Extended UNIQUAC Thermodynamic Modeling of Aqueous Two-Phase Systems, Water + Salt + Short-Chain Alcohol

Abstract

The extended UNIQUAC activity coefficient model for electrolyte solutions was used for simulating the water + short-chain alcohol (1-propanol, 2-propanol, and tert-butanol) + salt (NaCl, KCl, NH4Cl, Na2SO4, and K2SO4) systems in a wide temperature range (0–100 °C). Experimental data were used for determining the interaction parameters (water + alcohol and alcohol + ion) and the volume and surface area parameters. Parameters for water + ion interactions were taken from previous publications. Equilibrium calculations including SLLV, SLL, SLV, LLV, LV, SV, and SL were performed with the model. The results are largely in agreement with those obtained experimentally. Model parameters previously published for these systems were revised based on new data.