Modelling of liquid–liquid equilibria of mixed solvent electrolyte systems using the extended electrolyte NRTL

• Published in: Fluid phase equilibria Vol. 171; no. 1; pp. 45 - 58
• Main Authors: van Bochove, Gerard H, Krooshof, Gerard J.P, de Loos, Theo W
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 28.05.2000; Elsevier Science
• Subjects: Activity coefficient; Caprolactam; Chemistry; Electrolyte NRTL; Exact sciences and technology; General and physical chemistry; Liquid-liquid equilibria; Mixed solvent electrolyte solutions; Phase equilibria; Model; Caprolactam; Activity coefficient; Liquid–liquid equilibria; Mixed solvent electrolyte solutions; Electrolyte NRTL; Organic solvent; Perhydro-2-azepinone; Mixed solvent; Electrolyte solution; Lactam; Ammonium Sulfates; Aqueous solution; Thermodynamic properties; Phase equilibrium; Modeling; Liquid liquid equilibrium
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/S0378-3812(00)00347-2

Liquid–liquid equilibria of mixed solvent electrolyte systems were correlated using an extended electrolyte NRTL model. The electrolyte NRTL expression for the activity coefficients has been modified by taking into account the derivatives to the solvent composition of the physical properties and by a new Brønsted–Guggenheim (BG) expression. In addition to some ternary mixed solvent electrolyte systems, the model has been applied to the quaternary systems that are of importance in the extraction process of ε-caprolactam: water+ε-caprolactam+solvent+ammonium sulfate (AS). The liquid–liquid equilibria of the ternary and quaternary systems involved and the mean activity coefficients of the salt+water systems were used simultaneously to obtain the adjustable parameters. The results are compared to the original electrolyte NRTL of Chen.