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

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%.