ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Correlation of Vapour–Liquid Equilibrium Data of Ternary Systems

E. Graczová, P. Steltenpohl, L. Bálintová, and E. Kršačková

Department of Chemical and Biochemical Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, SK-812 37 Bratislava

E-mail: elena.graczova@stuba.sk

Received: 1 April 2004

Abstract: A method for correlation of vapour—liquid equilibrium (VLE) data of ternary systems is tested. For thermodynamic description of ternary VLE the excess molar Gibbs energy equation – NRTL equation, extended by the universal ternary contribution was used. Binary parameters of NRTL equation were obtained from the binary equilibrium data of corresponding systems; parameters of the universal ternary contribution were evaluated from the ternary VLE data. Execution of the proposed procedure for ternary VLE correlation is simple and the binary and ternary NRTL model parameters retain their physical meaning. Moreover, these parameters could be used also for VLE prediction of multicomponent systems containing the corresponding binary and ternary subsystems.
Procedure was applied for correlation of VLE of twelve ternary systems. Introduction of the ternary contribution into the original NRTL expression improved significantly correlation of ternary VLE data compared to the prediction based on binary equilibrium data only. Due to the use of ternary contribution, the mean deviation of the pressure values decreased 1.2 to 4.5 times and also the deviation of the component mole fraction in the vapour phase was partially improved. The results of correlation are comparable and sometimes even better than the direct fit of ternary VLE data.

Full paper in Portable Document Format: 586a442.pdf

Chemical Papers 58 (6) 442–446 (2004)