Analysis of Partition Coefficients and Ternary Liquid-Liquid Equilibrium Data for Highly Non-Ideal Systems
The objective of this research was to study the change in partition coefficient with concentration of solute in a liquid system consisting of two relatively immiscible solvents. This would require a consistency between data for infinite dilution partition coefficients and ternary LLE data at finite concentrations of the solute. Moreover an attempt would be made to model the infinite dilution and finite concentration behavior of these systems by a single thermodynamic model. During the course of our work, we found 35 ternary systems in the literature for which the infinite dilution partition coefficients and the ternary LLE data could not be predicted accurately by the currently available liquid state models.
Ternary liquid-liquid equilibrium data for hexane+1-butanol+water, carbon tetrachloride +propanoic acid+water, and water+propanoic acid+hexane were measured from very low concentrations of the solute to finite concentrations at 25°C. The measured partition coefficients showed good agreement with the literature values. UNIQUAC and modified UNIQUAC activity coefficient models were used to represent the data. The results showed large errors, exhibiting the inability of these models to correlate the data. Attempts are being made to apply some modified versions of quasi-chemical activity coefficient models to these systems.
KeywordsPartition Coefficient Ternary System Infinite Dilution UNIQUAC Model Finite Concentration
- Hansch, C., and A. Leo, Substituent Constants for Correlation analysis in Chemistry and Biology, 1979, Wiley – Interscience NYGoogle Scholar
- Javvadi, A. Partitioning of Higher Alcohols in Alkane – Water at Dilute Concentrations, Masters thesis, 2000, Department of Chemical Engineering, North Carolina A&T State UniversityGoogle Scholar
- Macedo, E.A., and P. Rasmussen, Liquid – Liquid Equilibrium Data Collection, DECHEMA, Chemistry Data Series, 1987, 5, Part 4.Google Scholar
- Rizvi, S. Z., Measurement of Liquid-Liquid Equilibrium and Infinite Dilution Partition Coefficients Data for Two Non-Ideal Systems, Masters Thesis, 2003, Department of Chemical Engineering, North Carolina A&T State University.Google Scholar
- Sorensen, J.M., and W. Art, Liquid – Liquid Equilibrium Data Collection, DECHEMA, Chemistry Data Series, 1979–1980, 5, Part 1–3.Google Scholar
- Tiegs, D., Gmehling, J., Medina, A., Soares, M., Bastos, J., Alessi, P., and I. Kikik, Activity Coefficients at Infinite Dilution, DECHEMA, Chemistry Data Series, 1986, Vol. 9, part 1.Google Scholar