Article pubs.acs.org/jced
Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Measurement and Correlation of Isobaric Vapor Liquid Equilibrium Data for Cyclopentyl Methyl Ether and Cyclopentanol Akash Patel,† Chintan Modi,‡ Milind Joshipura,§ and Nitin Bhate*,† †
Chemical Engineering Department, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat 390001, India Chemical Engineering Department, Shroff Rotary Institute of Chemical Technology, Ankleshwar, Gujarat 393135, India § Chemical Engineering Department, Institute of Technology, Nirma University, Ahmedabad, Gujarat 382481, India J. Chem. Eng. Data Downloaded from pubs.acs.org by UNIV OF LOUISIANA AT LAFAYETTE on 01/30/19. For personal use only.
‡
S Supporting Information *
ABSTRACT: Isobaric vapor−liquid equilibrium data for pure components cyclopentyl methyl ether (CPME) and cyclopentanol (CP) and their binary mixtures was generated using a modified ebulliometer. This data has been reported for five different pressures in the range of 71.50 to 101.79 kPa. Pure component boiling points were correlated using the Antoine equation and compared with the literature data. Binary vapor−liquid equilibrium data was modeled using Wilson, NRTL, and UNIQUAC models. Deviation plots for experimental and predicted temperatures are given. UNIQUAC and NRTL model predictions showed a better fit with the experimental values relative to the Wilson model.
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INTRODUCTION Cyclopentyl methyl ether (CPME) is a potential green solvent. It is used in organic synthesis in the place of hazardous, halogenated solvents or low boiling ethers like dimethyl and diethyl ether. CPME has some advantages over the conventional solvents like high boiling point, low peroxide formation, high recovery rate (>90%), low carbon dioxide emissions, low solubility in water, low vaporization energy, and high resistance to acids and bases.1 CPME is synthesized using three routes,2−4 namely, methylation of cyclopentanol with dimethyl sulfate (DMS), two step reaction between cyclopentanol and sodium hydroxide, and addition reaction of methanol to cyclopentene. All these routes involve separation of CPME from the reaction mass. Focusing on the first reaction, the separation of the product requires knowledge of vapor−liquid equilibrium data of CPME, cyclopentanol (CP), and DMS. To the best of our knowledge, the vapor−liquid equilibrium data for the CPME−CP system has not been reported in the literature. In this work, pure component vapor pressure data and isobaric T−x data were generated for the CPME−CP system at five different pressures. The vapor pressure data was modeled to determine the constants of the Antoine equation and compared with the reported data.5 The parameters of Wilson, UNIQUAC, and NRTL models were determined using the binary vapor−liquid equilibrium data.
Table 1. Sample Specification chemical name
source
cyclopentyl methyl ether cyclopentanol
5614-37-9
isopropyl alcohol
67-63-0
Loba Chemicals Ltd. Loba Chemicals Ltd. S.D. Fine Chemicals Ltd.
96-41-3
analysis method
0.999
GC
0.99
GC
0.99
GC
for an individual component showed a single peak ascertaining the absence of impurities. The pure component vapor pressure and binary VLE (T−x) data were generated at five different pressures ranging from 71.50 to 101.79 kPa using a differential ebulliometer setup (Figure 1) used in the previous investigation.6 Since the operating pressures were subatmospheric, the vapor phase was assumed to be ideal. The temperature was measured using a precalibrated mercury-inglass thermometer having a least count of 0.2 °C, and the pressure was measured with a mercury manometer with 0.1333 kPa (1 mmHg) accuracy. The VLE setup was first cleaned with acetone at atmospheric pressure and under vacuum for almost 2 to 3 h to remove traces of residual chemicals in the ebulliometer and the condenser. The setup was then purged with nitrogen to remove the traces of acetone. The pure
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EXPERIMENTAL SECTION CPME and CP were analytical grade reagents (Table 1). The purity was confirmed using a CHEMITO 1000 Gas Chromatograph with an FID detector. The chromatogram © XXXX American Chemical Society
CAS no.
mass fraction purity
Received: September 23, 2018 Accepted: January 17, 2019
A
DOI: 10.1021/acs.jced.8b00855 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Table 2. Antoine Correlation Coefficients for CPME and CPa CPME CP a
A
B
C
15.301 17.807
3798.883 5060.233
−23.528 −29.604
P = (71 to 102 kPa); ln(P/kPa) = A − B/(T/K + C).
