Estimation of Hansen Solubility Parameters with an Entropy-Based Solubility-Parameter-Translated SRK Equation of State

An entropy-based solubility parameter-translated Soave-Redlich-Kwong equation of state (eSPT-SRK EoS) was developed that incorporates two correction parameters which can be linearly correlated with the critical compressibility factor of pure substances. The correlated results gave an average relative deviation (ARD) value of 5.4 % at the critical density for a database of 28 widely-used chemicals. Estimation of liquid densities at standard temperature and pressure conditions gave ARD values of 5.8 % compared with the original SRK EoS of 22.2 %. The eSPT-SRK EoS was applied to calculate thermodynamic properties (entropy, fugacity, cohesive energy density) and was found to be reliable for estimating entropy-based Hansen-type solubility parameters (eHSP). The eSPT-SRK EoS was compared with a corrected form of the entropy-based solubility parameter-traslated Peng-Robinson EoS (eSPT-PR EoS) and both functional forms were found to give reliable eHSP values. Therefore, the formulation methodology can be applied to other cubic equations of state for specialized fluid mixtures.