Solid–Liquid Equilibria for the Glycine–Alcohol–NaCl–H₂O System

Abstract

An investigation of the solubility of glycine–alcohol (ethanol/1-propanol)–NaCl–H2O system was carried out by dynamic method over the temperature range from 283.15 to 333.15 K. The studied systems were glycine–alcohol (ethanol/1-propanol)–H2O, glycine–ethanol–NaCl (0.5, 1.0, 2.0 mol·kg–1 water)–H2O, glycine–1-propanol–NaCl (0.5 mol·kg–1 water)–H2O, and NaCl–alcohol (ethanol/1-propanol)–glycine (0.25 mol·kg–1 water )–H2O. The solubilities of glycine and NaCl were found to increase with increasing temperature and decrease with increasing concentration of alcohols. A chemical model was successfully developed based on the mixed solvent electrolyte (MSE) model by regressing experimental and literature solubilities data of glycine in the glycine–ethanol–NaCl–H2O and glycine–1-propanol–H2O systems. New sets of middle range and UNIQUAC interaction parameters were obtained. The average absolute deviation between regressed and experimental values was found to be less than 7%.