Table 3. Boiling Points of Pure Components: CPME and CPa CPME
a b
CP
P/kPa
Texp/K
Tpredb/K
72.04 78.83 85.94 89.82 101.39
368.2 371.2 373.4 375.4 379.2
368.13 370.96 373.73 375.16 379.15
P/kPa
Texp/K
Tpredb/K
71.47 78.36 85.50 89.49 102.00
403.4 406.2 408.6 409.4 413.6
403.39 405.95 408.41 409.70 413.48
Standard uncertainties are u(P) = 0.066 kPa; u(T) = 0.2 K. Calculated by eq 1.
Figure 1. Vapor liquid equilibrium setup: 1, ebulliometer; 1a, feed outlet; 1b, boiling chamber; 1c, Cottrell pump; 1d, drop counter; 1e, thermowell; 1f, feed inlet; 2, mercury-in-glass thermometer; 3, external belt heater; 4, U-tube mercury manometer; 5, jacketed internal coil condenser; 5a, cooling water inlet; 5b, cooling water outlet; 6, SS Ballast tank; 7, bypass line; 8, belt driven oil ring vacuum, pump; 9, nitrogen cylinder; 10, dimmerstat.
component or the mixture was charged in the ebulliometer and the heating started. The data was first generated at atmospheric pressure. The rate of heating was slowly increased to prevent bumping of the liquid which may lead to vapor loss and change in the composition. Sufficient time was given for the temperature to attain equilibrium. Moreover, the drop rate of condensate was also monitored continuously. The equilibrium condition was ascertained when the drop rate and the temperature were constant. The pressure was then lowered by applying vacuum and simultaneously adjusting the heating rate. This procedure was repeated for different pressures. The vacuum pump used was of Jebivak make powered by a 1/4th HP motor. The minimum pressure attainable using this pump was 450 mmHg. The desired pressure was set using a valve installed on the ballast tank, which was placed between the setup and the vacuum pump. The purpose of this tank was to minimize the fluctuations in the pressure during the application of vacuum. Prior to generating data with a different composition, the setup was cleaned with acetone and purged with nitrogen. The samples were analyzed for the liquid compositions on a gas chromatograph using a Chromosorb column with temperature programming of 90−180 °C and 10 °C/min and isopropyl alcohol (IPA) as the external standard. Synthetic samples comprising of CPME, CP, and IPA were prepared to generate the calibration curve. The sample of the binary mixture prepared prior to the start of the run and that withdrawn after completion giving sufficient time for the system to cool down were analyzed to determine the change in the composition. The maximum deviation in the compositions was about 1.5% based on the mole fraction.
Figure 2. Relative deviations of the experimental data, Texp, from the predicted values, Tpred, for CPME.
Figure 3. Relative deviations of the experimental data, Texp, from the predicted values, Tpred, for CP: ×, this work; Δ, Ambrose and Ghiassee.5
pressures in the range of 71.50 to 101.79 kPa. The parameters of Antoine correlation were obtained by regression analysis of the P−T data. Since the data was generated under isobaric conditions, the Antoine equation was rearranged (eq 1) to regress the parameters using the objective function based on temperature.
