A novel technique for rapid measurement of liquid-liquid-vapour equilibrium

A technique for obtaining liquid-liquid-vapour equilibria data in a single apparatus is described. The cell, equipped with two facing optical glass windows and a turbidimeter, is stirred at two regimes. At high agitation speed, the hollow shaft induces the vapour-phase recirculation in the liquid and allows very quick liquid vapour equilibria measurements, with a saw tooth temperature profile at each composition. At moderate agitation speeds, the liquid cloud point is detected by turbidimetry. The technique leads, in a matter of few days, to a complete set of data in a large P and T domain. As an example, an application to the MIBK-water binary system is presented. (C) 1998 Elsevier Science Ltd. All rights reserved.