenslund et al. [15] accompanied by a detailed

169

residual analysis of pressures and vapor-liquid compositions. In this sense, Figs. 2-5 include

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deviations for all data as suggested by Van Ness et al. [14] because when pressure and vapor phase

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residuals are informed the consistency reliability can be increased [35]. Consequently, the average

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residuals (BIAS), the mean absolute deviations (MAD) and the mean percentual deviations (MPD)

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of the F properties (F being y1 or p) are included in Table 4. All (BIAS, MAD and MPD) were

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calculated using n-2 data in the denominator of equations, according to Fredenslund et al. [15].

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Figs. 2-5 include the deviations of ester mole fraction in the vapor phase (y1) and pressure (p). It

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can be seen that the differences in p/MPa for all individual data were smaller than the uncertainty of

177

this paper and less than 7% of the data showed an absolute deviation higher than 0.01 in the ester

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mole fraction (vapor phase).

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It is observed in Figs. 3-4 that, for the MA2P at 0.6 MPa and EA2P at 0.3 MPa systems, only

180

few data show a small random scatter in the composition of the vapor phase (BIAS of y1 and p, both

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are small as seen in Table 4). The Legendre polynomials with 5 and 3 coefficients, respectively,

182

were used. However, in Fig. 2, which corresponds to the MA2P system at 0.3 MPa, a data set in the

183

low ester composition showed a random scatter of the pressure residuals, by using the Legendre

184

polynomials with 3 coefficients. In addition, the vapor phase composition exhibits a biased

185

residuals behavior that is not improved using 5 coefficients of the Legendre polynomials. This must

186

be attributed to some systematic experimental error (BIAS of y1 is significant as seen in Table 4). In

187

addition, it is observed (Fig. 5) for the EA2P system at 0.6 MPa (the Legendre polynomials with 5

188

coefficients were used), that the pressure residuals were not randomly scattered and showed a

189

sinusoidal and correlationable tendency. A biased random behavior of vapor phase composition

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residuals was observed around 0.2 and 0.6 ester mole fraction (see MPD of y1 in Table 4); this may

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result from pressure fluctuations during the experimental work which were not detected by the

192

pressure measurement equipment.

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After this, the area test of Redlich-Kister [12] and Herington [13] were used to check for data

194

reliability. The area tests for isobaric data and binary mixtures can be expressed as indicated in Eq.

195

(7).

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1



196

0

ln

E 1 H   T  1  dx1  dx1    2 0 RT   x  2    1 p

(7)

Taking into account that excess enthalpies (HE) can be as low as for isothermal systems, the

198

second term in Eq. (7) is negligible and can be removed. Then the Redlich and Kister [12] area test

199

can be expressed as: D  100

200

L W L W

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(8)

where D can be represented by the areas above (L) and below (W) of the abscissa axis in the

202

ln(1/2) vs. x1 plot. The consistency criterion in the Redlich and Kister [12] area test was

203

established as D<10%. Table 4 shows the Redlich and Kister [12] area test results for the binary

204

systems of this paper.

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Herington [13] proposed an empirical solution for the enthalpies term in Eq. (7). In order to

an

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estimate the right-hand side of Eq. (7), the following was defined: J  150

Tbp ,1  Tbp , 2 Tmin

(9)

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The consistency criterion in the Herington [13] area test was established as follows; if

209

│DJ│<10 the system is probably consistent. Results of the area test of Herington [13] applied to

210

the binary systems of this work are presented in Table 4. In addition, according to Wisniak et al.

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[35] the set of data are considered consistent when D<2 and probably consistent if │DJ│<2. The

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EA2P system at 0.6 MPa in this paper satisfied both criteria.

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Moreover, to verify the binary data of this study, the test of Kojima et al. [16] (PAI test) was

214

applied. In the area test of Kojima et al. [16] the right-hand side of Eq. (7) was replaced by using an

215

energetic parameter as shown in Eq. (10).

216

1

A*   ln 0

1 1 dx1    dx1 0 2

(10)

217

The results for the area consistency test (A*) of Kojima et al. [16] are shown in Table 4. The

218

point test of Kojima et al. [16] was also used to verify the consistency of data in this paper, by using

219

Eq. (11).

 *  d (G E RT ) / dx1  ln( 1 /  2 )  

220

(11)

221

The deviations of experimental data (*) as overall results are presented in Table 4. To verify the

222

experimental data using the infinite dilution test of Kojima et al. [16] the Eqs. (12) and (13) were

223

employed.

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 G E RT I    x1 x2 * 1

224

 G E RT     ln 2 I    1  x1 x 2  * 2

    2   ln     1

  

-1

(12) x1 0

-1

(13) x2  0

ip t

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          ln 1   ln 1     2     2 

Results of the limiting behavior (I*) for both components were represented by the excess Gibbs

227

free energy and the activity coefficients of both substances were expressed as percentage deviations

228

and are presented in Table 4.