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RESULTS AND DISCUSSION Saturation Temperature. Boiling point temperatures for CPME (1) and CP (2) were measured at five different B
DOI: 10.1021/acs.jced.8b00855 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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Table 4. GE Model Parameters for the CPME−CP System P/kPa model
parameters −1
a12/J·mol a21/J·mol−1 Δg12/J·mol−1 Δg21/J·mol−1 α Δu12/J·mol−1 Δu21/J·mol−1
Wilson NRTL
UNIQUAC
71.50
77.95
85.50
89.69
101.79
2609.78 2843.95 −451.36 5137.77 0.1 891.30 473.25
2727.55 2701.84 −1010.57 5789.65 0.1 755.69 595.24
2439.43 2882.54 −221.13 4800.93 0.1 963.58 389.31
2457.71 2652.21 −642.01 5122.17 0.1 847.70 448.76
2820.69 2468.61 −1358.24 6078.14 0.1 655.95 656.84
Table 5. P−T−x−y Data for CPME and CPa Wilson
NRTL
UNIQUAC
Wilson
NRTL
UNIQUAC
P/kPa
x1,exp
Texp/K
y1,pred
y1,pred
y1,pred
P/kPa
x1,exp
Texp/K
y1,pred
y1,pred
y1,pred
71.50 71.50 71.50 71.50 71.50 71.50 71.50 71.50 71.50 71.50 71.50
0.0000 0.0777 0.1752 0.2597 0.3766 0.4794 0.5810 0.6857 0.7999 0.8990 1.0000
403.4 387.8 380.8 376.2 373.0 372.8 371.2 370.8 370.4 368.8 367.9
0.0000 0.4808 0.6465 0.7067 0.7539 0.7834 0.8099 0.8392 0.8787 0.9263 1.0000
0.0000 0.4755 0.6511 0.7120 0.7559 0.7819 0.8061 0.8352 0.8770 0.9274 1.0000
0.0000 0.4762 0.6505 0.7115 0.7557 0.7820 0.8065 0.8356 0.8771 0.9272 1.0000
85.50 85.50 85.50 85.50
0.6857 0.7999 0.8990 1.0000
376.6 376.0 374.4 373.6
0.8324 0.8737 0.9232 1.0000
0.8285 0.8720 0.9242 1.0000
0.8289 0.8721 0.9240 1.0000
77.95 77.95 77.95 77.95 77.95 77.95 77.95 77.95 77.95 77.95 77.95
0.0000 0.0777 0.1752 0.2597 0.3766 0.4794 0.5810 0.6857 0.7999 0.8990 1.0000
405.8 391.0 382.6 379.2 375.6 375.4 375.0 373.6 373.2 371.2 370.6
0.0000 0.4726 0.6368 0.6972 0.7453 0.7759 0.8039 0.8349 0.8765 0.9257 1.0000
0.0000 0.4690 0.6420 0.7024 0.7466 0.7737 0.7996 0.8307 0.8750 0.9270 1.0000
0.0000 0.4694 0.6414 0.7018 0.7465 0.7740 0.8001 0.8311 0.8750 0.9267 1.0000
89.69 89.69 89.69 89.69 89.69 89.69 89.69 89.69 89.69 89.69 89.69
0.0000 0.0777 0.1752 0.2597 0.3766 0.4794 0.5810 0.6857 0.7999 0.8990 1.0000
409.8 395.6 388.2 385.2 380.6 379.6 378.8 378.2 377.6 376.0 375.1
0.0000 0.4409 0.6132 0.6798 0.7335 0.7676 0.7981 0.8313 0.8749 0.9254 1.0000
0.0000 0.4362 0.6168 0.6843 0.7354 0.7666 0.7952 0.8281 0.8735 0.9263 1.0000
0.0000 0.4368 0.6164 0.6838 0.7352 0.7667 0.7955 0.8284 0.8736 0.9261 1.0000
85.50 85.50 85.50 85.50 85.50 85.50 85.50
0.0000 0.0777 0.1752 0.2597 0.3766 0.4794 0.5810
408.4 394.0 386.2 382.2 378.6 378.0 377.0
0.0000 0.4548 0.6260 0.6906 0.7416 0.7734 0.8016
0.0000 0.4505 0.6303 0.6955 0.7434 0.7719 0.7980
0.0000 0.4510 0.6298 0.6950 0.7434 0.7722 0.7984
101.79 101.79 101.79 101.79 101.79 101.79 101.79 101.79 101.79 101.79 101.79
0.0000 0.0777 0.1752 0.2597 0.3766 0.4794 0.5810 0.6857 0.7999 0.8990 1.0000
413.4 398.4 393.0 388.2 385.0 383.6 383.0 381.8 381.4 380.4 379.3
0.0000 0.4405 0.6054 0.6689 0.7213 0.7558 0.7877 0.8230 0.8696 0.9229 1.0000
0.0000 0.4343 0.6094 0.6742 0.7238 0.7551 0.7849 0.8199 0.8683 0.9239 1.0000
0.0000 0.4354 0.6089 0.6733 0.7232 0.7549 0.7850 0.8201 0.8684 0.9237 1.0000
a
Standard uncertainties are u(T) = 0.2 K, u(P) = 0.066 kPa, and u(x1) = 0.015.
