- Email: [email protected]
Solid–liquid equilibrium and mixture properties for the binary systems of Alamine 336 with decane, dodecane, and 1-dodecanol
Fluid Phase Equilibria 361 (2014) 130–134
Contents lists available at ScienceDirect
Fluid Phase Equilibria journal homepage: www.elsevier.com/locate/fluid
Solid–liquid equilibrium and mixture properties for the binary systems of Alamine 336 with decane, dodecane, and 1-dodecanol So-Jin Park a,∗ , Rak-Hyun Kwon a , Young-Yoon Choi b a b
Department of Chemical Engineering, Chungnam National University, 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea Minerals and Materials Processing Division, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Republic of Korea
a r t i c l e
i n f o
Article history: Received 29 January 2013 Received in revised form 14 October 2013 Accepted 17 October 2013 Available online 28 October 2013 Keywords: Solid–liquid equilibrium Excess property Alamine 336
a b s t r a c t The separation of the extractant from the diluent solution is a crucial step in the development of clean technologies. Solid–liquid equilibrium (SLE) is used to develop an energy-saving recycling process for extracting solvent. The SLE of the binary systems {Alamine 336 + decane}, {Alamine 336 + dodecane}, and {Alamine 336 + 1-dodecanol}, which were used as selective solvents, diluents, and modifiers in the extraction of molybdenum (Mo), was determined at atmospheric pressure by the visual method. The experimental SLE data have been correlated by the Non-Random Two-Liquid (NRTL) model. In addition, we determined the excess molar volume (VE ) and deviations in molar refractivity (R) for the same binary mixtures at 298.15 K and correlated them with the Redlich–Kister equation. © 2013 Elsevier B.V. All rights reserved.
1. Introduction Molybdenum (Mo) is a strategic metal, used in nuclear energy applications and for missile and aircraft parts, and it is valuable as a catalyst in the refining of petroleum. Recently, the use of Mo has steadily increased, and the development of an environmentally friendly and efficient extraction process for Mo is therefore desirable [1]. Solvent extraction is commonly used with liquids, but can also be employed for solids. Applications for the solvent extraction of Mo from acidic, aqueous solutions of raw ore include processes for recycling the extractant from the diluent solution, and this process is a crucial step in the development of clean technologies. Many methods have been developed for recycling used extractant solutions. Among them, a scalable practical approach is crystallization which is one of the key steps in recovering used solutions after extraction [2]. To design a crystallization process, reliable solid–liquid equilibrium (SLE) data for the system involved must be provided and represented in the form of a phase diagram. Alamine 336, a commercial solvent of Mo used in industry, is a mixture of straight-chain tertiary amines with 8–10 carbon atoms per chain that contains 0.00275 mol g−1 of active amines [3]. Long-chain alkanols or alkanes are widely used as modifiers and diluents in the Mo extraction process [4,5]. Therefore, to develop
∗ Corresponding author. Tel.: +82 42 821 5684; fax: +82 42 823 6414. E-mail address: [email protected] (S.-J. Park). 0378-3812/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.fluid.2013.10.041
a recycling process, SLE data for the following binary systems were determined at atmospheric pressure by the visual method: {Alamine 336 + decane}, {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol}. The experimental data were then correlated and compared with the results of the Non-Random Two-Liquid (NRTL) model [6]. The excess molar volume (VE ) and refractive index deviation (R) of the mixture properties were used to understand the molecular interactions of non-ideal systems and also to design a separation process. VE and R were determined for the same binary mixtures at 298.15 K and atmospheric pressure from the directly measured density and refractive indices. The determined binary VE and R data were correlated by the Redlich–Kister equation [7].
2. Experimental 2.1. Materials The origin of the chemicals was as follows: decane (Sigma–Aldrich, USA), dodecane (Tokyo Chemical Industry, Japan), and 1-dodecanol (Sigma–Aldrich, USA). The commercial solvent, Alamine 336 (Henkel Co., Germany), contains more than 99% tertiary amine. All of the reagents were used without further purification. Their purity was determined by gas-chromatographic analysis. As shown in Table 1, the melting point, density and refractive index of the chemicals were compared with values from the literature [8–14].
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
aij RMSD M R T x Tfus,i
131
parameters used in the NRTL equations root mean square deviation molar mass universal gas constant temperature (K) mole fraction melting temperature
Greek letters density (g cm3 ) nD refractive indices activity coefficient in the liquid phase st standard deviation ϕi volume fraction of component i Subscripts component i i j phase j experimental value exp cal calculated value
Fig. 1. Schematic diagram of the SLE experimental system.
