M.M. Olaya

Liquid-liquid-solid equilibria for the quaternary system water + ethanol + 1-pentanol + sodium chloride at 25 °C

The equilibrium data of the quaternary system water-ethanol-acetone-sodium chloride at 25 °C have been determined. All equilibrium regions have been systematically studied. Tie-line and tie-triangle data for this system have been correlated using a modification of the Eisen-Joffe equation.

Comments on the problematic nature of the calculation of solid-liquid equilibrium

Abstract The problematic nature of the calculation of phase equilibria involving solid components is discussed. The concept of ‘the stability criterion’, as introduced, accounts for the necessity of a suitable set of parameters for any given activity coefficient model, yielding an appropriate shape of the Gibbs energy function in the whole domain of the equilibrium diagram. The use of a unique reference state (pure liquid at the temperature and pressure of the system), for both solid and liquid phases, is another fact that must be remembered when correlating and predicting these types of equilibria.