Article pubs.acs.org/jced
Liquid−Liquid Equilibrium for the Ternary System of Water + Acetone + Dihydromyrcenol at 358 K to 368 K under 0.8 MPa Jingjing Chen, Tingping Xie, Huidong Zheng,* Suying Zhao, and Liang’en Wang School of Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350108, P. R. China ABSTRACT: The liquid−liquid equilibrium data of a ternary system water + acetone + dihydromyrcenol were measured at 358 K to 368 K under 0.8 MPa. The reliability of the experimental data was calculated by the Othmer−Tobias and Hand correlations. The nonrandom two-liquid model and the universal quasichemical model were used to correlate the tie-lines. The calculated results coincide with the experimental data very well.
1. INTRODUCTION
2. EXPERIMENTS 2.1. Materials. The chemicals are listed in Table 1 and used without any further purification. Distilled water was used throughout the experiments.
Dihydromyrcenol (2,6-dimethyl-7-octen-2-ol) is one of the most popular perfumes nowadays. It is mainly applied in soaps and detergents because of its powerful citrus and lime-like aroma and excellent stability. Dihydromyrcenol is industrially produced by the direct hydration of dihydromyrcene (3,7dimethyl-1,6-octadiene) over the acid catalysts. But the solubility of dihydromyrcene and dihydromyrcenol in water is quite poor, and in industry the hydration reaction is still mostly carried out heterogeneously, though a large amount of solvent is added to improve the intermiscibility. Many investigations have been done on the hydration process,1−4 while only a few works on the liquid−liquid equilibrium (LLE) data of the water + solvent + dihydromyrcenol system5,6 are reported. These equilibrium data are quite necessary to learn the distribution of dihydromyrcenol in both the organic phase and aqueous phase (where the reaction mostly takes place), which aids the design and improvement of the separation process of dihydromyrcenol. 1,4-Dioxane is the most commonly used solvent in the production of dihydromyrcenol, and its boiling point is higher than that of water, which leads to high energy consumption in the separation process of the reaction mixture to distill water, solvent, and dihydromyrcene successively. In contrast, solvents with lower boiling points (e.g., acetone) seem to be more energy-efficient, increasing their potential for use in the industrial production of dihydromyrcenol. A production process using the low-boiling solvent acetone has been developed under 0.4−0.8 MPa, and a flash evaporator, which consumes much less energy,7 was introduced to recover most of the acetone. This work provides the LLE data of a ternary system of water + acetone + dihydromyrcenol from 358 K to 368 K under 0.8 MPa. The nonrandom two liquid (NRTL) and universal quasichemical (UNIQUAC) models are used to correlate the LLE data, and the interaction parameters are determined. © 2015 American Chemical Society
Table 1. Chemicals and Suppliers chemical acetone dihydromyrcenol ethanol cyclohexanone n-propanol
purity (mass %) analytical grade (> 99.5) technical grade (> 99.5) analytical grade (> 99.7) analytical grade (> 99.5) analytical grade (> 99.8)
supplier Sinopharm Chemical Reagent Co., Ltd. Huaian Wanbang Aromatic Chemicals Industry Co.,Ltd. Sinopharm Chemical Reagent Co., Ltd. Sinopharm Chemical Reagent Co., Ltd. Sinopharm Chemical Reagent Co., Ltd.