230

To apply Eqs. (10), (11), (12) and (13), the data from this study were correlated using the following relationships:

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cr

226





GE 2  x1 x2 B  C x1  x2   D x1  x2   ... RT

232

  ln 2   a  bx2  x1   c6 x1 x2  1  ....  1 

an

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(14)

(15)

The extended equation of Redlich-Kister was used (see Eqs. (14) and (15)), following Kojima et

234

al. [16] recommendations. To systematize the data tests using PAI test [16,36], the energetic

235

parameter was considered equal to 0.02 in all systems. For the same reason, Eq. (14) was employed

236

using 2 or 3 parameters for the correlations of the excess Gibbs free energy and 3 parameters were

237

always used in Eq. (15) for correlations of activity coefficients. Consequently, the aim was not to

238

minimize the different test results using the PAI test [16,36], because 3 have been the maximum

239

number of coefficients used in the different correlations. Moreover, considering the residual

240

pressure and the composition of the vapor phase (see Figs. 2-5), together with the results obtained

241

from the different tests (see Table 4) it may be indicated that the systems presented in this work

242

appeared to have some reliability.

243

3.4. Treatment of VLE data and prediction

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As in previous studies [2-5], the experimental data from every system were correlated to a

245

fitting function (FF) with a polynomial structure. Data correlations were performed using the

246

simplex method [30]. The same process was applied to literature data [8,10] (see Figs. 6-7). It can

247

be observed that the experimental results at 0.3 and 0.6 MPa present a good agreement with

248

literature data for both MA2P and EA2P binary systems. A symmetrical behavior can be seen in

249

Figs. 6-7 for the different systems with pressure increase. Therefore, considering literature data [8,

250

10] have a lower uncertainty than those obtained in this work, in addition, the literature data were

251

obtained with a glass-made ebulliometer [8, 10] of 8-times less capacity and 6-times lower

Page 8 of 26

252

recirculation time of mixture than the stainless-steel ebulliometer employed in this paper, and that is

253

why it can be informed, as previously [2], that the stainless-steel ebulliometer employed, enables to

254

obtain data that are in good agreement with the literature data and that can be considered reliable

255

according to the different thermodynamic verification tests applied. After the thermodynamic consistency of the experimental data was verified, the calculated

257

activity coefficients were correlated using the relation GE/RT vs. x1 in the following thermodynamic

258

models: Wilson, NRTL and UNIQUAC to obtain the interaction parameters for the activity-

259

coefficient models. The simplex method [30] was applied, using the minimization of the objective

260

function (OF) as follows [37]:



1

   γ 2

i

n

2,exp

 γ2,calc

1



2

i

cr

n

OF   γ1,exp  γ1,calc

(16)

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ip t

256

The standard deviation () showed that good correlations were obtained with the

263

thermodynamic models (see Table 5), and acceptable deviations were observed in the prediction of

264

temperature and ester mole fraction in the vapor phase.

an

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The VLE predictions for the binary systems MA2P and EA2P at 0.3 and 0.6 MPa were

266

obtained. The following group contribution methods to calculate the liquid-phase activity

267

coefficients were employed: the ASOG [17] method; the original UNIFAC [15] method, with the

268

structural and group-interaction parameters recommended by Hansen et al. [18], the UNIFAC-

269

Lyngby [19] method and the UNIFAC-Dortmund [20] method. Table 6 lists the MAD and MPD

270

between the experimental VLE data and those predicted by the different group contribution models.

271

It should be noted that, globally, the UNIFAC-1993 [20] version provides the best results in the

272

prediction of the activity coefficients, temperature, total pressure and mole fraction in the vapor

273

phase. However, the UNIFAC-1987 [19] was the best method to predict the EA2P system at 0.3

274

MPa and similarly, the best prediction of MA2P system at 0.3 MPa was obtained from the

275

UNIFAC-1993 [20]. The UNIFAC-1991 [18] version and the ASOG [17] models did not generate

276

good predictions of the systems. However, the AE2P system at 0.6 MPa was acceptably reproduced

277

by the ASOG [17] model. Figs. 8-9 show the experimental data for MA2P and EA2P at 0.3 and 0.6

278

MPa, together with the fitting curves predicted with the different group contribution models.

279

3.5. Azeotropic data

Ac ce p

te

d

M

265

280

The azeotropic data of EA2P at different pressures have been described in the literature [11].

281

The experimental study of this paper reports the azeotrope of this system at 0.3 and 0.6 MPa (see

282

Table 5) obtained using the natural cubic spline method to interpolate. All azeotropic data are

283

correlated using reduced properties for temperature (Tr) and pressure (pr), in a way indicated

284

previously [2,3], with a multiple linear regression routine. The procedure is as follows: the xaz vs

Page 9 of 26

285

(Tr, pr) function are first correlated and then the data Tr vs pr are fitted with a linearization of a

286

function. The results for azeotropic data in the systems EA2P are, respectively: xaz  4.33  3.84 

1 2  0.26  Log10 pr  Tr

1  0.98  0.32  Log10 pr Tr

(17)

(18)

Fig. 10 displays the singular points in the literature [11] and this work at 0.3 and 0.6 MPa. The

288

fitting curves for Eqs. (17) and (18) are plotted in Fig. 10. It can be observed that with increasing

289

pressure the azeotrope composition moved towards rich compositions of alcohol, which indicates

290

that the presence of the azeotrope in the AE2P system could disappear at high pressure. In addition,

291

the azeotropic data from this work are well positioned in Fig. 10 with the isobaric data reported by

292

Yan et al. [11] for similar or higher pressures.

us

cr

ip t

287

On the other hand, in Table 3 can be seen that the thermodynamic models have average errors

294

lower than 20% in the prediction of the azeotrope in the EA2P binary system at 0.6 MPa, while at

295

0.3 MPa the average error is close to 0.5%. However, with the group contribution models, globally

296

the UNIFAC-1987 [19] and UNIFAC-1993 [20] models return better predictions for the singular

297

point, with a mean error close to 11%, while at 0.3 MPa the ASOG [17] model has a 0.7% error in

298

prediction.

