Article pubs.acs.org/jced
Liquid−Liquid Equilibria for the Extraction of Chloropropanols from 1,2-Dichloropropane Using Water or 1,4-Butylene Glycol Bing Jia, Kun Xin, Xiaoxiao Bian, Chuanfu Zhu, Yingmin Yu, and Qingsong Li* The State Key Lab of Heavy Oil Processing, College of Chemical Engineering, China University of PetroleumEast China, Qingdao, Shandong 266580, People’s Republic of China ABSTRACT: Liquid−liquid equilibria (LLE) data for the extraction of chloropropanols from 1,2-dichloropropane using water or 1,4-butylene glycol as solvent at 303.15 and 323.15 K under atmospheric pressure have been determined. The distribution coefficients and separation factors were calculated to assess the effectiveness of extracting chloropropanols from 1,2-dichloropropane, and the consistency of LLE data was verified by the Othmer−Tobias and Hand equations. The binary interaction parameters among these compounds were obtained through correlation of the experimental data with the NRTL and UNIQUAC models; both models were successfully applied to correlate the experimental data of the studied systems, with all the root-meansquare deviation (RMSD) values being below 0.01.
liquids (NRTL)13 and universal quasi-chemical (UNIQUAC)14 activity coefficient models, and the binary interaction parameters were calculated with both models.
1. INTRODUCTION Propylene oxide (PO) is an important intermediate largely utilized in the chemical industry for the manufacturing of polyesters, polyurethanes, and solvents.1,2 In the traditional chlorohydrin process for the preparation of PO, 1,2dichloropropane (DCP) is one of the main byproducts; 130 kg of DCP is produced per 1 ton of PO.3 DCP is widely used as soil fumigants and insecticides, as a solvent in metal degreasing, and as an agent in galvanizing plants, as well as in some paint strippers, etc.4−6 Since the demand of PO’s downstream derivatives grows rapidly, and traditional thermal incineration of DCP produces toxic pollutants, quantitative recovery of DCP is economically advantageous.7 In the conventional chlorohydrin process, chloropropanols are an intermediate; the effluent stream contains DCP, chloropropanols, and a small amount of other components after the separation of PO. The remaining chlorinated volatile organic compounds especially DCP could be separated by reduced pressure distillation in the process of recovering DCP.8 Liquid−liquid extraction (LLE) of chloropropanols appears as another convenient choice for DCP upgrading. In order to understand and design a proper solvent extraction process, reliable liquid−liquid phase equilibria data are necessary.9,10 In this work, the experimental LLE data for the ternary systems of DCP + chloropropanols + solvents (water or 1,4butylene glycol) were measured at 303.15 and 323.15 K under atmospheric pressure. To the best of our knowledge, these data have never been reported up to now. The distribution coefficients and separation factors were defined and were used as the standard to evaluate the separation efficiency. In addition, the reliability of the measured LLE data was verified using the Othmer−Tobias11 and Hand equations.12 The experimental data were also correlated with non-random two © 2017 American Chemical Society
2. MATERIALS AND METHODS 2.1. Materials. Detailed infomation of the chemical reagents is listed in Table 1. 1,2-Dichloropropane and 1,4butylene glycol, were purchased from Sinopharm Chemical Reagent. Chloropropanols (1-chloro-2-propanol, 75%; remainder, mainly 2-chloro-1-propanol) were purchased from Alfa Aesar. Double-distilled water was prepared in our laboratory and employed throughout. All these chemicals were used without further purification as typical LLE studies do.15,16 2.2. Apparatus and Procedure. The experimental LLE data for ternary systems DCP + chloropropanols + solvents (water or 1,4-butylene glycol) were carried out at 303.15 and 323.15 K under atmospheric pressure. The details about experimental equipment have been presented in our previous work, and the reliability of the experimental system has been evaluated.17,18 The mixture was vigorously stirred for at least 1 h and then left to settle for at least 5 h to reach phase equilibrium. The evaporated compounds were completely condensed by the condenser to ensure the mass balance. When the phase equilibrium of the ternary mixture was reached, the mixture was split into the DCP-rich phase and the solvent-rich phase. The compositions of each distinct layer were accurately quantified through the internal standard; ethanol was chosen as the internal standard substance. And the compositions of each distinct layer were analyzed by gas Received: November 23, 2016 Accepted: February 10, 2017 Published: February 20, 2017 1130
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Table 1. Materials Description and UNIQUAC Structural Parameters (r and q) UNIQUAC paramsa
a
component
CAS
source
reported GC purity (mass %)
GC purity (mass %)
r
q
double-distilled water 1,2-dichloropropane 1,4-butylene glycol chloropropanols
7732-18-5 78-87-5 110-63-4 127-00-4
self-made Sinopharm Sinopharm Alfa Aesar
≥99.0 ≥99.0 ≥99.0
99.91 99.82 99.45 99.81
0.9200 3.595 3.757 3.485
1.400 3.056 3.328 2.930
Taken from the Aspen Plus V 8.4 physical properties data bank.
