Apparatus for Measuring Vapor-Liquid Equilibria and Phase Densities of Complex Aqueous Solutions

A new apparatus has been designed and constructed to measure the vapor- liquid equilibria and phase densities of corrosive, complex aqueous solutions containing organic solvents and salts. The apparatus is designed for isothermal operation from ambient temperatures to 400 K. Phase equilibrium measure- ments at higher temperatures may be achieved without density measurements. This paper presents a detailed description and performance testing of the apparatus. Measurements of the vapor pressures and saturated liquid densities of ethanol and the vapor pressure of an ethanol-water mixture (xethanol=0.6743 mole fraction) from 308 to 385 K at pressures to 15 MPa are used as perfor- mance tests.