2.2. Apparatus and Procedures. The LLE measurements were carried out in an 80 mL jacked stainless steel cell shown in Figure 1. In each experiment, a mixture of water, acetone, and dihydromyrcenol with a known overall composition was added into the cell. The temperature of the cell was controlled by the circulating water from a water bath and measured by a thermocouple with a precision of 0.1 K. Nitrogen was charged to keep the pressure in the cell at 0.8 MPa so that the mixture would not boil all through the experiments. The biphasic system was vigorously stirred for 8 h to allow the contact between the two liquid phases. Then the mixture was allowed to settle for 12 h before sampling to ensure that the equilibrium was achieved and the two liquid phases were separated completely. The samples of both the top phase (dihydromyrcenol-rich phase) and the bottom phase (water-rich phase) Received: December 1, 2014 Accepted: February 26, 2015 Published: March 10, 2015 1134
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conductivity detector and two packed columns (Porapak Q). The column temperature was 413 K constantly and the current was 150 mA. Hydrogen was used as carrier gas. Ethanol was used as the internal standard for the quantitative analysis of water. The acetone and dihydromyrcenol components in the samples were determined by a gas chromatograph (Varian 3900) equipped with a flame ionization detector (FID) and a capillary column (AT OV-101). The column temperature program was as follows: 333 K hold 1 min, 10 K/min heating 10 min, 433 K hold 2 min. Nitrogen was used as carrier gas. As the concentration of dihydromyrcenol in the water-rich phase is quite low, a higher FID sensitivity range of 12 was chosen in the analysis of dihydromyrcenol in the water-rich phase to ensure accurate measurements, while the range of 11 was chosen for the others. n-Propanol and cyclohexanone were used as the internal standards of acetone and dihydromyrcenol, respectively. Each sample was analyzed at least three times to ensure that the repeatability of the measured mass fraction is better than 2% for dihydromyrcenol in the water-rich phase and 0.5% for the others. All measured mass fraction were turned into mole fraction for the model correlation. The uncertainty of the dihydromyrcenol in the water-rich phase in mole fraction is 4· 10−5 (absolute value) when the fraction is less than 0.0005 and
Figure 1. Scheme of LLE set. 1, nitrogen inlet/outlet; 2, heating jacket; 3, magnetic stirrer; 4, heating water inlet; 5, thermocouple; 6, heating water outlet; 7, sample ports of top and bottom phases, respectively.
were carefully collected by syringes in duplicate for the quantitative analysis. 2.3. Analysis. The water component in the samples was determined by a gas chromatograph (GC1690, Kexiao Chemical Equipment Co., Ltd.) equipped with a thermal
Table 2. Experimental (exp) and Correlated Data for the Ternary System of Water (1) + Acetone (2) + Dihydromyrcenol (3) at 358 K, 363 K and 368 K under 0.8 MPaa dihydromyrcenol-rich phase xα,2 exp
water-rich phase xα,3
xβ,2
xβ,3
NRTL
UNIQUAC
exp
NRTL
UNIQUAC
exp
NRTL
UNIQUAC
exp
NRTL
UNIQUAC
0.0619 0.1889 0.3078 0.3656 0.4169 0.4376 0.4088 T/K = 363
0.0656 0.1930 0.3061 0.3722 0.4244 0.4421 0.4059
0.0646 0.1968 0.3085 0.3643 0.4157 0.4368 0.4040
0.8265 0.7306 0.5898 0.4699 0.3704 0.2764 0.1941 0.1231
0.8238 0.7335 0.5946 0.4761 0.3654 0.2663 0.1895 0.1202
0.8343 0.7297 0.5910 0.4721 0.3666 0.2758 0.2009 0.1211
0.0066 0.0226 0.0424 0.0577 0.0854 0.1070 0.1346