Table 2. Experimental LLE Data (Mole Fraction) for DCP (1) + Chloropropanols (2) + Solvents (3) Systems at 303.15 and 323.15 K under Atmospheric Pressurea,b solvents-rich phase solvent
DCP-rich phase
x1
x2
x3
x1
x2
x3
D
S
0.0023 0.0024 0.0019 0.0022 0.0020 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0020 0.0023 0.0024 0.0023 0.0023 0.0024 0.0025
0.0009 0.0023 0.0042 0.0085 0.0111 0.0135 0.0152 0.0171 0.0193 0.0070 0.0093 0.0106 0.0126 0.0148 0.0175 0.0185 0.0198 0.0215
0.9967 0.9954 0.9939 0.9893 0.9869 0.9844 0.9827 0.9808 0.9786 0.9909 0.9885 0.9874 0.9851 0.9828 0.9802 0.9791 0.9778 0.9760
0.9768 0.9696 0.9576 0.9321 0.9048 0.8822 0.8628 0.8380 0.8079 0.9003 0.8681 0.8506 0.8233 0.7994 0.7474 0.7331 0.6972 0.6692
0.0038 0.0109 0.0263 0.0456 0.0645 0.0812 0.1001 0.1194 0.1382 0.0526 0.0717 0.0898 0.1083 0.1252 0.1713 0.1898 0.2077 0.2222
0.0194 0.0195 0.0162 0.0223 0.0307 0.0365 0.0371 0.0426 0.0539 0.0471 0.0602 0.0597 0.0685 0.0754 0.0813 0.0771 0.0951 0.1086
0.2368 0.2110 0.1597 0.1864 0.1721 0.1663 0.1518 0.1432 0.1397 0.1331 0.1297 0.1180 0.1163 0.1182 0.1022 0.0975 0.0953 0.0968
100.59 85.25 80.49 78.98 77.85 69.84 62.39 57.15 53.73 57.05 53.62 50.20 41.65 39.37 33.20 31.07 27.69 25.90
0.1532 0.1643 0.1714 0.1743 0.1803 0.1827 0.1935 0.1997 0.2061 0.1746 0.1996 0.2037 0.2161 0.2167 0.2355 0.2408 0.2483
0.0130 0.0250 0.0327 0.0444 0.0571 0.0691 0.0850 0.1007 0.1370 0.0203 0.0365 0.0549 0.0721 0.0875 0.1028 0.1164 0.1305
0.8339 0.8107 0.7959 0.7813 0.7626 0.7482 0.7215 0.6996 0.6569 0.8051 0.7639 0.7414 0.7118 0.6958 0.6617 0.6428 0.6211
0.9907 0.9871 0.9817 0.9812 0.9739 0.9691 0.9598 0.9551 0.9233 0.9768 0.9668 0.9594 0.9418 0.9338 0.9171 0.9034 0.8877
0.0024 0.0062 0.0085 0.0122 0.0170 0.0212 0.0285 0.0334 0.0554 0.0060 0.0142 0.0221 0.0314 0.0394 0.0496 0.0575 0.0685
0.0069 0.0067 0.0098 0.0067 0.0091 0.0097 0.0117 0.0115 0.0213 0.0171 0.0190 0.0185 0.0268 0.0268 0.0333 0.0391 0.0438
5.417 4.032 3.847 3.639 3.359 3.259 2.982 3.015 2.473 3.383 2.570 2.484 2.296 2.221 2.073 2.024 1.905
water 303.15 K
323.15 K
1,4-butylene glycol 303.15 K
323.15 K
35.03 24.23 22.03 20.49 18.14 17.29 14.79 14.42 11.08 18.93 12.45 11.70 10.01 9.570 8.071 7.595 6.811
a
Standard uncertainties u are u(T) = 0.1 K, u(p) = 1 kPa, u(x1) = 0.00053, u(x2) = 0.00024, and u(x3) = 0.00049. bx1, mole fraction of DCP; x2, mole fraction of chloropropanols; x3, mole fraction of solvents.
