Many innovative Equations of State (EoS) have been developed in TTPL for the prediction of Thermophysical Properties and Phase Equilibriaand successfully applied to the analysis, design and optimization of separation processes for a great variety of systems. Some representative examples of thermodynamic modelling are presented below:

• Cubic EoS:Two new translated and modified EoS have been developed (t-mPR and t-vdW) and their predictive performance have been investigated over a wide range of non-polar systems and conditions.
• LCVM: A predictive G^E/EoS model has been developed and its capabilities have been investigated against other bibliographic models. Its superiority has been proved especially for highly asymmetric systems.
• Universal mixing rule (UMR): UMR is a mixing rule for cubic equations of state (CEoS) applicable to all type of system asymmetries. For the cohesion parameter of the CEoS the mixing rule involves the Staverman-Guggenheim part of the combinatorial term and the residual term of the original UNIFAC Gibbs free energy expression. For the co-volume parameter of the CEoS the quadratic concentration dependent mixing rule is used with the combining rule for the cross parameter. The UMR is applied to the Peng-Robinson EoS leading to what is referred to as the UMR-PRU model. Very satisfactory results are obtained using the existing interaction parameters of the Original UNIFAC model along with gas parameters evaluated for UMR-PRU model, for fluid phase equilibrium (VLE, LLE, SGE, etc.) predictions at low and high pressures for a wide range of system asymmetries including mixtures containing polymers.
• CPA: The equation combines the simplicity of a cubic equation of state (Soave-Redlich-Kwong or Peng-Robinson), which is used for the physical part, and the theoretical background of the perturbation theory employed for the chemical (or association) part. The resulting EoS (Cubic Plus Association, CPA) is not cubic with respect to volume and contains five pure compound parameters which are determined using vapor pressures and saturated liquid densities.Excellent description is obtained for both vapor pressures and saturated liquid volumes of pure associating compounds such as alcohols, phenols, glycols, acids and water. CPA has been also successfully applied to the correlation and prediction of phase equilibria (vapour-liquid, liquid-liquid, vapor-liquid-liquid) in a variety of systems where association is present as described in several publications.
• mS-UNIFAC: This model is a modification of S-UNIFAC for systems containing sugars and sugar derivatives, such as sugar esters. Through the use of a better combinatorial term and new data, the model becomes more reliable than S-UNIFAC, providing satisfactory predictions for multicomponent systems involved in the enzymatic esterification reactions for the production of fatty acid sugar esters.