2.2. Experimental apparatus and procedure A schematic diagram of the SLE experimental system is shown in Fig. 1. The SLE apparatus consisted of a triple-jacketed glass still, a cryostat and a temperature measuring system. The triple-jacket glass still is used so that the melting process can be observed visually. The exterior vacuum jacket of the glass still prevents water from the atmosphere from freezing on the glass surface at low temperatures, which would inhibit visual observation. The cryostat medium circulates through the center of this jacket to insulate the equilibrium cell from changes in the environment via the contact medium. In the equilibrium cell, a nitrogen atmosphere is used for dehumidification [15,16]. The SLE point (melting point of the crystal) of a given composition could be determined visually at the moment when the last crystal of the mixture disappeared. The temperature was determined with a platinum resistance thermometer, and a digital temperature readout box (ASL F250, UK). The overall uncertainty of the measurement was considered to be less than ±0.2 K, and the mole fraction was gravimetrically determined using an A&D microbalance (HA202, Japan) with an accuracy of ±1 × 10−5 g. The uncertainty in the mole fraction was estimated to be less than ±1 × 10−4 . To calculate VE in this study, the of pure solvents and binary mixtures was measured using a digital vibrating glass tube
densimeter (Anton Paar, model DMA 5000, Austria). According to the manufacturer’s specifications, the uncertainty of the measurement was less than ±5 × 10−6 g cm−3 for densities between 0 and 3 g cm−3 , and the accuracy of the temperature was ±0.01 K. The calibration and measurement procedures used in the present study have been previously described [17]. A digital precision refractometer (model RA-520N, KEM, Japan) was used to measure the nD of pure substances and mixtures, and R was obtained from the experimental nD data. According to the manufacturer, the uncertainty of the refractometer is ±5 × 10−5 and ±1 × 10−4 in the ranges of 1.32–1.40 and 1.40–1.58, respectively, and the accuracy of the temperature was ±5 × 10−2 K. The reproducibility of and nD measurement was checked periodically with double distilled water. In addition, the uncertainty was estimated to be <1 × 10−5 g cm−3 and 1 × 10−4 , respectively. The sample mixtures for the determination of and nD were prepared by adding 5 ml of each reagent into a vial using the aforementioned microbalance (A&D, HA202). 3. Results and discussion 3.1. Solid–liquid equilibrium The experimental SLE data for the three binary systems {Alamine 336 + decane}, {Alamine 336 + dodecane} and {Alamine
Table 1 Properties of the chemicals. Chemicals
Alamine 336 Decane Dodecane 1-Dodecanol
GC analysis (wt%)
>99.0 >99.0 >99.6 >99.5
Water content (wt%)
0.01 <0.01 <0.01 <0.01
Density/(g cm−3 ) at 298.15 K
Refractive index at 298.15 K
Tfus,i /K
Present study
Literature value
Present study
Literature value
Present study
Literature valueb
0.8114 0.7263 0.7457 0.8309
0.8111a 0.7262b 0.7455c 0.8308d
1.4490 1.4102 1.4195 1.4410
–
245.7 243.4 263.5 296.9
245.75 243.45 263.59 296.95
1.4097e 1.4192f 1.4420g
The uncertainty of the density was estimated to be less than ±5 × 10−6 g cm−3 and the accuracy of the temperature was ±0.01 K. The uncertainty of the refractometer was ±5 × 10−5 and ±1 × 10−4 in the range of 1.32–1.40 and 1.40–1.58, and the accuracy of the temperature was ±5 × 10−2 K. The uncertainty of the temperature is estimated to be ±0.2 K. a Ref. [8]. b Ref. [9]. c Ref. [10]. d Ref. [11]. e Ref. [12]. f Ref. [13]. g Ref. [14].
132
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
Fig. 2. SLE for the systems. (a) Alamine 336 (1) + decane (2); (b) Alamine 336 (1) + dodecane (2); (c) Alamine 336 (1) + 1-dodecanol (2); –, NRTL.
336 + 1-dodecanol} are given in Table 2. The experimental data were correlated with the NRTL model and displayed in Fig. 2. When a solid–solid phase transition does not occur within the considered temperature ranges, the SLE can be represented using a simplified form, such as Eq. (1) [18] ln(i xi ) = −
fus Hi R
1 1 − T Tfus,i
(1)
where xi is the mole fraction in the liquid phase, i is the activity coefficient in the liquid phase, fus Hi is the molar enthalpy of fusion, Tfus,i is the melting temperature, T is the absolute temperature, and R is the universal gas constant. The data are correlated with the NRTL model and the correlated NRTL model parameters are given in Table 3, along with the root-mean-square deviation (RMSD) between the experimental data and calculated values from the correlated parameters. The RMSD was <0.43 K for all of the systems, and it was determined according to Eq. (2)
RMSD =
1 (Texp − Tcal )2 n
(2)
(1) + 1-dodecanol (2)} are {x1 = 0.3790, T = 227.01 K}, {x1 = 0.8461, T = 244.97 K}, and {x1 = 0.9724, T = 245.43 K}, respectively. 3.2. Excess molar volumes and deviations in the molar refractivity and nD of the same binary systems used in the SLE determination were measured at 298.15 K using a digital vibrating tube densitometer and a precision digital refractometer, respectively. Subsequently, VE for the binary mixtures was calculated from the measured of pure substances and mixtures using Eq. (3)
E
3
V (cm mol
−1
xM i i i
)=
m
i
i
i
(3)
where xi , Mi and i are the mole fraction, molar mass and density of pure component i, respectively. m is the mixture density. R was also calculated from the molar refractivity (Rm ) values of each pure component and the mixture, which were derived from the measured and nD from Eq. (4) [19,20] R (cm3 mol−1 ) = Rm −
i Ri
(4)
i
As illustrated in Fig. 2, a single eutectic point was observed for all SLE systems. On the basis of the NRTL equation, the interpolated eutectic point for the systems {Alamine 336 (1) + decane (2)}, {Alamine 336 (1) + dodecane (2)} and {Alamine 336
Rm =
Ri =
Table 2 SLE data of binary systems. x1
T/K
x1
T/K
Alamine 336 (1) + decane (2)
0.0000 0.0500 0.1000 0.2000 0.3000 0.3800 0.4000
243.4 242.0 240.0 235.5 230.7 227.2 227.8
0.5000 0.6000 0.7000 0.8000 0.9000 0.9500 1.0000
232.5 236.0 238.9 241.7 243.9 244.8 245.7
0.0000 0.0500 0.1000 0.2000 0.3000 0.4000 0.5000
263.5 263.3 262.9 261.8 260.6 258.7 256.4
0.6000 0.7000 0.8000 0.8400 0.9000 0.9500 1.0000
253.9 250.7 246.9 245.2 245.4 245.5 245.7
0.0000 0.0500 0.1000 0.2000 0.3000 0.4000 0.5000
296.9 296.7 296.3 295.4 293.9 292.5 290.2
0.6000 0.7000 0.8000 0.9000 0.9500 0.9800 1.0000
287.3 283.3 275.6 263.9 254.1 245.5 245.7
The uncertainty of the temperature was estimated to be ±0.2 K. The uncertainty in the mole fraction was estimated to be less than ±1 × 10−4 .