three times to obtain a mean value. The uncertainty for the liquid phase compositions was calculated according to the GUM standard.19 A series of LLE data were obtained by changing the feed composition. 2.3. Uncertainty Calculation. There are two categories for calculating the uncertainty, named as “A” and “B”.19 In this work, type A was used to evaluate the uncertainty of each quantity q. The corresponding calculation equations are listed
chromatography (Agilent GC 6820 gas chromatograph) equipped with a Porapak N column (3 mm × 3 m) and a thermal conductivity detector. Hydrogen was used as the carrier gas at the rate of 60 mL min−1. The temperatures of the detector and injection port were 523.15 K. The temperature program started at 423.15 K and was held for 3 min, followed by a 15 K/min ramp to 523.15 K, and was maintained at this temperature for 3.4 min. Each sample was analyzed at least 1131
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as follows, and the meaning of each symbol is also shown in the documents of refs 17 and 18: n
s 2(qk ) =
∑ (qj − q ̅ )2 /(n − 1) j=1
(1)
s 2(q ̅ ) = s 2(qk )/n
(2)
u(xi) = s(X̅i )
(3)
The experimental standard deviation (s(qk)) is calculated, describing the variability of the observed values qk or, more specifically, their dispersion about their mean q.̅ Thus, for an input quantity Xi, the type A standard uncertainty u(xi) of its estimate xi = X̅ i is u(Xi) = s(X̅ i).
Figure 3. Ternary phase diagram for the 1,2-dichloropropane + chloropropanols + 1,4-butylene glycol system at 303.15 K: (+) experimental data; (☆) feed composition; (Δ) UNIQUAC model; (○) NRTL model.
3. RESULTS AND DISCUSSION 3.1. Experimental Data. The LLE data for the ternary systems DCP + chloropropanols + solvents (water or 1,4-
Figure 4. Ternary phase diagram for the 1,2-dichloropropane + chloropropanols + 1,4-butylene glycol system at 323.15 K: (+) experimental data; (☆) feed composition; (Δ) UNIQUAC model; (○) NRTL mode. Figure 1. Ternary phase diagram for the 1,2-dichloropropane + chloropropanols + water system at 303.15 K: (+) experimental data; (☆) feed composition; (Δ) UNIQUAC model; (○) NRTL model.
