Article pubs.acs.org/jced
High-Pressure Phase Behavior of Heptadecafluoro-1-decene and Nonafluoro-1-hexene in Supercritical Carbon Dioxide Dong Woo Cho,† Jungin Shin,‡ Won Bae,§ Hwayong Kim,*,† and Kyung Won Seo*,∥ †
School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, 559 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Republic of Korea ‡ Advanced R&D Center, LS Cable Ltd., 555, Hogye-Dong, Dongan-Gu, Anyang-Si, Gyeonggi, 431-831, Republic of Korea § R&D Institute, Miwon Specialty Chemical Co., Ltd., 405-3, Moknae-Dong, Ansan-Si, Gyeonggi, 425-100, Republic of Korea ∥ Department of Chemical Engineering, Division of Chemical Engineering and Materials Engineering, Ajou University, Wonchun-Dong, Yeongtong-Gu, Suwon, 443-749, Republic of Korea ABSTRACT: High-pressure phase behavior measurements of (CO2 + heptadecafluoro-1-decene) and (CO2 + nonafluoro1-hexene) binary mixture systems were carried out using a variable volume view cell. The experimental range of temperature and pressure are from 313.2 K to 343.2 K and up to 15 MPa, respectively. The correlation was performed using the Peng−Robinson equation of state and the van der Waals onefluid mixing rule. The critical constants, Tc and Pc, were estimated by the several group contribution methods. The acentric factor was estimated by the Lee−Kesler method.
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INTRODUCTION Fluorochemicals such as perfluoroalkenes and their derivatives have attracted research attention due to their specific and unusual properties.1 Fluorochemicals have relatively short and strong carbon−fluorine bonds. Carbon−fluorine bonds induce the saturation of bonding sites and protect organic molecules with fluorine from chemical attack. In the case of perfluoroalkenes and their derivatives, the chemical structure and weak intermolecular interaction induce various interesting and unique properties.1,2 Therefore, the novel properties of perfluorinated substances have been applied to a wide range of products and applications.3,4 The fluorinated or chlorinated solvents that have been used to synthesize per-fluorinated substances have been subjected to environmental regulation because of their high toxicity, environmental pollution, and the difficulty of waste treatment. The consequent need for new solvents for synthesis has led to the proposal of supercritical CO2 (scCO2) as a viable replacement for conventional organic, fluorinated, and chlorinated solvents because CO2 is not toxic, flammable, and expensive. Supercritical CO2 has a very low dielectric constant,5 a low polarizability per volume,6 and a strong quadrupole moment.7,8 These chemicophysical properties affect the solvent property. In general, supercritical CO2 is a suitable solvent for small molecules but a poor one for most large molecules and polymers with the exception of a few polymers, such as amorphous fluoro-polymers and polysiloxane.9 For the design and operation of the scCO2 process, the highpressure phase behavior measurement data of the mixture containing scCO2 are necessary. In the present study, the highpressure phase behavior measurement of CO2 + perfluoro © 2012 American Chemical Society
Figure 1. Chemical structure of (a) PFDecene and (b) PFHexene.
alkene binary systems, (CO2 + heptadecafluoro-1-decene (PFDecene)) and (CO2 + nonafluoro-1-hexene (PFHexene)), was conducted using the static method with a variable volume view cell (VVVC). The phase transition phenomena (the bubble point, critical point, and dew point) were observed at temperatures ranging from 313.2 K to 343.2 K. The correlation of these experimental data were conducted with the Peng− Robinson equation of state (PR-EOS)10 using the van der Waals Received: January 11, 2012 Accepted: April 18, 2012 Published: May 14, 2012 1745
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Table 3. Experimental Data for the CO2 + PFDecene System p/MPa
CO2 mole fraction
4.62 5.10 5.47 5.87 6.33 7.01 7.63 8.43 9.20 9.77 10.27 10.50
0.590 0.639 0.676 0.709 0.728 0.769 0.796 0.831 0.874 0.911 0.947 0.982
4.02 4.16 4.63 4.99 5.83 6.27 6.86 7.37 7.98 8.88 9.56 9.76
0.586 0.590 0.639 0.676 0.739 0.769 0.813 0.831 0.874 0.911 0.947 0.982
3.62 4.16 4.53 5.05 5.64 6.03 6.99 7.58 8.57 8.68
0.590 0.639 0.676 0.728 0.769 0.813 0.874 0.911 0.947 0.982
2.53 2.87 3.12 3.53 3.92 4.49 4.97 5.29 5.77 6.17 6.95 7.49 7.63
0.532 0.586 0.590 0.639 0.676 0.728 0.769 0.796 0.845 0.874 0.911 0.947 0.982
transitiona
σPb
BP BP BP BP BP BP BP BP BP BP CP DP
0.05 0.02 0.03 0.03 0.01 0.03 0.02 0.02 0.05 0.01 0.03 0.02
BP BP BP BP BP BP BP BP BP BP DP DP
0.01 0.01 0.02 0.03 0.01 0.02 0.04 0.02 0.01 0.02 0.03 0.03
BP BP BP BP BP BP BP BP BP DP
0.03 0.01 0.00 0.01 0.01 0.05 0.03 0.02 0.03 0.02
BP BP BP BP BP BP BP BP BP BP BP BP DP
0.02 0.02 0.02 0.02 0.02 0.02 0.00 0.05 0.05 0.01 0.01 0.01 0.05
T = 343.2 K
T = 333.2 K
T = 323.2 K
Figure 2. Pressure−composition (P−x) isotherms for (a) CO2 + PFDecene and (b) CO2 + PFHexene binary systems: ●, T = 342.2 K; ○, T = 333.2 K; ▼, T = 323.2 K; △, T = 313.2 K.