ϕi =
n2D − 1
xM i i i
n2D,i − 1
x Vi
(5)
m
n2D + 1
n2D,i + 1
System
Alamine 336 (1) + 1-dodecanol (2)
x M i
n
Alamine 336 (1) + dodecane (2)
−
Mi i
(6)
i
(7)
xV j j j
where ϕi , nD , nD,i and Vi are the volume fraction of pure component i in the mixture, the refractive index of the mixture, and the refractive index and molar volume of pure component i, respectively [21]. The results of the determined VE and R data are reported in Table 4 for the binary mixtures {Alamine336 + decane}, {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol}. The determined VE and R data were correlated with the Redlich–Kister polynomial from Eq. (8) V E or R (cm3 mol−1 ) = x1 x2
n
Ai (xi − x2 )i−1
(8)
i=1
The standard deviation of the fits, st , is defined as
st (cm3 mol−1 ) =
2
((V E or R)cal − (V E or R)exp )i i (N − n)
1/2 (9)
where N is the number of experimental data points and n is the number of fitted parameters. In addition, the experimental VE and
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
133
Table 3 GE model parameter and RMSD between the calculated and experimental data. Model equation
System
Aij /(J mol−1 )
Aji /(J mol−1 )
˛
RMSD (K)
NRTL
Alamine 336 (1) + decane (2) Alamine 336 (1) + dodecane (2) Alamine 336 (1) + 1-dodecanol (2)
−421.5460 1065.0200 −717.9200
−344.3480 1205.8101 2150.6001
1.56 0.94 0.22
0.13 0.11 0.43
R results for the binary systems are listed in Table 5. These data are also plotted in Figs. 3 and 4, respectively. As illustrated in Fig. 3, the measured V E of the system {Alamine 336 + decane} showed negative deviations from ideal behavior for the entire concentration range examined. This could have been primarily caused by the association of Alamine 336. In contrast, the systems {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol} showed Table 4 Density, excess molar volume, refractive index and deviations in the molar refractivity of binary systems at 298.15 K. System
x1
/g cm−3
VE /cm3 mol−1
nD
R/cm3 mol−1
Alamine 336 (1) + decane (2)
0.0509
0.7306
−0.0008
1.4116
−0.0006
0.1004 0.2006 0.3002 0.4002 0.5000 0.6003 0.6997 0.7998 0.9002 0.9499
0.7348 0.7430 0.7512 0.7596 0.7679 0.7765 0.7849 0.7936 0.8025 0.8069
−0.0013 −0.0019 −0.0023 −0.0024 −0.0024 −0.0022 −0.0017 −0.0012 −0.0007 −0.0003
1.4134 1.4175 1.4218 1.4258 1.4295 1.4330 1.4366 1.4405 1.4448 1.4469
−0.0008 −0.0007 −0.0004 −0.0002 −0.0004 −0.0006 −0.0007 −0.0006 −0.0003 −0.0001
0.0500
0.7486
0.0003
1.4209
0.0001
0.1000 0.2000 0.3000 0.4300 0.5000 0.6000 0.7000 0.8000 0.8999 0.9500
0.7516 0.7579 0.7644 0.7729 0.7775 0.7841 0.7908 0.7975 0.8045 0.8080
0.0003 0.0002 −0.0001 −0.0004 −0.0004 −0.0004 −0.0003 −0.0002 −0.0001 −0.0001
1.4223 1.4251 1.4279 1.4317 1.4337 1.4368 1.4398 1.4428 1.4459 1.4475
0.0001 0.0000 −0.0001 −0.0002 −0.0003 −0.0002 −0.0001 −0.0001 0.0000 0.0000
0.0502
0.8296
0.0004
1.4416
0.0002
0.1000 0.2009 0.3003 0.4002 0.5000 0.6007 0.7000 0.8001 0.8999 0.9501
0.8286 0.8271 0.8258 0.8241 0.8223 0.8204 0.8184 0.8165 0.8144 0.8130
0.0004 −0.0003 −0.0011 −0.0016 −0.0018 −0.0018 −0.0018 −0.0018 −0.0015 −0.0009
1.4421 1.4431 1.4440 1.4449 1.4458 1.4466 1.4473 1.4480 1.4485 1.4487
0.0003 0.0001 −0.0001 −0.0002 −0.0002 −0.0002 −0.0002 −0.0003 −0.0003 −0.0003
Alamine 336 (1) + dodecane (2)
Alamine 336 (1) + 1-dodecanol (2)
The uncertainty of and nD was estimated to be <1 × 10−5 g cm−3 and 1 × 10−4 , respectively.
