To calculate activity coefficients and vapor pressure, it is essential to define appropriate models. Common approaches for estimating activity coefficients include various excess Gibbs energy models . In this study, the local composition activity coefficient models NRTL , UNIFAC and UNIQUAC were used to estimate 𝛾 𝑖 in Eq. ( ). NRTL and UNIQUAC empirical interaction parameters were optimized from FP experimental data by minimizing the quadratic error between predicted and experimental values. As UNIFAC is a predictive model, no parameter optimization was needed for it.