ABSTRACT
Mixtures containing associating compounds, represent highly non-ideal phase behavior, due to the presence of powerful hydrogen bonding interactions. Up to now, several associating models such as SAFT variants have been applied to such systems. The CPA EoS was introduced by Kontogeorgis and his coworkers in order to combine a cubic EoS, and the SAFT theory. At the present survey, acid gas mixtures solubilities in IL [C8mim][PF6] has been thermodynamically modeled using CPA EoS. The AAD % for binary systems, including H2S+ IL and CO2+ IL are 8.74, 2.14 respectively. Moreover, for ternary systems AAD % is equal to 17.43.