Figure 2. Ternary phase diagram for the 1,2-dichloropropane + chloropropanols + water system at 323.15 K: (+) experimental data; (☆) feed composition; (Δ) UNIQUAC model; (○) NRTL model. Figure 5. Experimental separation factor versus the chloropropanols mole fraction (x2β) in the solvent phase for the ternary system DCP (1) + chloropropanols (2) + solvents (3).
butylene glycol) at desired temperatures are listed in Table 2 with all concentrations being represented by mole fraction. The corresponding triangular phase diagrams are presented in Figures 1−4. As shown in these figures, the feed composition points agree with the tie lines with great accuracy, which is in accordance with the lever rule and indicates the mass balance is satisfied during the experimental operations.20 To evaluate the capacity of solvents (water or 1,4-butylene glycol) to remove chloropropanols from DCP solution, the distribution coefficients (D) and separation factors (S) were calculated by the following equations:
D=
S=
X 2β X 2α
(4)
X 2β /X1β X 2α /X1α
(5)
where X2α and X1α are the mole fractions of chloropropanols and DCP in the DCP-rich phase, respectively. X2β and X1β are the mole fractions of chloropropanols and DCP in the solventrich phase, respectively. The values of D and S are also shown in Table 2. According to the table, the distribution coefficients 1132
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Table 3. Othmer−Tobias and Hand Equation Parameters, a and b, and Regression Coefficients, r2, for the DCP (1) + Chloropropanols (2) + Solvents (3) Studied Systems
where X1α and X2α are the mole fractions of DCP and chloropropanols in the DCP-rich phase, respectively. X2β and X3β are the mole fractions of chloropropanols and solvents in the solvent-rich phase, respectively. The fitting parameters, together with the regression coefficients (r2), for the four systems are listed in Table 3. The correlation factors (r2) approach one, which indicates the good reliability and consistency of the related experimental data. 3.2. Data Correlation. The NRTL and UNIQUAC models were applied to correlate the experimental date for the DCP + chloropropanols + solvents (water or 1,4-butylene glycol) ternary systems by using the Aspen Plus 8.4 software. The pure component structural parameters r (the number of segments per molecules) and q (the relative surface area per molecules) in the UNIQUAC model are listed in Table 1. The NRTL and UNIQUAC binary interaction parameters for the ternary system were calculated by minimizing the objective function (OF):
Othmer−Tobias solvent
a1
b1
r2
0.8195 0.6612
−2.538 −3.200
0.9849 0.9888
water 303.15 K 323.15 K 1,4-butylene glycol 303.15 K 323.15 K solvent
0.4502 0.5363
0.4811 0.6111 Hand
0.9910 0.9956
a2
b2
r2
0.8292 0.6356
−2.376 −3.096
0.9944 0.9904
water 303.15 K 323.15 K 1,4-butylene glycol 303.15 K 323.15 K
0.8295 0.8553
0.7804 0.6218
0.9978 0.9983
M
OF =
2
3
∑ ∑ ∑ (xijkexp − xijkcal)2 (8)
k=1 j=1 i=1
where M is the number of tie lines, xexp is the experimental mole fraction, and xcal is the calculated mole fraction. Subscripts i, j, and k refer to the components, the phases, and tie lines, respectively. The quality of the correlation is assessed by the corresponding root-mean-square deviation (RMSD) values using the following equation:
tend to decrease with the increasing concentration of chloropropanols; the separation factors reflect the same tendency. Figure 5 shows the separation factors in all cases are much larger than one, which indicates the capability of extracting chloropropanols from the DCP phase by water or 1,4-butylene glycol. In addition, it could be found that both the distribution coefficients and separation factors decrease as the temperature increases; thus, the lower temperature at 303.15 K is better than 323.15 K for chloropropanols extraction. The reliability of the experimental tie-line data were confirmed by plotting the Othmer−Tobias and Hand correlations: ⎛ 1 − x 3β ⎞ ⎛ 1 − x1α ⎞ ⎟⎟ = a1 + b1 ln⎜ ln⎜⎜ ⎟ ⎝ x1α ⎠ ⎝ x 3β ⎠
