Article pubs.acs.org/jced
Liquid−Liquid Equilibria of Binary and Ternary Systems Methanol/ Water + n‑Hexane, + n‑Octane, + n‑Dodecane, and + n‑Hexadecane in the Temperature Range between T = 283.15 K and T = 333.15 K Cécile Lindemann,† Pierre Duchet-Suchaux,‡ Antonio Razzouk,§ Ilham Mokbel,*,†,∥ and Jacques Jose† †
Université Claude Bernard Lyon 1, UMR 5615, 43 bd du 11 Novembre 1918, 69622 Villeurbanne, France TOTAL, 2 place Jean Millier -La Défense 6, 92400 Courbevoie, France § Laboratoire des Analyses Chimiques, Faculté des Sciences II, Université Libanaise, Fanar, Liban ∥ Université de Saint Etienne, Jean Monnet, Université de Lyon, F-42023 Saint Etienne, France ‡
ABSTRACT: Original very low solubility data for binary (methanol + dodecane) and ternary systems (methanol/water + hexane, or octane, or dodecane, or hexadecane) under atmospheric pressure at three temperatures between 283.15 and 333.15 K are reported. The experimental values were compared with literature data when available. Two models (NRTL and UNIQUAC) were used to correlate and predict the experimental data.
1. INTRODUCTION Gas hydrates (ice-like substances that can form in deep-sea sediments) cause severe problems in cold regions (North Sea) when appearing in a pipe-line transporting gas and oil with some water. They could lead to a full blockage of the pipe and, thus, interruption of the production and creation of possible overpressures that could degenerate into dramatic safety concerns. To inhibit hydrate formation, hydrophilic solvents are often injected, among which methanol or monoethylene glycol is very common.1,2 The determination of methanol flow rate to be injected requires, in addition to a reliable hydrate model, quality data of the vapor−liquid−liquid equilibrium of hydrocarbon− water−methanol mixtures in order to estimate the methanol “lost” in the hydrocarbon phase.3 The present study is part of a series of work to address the problems of gas hydrates.4,5 One binary system (methanol + n-dodecane) and four ternary systems (methanol/water + n-hexane, or + n-octane, or + n-dodecane, or + n-hexadecane) under atmospheric pressure and at three temperatures (between 283.15 and 333.15 K) were studied. This temperature range has been selected to avoid a solid paraffinic phase during the experiment. On the other hand, the temperature-dependent parameters of the thermodynamic model need several measurements to be fitted. Three concentrations of the methanol in the aqueous phase, in accordance with those used for hydrates prevention, were studied. The minor compounds in each phase were determined and the experimental data correlated by NRTL and UNIQUAC models. © XXXX American Chemical Society
2. EXPERIMENTAL SECTION 2.1. Materials. Methanol and the four hydrocarbons were obtained from Sigma-Aldrich. Their CAS number and purity are given in Table 1. Deionized water (conductivity = 18 MΩ· cm) from a Millipore Milli-Q system was used in this work. Table 1. Mass Fraction Purity of the Used Compounds Purity (mass fraction) Compound
CAS number
Sigma-Aldrich
methanol n-hexane n-octane n-dodecane n-hexadecane
67-56-1 110-54-3 111-65-9 112-40-3 544-76-3
>0.99 >0.99 0.98 >0.99 0.99
2.2. Calibration and Analysis. Liquid−liquid equilibrium was carried out using a glass cell of about 300 mL. The experimental conditions (mixture stirring/decantation time and sampling, calibration, analysis, and uncertainties of measurements) are the same as described in our previous work.4,5 The gas chromatography conditions for analytical determination of the solute are reported in Table 2. Water in the organic phase was determined by Karl Fischer (KF) titration. Received: January 8, 2016 Accepted: May 25, 2016
A
DOI: 10.1021/acs.jced.6b00022 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Table 4. Experimental Liquid−liquid Equilibrium Data at P = 101.3 kPa for the Ternary System Methanol (1) + Water (2) + n-Octane (3) Expressed in Mole Fractions (xi)a
Table 2. Analytical Conditions Used To Determine Mole Fraction of Hydrocarbons (C6, C8, C12, and C16) and Methanol GC Type Column type Column length Column i.d. Film thickness Injector type Injection volume Detector type He (Carrier gas)
GC-1
GC-2
GC-3
HP 6890 Rtx-35 Amine 30 m 0.32 mm 1 μm Split 1 μL FID 70 kPa
HP 5890 A Rtx-35 Amine 30 m 0.32 mm 1 μm Split 1 μL FID 70 kPa
HP 6890 HP-1 30 m 0.25 mm 0.25 μm Split 1 μL Mass Spectrometry 1 mL·min−1
Polar phase x1
For dodecane and hexadecane in the aqueous phase, liquid− liquid extraction using dichloromethane solvent was carried out with the aim to concentrate the hydrocarbon. A known amount of dichloromethane, containing the internal standard, was added to a precise amount (by weight) of the polar phase. After stirring and decantation, the organic phase was recovered and analyzed by chromatography. A second liquid−liquid extraction showed that the entire hydrocarbon was recovered in the first extraction. The global uncertainty U was calculated as U2 = U2calibration + U2measurement. The interval of confidence of 95% leads to an expanded relative uncertainty, ur, twice the value of the global relative uncertainty: Ur = U/x (x = mole fraction of the hydrocarbon) and ur = 2Ur. The uncertainty on the mole fraction of water determined by Karl Fischer is estimated to be 5%.