Fig. 3. VE (cm3 mol−1 ) of binary systems at 298.15 K: •, Alamine336 (1) + decane (2); , Alamine 336 + dodecane (2); , Alamine 336 (1) + 1-dodecanol (2). Solid curves were calculated from the Redlich–Kister parameters.
positive deviations in the non-polar long-chain hydrocarbon and heavy alcohol-rich region, whereas it showed a negative deviation in the Alamine 336-rich region. The measured R of all of the systems also showed results similar to those for VE , however, the system {Alamine 336 + decane} showed a type of ‘negative of W’. This may have been caused not only by differences in the molecular size and interaction but also by differences in the extent
Fig. 4. R (cm3 mol−1 ) of binary systems at 298.15 K: •, Alamine336 (1) + decane (2); , Alamine336 + dodecane (2); , Alamine336 (1) + 1-dodecanol (2). Solid curves were calculated from the Redlich–Kister parameters.
Table 5 Fitted Redlich–Kister parameters and standard deviations of mixtures containing Alamine336 (1), decane (2), dodecane (3) and 1-doecanol (4) at 298.15 K. Systems VE
R
Alamine 336 (1) + decane (2) Alamine 336 (1) + dodecane (3) Alamine 336 (1) + 1-dodecanol (4)
A1 −0.0095 −0.0018 −0.0074
A2 0.0027 −0.0004 −0.0014
A3 −0.0016 0.0048 0.0023
A4 0.0029 0.0047 0.0179
st 0.0001 <0.0001 <0.0001
Alamine 336 (1) + decane (2) Alamine 336 (1) + dodecane (3) Alamine 336 (1) + 1-dodecanol (4)
−0.0015 −0.0010 −0.0008
−0.0043 0.0002 0.0003
−0.0073 0.0018 0.0010
0.0129 0.0017 0.0073
<0.0001 <0.0001 <0.0001
134
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
and structure of the H-bonding [22]. The binary VE and R data were correlated relatively well with the Redlich–Kister equation and the standard deviations were <0.01% for all of these systems. 4. Conclusions The SLE data indicated that mixtures of {Alamine 336 + decane}, {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol} presented simple eutectic points. The SLE data correlated well with the NRTL activity coefficient model within the deviation of ca 0.4 K. VE and R for the systems {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol} showed positive and negative deviations from ideal behavior due to molecular interactions and the different structures involved. Otherwise the VE and R for the system {Alamine 336 + decane} showed a type of negative deviation from ideal behavior. The binary VE and R data correlated well with the Redlich–Kister equation. Acknowledgements This research was supported by the General Research Project of the Korea Institute of Geo-science and Mineral Resources (KIGAM), which is funded by the Ministry of Knowledge Economy of Korea.
References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
[14] [15] [16] [17] [18] [19] [20] [21] [22]
R.H. Kown, J.I. Kim, S.J. Park, Y.Y. Choi, Fluid Phase Equilib. 324 (2012) 44–49. B. Harjo, K.M. Ng, C. Wibowo, Ind. Eng. Chem. Res. 46 (2007) 2814–2822. H. Uslu, Fluid Phase Equilib. 253 (2007) 12–18. P.K. Parhi, K.H. Park, H.I. Kim, J.T. Park, Hydrometallurgy 105 (2011) 195–200. L. Zeng, C.Y. Cheng, Hydrometallurgy 101 (2010) 141–147. A.V. Hof, M.L. Japas, C.J. Peters, Fluid Phase Equilib. 192 (2001) 27–48. O. Redlich, A.T. Kister, Ind. Eng. Chem. Res. 40 (1948) 345–348. E.C. Mercedes, M. José, Hydrometallurgy 61 (2001) 89–95. Dortmund Data Bank Software Package (DDBSP), Version 2006 Professional. Available from: http://www.ddbst.de J.L.E. Chevalier, P.J. Petrlno, Y.H. Gaston-Bonhomme, J. Chem. Eng. Data 35 (1990) 206–212. S¸. I˙ smail Kırbas¸lar, J. Chem. Thermodyn. 38 (2006) 696–700. T.E. Daubert, R.P. Danner, Data Compilation, Taylor and Francis, Bristol, PA, 1989. J.A. Riddick, W.B. Bunger, T.K. Sakano, Techniques of chemistry, organic solvents Physical Properties and Methods of Purifications, vol. II, John Wiley & Sons, New York, 1986. N.V. Sastry, M.K. Valand, J. Chem. Eng. Data 43 (1998) 152–157. J.I. Kim, S.J. Park, S.B. Kim, Fluid Phase Equilib. 295 (2010) 172–176. J.I. Kim, Y.Y. Choi, S.J. Park, J. Chem. Eng. Data 55 (2010) 1179–1185. T. Mathuni, J.I. Kim, S.J. Park, J. Chem. Eng. Data 56 (2011) 89–96. A. Jakob, R. Joh, C. Rose, J. Gmehling, Fluid Phase Equilib. 113 (1995) 117–126. T.M. Aminabhavi, B. Golalakrishina, J. Chem. Eng. Data 40 (1995) 856–861. A.H. Al-Dujaili, A.A. Yassen, A.M. Awwad, J. Chem. Eng. Data 45 (2000) 647–649. H.Y. Kwak, J.H. Oh, S.J. Park, K.Y. Paek, Fluid Phase Equilib. 262 (2007) 161–168. R.K. Biswas, H.P. Singha, J. Mol. Liquids 135 (2007) 179–187.