Table 1. Sample Descriptions chemical name PFDecene PFHexene CO2 a
initial mole fraction purification purity method
source Aldrich Aldrich Korea Industrial Gases
0.99 0.99 0.99999
none
final mole fraction purity 0.99 0.99 0.99999
analysis method GCa GCa
T = 313.2 K
Gas chromatography.
Table 2. Critical Constants and Acentric Factors for PR-EOS Tb/K component CO2 PFDecene
PFHexene
experiment 420.7
332.7
estimation
Tc/K
Pc/MPa
ω
remark
386.6 455.2 407.7 437.8 313.9 334.9 325.0 364.2
304.2 546.2 558.8 539.6 560.3 470.6 475.3 460.5 497.2
7.38 1.32 1.50 1.62 1.76 2.31 2.36 2.45 2.70
0.225 0.640 0.553 0.881 0.630 0.411 0.373 0.557 0.234
a b c d e b c d e
a BP: boiling point, CP: critical point, DP: dew point. bStandard deviation of pressure (σP), σP = ((∑nk=1(Pk − Paver)2)/n)1/2 where n is the number of measurements at each data point.
one-fluid mixing rule (vdW1). The critical constants for PR-EOS, critical temperature (Tc), and critical pressure (Pc), were obtained from the following four different group contribution methods, the Joback method,11 modified Joback method,9 Constantinou− Gani method (C-G method),12 and Nannoolal−Rarey method
a
The Properties of Gases and Liquids, 4th ed.20 bJoback and Lee−Kesler methods.14,16 cModified Joback and Lee−Kesler methods. 9,14 d Constantinou−Gani and Lee−Kesler methods.12,14 eNannoolal− Rarey and Lee−Kesler methods.14,17 1746
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Table 4. Experimental Data for the CO2 + PFHexene System p/MPa
CO2 mole fraction
5.09 5.52 5.67 6.18 6.67 6.94 7.45 8.46 9.70 12.50 13.99 13.36 12.91 12.30
0.595 0.620 0.651 0.708 0.732 0.763 0.803 0.826 0.865 0.892 0.915 0.930 0.948 0.970
4.38 4.78 4.82 5.43 5.85 6.21 6.55 7.06 7.46 10.21 11.66 11.27 10.53 10.23 3.71
0.595 0.620 0.647 0.708 0.732 0.763 0.803 0.844 0.865 0.892 0.915 0.930 0.948 0.970 0.595
transitiona
σPb
p/MPa
CO2 mole fraction
BP BP BP BP BP BP BP BP BP BP DP DP DP DP
0.01 0.03 0.02 0.04 0.02 0.02 0.04 0.01 0.03 0.05 0.01 0.05 0.05 0.03
4.14 4.54 4.73 5.05 5.26 5.47 5.53 6.06 6.53 7.93 9.14 8.60 8.43 7.72
0.620 0.661 0.708 0.732 0.763 0.803 0.807 0.844 0.865 0.892 0.915 0.930 0.948 0.970
BP BP BP BP BP BP BP BP BP BP DP DP DP DP BP
0.01 0.01 0.02 0.01 0.01 0.01 0.04 0.05 0.01 0.02 0.03 0.00 0.04 0.02 0.01
3.14 3.44 3.84 3.90 4.35 4.52 4.55 5.07 5.39 5.71 5.94 6.04 7.14 7.36 7.80
0.595 0.620 0.661 0.708 0.732 0.763 0.799 0.844 0.865 0.899 0.908 0.915 0.930 0.948 0.970
T = 343.2 K
transitiona
σPb
BP BP BP BP BP BP BP BP BP BP DP DP DP DP
0.01 0.01 0.05 0.02 0.01 0.02 0.01 0.03 0.05 0.02 0.01 0.05 0.02 0.04
BP BP BP BP BP BP BP BP BP BP BP BP BP BP DP
