Simultaneous CO2 and SO2 capture by using ionic liquids: a theoretical approach
Density Functional Theory (DFT) methods are used to analyze the mechanism of interaction between acid gases and ionic liquids based on 1-ethyl-3-methylimdazolium cation coupled with five different of anions. Single ionic pairs and ionic clusters containing six ionic pairs were used to model the interactions of the ionic liquid with acid gas molecules. The properties of the systems were analyzed based on geometric properties, interaction energies and Bader’s theory. The cluster approach gives more accurate representation of the behavior of ions and gases in bulk liquid phase, and despite computational challenges, cluster approach allows to quantify interactions beyond short range ones used in the single ionic pair – acid gas model commonly applied in the literature. The results reported herein points out efficient simultaneous capturing of both gases especially for ionic liquids containing acetate anion.