Contents lists available at ScienceDirect
Fluid Phase Equilibria journal homepage: www.elsevier.com/locate/fluid
Solid–liquid equilibrium and mixture properties for the binary systems of Alamine 336 with decane, dodecane, and 1-dodecanol So-Jin Park a,∗ , Rak-Hyun Kwon a , Young-Yoon Choi b a b
Department of Chemical Engineering, Chungnam National University, 220 Gung-Dong, Yuseong-Gu, Daejeon 305-764, Republic of Korea Minerals and Materials Processing Division, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Republic of Korea
a r t i c l e
i n f o
Article history: Received 29 January 2013 Received in revised form 14 October 2013 Accepted 17 October 2013 Available online 28 October 2013 Keywords: Solid–liquid equilibrium Excess property Alamine 336
a b s t r a c t The separation of the extractant from the diluent solution is a crucial step in the development of clean technologies. Solid–liquid equilibrium (SLE) is used to develop an energy-saving recycling process for extracting solvent. The SLE of the binary systems {Alamine 336 + decane}, {Alamine 336 + dodecane}, and {Alamine 336 + 1-dodecanol}, which were used as selective solvents, diluents, and modifiers in the extraction of molybdenum (Mo), was determined at atmospheric pressure by the visual method. The experimental SLE data have been correlated by the Non-Random Two-Liquid (NRTL) model. In addition, we determined the excess molar volume (VE ) and deviations in molar refractivity (R) for the same binary mixtures at 298.15 K and correlated them with the Redlich–Kister equation. © 2013 Elsevier B.V. All rights reserved.
1. Introduction Molybdenum (Mo) is a strategic metal, used in nuclear energy applications and for missile and aircraft parts, and it is valuable as a catalyst in the refining of petroleum. Recently, the use of Mo has steadily increased, and the development of an environmentally friendly and efficient extraction process for Mo is therefore desirable [1]. Solvent extraction is commonly used with liquids, but can also be employed for solids. Applications for the solvent extraction of Mo from acidic, aqueous solutions of raw ore include processes for recycling the extractant from the diluent solution, and this process is a crucial step in the development of clean technologies. Many methods have been developed for recycling used extractant solutions. Among them, a scalable practical approach is crystallization which is one of the key steps in recovering used solutions after extraction [2]. To design a crystallization process, reliable solid–liquid equilibrium (SLE) data for the system involved must be provided and represented in the form of a phase diagram. Alamine 336, a commercial solvent of Mo used in industry, is a mixture of straight-chain tertiary amines with 8–10 carbon atoms per chain that contains 0.00275 mol g−1 of active amines [3]. Long-chain alkanols or alkanes are widely used as modifiers and diluents in the Mo extraction process [4,5]. Therefore, to develop
∗ Corresponding author. Tel.: +82 42 821 5684; fax: +82 42 823 6414. E-mail address: [email protected] (S.-J. Park). 0378-3812/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.fluid.2013.10.041
a recycling process, SLE data for the following binary systems were determined at atmospheric pressure by the visual method: {Alamine 336 + decane}, {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol}. The experimental data were then correlated and compared with the results of the Non-Random Two-Liquid (NRTL) model [6]. The excess molar volume (VE ) and refractive index deviation (R) of the mixture properties were used to understand the molecular interactions of non-ideal systems and also to design a separation process. VE and R were determined for the same binary mixtures at 298.15 K and atmospheric pressure from the directly measured density and refractive indices. The determined binary VE and R data were correlated by the Redlich–Kister equation [7].
2. Experimental 2.1. Materials The origin of the chemicals was as follows: decane (Sigma–Aldrich, USA), dodecane (Tokyo Chemical Industry, Japan), and 1-dodecanol (Sigma–Aldrich, USA). The commercial solvent, Alamine 336 (Henkel Co., Germany), contains more than 99% tertiary amine. All of the reagents were used without further purification. Their purity was determined by gas-chromatographic analysis. As shown in Table 1, the melting point, density and refractive index of the chemicals were compared with values from the literature [8–14].
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
aij RMSD M R T x Tfus,i
131
parameters used in the NRTL equations root mean square deviation molar mass universal gas constant temperature (K) mole fraction melting temperature
Greek letters density (g cm3 ) nD refractive indices activity coefficient in the liquid phase st standard deviation ϕi volume fraction of component i Subscripts component i i j phase j experimental value exp cal calculated value
Fig. 1. Schematic diagram of the SLE experimental system.