299

4. Conclusions

M

an

293

The isobaric VLE data for four binary systems of MA2P and EA2P at 0.3 and 0.6 MPa were

301

determined with a dynamic stainless steel ebulliometer. The experimental data evidence that at 0.3

302

and 0.6 MPa an azeotrope exists in the EA2P system. The calculated activity coefficients for all the

303

systems exhibited positive deviation from ideal behavior. The VLE data were examined by using

304

the Redlich-Kister and Herington area tests; the PAI test and the point-to-point test. From the results

305

obtained after applying the different consistency tests it may be indicated that globally, data

306

obtained for each of the studied systems are of acceptable quality. The binary parameters of the

307

Wilson, NRTL and UNIQUAC models were calculated and the obtained MAD of y1 and T indicated

308

that these activity coefficient models are suitable for correlating the VLE data of this study. The

309

group contribution models, the ASOG, the original UNIFAC, the UNIFAC-Lyngby and the

310

UNIFAC-Dortmund, were applied, and the predictions were verified with respect to the

311

experimental data of this work. The UNIFAC-Lyngby and the UNIFAC-Dortmund models gave

312

good predictions. The MAD in the different properties obtained with the original UNIFAC and the

313

ASOG models was not reasonable.

Ac ce p

te

d

300

314 315 316

Page 10 of 26

AUTHOR INFORMATION

318

Corresponding Author

319

* Tel./fax: +34-928-458658. E-mail: [email protected]

320

Notes

321

The authors declare no competing financial interest.

322

Funding

323

This work was supported by the authors and by the ULPGC. This work has not financial support of

324

the Spanish government.

325

References

326

[1] M. Van Winkle, Distillation, McGraw-Hill, New York, 1967.

327

[2] P. Susial, A. Sosa-Rosario, R. Rios-Santana, J. Chem. Eng. Data 55 (2010) 5701–5706.

328

[3] P. Susial, R. Rios-Santana, A. Sosa-Rosario, J. Chem. Eng. Jpn. 43 (2010) 650–656.

329

[4] P. Susial, A. Sosa-Rosario, J.J. Rodríguez-Henríquez, R. Rios-Santana, J. Chem. Eng. Jpn. 44

cr

us

an

330

ip t

317

(2011) 155–163.

[5] P. Susial, R. Rios-Santana, A. Sosa-Rosario, Braz. J. Chem. Eng. 28 (2011) 325–332.

332

[6] I. Nagata, T. Ohta, S. Nakagawa, J. Chem. Eng. Jpn. 9 (1976) 276–281.

333

[7] I. Nagata, Can. J. Chem. Eng. 41 (1963) 21–23.

334

[8] J. Ortega, P. Susial, J. Chem. Eng. Jpn. 26 (1993) 259–265.

335

[9] J. Gmehling, U. Onken, W. Arlt, W. Vapor-Liquid Equilibrium Data Collection. Chemistry Data

338 339 340

d

te

337

Series, Vol 1, Part. 2b, Dechema, Frankfurt, 1990. [10] J. Gmehling, U. Onken, Vapor-Liquid Equilibrium Data Collection. Chemistry Data Series,

Ac ce p

336

M

331

Vol 1, Part. 2i, Dechema, Frankfurt, 2007. [11] Gmehling, J., J. Menke, J. Krafczyk and K. Fischer; Azeotropic Data, Part 1, Ed. Wiley-VCH Verlag, 2 ed., Weinheim, 2004.

341

[12] O. Redlich, A.T. Kister, Ind. and Eng. Chem. 40 (1948) 345–348.

342

[13] E.F.G. Herington, J. Inst. Petrol. 37 (1951) 457–470.

343

[14] H.C. Van Ness, S.M. Byer, R.E. Gibbs, AIChE J. 19 (1973) 238–244.

344

[15] A. Fredenslund, J. Gmehling, P. Rasmussen, Vapor-liquid Equilibria Using UNIFAC. A Group

345

Contribution Model, Elsevier, Amsterdam,1977.

346

[16] K. Kojima, H.M. Moon, K. Ochi, Fluid Phase Equilib. 56 (1990) 269-284.

347

[17] K. Kojima, K. Tochigi, Prediction of Vapor-Liquid Equilibria by the ASOG Method.

348 349 350

Kodansha Ltd., Japan, 1979. [18] H.K. Hansen, P. Rasmussen, A. Fredenslund, M. Schiller, J. Gmehling, Ind. Eng. Chem. Res. 30 (1991) 2352–2355.

Page 11 of 26

351

[19] B.L. Larsen, P. Rasmussen, A. Fredenslund, Ind. Eng. Chem. Res. 26 (1987) 2274–2286.

352

[20] J. Gmehling, J. Li, M. Schiller, Ind. Eng. Chem. Res. 32 (1993) 178–193.

353

[21] P. Susial, J.C. Apolinario, J.J. Rodríguez-Henríquez, V.D. Castillo, E.J. Estupiñan, Fluid Phase

354

Equilib. 331 (2012) 12–17. [22] J. Ortega, P. Susial, ELDATA: Int. Electron. J. Phys. Chem. Data 2 (1996) 239–248.