(6)
⎛ x 2β ⎞ ⎛x ⎞ ln⎜⎜ ⎟⎟ = a1 + b2 ln⎜ 2α ⎟ ⎝ x1α ⎠ ⎝ x 3β ⎠
(7)
⎧M 2 3 exp cal 2 ⎫1/2 − xijk (xijk ) ⎪ ⎪ ⎬ RMSD = ⎨∑ ∑ ∑ ⎪ 6M ⎪k=1 j=1 i=1 ⎭ ⎩ exp
(9)
cal
the corresponding M, x , x , k, j, and i being the same as those in the OF equation. These RMSD values and optimized binary interaction parameters for NRTL and UNIQUAC models are presented in Table 4. Generally, all the RMSD% values are less than 0.61, which indicate the goodness of the correlation for the experimental data using both models. The experimental data and calculated data from NRTL and UNIQUAC models are
Table 4. Binary Energy Parameters of NRTL and UNIQUAC Models for the Systems DCP (1) + Chloropropanols (2) + Solvents (3) NRTL params T (K)
i−j
gij − gjj
303.15 K
1−2 1−3 2−3 1−2 1−3 2−3
5642.78 6517.88 −1002.24 4262.40 5031.06 −132.35
1−2 1−3 2−3 1−2 1−3 2−3
281353.77 10819.05 −1700.36 −3801.49 9593.70 −1701.49
a
gji −
UNIQUAC params α
RMSD
uij − ujjb
uji − uiib
RMSD
1195.48 12356.29 11432.46 −874.83 13746.46 8259.30
0.30 0.23 0.30 0.30 0.23 0.30
0.0013
1016.42 6149.80 262.90 3095.89 4746.10 4427.90
1970.15 1585.90 1981.21 −1533.27 1995.97 −1181.03
0.0012
15530.63 4113.07 284771.13 15051.42 3829.17 −3097.25
0.34 0.34 0.34 0.34 0.34 0.34
−2487.73 3964.93 −1472.45 −1366.95 3435.06 −1711.78
−869.51 −130.38 −2847.39 −1216.32 33.10 −1601.46
giia
water
323.15 K
1,4-butylene glycol 303.15 K
323.15 K
a
0.0016
0.0029
0.0027
0.0013
0.0044
0.0061
gij is interaction energy between species i and j in the ternary system (J/mol). buij is the UNIQUAC binary interaction parameter (J/mol). 1133
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(12) Hand, D. B. The distribution of consolute liquid between two immiscible liquids. J. Phys. Chem. 1929, 34, 1961−2000. (13) Renon, H.; Prausnitz, J. M. Local compositions in thermodynamic excess functions for liquid mixtures. AIChE J. 1968, 14, 135−144. (14) Abrams, D. S.; Prausnitz, J. M. Statistical thermodynamics of liquid mixtures: A new expression for the excess Gibbs energy of partly or completely miscible systems. AIChE J. 1975, 21, 116−128. (15) Chen, Y.; Lv, R.; Wang, H. M.; Liao, M. C.; Li, L. B. Ternary liquid - liquid equilibria for methyl isopropyl ketone + (resorcinol or hydroquinone) + water systems at different temperatures. Fluid Phase Equilib. 2016, 429, 93−97. (16) Yang, C. F.; Qian, Y.; Guo, J. W.; Chen, J. R.; Peng, J. P. Liquidliquid equilibria for the ternary system methyl isobutyl ketone + mbenzenediol + water. J. Chem. Eng. Data 2014, 59, 3324−3328. (17) Dai, F. F.; Xin, K.; Song, Y. H.; Shi, M. D.; Zhang, H. P.; Li, Q. S. Liquid-liquid equilibria for the extraction of phenols from alkane using ethylene glycol. Fluid Phase Equilib. 2016, 419, 50−56. (18) Dai, F. F.; Xin, K.; Song, Y. H.; Shi, M. D.; Yu, Y. M.; Li, Q. S. Liquid-liquid equilibria for the ternary system containing 1-butanol + methoxy(methoxymethoxy)methane + water at temperatures of 303.15, 323.15 and 343.15 K. Fluid Phase Equilib. 2016, 409, 466−471. (19) BIPM; IEC; IFCC; ILAC; ISO; IUPAC; IUPAP; OIML Evaluation of measurement dataGuide to the expression of uncertainty in measurement, JCGM 100:2008; Joint Committee for Guides in Metrology: Paris, 2008. (20) Li, Y. X.; Xu, Q.; Liu, S. L.; Li, H. M.; Zhang, F. B.; Zhang, G. L.; Xia, Q. Liquid-liquid equilibrium for the ternary system of isopropyl acetate + 2-propanol + glycerol at different temperatures under atmospheric pressure. Fluid Phase Equilib. 2016, 412, 199−204.
plotted in Figures 1−4; there is a good coincidence between the calculated data and experimental data.