x2
0.1942 0.3599 0.5663
0.8057 0.6399 0.4315
0.1942 0.3598 0.5658
0.8057 0.6398 0.4312
0.1942 0.3598 0.5651
0.8057 0.6397 0.4306
x1
283.15 K 2.20 × 10−5 1.78 × 10−3 1.78 × 10−4 3.86 × 10−3 −3 2.18 × 10 8.51 × 10−3 303.15 K 3.51 × 10−5 3.84 × 10−3 3.21 × 10−4 7.64 × 10−3 −3 2.95 × 10 1.52 × 10−2 323.15 K 5.32 × 10−5 7.15 × 10−3 −4 4.86 × 10 1.29 × 10−2 −3 4.23 × 10 2.40 × 10−2
0.1942 0.2727 0.3599 0.5673
0.8057 0.7272 0.6400 0.4322
2.95 9.90 3.98 4.20
0.1942 0.2727 0.3599 0.5670
0.8057 0.7272 0.6400 0.4321
5.15 1.79 6.29 8.69
0.1942 0.2727 0.3599 0.5666
0.8057 0.7272 0.6399 0.4318
9.67 3.74 1.40 1.53
x1
283.15 K × 10−6 1.97 × 10−3 × 10−6 2.66 × 10−3 × 10−5 4.12 × 10−3 −4 × 10 8.38 × 10−3 303.15 K × 10−6 4.38 × 10−3 × 10−5 5.75 × 10−3 −5 × 10 8.30 × 10−3 −4 × 10 1.58 × 10−2 333.15 K × 10−6 1.02 × 10−2 −5 × 10 1.29 × 10−2 −4 × 10 1.83 × 10−2 × 10−3 3.37 × 10−2
x2 3.67 3.44 2.95 2.54
× × × ×
10−4 10−4 10−4 10−4
8.95 8.15 8.73 9.45
× × × ×
10−4 10−4 10−4 10−4
1.38 1.36 1.35 1.32
× × × ×
10−3 10−3 10−3 10−3
Table 5. Experimental Liquid−liquid Equilibrium Data at P = 101.3 kPa for the Ternary System Methanol (1) + Water (2) + n-Dodecane (3) Expressed in Mole Fractions (xi)a Polar phase
Hydrocarbon-rich phase x3
x3
Relative uncertainties: ur(xi) = 0.10 when 10−6 ≤ xi < 10−3; ur(xi) = 0.01 when 10−3 ≤ xi ≤ 10−2; ur(xi) = 0.001 when xi ≥ 0.1; u(T) = 0.1 K; and u(p) = 0.3 kPa.