356

[23] P. Hernandez, J. Ortega, J. Chem. Eng. Data 42 (1997) 1090–1100.

357

[24] A.B. Pereiro, A. Rodriguez, J. Chem. Thermodynamics 39 (2007) 1219–1230.

358

[25] J. Ocón, Anales R. Soc. Esp. Fis. Quim. 49 (1953) 295-300.

359

[26] J. Ocón, Anales R. Soc. Esp. Fis. Quim. 65 (1969) 623–629.

360

[27] L.C. Yen, S.S. Woods, AIChE J. 12 (1966) 95–99.

361

[28] P. Susial, A. Sosa-Rosario, R. Rios-Santana, Chin. J. Chem. Eng. 18 (2010)1000–1007.

362

[29] P. Susial, J.J. Rodríguez-Henriquez, J.C. Apolinario, V.D. Castillo, E.J. Estupiñan, J. Serb.

cr

us

an

363

ip t

355

Chem. Soc. 77 (2012) 1243–1257.

[30] J. Nelder, R. Mead, R. Comput. J. 7 (1967) 308–313.

365

[31] E. Hála, J. Pick, V. Fried, O. Vilím, Vapour–Liquid Equilibrium, 2nd ed., Pergamon Press,

366

M

364

Oxford, UK, 1967.

[32] J.G. Hayden, J.P. O’Connell, Ind. Eng. Chem. Process Des. Dev. 14 (1975) 209–216.

368

[33] J.A. Riddick, W.B. Bunger, T.K. Sakano, Organic Solvents, 4th ed., Wiley-Interscience, New

371

te

370

York, 1986.

[34] C.L. Yaws, Yaws Handbook of Thermodynamic and Physical Properties of Chemical Compounds, Knovel, Norwich, New York, 2003.

Ac ce p

369

d

367

372

[35] J. Wisniak, A. Apelblat, H. Segura, Phys Chem. Liq. 35 (1997) 1-58.

373

[36] K. Kurihara, Y. Egawa, K. Ochi, K. Kojima, Fluid Phase Equilib. 219 (2004) 75-85.

374

[37] M.J. Holmes, M. Van Winkle, Ind. Eng. Chem. 62 (1970) 21-31.

375

Page 12 of 26

375 376 377 378

Table 1 Densities and excess molar volumes for binary systems at 298.15 K and atmospheric pressure.a x1

ij (kg m-3) 109· v E (m3 mol-3)

x1

ij (kg m-3) 109· v E (m3 mol-3)

Methyl Acetate (1) + 2-Propanol (2) 0.5861 0.6411 0.6930 0.7229 0.7370 0.8370 0.8411 0.9748 1.0000

862.2 870.4 878.3 882.8 885.0 900.6 901.3 923.0 927.3

548 522 481 460 444 322 311 65 0

ip t

0 139 250 327 393 509 546 574 578

cr

781.3 787.4 794.3 799.9 805.5 819.4 826.3 836.1 847.6

us

0.0000 0.0497 0.1031 0.1458 0.1879 0.2898 0.3393 0.4082 0.4875

Ethyl Acetate (1) + 2-Propanol (2) 833.4 839.2 846 855.7 862.4 867.6 872.9 879.8 884.1 887.4 894.6

an

0.4444 0.4950 0.5548 0.6433 0.7048 0.7517 0.8011 0.8647 0.9057 0.9352 1.0000

M

0 82 210 252 302 384 428 467 496 514 523

d a

Uncertainties u u(x1)=±0.0002,

Ac ce p

379 380 381 382 383

781.3 783.6 791.1 794.6 797.8 804.5 810.4 814.5 821.2 827.4 828.4

te

0.0000 0.0217 0.0840 0.1125 0.1398 0.1964 0.2455 0.2810 0.3376 0.3907 0.3999

are:

u(T)=±0.01

K,

542 538 520 495 456 404 356 267 216 151 0

u(p)=±0.0005

MPa,

u(ρij)=±0.1 kg·m-3, u(109· v E )=±12 m3·mol-1

Page 13 of 26

383 384 385

Table 2 Experimental vapor pressures of methyl acetate.a

a

pi0/kPa 360 395 420 470 505 530 580 602 640 755 780 815 855 935 960 1025 1112

T/K 423.64 424.27 425.80 426.61 427.25 431.25 432.05 433.52 434.22 434.93 435.73 436.49 437.35 438.03 438.63 439.35 440.04

pi0/kPa 1167 1182 1220 1240 1257 1357 1380 1420 1440 1460 1482 1505 1530 1550 1567 1590 1610

ip t

T/K 372.25 376.23 378.25 382.65 386.11 387.55 391.35 393.28 395.55 403.17 404.72 406.66 408.89 413.08 414.32 417.37 421.29

Uncertainties u are: u(T)=±0.03 K, u(pi0)= ±0.004 MPa

Ac ce p

te

d

M

386 387 388 389

pi0/kPa 81.5 85.5 88.0 91.0 93.0 98.0 108 118 126 136 142 152 167 190 207 220 320

cr

T/K 323.64 325.18 326.45 326.95 327.60 329.29 331.95 334.55 336.45 338.65 340.05 342.83 345.72 350.06 352.80 354.78 368.05

us

pi0/kPa 16.0 16.5 24.0 29.0 32.5 35.0 36.5 41.0 46.0 47.5 53.0 58.5 63.5 68.5 72.0 75.5 78.0

an

T/K 284.16 284.55 292.99 297.60 300.03 302.07 303.13 305.94 309.05 309.60 312.17 314.74 316.82 318.73 320.22 321.39 322.46

