本研究主要探討醋酸與乙酸異丁酯於一大氣壓下之汽液相平衡，採用汽相循環式汽液平衡，進行常壓下之汽液相平衡實驗，溫度與汽液相組成分別由熱偶計量得與GC分析之。
在雙成份系統中，多重共沸是一種很特殊的情形，然而醋酸與乙酸異丁酯於常壓下的汽液平衡即會產生兩個共沸點。在數據處理方面，數據能通過Fredenslund所提出的點對點的熱力學一致性測試，再以UNIQUAC、 NRTL、 van Laar模式與Legendre polynomial進行迴歸，比較迴歸結果可判斷Legendre polynomial對此系統的擬合度較好。
為了去除共沸點，加入醋酸鉀於此系統中直到達到飽合溶液並重新量測汽液平衡之數據。由其結果可知加入此鹽類後可使得共沸點消失。

In this research, the isobaric vapor-liquid equilibrium data for isobutyl acetate and acetic acid were measured at atmospheric pressure. A condensed vapor phase recirculating apparatus is used for our experiment. The equilibrium temperature was measured by thermocouple, the vapor and liquid samples were analyzed by GC to determine the compositions。
Polyazeotropy in binary systems is a uncommon behavior of vapor-liquid equilibrium at a given pressure or temperature. Isobutyl acetate and acetic acid mixture exists two azeotropes at 101.3kPa. Experimental data are thermodynamically consistent according to the point-to-point test of Fredenslund and the data were correlated using NRTL、UNIQUAC、van Laar model and Legendre polynomial.
In order to remove the azeotropes , potassium acetate was added to the mixture and run the experiments. It is found that azeotropes disappear by salt effect.

Abrams, D. and Prausnitz, J.,“Statistical Thermodynamics of Liquid Mixtures: A New Expression for the Excess Gibbs Energy of Partly and Completely Miscible Systems.”AIChE J., 1975, 21, 116-128.
Aucejo, A.; Monton, J. B.; Munoz, R. and Wisniak, J.,“Double Azeotropy in the Benzene + Hexafluorobenzene System.”J. Chem. Eng. Data, 1996, 41, 21-24.
Aucejo, A.; Loras, S.; Munoz, R.; Wisniak J. and Segura H.,“Phase Equilibria and Multiple Azeotropy in the Associating System Methanol + Diethylamine.”J. Chem. Eng. Data, 1997, 42, 1201-1207
Box, M. J.; “Improved Parameter Estimation in Engineering and Science,”Technometrics, 12, 1970, No.2, pp.219-229
Britt, H. I., and Luecke, R. H. “The Estimation of Parameter in Nonlinear, Implicit Models,”Technometrics, 1973, 15, No. 2, pp. 233 – 247
Burguet, M. C.; Monton, J. B.; Munoz, R.; Wisniak, J. and Segura, H.,“Polyazeotropy in Associating Systems: The 2-Methylpropyl Ethanoate + Ethanoic Acid System.”J. Chem. Eng. Data, 1996, 41, 1191-1195.
Christensen, S. and Olson, J.,“Phase Equilibria and Multiple Azeotropy of the Acetic Acid - Isobutyl Acetate System.”Fluid Phase Equilibria, 1992, 79, pp.187-199.
Dohnal, V., and Dona, F. “Verification of the Accuracy of Complete Binary Vapor–Liquid Equilibrium Data.”Fluid Phase Equilibria, 1985, 19, pp.1-12
Fabries, J. F., and Renon, H. “Method of Evaluation and Reduction of Vapor–Liquid Equilibrium Data of Binary Mixture.”AIChE J., 1975, 21, No. 4, pp.735-743
Fredenslund, A.; Jones, R. L. and Prausnitz, J. M.,“Group-contribution estimation of activity coefficients in nonideal liquid mixtures.”AIChE J. 1975, 21, 1086-1098.
Fredenslund, A. ; Gmehling, J. and Rasmussen, P. “Vapor–Liquid Equilibria Using UNIFAC,”Elsevier, Amsterdam, 1977.
Fu, Y.; Sandler, S. and Orbey, H., “A Modified UNIQUAC Model That Includes Hydrogen Bonding.” Ind. Eng. Chem. Res., 1995, 34, 4351-4363.
Gaw, W. J. and Swinton, F. L.“Thermodynamic Properties of Binary Systems Containing Hexafluorobenzene. Part 4. Excess Gibbs Free Energies of the Three Systems Hexafluorobenzene + Benzene, Toluene, and p-Xylene.” Trans. Faraday Soc., 1968, 64, 2023-2034.
Hayden, J. and O’Connell, J.“A Generalized Method for Predicting Second Virial Coefficients.” Ind. Eng. Chem. Process Des. Dev., 1975, 14, 209-216.
Herington, E. F. “Herington Test for the Consistency of Experimental Isobaric Vapour-Liquid Equilibrium Data,”J. Inst. Pet., 1951, Vol. 37, 457-470.
Kao, C.; Paulaitis, M. and Yokozeki, A., “Double Azeotropy in Binary Mixtures of NH3 and CHF2CF3.”Fluid Phase Equilibria, 1997, 127, 191-203.
