OPTIMIZATION OF GIBBS FREE ENERGY MODEL FOR BINARY MIXTURE

Thermodynamics is mostly concerned with a theory dealing with equilibrium and into one concerned with irreversible processes. The development of an accurate theory for associating fluids has been a challenging field of research in Thermodynamics. Phase Equilibrium study is the key job to be carried out in any equipment design. Experimental phase equilibrium experiments has been carried out for binary system using differential Ebulliometer. In chemical industries during the process design especially for distillation and liquid-liquid separation systems, it is important to evaluate activity coefficients values to carry out phase equilibrium calculations. However, experimental data on activity coefficients from literature survey of various types of liquid solutions are mostly unavailable at desired temperature or composition in which we are interested. In such cases activity coefficient models - which relate GE to solution composition (at a given T & P) are useful. These models are all characterized by a set of parameters that are temperature dependent. The Vapour liquid equilibrium (VLE) equation is which in which the vapour and liquid phase composition is in equilibrium at desired temperature and pressure. The VLE relation that applies to low pressure systems is that containing an ideal gas phase, but a non-ideal liquid phase. With this purpose and due to the lack of accurate experiment equipment we have taken Vapour liquid equilibrium (VLE) data from others work. Here we present the various forms of activity coefficient models commonly used for VLE calculations. Such models are divided into two groups depending upon their application to various types of solutions: 1. Margules 2-suffix/Margules 3-suffix/Van-Laar. 2. Wilson/NRTL /UNIQUAC. The experimental data were correlated by GE based models (Margules 2-suffix, Margules 3-suffix, Van-Laar,Wilson, NRTL, UNIQUAC). In the present work activity coefficient model parameter will be regressed using experimental P-T-X data. Experimental P-T-X data were modelled to find Vapour phase composition using GE based models with regressed parameters (Binary Interaction parameters) and optimize the best suitable model for binary system.