Page 14 of 26

Table 3 Experimental data T-x1-y1 and calculated values for the activity coefficients of the liquid phase.a

us

cr

ip t

T/K x1 y1 γ1 γ2 methyl acetate (1)+2-propanol (2) at 0.6 MPa 409.88 0.000 0.000 1.00 408.91 0.027 0.059 1.53 0.99 408.43 0.040 0.086 1.52 0.99 406.60 0.086 0.176 1.51 0.98 403.73 0.164 0.299 1.43 0.99 402.67 0.203 0.342 1.35 1.00 401.76 0.238 0.375 1.29 1.02 400.13 0.310 0.450 1.24 1.04 399.35 0.355 0.487 1.19 1.06 399.02 0.376 0.503 1.17 1.07 398.52 0.401 0.524 1.15 1.08 398.15 0.425 0.545 1.14 1.09 397.14 0.484 0.595 1.12 1.11 396.83 0.503 0.611 1.11 1.12 396.54 0.518 0.625 1.11 1.12 396.21 0.535 0.641 1.11 1.12 395.43 0.596 0.687 1.09 1.15 394.93 0.647 0.723 1.07 1.19 394.40 0.695 0.754 1.05 1.24 394.02 0.735 0.783 1.04 1.27 393.79 0.763 0.803 1.04 1.30 393.53 0.790 0.823 1.03 1.32 393.24 0.834 0.857 1.02 1.36 393.17 0.851 0.870 1.02 1.38 393.11 0.878 0.891 1.02 1.42 393.08 0.917 0.923 1.01 1.51 393.06 0.943 0.946 1.00 1.56 393.05 0.967 0.968 1.00 1.59 393.01 1.000 1.000 1.00

a

Uncertainties u u(x1)=u(y1)=±0.002

Ac ce p

393 394 395 396

te

d

M

T/K x1 y1 γ1 γ2 methyl acetate (1)+2-propanol (2) at 0.3 MPa 386.19 0.000 0.000 1.00 384.82 0.034 0.076 1.36 1.00 382.05 0.086 0.186 1.41 1.01 379.28 0.149 0.308 1.45 1.01 378.24 0.181 0.349 1.39 1.02 377.26 0.212 0.392 1.37 1.03 376.31 0.262 0.443 1.28 1.04 375.58 0.289 0.470 1.25 1.05 374.09 0.336 0.519 1.24 1.07 373.60 0.358 0.540 1.22 1.08 373.36 0.370 0.550 1.21 1.08 371.70 0.463 0.622 1.15 1.13 370.75 0.516 0.662 1.12 1.16 370.02 0.568 0.695 1.09 1.20 369.56 0.598 0.718 1.08 1.21 369.15 0.638 0.737 1.06 1.27 368.76 0.675 0.760 1.04 1.31 368.34 0.709 0.781 1.03 1.36 367.97 0.749 0.811 1.02 1.37 367.41 0.785 0.834 1.02 1.44 367.26 0.815 0.854 1.01 1.48 367.12 0.841 0.874 1.00 1.49 366.72 0.873 0.897 1.00 1.55 366.43 0.908 0.921 1.00 1.65 366.16 0.944 0.950 1.00 1.73 365.55 1.000 1.000 1.00

an

389 390 391 392

are:

u(T)=±0.03

K,

u(p)=±0.004

MPa,

Page 15 of 26

Table 3 (Continued).a

us

cr

ip t

T/K x1 y1 γ1 γ2 ethyl acetate (1)+2-propanol (2) at 0.6 MPa 409.88 0.000 0.000 1.00 409.77 0.004 0.006 1.76 1.00 409.71 0.007 0.010 1.67 1.00 409.42 0.026 0.035 1.59 1.00 409.32 0.039 0.051 1.55 1.00 409.15 0.060 0.079 1.56 1.00 408.95 0.088 0.108 1.47 1.00 408.88 0.104 0.126 1.45 1.00 408.82 0.127 0.149 1.41 1.00 408.79 0.151 0.172 1.37 1.00 408.72 0.179 0.198 1.33 1.01 408.65 0.205 0.223 1.31 1.01 408.67 0.276 0.274 1.19 1.03 408.73 0.303 0.296 1.17 1.04 408.79 0.334 0.316 1.14 1.06 408.82 0.399 0.371 1.12 1.07 408.88 0.429 0.391 1.09 1.09 409.13 0.481 0.437 1.08 1.10 409.25 0.513 0.458 1.06 1.13 409.80 0.599 0.533 1.05 1.16 409.97 0.626 0.558 1.04 1.18 410.34 0.653 0.583 1.04 1.18 410.59 0.678 0.606 1.03 1.20 410.91 0.699 0.627 1.03 1.20 411.94 0.775 0.704 1.02 1.24 412.54 0.818 0.752 1.02 1.27 412.97 0.840 0.776 1.01 1.29 413.37 0.863 0.802 1.01 1.31 413.89 0.886 0.830 1.01 1.34 414.27 0.911 0.860 1.00 1.40 414.88 0.933 0.889 1.00 1.45 415.30 0.950 0.916 1.00 1.45 415.57 0.960 0.932 1.00 1.46 416.66 0.989 0.978 1.00 1.67 416.84 0.995 0.989 1.00 1.83 417.02 1.000 1.000 1.00