2.2. Experimental apparatus and procedure A schematic diagram of the SLE experimental system is shown in Fig. 1. The SLE apparatus consisted of a triple-jacketed glass still, a cryostat and a temperature measuring system. The triple-jacket glass still is used so that the melting process can be observed visually. The exterior vacuum jacket of the glass still prevents water from the atmosphere from freezing on the glass surface at low temperatures, which would inhibit visual observation. The cryostat medium circulates through the center of this jacket to insulate the equilibrium cell from changes in the environment via the contact medium. In the equilibrium cell, a nitrogen atmosphere is used for dehumidification [15,16]. The SLE point (melting point of the crystal) of a given composition could be determined visually at the moment when the last crystal of the mixture disappeared. The temperature was determined with a platinum resistance thermometer, and a digital temperature readout box (ASL F250, UK). The overall uncertainty of the measurement was considered to be less than ±0.2 K, and the mole fraction was gravimetrically determined using an A&D microbalance (HA202, Japan) with an accuracy of ±1 × 10−5 g. The uncertainty in the mole fraction was estimated to be less than ±1 × 10−4 . To calculate VE in this study, the of pure solvents and binary mixtures was measured using a digital vibrating glass tube
densimeter (Anton Paar, model DMA 5000, Austria). According to the manufacturer’s specifications, the uncertainty of the measurement was less than ±5 × 10−6 g cm−3 for densities between 0 and 3 g cm−3 , and the accuracy of the temperature was ±0.01 K. The calibration and measurement procedures used in the present study have been previously described [17]. A digital precision refractometer (model RA-520N, KEM, Japan) was used to measure the nD of pure substances and mixtures, and R was obtained from the experimental nD data. According to the manufacturer, the uncertainty of the refractometer is ±5 × 10−5 and ±1 × 10−4 in the ranges of 1.32–1.40 and 1.40–1.58, respectively, and the accuracy of the temperature was ±5 × 10−2 K. The reproducibility of and nD measurement was checked periodically with double distilled water. In addition, the uncertainty was estimated to be <1 × 10−5 g cm−3 and 1 × 10−4 , respectively. The sample mixtures for the determination of and nD were prepared by adding 5 ml of each reagent into a vial using the aforementioned microbalance (A&D, HA202). 3. Results and discussion 3.1. Solid–liquid equilibrium The experimental SLE data for the three binary systems {Alamine 336 + decane}, {Alamine 336 + dodecane} and {Alamine
Table 1 Properties of the chemicals. Chemicals
Alamine 336 Decane Dodecane 1-Dodecanol
GC analysis (wt%)
>99.0 >99.0 >99.6 >99.5
Water content (wt%)
0.01 <0.01 <0.01 <0.01
Density/(g cm−3 ) at 298.15 K
Refractive index at 298.15 K
Tfus,i /K
Present study
Literature value
Present study
Literature value
Present study
Literature valueb
0.8114 0.7263 0.7457 0.8309
0.8111a 0.7262b 0.7455c 0.8308d
1.4490 1.4102 1.4195 1.4410
–
245.7 243.4 263.5 296.9
245.75 243.45 263.59 296.95
1.4097e 1.4192f 1.4420g
The uncertainty of the density was estimated to be less than ±5 × 10−6 g cm−3 and the accuracy of the temperature was ±0.01 K. The uncertainty of the refractometer was ±5 × 10−5 and ±1 × 10−4 in the range of 1.32–1.40 and 1.40–1.58, and the accuracy of the temperature was ±5 × 10−2 K. The uncertainty of the temperature is estimated to be ±0.2 K. a Ref. [8]. b Ref. [9]. c Ref. [10]. d Ref. [11]. e Ref. [12]. f Ref. [13]. g Ref. [14].
132
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
Fig. 2. SLE for the systems. (a) Alamine 336 (1) + decane (2); (b) Alamine 336 (1) + dodecane (2); (c) Alamine 336 (1) + 1-dodecanol (2); –, NRTL.
336 + 1-dodecanol} are given in Table 2. The experimental data were correlated with the NRTL model and displayed in Fig. 2. When a solid–solid phase transition does not occur within the considered temperature ranges, the SLE can be represented using a simplified form, such as Eq. (1) [18] ln(i xi ) = −
fus Hi R
1 1 − T Tfus,i
(1)
where xi is the mole fraction in the liquid phase, i is the activity coefficient in the liquid phase, fus Hi is the molar enthalpy of fusion, Tfus,i is the melting temperature, T is the absolute temperature, and R is the universal gas constant. The data are correlated with the NRTL model and the correlated NRTL model parameters are given in Table 3, along with the root-mean-square deviation (RMSD) between the experimental data and calculated values from the correlated parameters. The RMSD was <0.43 K for all of the systems, and it was determined according to Eq. (2)
RMSD =
1 (Texp − Tcal )2 n
(2)
(1) + 1-dodecanol (2)} are {x1 = 0.3790, T = 227.01 K}, {x1 = 0.8461, T = 244.97 K}, and {x1 = 0.9724, T = 245.43 K}, respectively. 3.2. Excess molar volumes and deviations in the molar refractivity and nD of the same binary systems used in the SLE determination were measured at 298.15 K using a digital vibrating tube densitometer and a precision digital refractometer, respectively. Subsequently, VE for the binary mixtures was calculated from the measured of pure substances and mixtures using Eq. (3)
E
3
V (cm mol
−1
xM i i i
)=
m
i
i
i
(3)
where xi , Mi and i are the mole fraction, molar mass and density of pure component i, respectively. m is the mixture density. R was also calculated from the molar refractivity (Rm ) values of each pure component and the mixture, which were derived from the measured and nD from Eq. (4) [19,20] R (cm3 mol−1 ) = Rm −
i Ri
(4)
i
As illustrated in Fig. 2, a single eutectic point was observed for all SLE systems. On the basis of the NRTL equation, the interpolated eutectic point for the systems {Alamine 336 (1) + decane (2)}, {Alamine 336 (1) + dodecane (2)} and {Alamine 336
Rm =
Ri =
Table 2 SLE data of binary systems. x1
T/K
x1
T/K
Alamine 336 (1) + decane (2)
0.0000 0.0500 0.1000 0.2000 0.3000 0.3800 0.4000
243.4 242.0 240.0 235.5 230.7 227.2 227.8
0.5000 0.6000 0.7000 0.8000 0.9000 0.9500 1.0000
232.5 236.0 238.9 241.7 243.9 244.8 245.7
0.0000 0.0500 0.1000 0.2000 0.3000 0.4000 0.5000
263.5 263.3 262.9 261.8 260.6 258.7 256.4
0.6000 0.7000 0.8000 0.8400 0.9000 0.9500 1.0000
253.9 250.7 246.9 245.2 245.4 245.5 245.7
0.0000 0.0500 0.1000 0.2000 0.3000 0.4000 0.5000
296.9 296.7 296.3 295.4 293.9 292.5 290.2
0.6000 0.7000 0.8000 0.9000 0.9500 0.9800 1.0000
287.3 283.3 275.6 263.9 254.1 245.5 245.7
The uncertainty of the temperature was estimated to be ±0.2 K. The uncertainty in the mole fraction was estimated to be less than ±1 × 10−4 .
