REPRESENTATION OF LIQUID-LIQUID EQUILIBRIUM OF MIXED-SOLVENT ELECTROLYTE SYSTEMS USING THE EXTENDED ELECTROLYTE NRTL MODEL

The three-contribution electrolyte NRTL model [1] with an additional t erm of Bronsted-Guggenheim type is applied to represent the liquid-liq uid equilibrium (LLE) in mixed-solvent electrolyte systems. The Bronst ed-Guggenheim term compensates for the inadequacies of the Debye-Hucke l and Born equations when they are extended to mixed-solvent electroly te systems. Attention is given to the definition of reference and stan dard states. The importance of the electrolyte solution chemistry is e mphasized. The extended electrolyte NRTL model is compared with the Ze rres-Prausnitz model [2] on correlation of LLE data for four ternary a queous-organic solvent electrolyte systems.