Sustainable development in industrial processes depends on improving predictive capabilities and minimizing trial-and-error in process design, which helps reduce resource consumption in research, development, and operation. To support this, predictive thermodynamic models offer a valuable tool for simulating and optimizing process conditions efficiently.
Among these, COSMO-RS and its variants are reliable methods for predicting phase equilibria and thermodynamic properties. However, like other activity coefficient models, COSMO-RS does not account for pressure effects and therefore fails to accurately describe vapor-phase behavior. Previous efforts to combine COSMO-RS with equations of state often require binary interaction parameters, which compromises the predictive nature of the model.
To address this, Soares et al. proposed COSMO-SAC-Phi, an extended equation of state based on COSMO-SAC, where each substance is represented as a pseudo-mixture of real molecules and a virtual component for free volume. This formulation introduces pressure dependence while preserving the predictive character of the original model.
Building on this idea, this research introduces openCOSMO-RS-Phi, a new equation of state based on the open-source and freely available openCOSMO-RS model. This extension incorporates pressure dependence while preserving the predictive strengths of the original approach. The goal is to provide an accurate, pressure-sensitive equation of state that remains fully predictive and openly available to the academic community as a free, open-source tool.
Furthermore, developments on open-COSMO-RS-Phi are done in order to be compatible with openCOSMO-RS-ES, an expansion of the model made to accomodate electrolyte systems.