0.0066 0.0218 0.0416 0.0591 0.0831 0.1058 0.1395
0.0057 0.0223 0.0419 0.0594 0.0853 0.1076 0.1366
0.00009 0.00015 0.00017 0.00032 0.00053 0.00089 0.00135 0.00276
0.00008 0.00010 0.00018 0.00032 0.00051 0.00086 0.00132 0.00256
0.00010 0.00014 0.00017 0.00032 0.00053 0.00088 0.00137 0.00280
0.0497 0.1959 0.2940 0.3668 0.4241 0.4350 0.3800 T/K = 368
0.0506 0.1912 0.2962 0.3655 0.4212 0.4410 0.3850
0.0507 0.1946 0.2920 0.3635 0.4229 0.4334 0.3849
0.8243 0.7553 0.5982 0.4702 0.3764 0.2764 0.1905 0.1091
0.8220 0.7606 0.5986 0.4699 0.3786 0.2714 0.1811 0.1090
0.8289 0.7560 0.5967 0.4766 0.3796 0.2747 0.1964 0.1145
0.0050 0.0226 0.0385 0.0583 0.0810 0.1035 0.1344
0.0050 0.0221 0.0365 0.0586 0.0773 0.1059 0.1411
0.0050 0.0227 0.0382 0.0595 0.0800 0.1061 0.1364
0.00009 0.00011 0.00019 0.00027 0.00055 0.00081 0.00145 0.00287
0.00009 0.00011 0.00020 0.00030 0.00054 0.00082 0.00141 0.00278
0.00010 0.00011 0.00019 0.00027 0.00054 0.00079 0.00148 0.00296
0.0577 0.2134 0.3053 0.3638 0.4133 0.4021 0.3423
0.0547 0.2079 0.2994 0.3562 0.4151 0.4030 0.3501
0.0548 0.2116 0.3057 0.3619 0.4101 0.4050 0.3422
0.8194 0.7465 0.5740 0.4667 0.3726 0.2638 0.1689 0.0957
0.8200 0.7516 0.5820 0.4697 0.3755 0.2666 0.1720 0.0907
0.8235 0.7509 0.5771 0.4640 0.3725 0.2700 0.1747 0.1010
0.0053 0.0244 0.0396 0.0572 0.0793 0.0957 0.1530
0.0055 0.0237 0.0403 0.0573 0.0764 0.0963 0.1483
0.0056 0.0250 0.0407 0.0584 0.0785 0.0965 0.1534
0.00010 0.00011 0.00020 0.00036 0.00056 0.00082 0.00120 0.00259
0.00010 0.00012 0.00023 0.00037 0.00056 0.00086 0.00126 0.00284
0.00011 0.00011 0.00020 0.00036 0.00056 0.00082 0.00125 0.00273
T/K = 358
a x: mole fraction; α, β: dihydromyrcenol-rich phase and water-rich phase, respectively. The standard uncertainty for the temperature u(T) is 0.1 K, the standard uncertainty for the pressure u(P) is 10 kPa, and the relative standard uncertainty for the mole fractions ur(x) is 5% for the dihydromyrcenol in water-rich phase and 2% for the others.
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Figure 2. Binodal curves of the ternary system of water (1) + acetone (2) + dihydromyrcenol (3) at 358 K (a), 363 K (b), and 368 K (c) under 0.8 MPa.
is 5 % when the fraction is greater than 0.0005; the uncertainty of acetone is 3 % when the fraction is less than 0.05 and is 1 % when the fraction is greater than 0.05; the uncertainty of the fraction of water and dihydromyrcenol in the dihydromyrcenolrich phase is 1 %.
3. RESULTS AND DISCUSSION 3.1. Experimental Data. The measured LLE data for the ternary system of water (1) + acetone (2) + dihydromyrcenol (3) at 358 K, 363 K, and 368 K under 0.8 MPa are listed in Table 2. The binodal curves of the system are presented in Figure 2. All compositions are expressed as mole fraction. The experiment results show that the water + acetone + dihydromyrcenol system behaves as a type-I system with a large biphasic area between water and dihydromyrcenol. The miscibility of water and dihydromyrcenol increases obviously with the increasing concentration of acetone. Within the experiment temperature range, the increase of temperature seems to have no remarkable effect on the mutual solubility of the system. As the comparison in Figure 3 shows, the biphasic area of this work and the reported water + 1,4-dioxane + dihydromyrcenol system6 almost overlap with each other at the same temperature (358 K), which suggests acetone could be a good solvent in the hydration system as well as 1,4-
Figure 3. Biphasic area of the two ternary systems (1,4-dioxanesolvent6 and acetone-solvent) at 358 K.