Table 3. Experimental Liquid−liquid Equilibrium Data at P = 101.3 kPa for the Ternary System Methanol (1) + Water (2) + n-Hexane (3) Expressed in Mole Fractions (xi)a Polar phase
x2
a
3. RESULTS AND DISCUSSION In Tables 3−6 are reported experimental data of the systems methanol/water + hexane, or + octane, or + dodecane, or +
x1
Hydrocarbon-rich phase
Hydrocarbon-rich phase
x1
x2
0.1942 0.3599 0.5675 0.9978
0.8057 0.6400 0.4324 0
4.20 2.84 2.60 2.19
0.1942 0.3599 0.5675 0.9958
0.8057 0.6400 0.4324 0
1.54 4.23 4.37 4.18
0.1942 0.3599 0.5675 0.9945
0.8057 0.6400 0.4324 0
2.70 6.46 7.22 5.49
x3
x2 4.08 × 10−4 3.21 × 10−4 2.85 × 10−4
x1
283.15 K × 10−8 2.19 × 10−3 −6 × 10 4.19 × 10−3 −5 × 10 7.60 × 10−3 × 10−3 5.37 × 10−2 303.15 K × 10−7 4.81 × 10−3 −6 × 10 8.66 × 10−3 × 10−5 1.43 × 10−2 × 10−3 8.80 × 10−2 323.15 K × 10−7 9.06 × 10−3 × 10−6 1.48 × 10−2 × 10−5 2.51 × 10−2 −3 × 10 1.38 × 10−1
x2 3.05 × 10−4 2.32 × 10−4 2.02 × 10−4 0 8.89 × 10−4 8.55 × 10−4 8.06 × 10−4 0 1.46 × 10−3 1.22 × 10−3 1.08 × 10−3 0
Relative uncertainties: ur(xi) = 0.20 when 10−8 ≤ xi < 10−6; ur(xi) = 0.10 when 10−6 ≤ xi < 10−3; ur(xi) = 0.01 when 10−3 ≤ xi ≤ 10−2; ur(xi) = 0.001 when xi ≥ 0.1; u(T) = 0.1 K; and u(p) = 0.3 kPa. a
7.56 × 10−4 7.72 × 10−4 8.45 × 10−4
plotting the mole fraction of methanol and water (in the organic phase) versus the number of carbons of the alkane (Figures 2 and 3). Schmelzer et al.6 studied methanol/water + tridecane, a mixture undetermined in the present work. We positioned the authors’ points in Figures 1−3). Their values are not consistent with our experimental results; they are systematically higher. When studying more closely Schmelzer et al.’s6 measurements, we noticed that their solubility data of C13 in pure water are 1 × 10−5 at 30 and 60 °C. This is even higher than the solubility of C6 in water, namely 2 × 10−6 at 30 °C, the value from Jönsson et al.,7 which is in agreement with our previous published data.5
1.25 × 10−3 1.26 × 10−3 1.51 × 10−3
Relative uncertainties: ur(xi) = 0.10 when 10−5 ≤ xi < 10−3; ur(xi) = 0.01 when 10−3 ≤ xi ≤ 10−2; ur(xi) = 0.001 when xi ≥ 0.1; u(T) = 0.1 K; and u(p) = 0.3 kPa.
a
hexadecane. Due to the lack of data in the literature, we checked the consistency of our results by plotting the mole fraction of each n-alkane versus the number of carbons (in logarithmic scale). Figure 1 illustrates an example of data obtained at 303.15 K. This straight line is also observed when B
DOI: 10.1021/acs.jced.6b00022 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Table 6. Experimental Liquid−liquid Equilibrium Data at P = 101.3 kPa for the Ternary System Methanol (1) + Water (2) + n-Hexadecane (3) Expressed in Mole Fractions (xi)a Polar phase x1
x2
0.3599
0.6400
0.3599
0.6400
0.3599
0.6400
Hydrocarbon-rich phase x3
x1
293.15 K 1.82 × 10−7 5.63 × 10−3 303.15 K 2.79 × 10−7 8.17 × 10−3 323.15 K 4.49 × 10−7 1.57 × 10−2
x2 4.28 × 10−4 7.00 × 10−4 1.16 × 10−3
Relative uncertainties: ur(xi) = 0.20 when 10 ≤ xi < 10−6; ur(xi) = 0.10 when 10−6 ≤ xi < 10−3; ur(xi) = 0.01 when 10−3 ≤ xi ≤ 10−2; ur(xi) = 0.001 when xi ≥ 0.1; u(T) = 0.1 K; and u(p) = 0.3 kPa. a
−7
Figure 3. Mole fraction of water in the organic phase versus the number of carbons of the alkane at 303.15 K. Weight % of water in the polar phase: ◇, 70% this work; □, 50% this work; Δ, 30% this work; ×, 36% ref 6.
Figure 1. Mole fraction of n-alkanes in the polar phase versus number of carbons at 303.15 K. Weight % of water in the polar phase: ◆, 70% this work; ■, 50% this work; ▲, 30% this work; ×, 36% ref 6.