ϕi =
n2D − 1
xM i i i
n2D,i − 1
x Vi
(5)
m
n2D + 1
n2D,i + 1
System
Alamine 336 (1) + 1-dodecanol (2)
x M i
n
Alamine 336 (1) + dodecane (2)
−
Mi i
(6)
i
(7)
xV j j j
where ϕi , nD , nD,i and Vi are the volume fraction of pure component i in the mixture, the refractive index of the mixture, and the refractive index and molar volume of pure component i, respectively [21]. The results of the determined VE and R data are reported in Table 4 for the binary mixtures {Alamine336 + decane}, {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol}. The determined VE and R data were correlated with the Redlich–Kister polynomial from Eq. (8) V E or R (cm3 mol−1 ) = x1 x2
n
Ai (xi − x2 )i−1
(8)
i=1
The standard deviation of the fits, st , is defined as
st (cm3 mol−1 ) =
2
((V E or R)cal − (V E or R)exp )i i (N − n)
1/2 (9)
where N is the number of experimental data points and n is the number of fitted parameters. In addition, the experimental VE and
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
133
Table 3 GE model parameter and RMSD between the calculated and experimental data. Model equation
System
Aij /(J mol−1 )
Aji /(J mol−1 )
˛
RMSD (K)
NRTL
Alamine 336 (1) + decane (2) Alamine 336 (1) + dodecane (2) Alamine 336 (1) + 1-dodecanol (2)
−421.5460 1065.0200 −717.9200
−344.3480 1205.8101 2150.6001
1.56 0.94 0.22
0.13 0.11 0.43
R results for the binary systems are listed in Table 5. These data are also plotted in Figs. 3 and 4, respectively. As illustrated in Fig. 3, the measured V E of the system {Alamine 336 + decane} showed negative deviations from ideal behavior for the entire concentration range examined. This could have been primarily caused by the association of Alamine 336. In contrast, the systems {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol} showed Table 4 Density, excess molar volume, refractive index and deviations in the molar refractivity of binary systems at 298.15 K. System
x1
/g cm−3
VE /cm3 mol−1
nD
R/cm3 mol−1
Alamine 336 (1) + decane (2)
0.0509
0.7306
−0.0008
1.4116
−0.0006
0.1004 0.2006 0.3002 0.4002 0.5000 0.6003 0.6997 0.7998 0.9002 0.9499
0.7348 0.7430 0.7512 0.7596 0.7679 0.7765 0.7849 0.7936 0.8025 0.8069
−0.0013 −0.0019 −0.0023 −0.0024 −0.0024 −0.0022 −0.0017 −0.0012 −0.0007 −0.0003
1.4134 1.4175 1.4218 1.4258 1.4295 1.4330 1.4366 1.4405 1.4448 1.4469
−0.0008 −0.0007 −0.0004 −0.0002 −0.0004 −0.0006 −0.0007 −0.0006 −0.0003 −0.0001
0.0500
0.7486
0.0003
1.4209
0.0001
0.1000 0.2000 0.3000 0.4300 0.5000 0.6000 0.7000 0.8000 0.8999 0.9500
0.7516 0.7579 0.7644 0.7729 0.7775 0.7841 0.7908 0.7975 0.8045 0.8080
0.0003 0.0002 −0.0001 −0.0004 −0.0004 −0.0004 −0.0003 −0.0002 −0.0001 −0.0001
1.4223 1.4251 1.4279 1.4317 1.4337 1.4368 1.4398 1.4428 1.4459 1.4475
0.0001 0.0000 −0.0001 −0.0002 −0.0003 −0.0002 −0.0001 −0.0001 0.0000 0.0000
0.0502
0.8296
0.0004
1.4416
0.0002
0.1000 0.2009 0.3003 0.4002 0.5000 0.6007 0.7000 0.8001 0.8999 0.9501
0.8286 0.8271 0.8258 0.8241 0.8223 0.8204 0.8184 0.8165 0.8144 0.8130
0.0004 −0.0003 −0.0011 −0.0016 −0.0018 −0.0018 −0.0018 −0.0018 −0.0015 −0.0009
1.4421 1.4431 1.4440 1.4449 1.4458 1.4466 1.4473 1.4480 1.4485 1.4487
0.0003 0.0001 −0.0001 −0.0002 −0.0002 −0.0002 −0.0002 −0.0003 −0.0003 −0.0003
Alamine 336 (1) + dodecane (2)
Alamine 336 (1) + 1-dodecanol (2)
The uncertainty of and nD was estimated to be <1 × 10−5 g cm−3 and 1 × 10−4 , respectively.