397 398 399 400

Ac ce p

te

d

M

T/K x1 y1 γ1 γ2 ethyl acetate (1)+2-propanol (2) at 0.3 MPa 386.19 0.000 0.000 1.00 386.03 0.008 0.014 1.83 1.00 385.63 0.027 0.044 1.72 1.00 385.35 0.048 0.073 1.62 1.00 385.11 0.062 0.090 1.56 1.00 384.79 0.081 0.116 1.55 1.00 384.37 0.120 0.162 1.48 1.01 384.04 0.144 0.191 1.46 1.01 383.53 0.191 0.240 1.40 1.02 383.14 0.239 0.283 1.34 1.04 383.06 0.254 0.297 1.32 1.04 382.67 0.346 0.372 1.23 1.07 382.61 0.375 0.398 1.22 1.08 382.59 0.402 0.417 1.19 1.09 382.54 0.436 0.442 1.17 1.11 382.54 0.491 0.479 1.12 1.15 382.55 0.555 0.524 1.09 1.20 382.56 0.573 0.541 1.09 1.20 382.69 0.619 0.581 1.08 1.22 383.57 0.749 0.689 1.03 1.34 383.89 0.775 0.717 1.03 1.34 385.02 0.857 0.805 1.02 1.41 385.44 0.883 0.838 1.01 1.41 386.22 0.927 0.895 1.01 1.43 386.65 0.946 0.921 1.01 1.43 387.25 0.978 0.964 1.01 1.57 387.71 0.993 0.986 1.00 1.89 387.85 1.000 1.000 1.00

an

396

a

Uncertainties u u(x1)=u(y1)=±0.002

are:

u(T)=±0.03

K,

u(p)=±0.004

MPa,

Page 16 of 26

Table 4 Results of thermodynamic consistency test. EA2P MA2P Parameter\system 0.3 MPa 0.6 MPa 0.3 MPa 0.6 MPa 0.1078 0.1196 0.1320 0.1158 L W 0.1535 0.1103 0.1227 0.1120 D 17.49 4.04 3.65 1.67 J 8.34 6.52 0.69 2.55 fails passes passes passes Redlich-Kister [12] test Herington [13] test passes passes passes passes 0.020 0.020 0.020 0.020   * 100 A  3 2.9 2.9 2.3 1.6 Kojima et al. [16] area test 100 n * i1   5 n Kojima et al. [16] point test 100 I1*  30

passes

passes

2.8 22.2

100 I 2*  30

Kojima et al. [16] infinite dilution test 103 MAD(y1) MPD(y1) 103 BIAS(y1) MAD(p/kPa) MPD(p) BIAS(p/kPa) Van Ness et al. [14] test

passes

4.6

4.0

4.7

passes

passes

passes

25.4

7.1

11.1

20.2

22.0

10.0

0.4

passes 7.7 1.86 -7.5 1.0 0.34 -0.1 passes

passes 5.2 1.85 -0.7 0.6 0.11 0.0 passes

passes 3.4 1.30 0.03 0.6 0.16 0.1 passes

passes 4.9 2.67 -1.2 1.2 0.20 0.2 passes

te

d

M

an

passes

403 404 405

us

passes

100 n Fexp  Fcal 1 n 1 n F F F F F F     ; MPD( ) ( ) ; MAD( )  exp cal  exp cal  F n2 1 n2 1 n2 1 exp

Ac ce p

402

cr

ip t

400 401

BIAS(F ) 

Page 17 of 26

405 406 407 408

Table 5 Correlation parameters for GE/RT with average and standard deviations and predictions of azeotropic points. model

parameters

MAD(y1) MAD(T)/K σ(γ1)

Wilson

Δλ12/(J·mol-1) = 97.5

Δλ21/(J·mol-1) = 1762.8

NRTL (α=0.47)

-1

g12/(J·mol ) = 2105.8

-1

g21/(J·mol ) = -169.5

0.010

0.38

UNIQUAC (Z=10)

Δu12/(J·mol-1) = 1240.6

Δu21/(J·mol-1) = -470.8

0.009

0.32

σ(γ2) σ(GE/RT)

methyl acetate (1) + 2-propanol (2) a 0.3 MPa 0.32

Δλ12/(J·mol ) = 974.1

Δλ21/(J·mol-1) = 653.3

NRTL (α=0.47)

-1

g12/(J·mol ) = 631.9

g21/(J·mol-1) = 980.5

UNIQUAC (Z=10)

Δu12/(J·mol-1) = 253.7

Δu21/(J·mol-1) = 352.2

Wilson

Δλ12/(J·mol-1) = 2143.0

Δλ21/(J·mol-1) = -345.1

NRTL (α=0.47)

-1

g12/(J·mol ) = 420.8

g21/(J·mol-1) = 1381.3

UNIQUAC (Z=10)

Δu12/(J·mol-1) = 533.0

Δu21/(J·mol-1) = 104.1

Wilson

Δλ12/(J·mol-1) = 2177.0

Δλ21/(J·mol-1) = -510.6

NRTL (α=0.47)

-1

g12/(J·mol ) = 413.0

-1

g21/(J·mol ) = 1269.9

UNIQUAC (Z=10)