The estimated values of the parameters are given in Table 2. The P−T data generated along with the predicted values of saturation temperatures is reported in Table 3. The experimental values were compared with the predicted values and reported values. These are represented as deviation plots in Figures 2 and 3, respectively. It is observed that the experimental data shows a close match with the predicted and the reported data. Binary Vapor Liquid Equilibria. Isobaric T−x data was generated for the CPME−CP system for compositions in the range of 0.07 to 0.90 mole fraction CPME. Five data sets were for pressures ranging from 71.50 to 101.79 kPa. The parameters of Wilson, UNIQUAC, and NRTL models7 were determined by regression analysis. A two step process as discussed in previous work6 was followed to regress the model
Table 6. RMSD (T) and %AAD (T) for the CPME−CP System Wilson
NRTL
UNIQUAC
P/kPa
RMSD (T)
%AAD (T)
RMSD (T)
%AAD (T)
RMSD (T)
%AAD (T)
71.5 77.95 85.5 89.69 101.79 average
0.598 0.650 0.587 0.577 0.624 0.607
0.121 0.121 0.109 0.110 0.122 0.116
0.549 0.537 0.503 0.560 0.650 0.560
0.112 0.090 0.090 0.114 0.116 0.105
0.552 0.550 0.511 0.560 0.645 0.563
0.113 0.093 0.090 0.114 0.117 0.105
Tisat /K =
Bi − Ci Ai − lnP /kPa
(1) C
DOI: 10.1021/acs.jced.8b00855 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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parameters were obtained for values of α ranging from 0.1 to 0.6. The value which gave the minimum value of RMSD was considered. The model parameters are given in Table 4. Equilibrium vapor mole fractions (y) were obtained using BUBL T calculations. The T−x data generated at five different pressures along with the model predictions and vapor compositions is reported in Table 5, and the RMSD (T) and %AAD (T) values based on the three models under consideration are summarized in Table 6. The deviation in the model predictions with the experimental values is shown in Figure 4. The experimental and predicted T−x along with estimated y when plotted in the form of isobaric T−x−y diagrams for all the pressures shows a similar trend. Hence, the data for 101.79 kPa has been shown as a representative plot in Figure 5. The liquid and the vapor mole fractions in this plot are based on CPME. This figure indicates that the model predictions compare very well with the experimental values. This is evident from the RMSD (T) and %AAD (T) values reported in Table 6. Relative to Wilson, the NRTL and UNIQUAC models show a better match with the experimental data and are almost comparable. Also, the dependence of relative volatility on the pressure is not significant. The data indicates possibility of an azeotrope near pure CPME composition. Since ebulliometeric measurements do not allow determination of experimental azeotropic compositions, they need to be calculated using the regressed model parameters. These values fall in the range of 0.99 to 0.995 mole fraction of CPME.