Fig. 3. VE (cm3 mol−1 ) of binary systems at 298.15 K: •, Alamine336 (1) + decane (2); , Alamine 336 + dodecane (2); , Alamine 336 (1) + 1-dodecanol (2). Solid curves were calculated from the Redlich–Kister parameters.
positive deviations in the non-polar long-chain hydrocarbon and heavy alcohol-rich region, whereas it showed a negative deviation in the Alamine 336-rich region. The measured R of all of the systems also showed results similar to those for VE , however, the system {Alamine 336 + decane} showed a type of ‘negative of W’. This may have been caused not only by differences in the molecular size and interaction but also by differences in the extent
Fig. 4. R (cm3 mol−1 ) of binary systems at 298.15 K: •, Alamine336 (1) + decane (2); , Alamine336 + dodecane (2); , Alamine336 (1) + 1-dodecanol (2). Solid curves were calculated from the Redlich–Kister parameters.
Table 5 Fitted Redlich–Kister parameters and standard deviations of mixtures containing Alamine336 (1), decane (2), dodecane (3) and 1-doecanol (4) at 298.15 K. Systems VE
R
Alamine 336 (1) + decane (2) Alamine 336 (1) + dodecane (3) Alamine 336 (1) + 1-dodecanol (4)
A1 −0.0095 −0.0018 −0.0074
A2 0.0027 −0.0004 −0.0014
A3 −0.0016 0.0048 0.0023
A4 0.0029 0.0047 0.0179
st 0.0001 <0.0001 <0.0001
Alamine 336 (1) + decane (2) Alamine 336 (1) + dodecane (3) Alamine 336 (1) + 1-dodecanol (4)
−0.0015 −0.0010 −0.0008
−0.0043 0.0002 0.0003
−0.0073 0.0018 0.0010
0.0129 0.0017 0.0073
<0.0001 <0.0001 <0.0001
134
S.-J. Park et al. / Fluid Phase Equilibria 361 (2014) 130–134
and structure of the H-bonding [22]. The binary VE and R data were correlated relatively well with the Redlich–Kister equation and the standard deviations were <0.01% for all of these systems. 4. Conclusions The SLE data indicated that mixtures of {Alamine 336 + decane}, {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol} presented simple eutectic points. The SLE data correlated well with the NRTL activity coefficient model within the deviation of ca 0.4 K. VE and R for the systems {Alamine 336 + dodecane} and {Alamine 336 + 1-dodecanol} showed positive and negative deviations from ideal behavior due to molecular interactions and the different structures involved. Otherwise the VE and R for the system {Alamine 336 + decane} showed a type of negative deviation from ideal behavior. The binary VE and R data correlated well with the Redlich–Kister equation. Acknowledgements This research was supported by the General Research Project of the Korea Institute of Geo-science and Mineral Resources (KIGAM), which is funded by the Ministry of Knowledge Economy of Korea.
References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
[14] [15] [16] [17] [18] [19] [20] [21] [22]
R.H. Kown, J.I. Kim, S.J. Park, Y.Y. Choi, Fluid Phase Equilib. 324 (2012) 44–49. B. Harjo, K.M. Ng, C. Wibowo, Ind. Eng. Chem. Res. 46 (2007) 2814–2822. H. Uslu, Fluid Phase Equilib. 253 (2007) 12–18. P.K. Parhi, K.H. Park, H.I. Kim, J.T. Park, Hydrometallurgy 105 (2011) 195–200. L. Zeng, C.Y. Cheng, Hydrometallurgy 101 (2010) 141–147. A.V. Hof, M.L. Japas, C.J. Peters, Fluid Phase Equilib. 192 (2001) 27–48. O. Redlich, A.T. Kister, Ind. Eng. Chem. Res. 40 (1948) 345–348. E.C. Mercedes, M. José, Hydrometallurgy 61 (2001) 89–95. Dortmund Data Bank Software Package (DDBSP), Version 2006 Professional. Available from: http://www.ddbst.de J.L.E. Chevalier, P.J. Petrlno, Y.H. Gaston-Bonhomme, J. Chem. Eng. Data 35 (1990) 206–212. S¸. I˙ smail Kırbas¸lar, J. Chem. Thermodyn. 38 (2006) 696–700. T.E. Daubert, R.P. Danner, Data Compilation, Taylor and Francis, Bristol, PA, 1989. J.A. Riddick, W.B. Bunger, T.K. Sakano, Techniques of chemistry, organic solvents Physical Properties and Methods of Purifications, vol. II, John Wiley & Sons, New York, 1986. N.V. Sastry, M.K. Valand, J. Chem. Eng. Data 43 (1998) 152–157. J.I. Kim, S.J. Park, S.B. Kim, Fluid Phase Equilib. 295 (2010) 172–176. J.I. Kim, Y.Y. Choi, S.J. Park, J. Chem. Eng. Data 55 (2010) 1179–1185. T. Mathuni, J.I. Kim, S.J. Park, J. Chem. Eng. Data 56 (2011) 89–96. A. Jakob, R. Joh, C. Rose, J. Gmehling, Fluid Phase Equilib. 113 (1995) 117–126. T.M. Aminabhavi, B. Golalakrishina, J. Chem. Eng. Data 40 (1995) 856–861. A.H. Al-Dujaili, A.A. Yassen, A.M. Awwad, J. Chem. Eng. Data 45 (2000) 647–649. H.Y. Kwak, J.H. Oh, S.J. Park, K.Y. Paek, Fluid Phase Equilib. 262 (2007) 161–168. R.K. Biswas, H.P. Singha, J. Mol. Liquids 135 (2007) 179–187.