Unusual S-shaped binodal curves of the systems water plus lithium chlorideplus 1-butanol or 2-butanol or 2-methyl-1-propanol

Solid-liquid-liquid equilibrium data of the ternary systems water + LiCl 2-butanol, water + LiCl + 2-methyl-1-propanol (i-butanol) and water + LiCl + l-butanol have been experimentally determined at 25 degrees C. The equili brium diagrams determined show differences between the systems. In the syst em with l-butanol, the solid phase of the Liquid-liquid-solid region is mon ohydrated salt. However, in the systems with 2-butanol and 2-methyl-1-propa nol it is anhydrous salt. With respect to the liquid + liquid zone, the thr ee diagrams are very similar with an unusual S-shaped solubility curve in t he organic branch that can be explained depending on whether the organic so lvent takes part in the solvation of ions. The more salt, the more numbers of ions solvated by water and organic solvent and the solubility of water a nd salt in the organic phase increase notably producing the unusual S-shape d solubility curve. (C) 1999 Elsevier Science B.V. All rights reserved.