dioxane, while the more energy-efficient acetone may be a better choice for the industrial hydration process. The experiment data are ascertained by the Othmer−Tobias correlation8 (eq 1) and the Hand correlation9 (eq 2) at all three temperatures as follows: log 1136
1 − x′β ,1 x′β ,1
= A1 log
1 − xα′ ,3 xα′ ,3
+ B1
(1)
DOI: 10.1021/je501089z J. Chem. Eng. Data 2015, 60, 1134−1138
Journal of Chemical & Engineering Data log
1 − x′β ,2 x′β ,1
= A 2 log
1 − xα′ ,3 xα′ ,3
Article
+ B2
and acetone + dihydromyrcenol pairs, 0.2 for water + dihydromyrcenol pair. For the UNIQUAC model, the pure component structural parameters (r, q and q′) are listed in Table 4.
(2)
where x′ is the mass fraction; A1 and B1 are constants of the Othmer−Tobias correlation; A2 and B2 are constants of the Hand correlation. The correlation plots are shown in Figures 4 and 5. The parameters of the correlation are given in Table 3. The correlation results suggest that the measured data in this work are reliable.
Table 4. UNIQUAC Structural Parameters of the Pure Components12 component
r
q
q′
water acetone dihydromyrcenol
0.92 2.57 7.6274
1.40 2.34 6.768
1.00 2.34 6.768
The estimation of binary interaction parameters of both models was based on the minimization of the following objective function (OF):13 N
OF =
⎛
3
γα , ik
∑ ∑ ⎜⎜ln k=1 i=1
γβ , ik
⎝
− ln
γβ , ik ⎞ ⎟ /3N γα , ik ⎟⎠
(3)
where γ is the activity coefficient; x is the mole fractions; the subscripts α and β are the organic phase and the aqueous phase, respectively; the subscripts i and k denote the components and tie-lines, respectively; N is the total number of tie-lines. To predict the equilibrium with the obtained parameters, a procedure similar to that proposed by Zeng14 has been followed. The root-mean-square deviation (RMSD) defined as Figure 4. Othmer−Tobias correlation for the LLE data of water (1) + acetone (2) + dihydromyrcenol (3) system.
N
RMSD =
2
3
∑ ∑ ∑ (xijkexp − xijkcal)/6N , (4)
k=1 j=1 i=1
where the subscript j denotes different phases, was calculated to evaluate the predicted results. The predicted LLE data are present in Table 1. The obtained binary interaction parameters for each model and the RMSD are listed in Table 5. As the results show, both NRTL model and UNIQUAC model can accurately predict the phase equilibrium of the water + acetone + dihydromyrcenol system. Table 5. Binary Interaction Parameters for the NRTL and UNIQUAC Model and the RMSD Values binary interaction parameters NRTL i−j 1−2 1−3 2−3 RMSD
Figure 5. Hand correlation for the LLE data of water (1) + acetone (2) + dihydromyrcenol (3) system.
−1
Δgij/J·mol
6687.55 26338.72 516.37 0.0027
UNIQUAC −1
Δgji/J·mol
Δuij/J·mol−1
60417.10 1439.05 −658.17
1641.52 −978.68 2138.60 0.0036
Δuji/J·mol−1 −31991.58 −6584.03 −2982.55
Table 3. Correlation Parameters for the LLE Data of Water (1) + Acetone (2) + Dihydromyrcenol (3) System Othmer−Tobias correlation
4. CONCLUSIONS The liquid−liquid equilibrium data of the ternary system of water + acetone + dihydromyrcenol were measured at 358 K, 363 K, and 368 K under 0.8 MPa. The solubility of dihydromyrcenol and water increases as acetone is added. A comparison with the reported data of water + 1,4-dioxane + dihydromyrcenol system shows acetone is a potential solvent in the industrial process of dihydromyrcene hydration. The NRTL model and the UNIQUAC model were used to correlate the experimental data, and the binary interaction parameters of each model are determined. The predicted
Hand correlation
T/K
A1
B1
R2
A2
B2
R2
358 363 368
1.0157 1.0077 1.0165
0.3991 0.4144 0.4388
0.9788 0.9729 0.9717
0.8705 0.8693 0.8935
−0.7730 −0.8120 −0.8095
0.9966 0.9964 0.9945
3.2. Correlation of Experimental Data. The experimental tie lines were correlated to both the NRTL model10 and the UNIQUAC model.11 For the NRTL model, the value of nonrandomness parameter αij was set to 0.3 for water + acetone 1137
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results coincide with the experimental data very well, and the RMSD values are 0.0029 for NRTL model and 0.0045 for UNIQUAC model.