0.02 0.02 0.02 0.01 0.04 0.01 0.05 0.03 0.00 0.01 0.00 0.01 0.01 0.00 0.03
T = 333.2 K
T = 333.2 K
T = 313.2 K
BP: boiling point, CP: critical point, DP: dew point. bStandard deviation of pressure (σP), σP = ((∑nk=1(Pk − Paver)2)/n)1/2 where n is the number of measurements at each data point. a
(N-R method).13 The acentric factor was estimated using the Lee−Kesler method (L-K method).14
Table 5. Calculation Results with PR-EOS for the Two CO2 + Perfluoroalkene Systems
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kij
model
EXPERIMENTAL SECTION AND CORRELATION Materials. 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadecafluoro-1-decene (PFDecene) [min. 99 mol %, CAS No. 21652-58-4] and 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene (PFHexene) [min. 99 mol %, CAS No. 19430-93-4] were obtained from Aldrich. CO2 (min. 99.999 mol %) was acquired from Korea Industrial Gases. The purity verification was tested. The chemicals were used without further purification. Table 1 shows the description of samples. Figure 1 shows the chemical structure of PFHexene and PFDecene. Apparatus and Procedure. The observation of phase transition was conducted using a VVVC apparatus as described elsewhere.9 The detailed experimental procedure was explained in a previous study.9 The combined expanded uncertainties of CO2 mole fraction were estimated at ± 0.00089 (coverage factor, k = 2).15 The mixture in the cell was compressed to the desired operation pressure using a high-pressure generator (High-Pressure Equipment Co., model 62-6-10). The pressure was measured by a digital pressure transducer (Paroscientific Inc., model 43KR-HHT-101, accurate to 0.01 % of reading) and a pressure
Jobacka modified Jobackb C-Gc N-Rd Jobacka modified Jobackb C-Gc N-Rd
CO2 + PFDecene System −0.0175 −0.0363 −0.055 −0.0557 CO2 + PFHexene System −0.0651 −0.0627 −0.0736 −0.092
AADP/%e 5.12 3.47 3.35 3.37 9.86 9.86 9.82 9.77
a
Joback and L-K methods.14,16 bModified Joback and L-K methods.9,14 C-G and L-K methods.12,14 dN-R and L-K methods.14,17 eThe absolute average deviation of pressure (AADP) percent for the correlation is as follows: c
AADP(%) =
1 Nexp
Nexp
∑ i
Piexp − Pical ·100 Piexp
where N is the number of experimental data points. Pexp and Pcal i i are the experimental and calculated pressures, respectively. 1747
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Figure 3. Results correlated with PR-EOS using (a) Joback, (b) modified Joback, (c) Constantinou−Gani, and (d) Nannoolal−Rarey methods for the CO2 + PFDecene system: ●, T = 342.2 K; ○, T = 333.2 K; ▼, T = 323.2 K; △, T = 313.2 K.