Δu12/(J·mol-1) = 533.0

Δu21/(J·mol-1) = 63.3

0.004 0.004 0.004

0.04

0.008

0.04

0.006

0.02 0.02 0.02

0.01 0.01 0.01

0.007 0.008 0.007

0.11 0.11 0.11

0.03 0.03 0.03

0.07 0.07 0.07

0.003 0.003 0.003

0.47 0.55 0.48

0.04 0.04 0.04

0.07 0.07 0.07

0.013 0.015 0.013

0.28 0.29 0.29

us

ethyl acetate (1) + 2-propanol (2) a 0.3 MPa

0.003 0.003 0.003

0.007

0.04

cr

Wilson

0.04

0.05

methyl acetate (1) + 2-propanol (2) a 0.6 MPa -1

0.05

ip t

0.009

0.004 0.005 0.005

M

azeotropic data

an

ethyl acetate (1) + 2-propanol (2) a 0.6 MPa

this work

Wilson

NRTL

UNIQUAC

ethyl acetate (1) + 2-propanol (2) a 0.3 MPa

x1aexp Taz exp/K

0.456 382.53

x1aexp Taz exp/K

0.267 408.65

0.454 382.43

0.457 382.37

0.455 382.42

411 412

te

410

σ (F ) 

Ac ce p

409

d

ethyl acetate (1) + 2-propanol (2) a 0.6MPa

0.313 407.81

 F n

1

exp

0.321 407.72

0.315 407.81

 Fcal 

2

n2

Page 18 of 26

412 413 414 415

Table 6 Mean errors and average deviations in the prediction of VLE data using ASOG and UNIFAC models.

x1az exp=0.456 Taz exp/K=382.53 MAD(y1) MPD(γ) MAD(T)/K MAD(p)/MPa

416 417 418 419

UNIFAC-1993 OH/COOC [20]

ip t

0.010 3.39 0.43 0.003

cr

us

an

Ac ce p

x1az exp = 0.267 Taz exp/K = 408.65

M

MAD(y1) MPD(γ) MAD(T)/K MAD(p)/MPa

d

MAD(y1) MPD(γ) MAD(T)/K MAD(p)/MPa

te

MAD(y1) MPD(γ) MAD(T)/K MAD(p)/MPa

ASOG UNIFAC-1987 UNIFAC-1991 OH/COO [17] OH/COOC [18] OH/COOC [19] methyl acetate (1) + 2-propanol (2) at 0.3 MPa 0.020 0.019 0.007 8.96 8.43 2.91 2.06 2.00 0.45 0.017 0.016 0.004 methyl acetate (1) + 2-propanol (2) at 0.6 MPa 0.021 0.017 0.011 10.42 8.42 5.47 2.31 1.93 1.28 0.033 0.027 0.017 ethyl acetate (1) + 2-propanol (2) at 0.3 MPa 0.011 0.019 0.002 6.25 9.59 1.55 0.97 1.52 0.17 0.008 0.012 0.001 azeotropic data 0.448 0.481 0.445 381.11 380.31 382.61 ethyl acetate (1) + 2-propanol (2) at 0.6 MPa 0.014 0.022 0.011 7.341 10.37 6.10 1.49 2.07 0.81 0.021 0.030 0.011 azeotropic data 0.342 0.383 0.216 406.26 405.67 409.34

0.008 2.70 0.50 0.007 0.011 6.27 1.08 0.008

0.463 384.02 0.011 5.79 0.76 0.010 0.219 409.51

Page 19 of 26

FIGURE CAPTIONS Fig. 1. Excess molar volume vs ester mole fraction at 298.15 K of MA2P () and EA2P () and fitting curves. Comparison with literatura data: () by Ortega and Susial [22] for MA2P or () by Hernandez and Ortega [23] and () by Pereiro and Rodriguez [24] for EA2P.

ip t

Fig. 2. Results of (y1) () and (p) () from thermodynamic consistency test for MA2P system at 0.3 MPa using the Fredenslund et al. [15] routine.

us

cr

Fig. 3. Consistency analysis results of (y1) () and (p) () for MA2P system at 0.6 MPa using the Fredenslund et al. [15] routine.

an

Fig. 4. Results of (y1) () and (p) () from thermodynamic consistency test for EA2P system at 0.3 MPa using the Fredenslund et al. [15] routine.

M

Fig. 5. Consistency analysis results of (y1) () and (p) () for EA2P system at 0.6 MPa using the Fredenslund et al. [15] routine.

te

d

Fig. 6. Experimental points () and () of (y1-x1) vs. x1 representation for MA2P system at 0.3 and 0.6 MPa, respectively. Fitting curves of data and bibliographic [8] data at 74.66 (), 101.32 () and 127.99 () kPa. Fig. 7. Fitting curves with experimental data () and () of (y1-x1) vs. x1 plot for EA2P at 0.3 and 0.6 MPa, respectively; also with Hernandez and Ortega [10] data at 101.32 kPa 99 ().

Ac ce p

419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464

Fig. 8. Experimental VLE data of MA2P (", ") and EA2P (, ) at 0.3 MPa. Curves for the prediction models (- - - - - -) UNIFAC-1993 [20] on MA2P system and () UNIFAC-1987 [19] on EA2P system. Fig. 9. Equilibrium diagram of MA2P (, ) and EA2P (, ) binary systems at 0.6 MPa. Curves for the prediction models (- - - - - -) UNIFAC-1993 [20] on MA2P system and () UNIFAC-1987 [19] on EA2P system. Fig. 10. Plot o azeotropic data in reduced coordinates for the EA2P system () from this work and () from literature [11] with Eqs. (17) and (18) fitting curves.

