Application of GC-SAFT EOS to polar systems using a segment approach

Abstract The GC-SAFT equation of state proposed by Tamouza et al. (Fluid Phase Equilib. 222–223 (2004) 67) is here extended to model phase equilibria of polar fluid (dipolar and quadrupolar) mixtures using an extension of the theory from Gubbins and Twu (Chem. Eng. Sci. 33 (1978) 863) to chain molecules inspired by the segment approach proposed by Jog and Chapman (Mol. Phys. 97 (1999) 307). Systematic tests with three different SAFT EOSs versions are carried out on vapor–liquid equilibria (VLE) of pure 1-alkanol, alkyl-benzenes, xylenes and their binary mixtures. Binary mixtures with n -alkanes and cyclohexane are also investigated. The tests on these systems were as comprehensive as possible. Vapor pressure of heavy polar compounds is predicted satisfactorily within 5–8% for GC-SAFT-0 and GC-PC-SAFT, 3–4% for GC-VR-SAFT. The average deviation on bubble pressure is about 4% and 1–3% on dipolar and quadrupolar mixtures, respectively, for the three versions of GC-SAFT. Computations of mixtures VLE were made assuming zero binary parameters ( k ij  =  l ij  = 0). The current approach compares well to an earlier treatment by Tamouza et al. (Fluid Phase Equilib. 222–223 (2004) 67; Fluid Phase Equilib. 228–229 (2005) 409) restricted to some of the polar systems modeled here.

[1]  Javier Vijande,et al.  Description of PVT behaviour of hydrofluoroethers using the PC-SAFT EOS , 2004 .

[2]  Stanley H. Huang,et al.  Equation of state for small, large, polydisperse, and associating molecules , 1990 .

[3]  T. W. Loos,et al.  Phase equilibria modeling by the quasilattice equation of state for binary and ternary systems composed of carbon dioxide, water and some organic components , 1995 .

[4]  Joachim Gross,et al.  Thermodynamic modeling of complex systems using PC-SAFT , 2005 .

[5]  George Jackson,et al.  THE THERMODYNAMICS OF MIXTURES AND THE CORRESPONDING MIXING RULES IN THE SAFT-VR APPROACH FOR POTENTIALS OF VARIABLE RANGE , 1998 .

[6]  Walter G Chapman,et al.  Application of Wertheim's thermodynamic perturbation theory to dipolar hard sphere chains , 1999 .

[7]  K. Gubbins,et al.  Phase equilibria calculations with a modified SAFT equation of state. 1. Pure alkanes, alkanols, and water , 1996 .

[8]  Joachim Gross,et al.  Application of perturbation theory to a hard-chain reference fluid: an equation of state for square-well chains , 2000 .

[9]  Jean-Charles de Hemptinne,et al.  Application of group contribution SAFT equation of state (GC-SAFT) to model phase behaviour of light and heavy esters , 2005 .

[10]  K. Gubbins,et al.  Thermodynamics of polyatomic fluid mixtures—I theory , 1978 .

[11]  K. Gubbins,et al.  Theory of fluids of non-axial quadrupolar molecules , 1981 .

[12]  Michiel Sprik,et al.  A polarizable model for water using distributed charge sites , 1988 .

[13]  Keith E. Gubbins,et al.  Theory of molecular fluids , 1984 .

[14]  E. Karakatsani,et al.  Perturbed chain-statistical associating fluid theory extended to dipolar and quadrupolar molecular fluids. , 2006, The journal of physical chemistry. B.

[15]  E. Karakatsani,et al.  Phase equilibrium calculations for multi-component polar fluid mixtures with tPC-PSAFT , 2007 .

[16]  G. Sadowski,et al.  Application of the Perturbed-Chain SAFT equation of state to polar systems , 2004 .

[17]  J. Valderrama,et al.  Generalized binary interaction parameters in the Wong–Sandler mixing rules for mixtures containing n-alkanols and carbon dioxide , 2005 .

[18]  J. D. Hemptinne,et al.  Application to binary mixtures of a group contribution SAFT EOS (GC-SAFT) , 2005 .

[19]  J. D. Hemptinne,et al.  Application of GC-SAFT EOS to polycyclic aromatic hydrocarbons , 2007 .

[20]  R. C. Weast CRC Handbook of Chemistry and Physics , 1973 .

[21]  J. D. Hemptinne,et al.  Group contribution method with SAFT EOS applied to vapor liquid equilibria of various hydrocarbon series , 2004 .

[22]  George Jackson,et al.  Statistical associating fluid theory for chain molecules with attractive potentials of variable range , 1997 .

[23]  K. Gubbins,et al.  Phase equilibria calculations with a modified SAFT equation of state. 2. Binary mixtures of n-alkanes, 1-alkanols, and water , 1996 .

[24]  E. Karakatsani,et al.  Evaluation of the Truncated Perturbed Chain-Polar Statistical Associating Fluid Theory for Complex Mixture Fluid Phase Equilibria , 2006 .

[25]  E. Macedo,et al.  Extension of the A-UNIFAC model to mixtures of cross- and self-associating compounds , 2005 .

[26]  M. Maroncelli,et al.  Dipole Solvation in Nondipolar Solvents: Experimental Studies of Reorganization Energies and Solvation Dynamics† , 1996 .

[27]  Joachim Gross,et al.  An equation-of-state contribution for polar components : Quadrupolar molecules , 2005 .

[28]  Ioannis G. Economou,et al.  Extended statistical associating fluid theory (SAFT) equations of state for dipolar fluids , 2005 .

[29]  Gabriele Sadowski,et al.  Perturbed-Chain SAFT: An Equation of State Based on a Perturbation Theory for Chain Molecules , 2001 .

[30]  Walter G Chapman,et al.  A Parametric Study of Dipolar Chain Theory with Applications to Ketone Mixtures , 2003 .

[31]  G. Sadowski,et al.  Modeling of Polar Systems with the Perturbed-Chain SAFT Equation of State. Investigation of the Performance of Two Polar Terms , 2005 .

[32]  George Jackson,et al.  New reference equation of state for associating liquids , 1990 .

[33]  L. Verlet,et al.  Perturbation theories for polar fluids , 1974 .

[34]  M. Wertheim Theory of polar fluids , 1979 .

[35]  Walter G Chapman,et al.  Application of Dipolar Chain Theory to the Phase Behavior of Polar Fluids and Mixtures , 2001 .

[36]  A. Stogryn,et al.  Molecular multipole moments , 1966 .