Figure 4. Solubility of the methanol (1) + n-dodecane (2) system.x1 is the mole fraction of methanol in the hydrocarbon-rich phase: □, this work; ○, ref 8; Δ, ref 9.x2 is the mole fraction of n-dodecane in the polar phase: ■, this work; ●, ref 8; ▲, ref 9.
the solubility data of dodecane in methanol obtained in the present study are four times lower than those of Casás et al.8 However, Lasich et al.’s9 value at 313.14 K is in very good agreement with our experimental points. Previous studies of the ternary system methanol + water + hexane were carried out by Liu et al.10 at three mass percent of water in methanol (70%, 50%, and 30% w/w) and by Kogan et al.11 at 30% (Figures 5−7). In the case of methanol solubility in the organic phase (Figure 5 and 6), our values of methanol are twice as high as those of Liu et al. (when the water content in the mixture is 70 and 50%). On the other hand, at 30% w/w of water, our experimental solubility of methanol is in accord with Liu et al.’s10 values (same order of magnitude) (Figure 7). The solubility of water in the organic phase reported by Liu significantly deviate from our results (by 1 order of magnitude). In addition, some inconsistency is observed, as the authors’ solubility of water decreases when the temperature increases. In Figure 7b are reported the solubility of hexane in the polar phase. Our experimental points lay between those of Liu et al.10 and Kogan et al.11 Lasich et al.9 reported data for the system methanol + water + dodecane. The comparison with our data could not be undertaken because, first, the investigated concentrations of methanol in the polar phase are different from the present study and, second, the uncertainty of their measurements is higher than the solubility values. No data for
Figure 2. Mole fraction of methanol in the organic phase versus the number of carbons of the alkane at 303.15 K. Weight % of water in the polar phase: ◆, 70% this work; ■, 50% this work; ▲, 30% this work; ×, 36% ref 6.
The mole fraction of methanol and water in the organic phase varies slightly with the number of carbons of the alkanes (the order of magnitude of the mole fraction is the same for all the alkanes from hexane to hexadecane). With the aim to check the reliability of our measurements, the few data found in the open literature were compared to our results. Casás et al.8 and Lasich et al.9 reported solubility the data of methanol in dodecane. Our values are in very good agreement with those obtained by Casás et al.,8 whereas Lasich et al.’s9 values are higher by 35% (Figure 4). On the other hand, C
DOI: 10.1021/acs.jced.6b00022 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Figure 5. Solubility of the methanol (1) + water (2) + n-hexane (3) system with 70 wt % of water in the polar phase (xpol 2 = 0.81).x1 is the mole fraction of methanol in the hydrocarbon-rich phase: ▲, this work; Δ, ref 10. x2 is the mole fraction of water in the hydrocarbonrich phase: ◆, this work; ◇, ref 10.
Figure 7. Methanol (1) + water (2) + n-hexane (3) system with 30 wt % of water in the polar phase (xpol 2 = 0.43). (a) x1 is the mole fraction of methanol in the hydrocarbon-rich phase: ▲, this work; Δ, ref 10; ×, ref 11. x2 is the mole fraction of water in the hydrocarbon-rich phase: ◆, this work; ◇, ref 10. (b) x3 is the mole fraction of hexane in the polar phase: ●, this work; ○, ref 10; +, ref 11.
Figure 6. Mutual solubility of the methanol (1) + water (2) + nhexane (3) system with 50 wt % of water in the polar phase (xpol 2 = 0.64). x1 is the mole fraction of methanol in the hydrocarbon-rich phase: ▲, this work; Δ, ref 10. x2 is the mole fraction of water in the hydrocarbon-rich phase: ◆, this work; ◇, ref 10.
data12 and were calculated using the following objective function:
comparison were found for the system methanol + water + hexadecane.