Page 20 of 26

464

Research highlights

465

- Vapor pressures of Methyl Acetate were measured from 0 to 1.6 MPa.

466

- (Vapor+liquid) equilibria of Methyl Acetate + 2-Propanol and Ethyl Acetate + 2-Propanol at 0.3

469 470 471 472

- Data were verified with different thermodynamic consistency test. All the systems of this paper showed positive consistency.

ip t

468

and 0.6 MPa were investigated.

- Analysis of VLE data shown that Ethyl Acetate + 2-Propanol have a minimum boiling azeotrope at 0.3 and 0.6 MPa.

cr

467

- The azeotropic point of the Methyl Acetate + 2-Propanol at 0.6 MPa not was found.

us

473 474

Ac ce p

te

d

M

an

475 476

Page 21 of 26

Figure(s)

600

400

ip t

300

200

cr

vE.109/(m3.mol-1)

500

0

0.2

0.4

an

0

us

100

0.6

0.8

1

M

x1 Fig. 1. Excess molar volume vs ester mole fraction at 298.15 K of MA2P (,) and EA2P (&) and fitting curves. Comparison with literatura data: (/) by Ortega and Susial [22] for MA2P or (5) by Hernandez and Ortega [23] and (8) by Pereiro and Rodriguez [24] for EA2P. 0.006

d

0.004

Ac ce pt e

0.01

y1,exp - y1,calc

0.005

0.002

0

0

(pexp - pcalc)/MPa

0.015

-0.005

-0.002

-0.01

-0.004

-0.015

0

0.2

0.4

0.6

0.8

1

-0.006

x1 Fig. 2. Results of (δy1) (,) and (δp) (/) from thermodynamic consistency test for MA2P system at 0.3 MPa using the Fredenslund et al. [15] routine.

Page 22 of 26

0.01

0.004

0.005

0.002

0

0

-0.002

cr

-0.005

-0.004

0

0.2

0.4

an

us

-0.01

-0.015

ip t

0.006

(pexp - pcalc)/MPa

y1,exp - y1,calc

0.015

0.6

0.8

1

-0.006

M

x1 Fig. 3. Consistency analysis results of (δy1) (,) and (δp) (/) for MA2P system at 0.6 MPa using the Fredenslund et al. [15] routine. 0.006

d

0.004

Ac ce pt e

0.01

y1,exp - y1,calc

0.005

0.002

0

0

(pexp - pcalc)/MPa

0.015

-0.005

-0.002

-0.01

-0.004

-0.015

0

0.2

0.4

0.6

0.8

1

-0.006

x1 Fig. 4. Results of (δy1) (,) and (δp) (/) from thermodynamic consistency test for EA2P system at 0.3 MPa using the Fredenslund et al. [15] routine.

Page 23 of 26

0.01

0.004

0.005

0.002

0

0

-0.002

cr

-0.005

-0.004

0

0.2

an

us

-0.01

-0.015

ip t

0.006

(pexp - pcalc)/MPa

y1,exp - y1,calc

0.015

0.4

0.6

0.8

1

-0.006

M

x1 Fig. 5. Consistency analysis results of (δy1) (,) and (δp) (/) for EA2P system at 0.6 MPa using the Fredenslund et al. [15] routine.

Ac ce pt e

d

0.4

y1 - x 1

0.3

0.2

0.1

0

0

0.2

0.4

0.6

0.8

1

x1 Fig. 6. Experimental points (,) and (&) of (y1-x1) vs. x1 representation for MA2P system at 0.3 and 0.6 MPa, respectively. Fitting curves of data and bibliographic [8] data at 74.66 (A), 101.32 (5) and 127.99 (;) kPa.

Page 24 of 26

0.15

0.1

ip t

y1 - x1

0.05

cr

0

0

0.2

0.4

an

-0.1

us

-0.05

0.6

0.8

1

M

x1 Fig. 7. Fitting curves with experimental data (/) and (8) of (y1-x1) vs. x1 plot for EA2P at 0.3 and 0.6 MPa, respectively; also with Hernandez and Ortega [10] data at 101.32 kPa 99 (*).

d

392

Ac ce pt e

387

T/K

382

377

372

367

362

0

0.2

0.4

0.6

0.8

1

x1 Fig. 8. Experimental VLE data of MA2P (", ") and EA2P (/, /) at 0.3 MPa. Curves for the prediction models (- - - - - -) UNIFAC-1993 [20] on MA2P system and (⎯⎯⎯) UNIFAC-1987 [19] on EA2P system.

Page 25 of 26

420

416

T/K

412

408

ip t

404

cr

400

us

396

388

0

0.2

0.4

an

392

0.6

0.8

1

Ac ce pt e

d

M

x1 Fig. 9. Equilibrium diagram of MA2P (&, &) and EA2P (8, 8) binary systems at 0.6 MPa. Curves for the prediction models (- - - - - -) UNIFAC-1993 [20] on MA2P system and (⎯⎯⎯) UNIFAC1987 [19] on EA2P system.

Fig. 10. Plot o azeotropic data in reduced coordinates for the EA2P system (,) from this work and (/) from literature [11] with Eqs. (17) and (18) fitting curves.

Page 26 of 26