Kao, C.; Miller, R. N. and Sturgis, J. F., “Double Azeotropy in Binary Mixtures 1,1,1,2,3,4,4,5,5,5-Decafluoropentane + Tetrahydrofuran.”J. Chem. Eng. Data, 2001, 46, 229-233.
Kao, C.; Allen C, S.; Martin Schiller, and Sturgis, J. F. “Double Azeotropy in Binary Mixtures 1,1,1,2,3,4,4,5,5,5-Decafluoropentane High-Boiling Diastereomer +Tetrahydrofuran.”J. Chem. Eng. Data, 2004, 49, 532-536
Kenemy, S., and Manczinger, J. “Reduction of Thermodynamic Data by Means of the multiresponse Maximun Likelihood Principle.” AIChE J.,.1982, 28, No.1, pp.20-30
Kojima, K.; H. M. Moon and Ochi. K. “Thermodynamic Consistency Test of Vapor-Liquid Equilibrium Data.”Fluid Phase Equilibria, 1990, 56, 269-284.
Leu, A. D. and Robinson, D. B. “Vapor-Liquid Equilibrium in Selected Binary Systems of Interest to the Chemical Industry. In Experimental Results for Phase Equilibria and Pure Components Properties.” DIPPR Data Series 1; Cunningham, J. R., Jones, D. K., Eds.; DIPPR: New York, 1991.
Lloyd, L. and Wyatt, P. A. H., “The Vapor Pressure of Nitric Acid Solutions. Part I. New Azeotropes in the Water-Dinitrogen Pentoxide System. ” J. Chem. Soc., 1955, 2248-2252.
Loras, S.; Aucejo, A.; Monton, J. B.; Wisniak, J. and Segura, H. “Polyazeotropic Behavior in the Binary System 1,1,1,2,3,4,4,5,5,5- Decafluoropentane + Oxolane.” J. Chem. Eng. Data, 2001, 46, 1351-1356.
Monton, J. B.; Burguet, M. C.; Munoz, R.; Wisniak J. and Segura H. “Nonazeotropy in the System Methyl Ethanoate + 1,2-Epoxybutane.” J. Chem. Eng. Data, 1997, 42, 1195-1200.
O’Connell, J. A., and Prausnitz, J. “Empirical Correlation of Second Virial Coefficients for Vapor-Liquid Equilibria Calculation, ” Ind. Eng. Chem., Process Des. Dev., 1967, 6, No.2, pp.245-250
Pantio-Leal, H., and Reilly, P. M. “Statistical Estimation of Parameter in Vapor Liquid Equilibrium,”AIChE J., 1982, 28, No. 4, pp.580 -587
Prausnitz, J.; Anderson, T.; Grens, E.; Echert, C.; Hsieh, R. and J.P. O’Connel, “Computer Calculations for Multicomponent Vapor–Liquid and Liquid – Liquid equilibria,”Prentice Hall, Eaglewood Cliffs, NJ, 1980.
Prausnitz, J.; Lichtenthaler, R. and Azevedo, E. “Molecular Thermodynamics of Fluid-Phase Equilibria.”Prentice-Hall: Englewood Cliffs: NJ, 1986; pp 137-142, 333-348.
Renon, H. and Prausnitz, J., “Local Composition in Thermodynamic Excess Functions For Liquid Mixtures.”AIChE. J., 1968, 14, 135-144.
Segura, H. ; Wisniak, J. and Reich, R. “Polyazeotropy in Binary Systems. 2. Association Effect.”Ind. Eng. Chem. Res., 1996, 35, 3742-3758.
Spencer, C. F. and Danner, R.P. “Improved equation for prediction of saturated liquid density.”J. Chem. Eng. Data, 1972, 17, 236–241.
Srivastava, R. and Smith, B. D.“Total Pressure Vapor-Liquid Equilibrium Data for Binary Systems of Diethylamine with Acetone, Acetonitrile and Methanol.”J. Chem. Eng. Data, 1985, 30, 308-313.
Sutton, T. L., and Macgregor, J. F. “The analysis and Design of Binary Vapor Liquid Equilibrium Experiments, PartΙ: Parameter Estimation and Consistency Test,”The Canadian Journal of Chemical Engineering, 1977, 55, pp.602-608
Sutton, T. L., and Macgregor, J. F. “The analysis and Design of Binary Vapor Liquid Equilibrium Experiments, Part ΙΙ: The Design of Experiments,”The Canadian Journal of Chemical Engineering, 1977, 55, pp.609-613
Wilson. G.,“A New Expression for the Excess Free Energy of Mixing.”J. Am. Chem. Soc., 1964, 86, 127-130.
Wisniak, J.,“A New Test for the Thermodynamic Consistency of Vapor-Liquid Equilibrium.”Ind. Eng. Chem. Res., 1993,32, 1531-1533.
Wisniak J., “The Herington Test for Thermodynamic Consistency,” Ind. Eng. Chem. Res., 1994, 33, 177-180.
Wisniak, J.; Segura, H. and Reich, R.“Polyazeotropy in Binary Systems.”Ind. Eng. Chem. Res., 1996, 35, 4194-4202.