4. CONCLUSION The experimental LLE data for the ternary systems DCP + chloropropanols + solvents (water or 1,4-butylene glycol) ternary systems were determined at 303.15 and 323.15 K and atmospheric pressure. The distribution coefficients and selectivity values were reported. The accuracy of the experimental tie-line data was assessed by using Othmer− Tobias and Hand equations. Meanwhile, the corresponding optimum binary interaction parameters of the NRTL and UNIQUAC models were obtained; the maximum RMSD value was 0.006, indicating both models were successfully applied to correlate experimental data in this work.
■
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Qingsong Li: 0000-0003-1425-8822 Funding
This study is supported by China University of Petroleum (East China) Graduate Student Innovation Project Fund (Grant YCXJ2016049) Notes
The authors declare no competing financial interest.
■
REFERENCES
(1) Kertalli, E.; Kosinov, N.; Schouten, J. C.; Nijhuis, T. A. Chem. Eng. J. 2017, 307, 9−14. (2) Nijhuis, T. A.; Makkee, M.; Moulijn, J. A.; Weckhuysen, B. M. The production of propene oxide: catalytic processes and recent developments. Ind. Eng. Chem. Res. 2006, 45, 3447−3459. (3) Bartkowiak, M.; Lewandowski, G.; Milchert, E.; Pelech, R. Optimization of 1,2-diaminopropane preparation by the ammonolysis of waste 1,2-dichloropropane. Ind. Eng. Chem. Res. 2006, 45, 5681− 5687. (4) Bartkowiak, M.; Lewandowski, G.; Milchert, E. Technological parameters of the ammonolysis of waste 1,2-dichloropropane. J. Hazard. Mater. 2004, 106, 107−114. (5) Löffler, F. E.; Champine, J. E.; Ritalahti, K. M.; Sprague, S. J.; Tiedje, J. M. Complete reductive dechlorination of 1,2-dichloropropane by anaerobic bacteria. Appl. Environ. Microbiol. 1997, 63, 2870− 2875. (6) Sen, D.; Kim, M. G. Excess molar volumes and excess molar enthalpies of the binary mixtures of 1,2-dichloropropane with di- and triethylene glycol mono-alkyl ethers at T = 298.15K. Fluid Phase Equilib. 2009, 285, 30−35. (7) Šoós,̌ M.; Graczová, E.; Markoš, J.; Molnár, A.; Steltenpohl, P. Design and simulation of a distillation column for separation of dichloropropane from a multicomponent mixture. Chem. Eng. Process. 2003, 42, 273−284. (8) Steltenpohl, P.; Graczová, E. Vapor-liquid equilibria of selected components in propylene oxide production. J. Chem. Eng. Data 2008, 53, 1579−1582. (9) Mohammad Doulabi, F. S.; Mohsen-Nia, M. Ternary liquid-liquid equilibria for systems of (sulfolane + toluene or chloronaphthalene + octane). J. Chem. Eng. Data 2006, 51, 1431−1435. (10) Wang, B. H.; Rong, M. J.; Wang, P. P.; Chen, S. Liquid-liquid equilibria for the ternary system n-Butyl Acetate + pyrocatechol + water at different temperatures at 101.3 kPa. J. Chem. Eng. Data 2016, 61, 3184−3189. (11) Othmer, D. F.; Tobias, P. E. The line correlation. Ind. Eng. Chem. 1942, 34, 693−700. 1134
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