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indicator (Paroscientific Inc., model no. 730). The temperature was measured with a PRT-type thermometer (Hart Scientific, Inc., model 5622-32SR, accuracy of ± 0.045 K) fixed to the surface of the cell and displayed by an indicator (Hart Scientific, Inc., model 1502). The calibration of the pressure transducer and thermometer was done by Korea Testing Laboratory (KTL), a national calibration laboratory; the uncertainty of the thermometer was 0.022 K, while that of the pressure transducer was 0.002 MPa. In case of the CO2 + PFDecene binary mixture system, the combined expanded uncertainty of pressure measurement is estimated at ± 0.05 MPa (coverage factor, k = 2).15 The combined expanded uncertainty of pressure measurement for the CO2 + PFHexene is estimated at ± 0.25 MPa (coverage factor, k = 2).15
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RESULTS AND DISCUSSION
Tables 3 and 4 and Figure 2 show the results of high-pressure phase behavior measurement of the (CO2 + PFDecene) and (CO2 + PFHexene) binary mixture systems at T = (313.2, 323.2, 333.2, and 343.2) K and at pressures ranging from 2 MPa to 15 MPa. As shown in Figure 2, the phase transition of the (CO2 + PFDecene) system occurred at a lower pressure than that of the (CO2 + PFHexene) system, indicating that PFDecene was more soluble in scCO2 than PFHexene was. PFDecene has a longer CF2 side chain than PFHexene has. According to the literature,18 perfluoro polymer dissolves in scCO2 because the interaction between CF2 and scCO2 exists. Thus, when increasing the number of CF2 groups in the chemical structure of a molecule, the intermolecular interactions between CO2 and the molecule which contains CF2 groups are stronger. Although the molecular weight of PFDecene is more than that of PFHexene, PFDecene is more soluble in scCO2 than PFHexene. Experimental data on the critical constant (Tc, Pc) and acentric factor of PFDecene and PFHexene do not exist. As the next best thing, the group contribution method was adopted for the estimation of Tc and Pc. In case of the Joback, modified Joback, and N-R methods, the normal boiling point is positively necessary for the estimation of Tc. In this study, the normal boiling point was used as listed in the Aldrich catalog. The L-K method for the estimation of acentric factor was used. The Tc and Pc values were required for the estimation of acentric factor using the L-K method. In this study, the estimated Tc and Pc using different group contribution methods were used for the
THERMODYNAMIC MODELS
The correlation of the experimental data was carried out using the PR-EOS10 with vdW1. For the PR-EOS correlation, Tc, Pc, and the acentric factor (ω) of the pure component were positively necessary. However, there are no experimental data on the critical properties of PFDecene and PFHexene. As the next best thing, Tc and Pc were estimated using four different group contribution methods, the Joback method,16 modified Joback method,9 C-G method,12 and N-R method.17 The acentric factor (ω) was estimated by the L-K method.14 The estimation results were shown in Table 2. 1748
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Figure 4. Results correlated with PR-EOS using the (a) Joback, (b) modified Joback, (c) Constantinou−Gani, and (d) Nannoolal−Rarey methods for the CO2 + PFHexene system: ●, T = 342.2 K; ○, T = 333.2 K; ▼, T = 323.2 K; △, T = 313.2 K.
group parameters for the −CF2− and CF3− groups to calculate the boiling point, Tc, and Pc from the regression of the perfluoroalkane data. The C-G and N-R methods provided better correlation results than those of the Joback and modified Joback methods, as they reported not only the first order group of structural information, but also the second order and third order groups of structural information about the molecular fragments of the compounds.
estimation of acentric factor. The estimation results of the Tc, Pc, and the acentric factor (ω) are shown in Table 2. The simplex method algorithm19 was used for the determination of the binary interaction parameter, kij. The optimization of only one binary parameter was performed with our experimental data covering all of the temperature range data. The regression results of the experimental data using PR-EOS, kij, and the absolute average deviation of pressure (AADP) percent for the correlation are shown in Table 5. The PR-EOS with the C-G and N-R methods showed better correlation results than that of the Joback and modified Joback methods for the (CO2 + PFDecene) and (CO2 + PFHexene) systems. Figures 3 and 4 compare the experimental data and correlation results. In the (CO2 + PFDecene) system, the PR-EOS correlation using the Joback and modified Joback methods in correlating the parameters underestimated the experimental data near the critical region. On the other hand, the PR-EOS correlation using the C-G and N-R methods overestimated near the critical region. In the (CO2 + PFHexene) system, the PREOS correlation using the four group contribution methods in correlating the parameters underestimated the experimental data near the CO2-rich region. On the whole, the PR-EOS using the C-G and N-R group contribution methods provided better correlation results than those of the Joback and modified Joback methods. The Joback method includes a simple fluorine fragment (−F) term rather than more substituted constituents (i.e., −CF2− and CF3−). However, the modified Joback method and other methods give
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CONCLUSION High-pressure phase behavior measurements for the (CO2 + PFDecene) and (CO2 + PFHexene) binary mixture systems were conducted using a static method comprised of a VVVC at temperatures ranging from 313.2 K to 343.2 K and pressures up to 15 MPa. The experimental data were correlated by PR-EOS using vdW1. The Joback, modified Joback, C-G, and N-R group contribution methods were used for critical constant estimation. PR-EOS with the C-G and N-R methods showed better correlation results than did that with the Joback and modified Joback methods. PFDecene was more soluble in scCO2 than was PFHexene.