OF =
4. DATA CORRELATION BY NRTL AND UNIQUAC Reliable thermodynamic models are needed in process simulation and design. With this aim, we used UNIQUAC and NRTL models to correlate our experimental data. Temperature-dependent model parameters were used for representing the phase behavior over the entire experimental temperature range τij =
⎛A0 ij
τij = exp − ⎜⎜ ⎝
+
n=1
i
⎛
xicalc − xiexp P calc − P exp + P exp xiexp ⎝
yicalc − yiexp ⎞ ⎟ ⎟ yiexp ⎠
(3)
NRTL and UNIQUAC parameters for alkane−methanol were determined from the present experimental LLE. The minimized objective function used is the relative difference between the experimental and calculated compositions given by the relation
(1)
× T⎞ ⎟ ⎟ RT ⎠
2
+
Cij0 + CijT(T − 273.15) RT
N
∑ ∑ ⎜⎜
N
OF =
AijT
3
∑∑∑ k
(2)
2 j
i
exp calc xijk − xijk exp xijk
× 100 (4)
where i, j, and k are respectively the component, the phase, and the tie line. The different binary parameters are listed in Tables 7 and 8. The parameters (αij) of the NRTL equation between methanol and water, and methanol and alkane, were set to 0.3. The UNIQUAC structural parameters r and q (respectively
Aij0, AijT, Cij0, and CijT are respectively the binary parameters of the UNIQUAC and NRTL models. Alkane−water parameters were determined from the binary data previously published5 and reported in Tables 7 and 8. In the case of methanol−water, they were deduced from vapor pressures D
DOI: 10.1021/acs.jced.6b00022 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Table 7. Binary Interaction Parameters of the NRTL Model i
j
Cij0 (J·mol−1)
1 1 2
2 3 3
−1323.9 7396.8 24891
1 1 2
2 3 3
−1323.9 10041 31289
1 1 2
2 3 3
−1323.9 14434 44920
1 1 2
2 3 3
−1323.9 19084 54927
Cji0 (J·mol−1)
CijT (J·K−1·mol−1)
CjiT (J·K−1·mol−1)
αij0
−31.658 −37.304 −52.507
0.3 0.3 0.15
−31.658 −56.806 −34.369
0.3 0.3 0.15
−31.658 −49.207 −45.783
0.3 0.3 0.15
−31.658 −56.099 −23.171
0.3 0.3 0.15
Methanol (1) + Water (2) + n-Hexane (3) 3583.5 29.102 8904.1 −24.559 14538 60.734 Methanol (1) + Water (2) + n-Octane (3) 3583.5 29.102 9539.2 −15.899 15042 81.617 Methanol (1) + Water (2) + n-Dodecane (3) 3583.5 29.102 9383.0 −2.4149 16940 103.91 Methanol (1) + Water (2) + n-Hexadecane (3) 3583.5 29.102 10415 15.945 17000 172.17
Table 8. Binary Interaction Parameters of the UNIQUAC Model i
j
Aij0 (J·mol−1)
1 1 2
2 3 3
−2472.7 4760.0 1632.0
1 1 2
2 3 3
−2472.7 4058.4 2049.6
1 1 2
2 3 3
−2472.7 3087.8 3195.6
1 1 2
2 3 3
−2472.7 1657.7 3991.6
Aji0 (J·mol−1)
Methanol (1) + Water (2) + n-Hexane (3) 1620.9 9567.7 12677 Methanol (1) + Water (2) + n-Octane (3) 1620.9 10522 13322 Methanol (1) + Water (2) + n-Dodecane (3) 1620.9 12761 14975 Methanol (1) + Water (2) + n-Hexadecane (3) 1620.9 15072 16196
calculated volume parameter and surface area) are reported in Table 9.
Component
r
q
water methanol n-hexane n-octane n-dodecane n-hexadecane
0.9200 1.4311 4.4998 5.8486 8.5462 11.2438
1.400 1.432 3.856 4.936 7.096 9.256
As shown in Figures 8 and 9, the parameters of the NRTL and UNIQUAC models as a function of the number of carbons of the alkane could be correlated by a straight line. The agreement between the experimental data and the calculated values is expressed by the relative mean absolute deviation, RMAD, defined as follows: Ni
∑ 1
|xiexp − xicalc| xiexp
AjiT (J·mol−1·K−1)
3.9523 −11.999 11.064
0.2901 −7.4462 −7.1917
3.9523 −10.332 8.6478
0.2901 −9.4785 −7.9901
3.9523 −8.2195 4.3505
0.2901 −15.072 −12.710
3.9523 −4.3760 1.2782
0.2901 −20.621 −14.954
The results of RMAD for both models, UNIQUAC and NRTL, are listed in Tables 10 and 11. The NRTL and the UNIQUAC models present a mean relative deviation between 1 and 30% for the methanol and water in the organic phase and between 4 and 35% for the hydrocarbons in the polar phase, which is quite satisfactory given the low concentration of the hydrocarbon in the aqueous phase. The two models predict the solubility of the hydrocarbon in the polar phase with a mean deviation ranging between 4 and 34%. In Figure 10 is reported an example of distribution coefficients at 303 K, Kmethanol and Kwater, versus the mole fraction of methanol, xmethanol, for the system water−methanol− dodecane:
Table 9. UNIQUAC Structural, Area and Volume, Parameters for Pure Components
1 Δxi = × Ni
AijT (J·mol−1·K−1)
K methanol =
K water =
(xmethanol)org (xmethanol)aq
(6)
(xwater )org (xwater )aq
(7)
The experimental Kmethanol is in good agreement with the calculated values using the NRTL and UNIQUAC models
(5) E
DOI: 10.1021/acs.jced.6b00022 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Table 10. Average Relative Deviation between Experimental and Calculated Mole Fractions, in the Hydrocarbon (II) and Aqueous (I) Phases, with the NRTL Modela Tmin
Tmax
283.15 283.15 293.15
Δxi =
N2
N3
ΔxII1 (%)
ΔxII2 (%)
Methanol (1) + Water (2) + n-Hexane (3) 323.15 9 9 9 19.2 24.9 Methanol (1) + Water (2) + n-Octane (3) 333.15 12 12 12 14.8 20.2 Methanol (1) + Water (2) + n-Dodecane (3) 323.15 12 9 12 26.9 13.9 Methanol (1) + Water (2) + n-Hexadecane (3) 333.15 3 3 3 0.24 12.2
283.15
a
N1
1 Ni
×
exp calc N |x − x | ∑1 i i x exp i i
ΔxI3 (%) 26.6 22.2 37.3 3.47
and Ni = number of experimental data
points for compound i.
Table 11. Average Relative Deviation between Experimental and Predicted Mole Fractions, in the Hydrocarbon (II) and Aqueous (I) Phases, with the UNIQUAC Modela Tmin
Tmax
283.15 283.15 293.15 a
Δxi =
N2
N3
ΔxII1 (%)
ΔxII2 (%)
Methanol (1) + Water (2) + n-Hexane (3) 323.15 9 9 9 17.4 16.4 Methanol (1) + Water (2) + n-Octane (3) 333.15 12 12 12 13.9 21.6 Methanol (1) + Water (2) + n-Dodecane (3) 323.15 12 9 12 24.9 31.3 Methanol (1) + Water (2) + n-Hexadecane (3) 333.15 3 3 3 1.93 21.0
283.15
Figure 8. Binary interaction parameters of the NRTL model, versus the number of carbons of the alkane: (A) between methanol (1) and alkane (2); (B) between water (1) and alkane (2). ●, C120; ■, C210.
N1
1 Ni
exp calc Ni |xi − xi | 1 xiexp
×∑
ΔxI3 (%) 33.9 24.0 28.6 3.50
and Ni = number of experimental data
points for compound i.
Figure 9. Binary interaction parameters of the UNIQUAC model, versus the number of carbons of the alkane: (A) between methanol (1) and alkane (2); (B) between water (1) and alkane (2).●, A120; ■, A210.
Figure 10. Distribution coefficients Kmethanol (A) and Kwater (B) of the system water−methanol−dodecane at 303.15 K: + , this work; ×, UNIQUAC ; □, NRTL.
except for the binary system methanol−dodecane (at xmethanol = 1). In the case of Kwater, only the UNIQUAC model satisfactorily matches the experimental values, except for the composition xmethanol = 0.6. F
DOI: 10.1021/acs.jced.6b00022 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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(11) Kogan, V. B.; Deizenrot, I. V.; Kuldyaeva, T. A.; Fridman, V. M. Solubility in systems consisting of methanol, water, and normal paraffin hydrocarbons. J. Appl. Chem. USSR 1956, 29, 1493−1497. (12) Mokbel, I.; Kasehgari, H.; Rauzy, E.; Jose, J. Static measurements of the total vapour pressures of water-methanol mixtures at temperatures between 243 and 313 K. ELDATA: Int. Electron. J. Phys. .Chem. 1995, 1, 135−138.
5. CONCLUSION We reported low solubility data (between 10−3 and 10−8 in mole fraction) of the systems methanol/water/n-alkanes (hexane, octane, dodecane, and hexadecane). The experimental solubility of methanol in the binary system methanol + dodecane is in good agreement with literature data whereas the solubility of dodecane in methanol is higher than the present study. No solubility data lower than 10−3 in mole fraction was found in the literature. The measured data were correlated with the NRTL and UNIQUAC models. The distribution coefficient is better represented by the UNIQUAC model than by the NRTL model.
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. Funding
The authors acknowledge Total for the financial support of this research. Notes
The authors declare no competing financial interest.
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REFERENCES
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DOI: 10.1021/acs.jced.6b00022 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
