Thermodynamic consistency test for thevapour- liquid equilibrium (vle) data: a review

Vapour-Liquid equilibrium (VLE) data plays very important role in the field of mass transfer operations like distillation column design. Distillation column is one of important unit operation and equipment used for separation of pure component from the binary mixture or multicomponent mixture. Vapour liquid equilibrium of binary mixture can be used to derive information aboutmolecular interaction between the components of the mixtures. Vapour liquid equilibrium data provide information for calculation of thermodynamic properties and optimization of thermodynamic cycles. The equilibrium vapour composition is related to the liquid composition, this is called vapour-liquid equilibrium. Thermodynamic consistency test for vapour liquid equilibrium data have been developed, providing that at constant temperature and pressure, activity coefficients determined using accurate VLE data must satisfy Gibbs-Duhem (GD) equation. There are few test available to check thermodynamic consistency of VLE data. These are 1) Area test 2) Point to point test 3) Van Ness test 4) An infinite dilution test 5) Differential test etc. In this review paper while comparative study of the various thermodynamic consistency test and it is find that Area test is widely used for the
consistency.