Development of New Cohesion Factor Model for a three parameter Cubic Equation of State

Abstract

An Equation of state is a powerful tool in accurate representation of thermodynamic properties of a wide variety of pure fluids in a wide range of temperature and pressure. The current work deals with developing a new cohesion factor model for a three parameter cubic equation of state.The three parameter cubic equation of state has been successfully implemented to predict the thermodynamic properties of ionic liquids. The cohesion factor models were developed using two approaches. i) Cohesion factor development based on boilings points. ii) Cohesion factor development based on vapour pressures(predicted at zero-pressure fugacity). Six mathematical forms of cohesion factor expressions were developed using both the approaches. These twelve models were compared for estimating ionic liquids liquid density and vapour pressure. It was found that cohesion factor models developed based on boiling points did not perform well for vapour pressure prediction, but those developed based on vapour pressures predicted both the vapour pressures as well as density very well. Amognst the six mathematical expressions heyen-1 type cohesion factor model preformed well for predicting the two properties.