■
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. Funding
Acknowledgement is made for the financial support from the National Natural Science Foundation of China (No. 21106020, No. 21376053). Notes
The authors declare no competing financial interest.
■
REFERENCES
(1) Liu, Y.; Zhou, Z.; Yang, G.; Wu, Y.; Zhang, Z. A Study of Direct Hydration of Dihydromyrcene to Dihydromyrcenol Using Cation Exchange Resins as Catalyst. Int. J. Chem. React. Eng. 2010, 8 (1), 1− 15. (2) Kozhevnikov, I. V.; Sinnema, A.; van der Weerdt, A. J. A.; van Bekkum, H. Hydration and Acetoxylation of Dihydromyrcene Catalyzed by Heteropoly Acid. J. Mol. Catal. A: Chem. 1997, 120, 63−70. (3) Liu, Y.; Zhou, Z.; Yang, G.; Wu, Y.; Zhang, Z. Kinetics Study of Direct Hydration of Dihydromyrcene in a Jet Reactor. Ind. Eng. Chem. Res. 2010, 49, 3170−3175. (4) Botella, P.; Corma, A.; López Nieto, J. M.; Valencia, S.; Lucas, M. E.; Sergio, M. Selective Hydration of Dihydromyrcene to Dihydromyrcenol over H-beta Zeolite. Influence of the Microstructural Properties and Process Variables. Appl. Catal. A: Gen. 2000, 203, 251−258. (5) Qiu, T.; Li, S.; Li, S.; Wu, Y. Liquid−Liquid Phase Equilibria of the Ternary System of Water/1,4-Dioxane/Dihydromyrcene. Fluid Phase Equilib. 2009, 280, 84−87. (6) Wang, B.; Qiu, T.; Li, S. Liquid−Liquid Equilibrium for the System Water + 1,4-Dioxane + 2,6-Dimethyloct-7-en-2-ol over the Temperature Range of (343.2 to 358.2) K. J. Chem. Eng. Data 2010, 55, 558−560. (7) Vardharaj P. M., Arvind L. Method for Selective Hydration of Aroma Olefins to Alcohols in Continuous Solid Catalyst Column Reactor, PCT WO 2012/017447 A2. 2012. (8) Othmer, D. F.; Tobias, P.E. Tie Line Correlation. Ind. Eng. Chem. 1942, 34, 690−692. (9) Hand, D. B. Dineric Distribution. J. Phys. Chem. 1930, 34 (9), 1961−2000. (10) Renon, H.; Prausnitz, J.M. Local Compositions in Thermodynamic Excess Functions for Liquid Mixtures. AIChE J. 1968, 1 (14), 135−139. (11) 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 (1), 116− 128. (12) Li S. On Liquid−Liquid Equilibrium of Dihydromyrcene Hydration System. Master Thesis: Fuzhou University, China, 2008. (13) Zhao, S.; Chen, H.; Chen, X.; Zhou, J.; Wang, L. Liquid−Liquid Equilibrium of Ternary and Quaternary Systems Including Methyl Acetate, Benzene, Toluene, and Water at 283.2 K under Atmosphere. J. Chem. Eng. Data 2010, 55, 5276−5279. (14) Zeng, Y.; Chen, X.; Guo, C.; Zhao, S.; Zheng, H.; Wang, L. Measurement and Correlation of Liquid−Liquid Equilibrium Data for Water + Methanol + Methyl Acetate + Potassium Acetate. Fluid Phase Equilib. 2013, 354, 319−325.
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