(126j) A Computationally Efficient Polar Cubic Equation of State for Predictive Modeling of the Phase Behavior and Critical Phenomena of Polar and Aromatic Mixtures

A polar cubic equation of state (EOS) is developed by incorporating the dipolar theory of Jog and Chapman into the Soave-Redlich-Kwong (SRK) EOS. To enhance computational efficiency, we propose simplifying assumptions in the dipolar term of Jog and Chapman to reduce the double and triple sums in the theory to single sums. The simplified version of the dipolar theory can lead to orders of magnitude reduction in computational time for multicomponent systems and can be used with either cubic EOS or SAFT-based EOS. The proposed model, which we here call Simplified Polar-SRK (SP-SRK), is parametrized in a similar fashion to classical cubic EOS to exactly reproduce Tci, Pci, wi, and will self-consistently reduce to the base SRK EOS in the absence of polar interactions, making it suitable for integration into reservoir/process simulators as a plug-in. Binary VLE data with a non-polar reference hydrocarbon is used to extract the polarity of the respective functional group. The model shows superior performance in capturing the phase behavior of polar mixtures compared to the base SRK, and improved performance near the critical region compared to more advanced models such as polar PC-SAFT. Additionally, including the polar term allows for the mapping of pi-pi bonds in aromatics onto a dipolar free energy for more accurate description of aromatic molecules without the need of binary interaction parameters (kij).