Figure 4. Relative differences ΔT/T = {T(exp) − T(pred)}/T(exp) of the experimental temperatures for the CPME−CP system (71.5− 101.79 kPa): ×, Wilson; Δ, NRTL; ○, UNIQUAC.
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CONCLUSIONS The saturation temperatures for CPME and CP were determined at five different pressures, and the parameters of the Antoine equation were evaluated. The data shows a good match with the predicted and the literature values with the % deviation in the temperatures being ±0.12. For the binary system, all the three models predict the experimental T−x data very well with NRTL and UNIQUAC models showing the best fit. The average RMSD (T) values for NRTL and UNIQUAC are 0.560 and 0.563, respectively, and that for Wilson is 0.607. The average %AAD (T) values for the NRTL, UNIQUAC, and Wilson models are 0.105, 0.105, and 0.116 respectively. The system indicates possibility of an azeotrope in the higher concentration region of CPME.
Figure 5. Isobaric (101.79 kPa) T−x−y plot for the CPME−CP system: ▲, experimental; ···, Wilson; − −, NRTL; − · -, UNIQUAC.
parameters and estimate the vapor phase mole fraction. First, BUBL P calculations were performed to regress the parameters of the activity coefficient models under consideration by minimizing the RMSD based on the pressure. In the second step, BUBL T calculations were done using the regressed parameters to determine the vapor phase mole fractions and the predicted value of temperature. The procedure is outlined in the Supporting Information. The validity of these were checked with the values of RMSD (T) and %AAD (T) using the eqs 2 and 3, respectively:
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S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jced.8b00855. Procedure for calculations (PDF)
n
RMSD(T ) =
n
(
∑i = 1 100 %AAD(T ) =
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∑i = 1 (Tiexp − Tipred)2 n Tiexp − Tipred Tiexp
n
ASSOCIATED CONTENT
(2)
AUTHOR INFORMATION
Corresponding Author
)
*E-mail:
[email protected]. ORCID
(3)
Nitin Bhate: 0000-0003-4858-0019
where n is the number of data points and Texp and Tpred i i indicate the experimental and the predicted temperatures, respectively. The model parameters were estimated by minimizing the RMSD using the GRG-II algorithm in the SOLVER feature of MS-EXCEL. In the case of the NRTL model, regression was done keeping the parameter α constant. Different sets of model
Notes
The authors declare no competing financial interest.
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REFERENCES
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DOI: 10.1021/acs.jced.8b00855 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
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(2) Watanabe, K.; Yamagiwa, N.; Torisawa, Y. Cyclopentyl Methyl Ether as a new and alternative process solvent. Org. Process Res. Dev. 2007, 11, 251−258. (3) Jeong, W. J.; Cho, H.; Lim, J. S. Vapour-liquid equilibria for the binary mixtures of methanol + cyclopentyl methyl ether (CPME). Korean J. Chem. Eng. 2016, 33, 2961−2967. (4) Jeong, W. J.; Lim, J. S. Measurement and correlation of the isothermal VLE data for the binary mixtures of cyclopentene (CPEN) + cyclopentyl methyl ether (CPME). Korean J. Chem. Eng. 2017, 34, 463−469. (5) Ambrose, D.; Ghiassee, N. B. Vapour pressures and critical temperatures and critical pressures of C5 and C6 cyclic alcohols and ketones. J. Chem. Thermodyn. 1987, 19, 903−909. (6) Rana, B. K.; Bhate, N. V.; Mahajani, S. M.; Dabke, S. P. Vapourliquid equilibrium for the 2-Ethoxyethanol − 2- Ethoxyethyl acetate system. J. Chem. Eng. Data 2012, 57, 3483−3487. (7) Smith, J. M.; Van Ness, H. C.; Abbott, M. Introduction to Chemical Engineering Thermodynamics, Sixth ed.; McGraw Hill: New York, 2001; p 418, 419, and 707.
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DOI: 10.1021/acs.jced.8b00855 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