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AUTHOR INFORMATION
Corresponding Author
*Tel.: +82-2-880-7406; fax: +82-2-888-6695; e-mail address:
[email protected] (H.K.). Tel.: +82-31-219-2387; e-mail address:
[email protected] (K.W.S.). 1749
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Funding
(20) Reid, R. C.; Prausnitz, J. M.; Poling, B. E. The Properties of Gases and Liquids, 4th ed.; McGraw-Hill: New York, 1987.
This study was supported by the BK21 project of the Ministry of Education and the National Research Foundation of Korea Grant funded by the Korean Government (MEST; No. 200900789570). Notes
The authors declare no competing financial interest.
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REFERENCES
(1) Dias, A. M. A.; Freire, M.; Coutinho, J. A. P.; Marrucho, I. M. Solubility of oxygen in liquid perfluorocarbons. Fluid Phase Equilib. 2004, 222−223 (0), 325−330. (2) Riess, J. G. Oxygen Carriers (“Blood Substitutes”) Raison d’Etre, Chemistry, and Some Physiology Blut ist ein ganz besondrer Saft1. Chem. Rev. 2001, 101 (9), 2797−2920. (3) Walters, A.; Santillo, D. Uses of Perfluorinated Substances, Technical Note 6/2006; Greenpeace Research Laboratories: Exeter, U.K., 2006. (4) Daikin Industries. http://www.daikin.com/chm/ (accessed Nov 15, 2011). (5) Hourri, A.; St-Arnaud, J. M.; Bose, T. K. Solubility of solids in supercritical fluids from the measurements of the dielectric constant: Application to CO2−naphthalene. Rev. Sci. Instrum. 1998, 69 (7), 2732−2737. (6) Bose, T. K.; Cole, R. H. Dielectric and Pressure Virial Coefficients of Imperfect Gases. II. CO2−Argon Mixtures. J. Chem. Phys. 1970, 52 (1), 140−147. (7) DeSimone, J. M.; Tumas, W. Green chemistry using liquid and supercritical carbon dioxide; Oxford University Press: Oxford, 2003; p xvi. (8) Kemmere, M. F. Supercritical Carbon Dioxide for Sustainable Polymer Processes; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, Germany, 2006; pp 1−14. (9) Bae, W.; Shin, H.; Kim, H. High pressure phase behavior of carbon dioxide + heptadecafluorodecyl acrylate and carbon dioxide + heptadecafluorodecyl methacrylate systems. Phys. Chem. Chem. Phys. 2004, 6 (9), 2295−2300. (10) Peng, D.-Y.; Robinson, D. B. A New Two-Constant Equation of State. Ind. Eng. Chem. Fundam. 1976, 15 (1), 59−64. (11) Joback, K. G. A unified approach to physical property estimation using multivariate statistical techniques. M.S. Thesis, Massachusetts Institute of Technology, Cambridge, MA, 1984. (12) Constantinou, L.; Gani, R. New group contribution method for estimating properties of pure compounds. AIChE J. 1994, 40 (10), 1697−1710. (13) Nannoolal, Y.; Rarey, J.; Ramjugernath, D. Estimation of pure component properties: Part 2. Estimation of critical property data by group contribution. Fluid Phase Equilib. 2007, 252 (1−2), 1−27. (14) Lee, B. I.; Kesler, M. G. A generalized thermodynamic correlation based on three-parameter corresponding states. AIChE J. 1975, 21 (3), 510−527. (15) Chirico, R. D.; Frenkel, M.; Diky, V. V.; Marsh, K. N.; Wilhoit, R. C. ThermoMLAn XML-Based Approach for Storage and Exchange of Experimental and Critically Evaluated Thermophysical and Thermochemical Property Data. 2. Uncertainties. J. Chem. Eng. Data 2003, 48 (5), 1344−1359. (16) Joback, K. G.; Reid, R. C. Estimation of Pure-Component Properties from Group-Contributions. Chem. Eng. Commun. 1987, 57 (1), 233−243. (17) Nannoolal, Y.; Rarey, J.; Ramjugernath, D. Estimation of pure component properties. Part 2. Estimation of critical property data by group contribution. Fluid Phase Equilib. 2007, 252 (1−2), 1−27. (18) DeSimone, J. M.; Maury, E. E.; Menceloglu, Y. Z.; McClain, J. B.; Romack, T. J.; Combes, J. R. Dispersion Polymerizations in Supercritical Carbon Dioxide. Science 1994, 265 (5170), 356−359. (19) Nelder, J. A.; Mead, R. A Simplex Method for Function Minimization. Comput. J. 1965, 7 (4), 308−313. 1750
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