Determination of SO2 solubility in ionic liquids: COSMO-RS and modified Sanchez-Lacombe EOS

Abstract With more stringent standards regarding the emission of greenhouse gases, capturing or removal of these detrimental pollutants has become of significant importance in industrial plants. In this presented investigation, e ∗ -modified Sanchez–Lacombe equation of state and COSMO-RS-Lei and COSMO-RS-ADF models have been employed in order to estimate the solubility of sulfur dioxide (SO 2 ) in different ionic liquids (ILs) as chemical sorbents with different cations and anions. The experimental data of Imidazolium, Pyridinium, Guanidinium and Ammonium based ionic liquids such as experimental data of density and the amount of SO 2 solubility into ionic liquids in a wide range of temperature and pressure have been obtained from the literature. The characteristic parameters of the e ∗ -modified Sanchez–Lacombe EOS have been adjusted by applying a database including 580 experimental data points of ILs density for 4 SO 2 /IL systems. In order to confirm the accuracy of the mentioned models, the phase equilibrium (PTx) diagrams of the SO 2 /ILs systems have been drawn and predicted data are compared with experimental data. According to the figures and also reported tables which contain the amount of calculated errors, It can be claimed that presented models in this study are capable to predict the amount of SO 2 solubility into ionic liquids within the value of AARD% around 5%, 63% and 62% for e ∗ -modified Sanchez–Lacombe EOS, COSMO-RS-Lei and COSMO-RS-ADF respectively.