VLE Predictions of Strongly Non-Ideal Binary Mixtures by Modifying Van Der Waals and Orbey-Sandler Mixing Rules

Document Type: Research Article


1 Department of Chemical Engineering, Semnan University, Semnan, I.R. IRAN

2 Department of Chemical Engineering, Amirkabir University of Technology, Tehran, I.R. IRAN


By proposing a predictive method with no adjustable parameter and by using infinite dilution activity coefficients of components in binary mixtures obtained from UNIFAC model, the binary interaction parameters (k12) in van der Waals mixing rule (vdWMR) and Orbey-Sandler mixing rule (OSMR) have been evaluated. The predicted binary interaction parameters are used in Peng-Robinson-Stryjek-Vera equation of state (PRSV-EoS) to obtain the vapor-liquid equilibrium (VLE) for six strongly polar and asymmetric binary mixtures. The binary interaction parameters evaluated by correlation of VLE experimental data and by PRSV EoS are also used in VLE calculations of the same binary mixtures. The average absolute deviations (AADs%) of the calculated results by both predictive and correlative methods are reported. The results indicate that although the correlative method has a more flexibility to fit the VLE experimental data, the AAD% of the predictive method is comparable and in some cases even better than that of correlative method.


Main Subjects

[1] Cheng, Chen-His, Chen, Yan-Ping, Vapor-Liquid Equilibria of Carbon Dioxide with Isopropyl Acetate, Diethyl Carbonate and Ethyl Butyrate at Elevated Pressures, Fluid Phase Equilibria, 234, 77 (2005).

[2] Bamberger, A., Sieder, G., Maurer, G., High-Pressure Phase Equilibrium of the Ternary System Carbon Dioxide + Water + Acetic Acid at Temperatures from 313 to 353 K, J. of Supercritical Fluids, 32, 15 (2004).

[3] Kodama,  D.,  Miyazaki,  J., Kato, M., Sako, T., High Pressure Phase Equilibrium for Ethylene + 1-Propanol System at 283.65 K, Fluid Phase Equilibria, 219, 19 (2004).

[4] Stryjek, R., Vera, J. H., PRSV: An Improved Peng-Robinson Equation of State with New Mixing Rule for Strongly Nonideal Mixtures, The Canadian Journal of Chemical Engineering, 64, 334 (1986).

[5] Huron, M. J., Vidal, J., New Mixing Rules in Simple Equations of State for Representing Vapor-Liquid Equilibria of Strongly Nonideal Mixtures, Fluid Phase Equilibria, 3, 255, (1979).

[6] Dahl, S., Michelsen, M. L., High-Pressure Vapor-Liquid Equilibrium with a UNIFAC-Based Equation of State, AIChE J., 36, 12, 1829 (1990).

[7] Heidemann, R. A., Kokal, S. L., Combined Excess Free Energy Models and Equations of State, Fluid Phase Equilibrium, 56, 17 (1990).

[8] Holderbaum, T., Gmehling, J., PRSK: A Group Contribution Equation of State Based on UNIFAC, Fluid Phase Equilibrium, 70, 251 (1990).

[9] Wong, S. H., Sandler, S.I., A Theoretically Correct Mixing Rule for Cubic Equations of State, AIChE J., 38, 5, 671 (1992).

[10] Orbey, H., Sandler, S.I., Reformulation of Wong-Sandler Mixing Rule for Cubic Equations of State, AIChE J., 41, 3, 683 (1995).

[11] Twu, C., Coon, J. E., Mixing Rules Constrained by vdW Mixing Rule and Second Virial Coefficient, AIChE J., 42, 3212 (1996).

[12] Renon, H. and Prausnitz, J. M., Local Compositions in  Thermodynamic  Excess  Functions   for  Liquid Mixtures, AIChE J., 14, 135 (1965).

[13] Van Laar, J. J., Z. Phys. Chem., 72, 723 (1910).

[14] Larsen, Bent L., Rasmussen, P., Fredenslund, A., A Modified  UNIFAC  Group-Contribution  Model  for     Prediction of Phase Equilibria and Heats of Mixing, Ind. Eng. Chem. Res., 26, 2274 (1987).

[15] Abrams, D. S. and Prausnitz, J. M., Statistical Thermodynamics of Liquid Mixtures: A New Expression for the Excess Gibbs Energy of Partly or Completely Miscible Systems, AIChE J., 21, 116 (1975).

[16] Khodakarami,  B.,  Modarress, H. and Lotfollahi, M. N., Study of the High-Pressure Vapor-Liquid Equilibria for Strongly Non-Ideal Binary and Ternary Mixtures, Canadian Journal of Chemical Engineering, 83, 354 (2005).

[17] Ruivo,  R.,  Paiva,  A.  and  Simoes,  P.,  Phase Equilibria of the Ternary System Methyl Oleate / Squalene / Carbon Dioxide at High Pressure Conditions, J. of Supercritical Fluids, 29, 77 (2004).

[18] Rudolph, E. S. J., Langeveld, J. H., de Loos, Th. W. and Swaan Arons, J. de, Phase Behavior of Water + Nonionic Surfactant Systems: Experiments and Modeling Applying the Peng-Robinson Equation of State with the Wong-Sandler Mixing Rules and the UNIQUAC gE-model , Fluid Phase Equilibria, 173, 1 (2000).

[19] Keshtkar,  A.,  Jalali,  F.  and Moshfeghian, M., Evaluation of Vapor-Liquid Equilibrium of CO2 Binary Systems Using UNIQUAC- Based Huron-Vidal Mixing Rules, Fluid Phase Equilibria, 140,
1-2, 107, (1997).

[20] Panagiotopoulos,  A. Z.,  and  Reid,  R.C., "New Mixing Rules for Cubic Equation of State for Highly Polar Assymetric Mixtures", ACS symposium Series 300, American Chemical Society, Washington, D.C., 571-582 (1986).

[21] Adachi, Y., and Sugie, H., A New Mixing Rule- Modified Conventional Mixing Rule, Fluid Phase Equilibria, 23, 103 (1986).

[22] Sandoval, R., Wilseck-Vera, G., and Vera, I. H., Prediction of the Ternary Vapor-Liquid Equilibria with the PRSV Equation of State, Fluid Phase Equilibria, 52, 119 (1989).

[23] Smith, J. M., Van Ness, H. C. and Abbott, M. M., “Introduction to Chemical Engineering Thermo-dynamics”, Sixth Edition, McGrow-Hill (2001).

[24] Elbaccouch, M. M., Raymond, M. B. and Elliot, J.Richard, J. Chem. Eng. Data., 45, 280 (2000).

[25] Gmehling, J., Onken, V., Vapor-Liquid Equilibrium for Mixture of Low Boiling Substances, Dechema, Vol I, Part 2a (1986).

[26] Wu,  H. S.,  Hagewiesche, D., and Sandler, S. I., Vapor - Liquid Equilibria of 2-Propanol + Water + N,N-dimethyl Formamide, Fluid Phase Equilibria, 43, 77 (1988).