Prediction of CO2 solubility in polar aprotic solvents using the PC-SAFT equation of state

In this work, the PC-SAFT equation of state (EoS) is used to predict the solubility of CO2 in polar aprotic solvents (PASs). The PAS molecules are modeled as pseudo-associating molecules to mimic the polar interaction. Four scenarios are considered to study the CO2 solubility in PASs. In scenario I, the CO2 and PAS molecules are considered inert molecules (non-associating), in scenario II, the CO2 molecules are modeled as inert, in scenario III the PAS molecules are considered inert, and in scenario IV all components are modeled as associating molecules. In scenario IV, the cross-association between PAS and CO2 molecules is considered. The vapor-liquid equilibrium (VLE) of binary systems is predicted without using any additional adjustable parameters. The ARD values of scenarios Ito III for all binary systems are almost the same. The average ARD values of scenarios I to III, and IV are about 22.3%, and 11.6%, respectively. The results show that by considering the cross association between CO2 and PAS the model performance improves dramatically. Therefore, considering non- auto associative molecules as associative ones is a trick that improves the model prediction capability.