CO₂/N₂ Selectivity Prediction in Supported Ionic Liquid Membranes (SILMs) by COSMO-RS

Abstract

The quantum chemical COSMO-RS method was applied to describe supported ionic liquid membranes (SILMs) with an enhanced capacity of selective separation of CO2 from N2, in order to contribute to the design of CO2 postcombustion capture technologies based on ionic liquid (IL) solvents. First, the predictive capability of the COSMO-RS method was evaluated through a comparison with a wide range of selectivity experimental data, and a further optimization based on the Henry’s Law constant of each solute in ILs was developed to improve the prediction of CO2/N2 selectivity in SILMs. Afterward, the optimized COSMO-RS approach was applied to design suitable SILM systems for CO2/N2 separation by driving a computational screening of 224 ILs, with results illustrating the capability of [SCN−]-based ILs to enhance the selective separation of CO2 from N2. Finally, to better understand SILM behavior in CO2 separation, the CO2/N2 selectivity differences among ILs were successfully related to the excess enthalpy of CO2−IL and N2−IL mixtures in solution predicted by COSMO-RS. In addition, the intermolecular interactions (electrostatic, hydrogen bonding, and van der Waals) between CO2−IL and N2−IL systems in the liquid phase, quantified by COSMO-RS, were analyzed in order to contribute to the rational selection of SILMs with positive characteristics for CO2/N2 selective separation.

Screening of RTILs for propane/propylene separation using COSMO-RS methodology

“…In previous works Palomar et al found out that gas-liquid [25,29,30], liquid-liquid [33] and solid-liquid [34] equilibrium data for favorable separation processes based on IL solvents were associated to a higher exothermicity of the mixing process. This methodology was applied in this case to analyze the solubility of different silver salts in a certain ionic liquid containing the same anion.…”

“…The main drawback is that most of the parameters of these models must be determined from a large amount of experimental data, which is not available for the vast majority of ionic liquids [25]. On the contrary, the quantum chemistry based of the ''conductor-like screening model for real solvents'' (COSMO-RS) method has a small and general parameter set that does not need to be adjusted to specific ILs and therefore it can be applied in a predictive way to the full range of ILs [24].…”

Removal of chlorinated organic volatile compounds by gas phase adsorption with activated carbon

“…Subsequently, the quantum-chemical COSMO-RS (Conductor-like Screening Model for Real Solvents) model, developed by Klamt and co-workers [34], is used to analyze the Cl-VOC-AC interactions. Previous works have showed that COSMO-RS method can successfully be applied to predict thermodynamic adsorption [35,36] and absorption [37][38][39][40] data. In this work, COSMO-RS predictions of Henry's law constants, as thermodynamic parameter of reference for solute-adsorbent interactions of MCM, DCM and TCM in differently functionalized AC models (Fig.…”

Design and screening of ionic liquids for C2H2/C2H4 separation by COSMO‐RS and experiments

“…Recently, it has been used to predict the activity coefficients, 26,27 gas solubilities [28][29][30] and separation selectivity of various gases in ILs, such as CO 2 /N 2 , 31 C 2 H 4 /C 2 H 6 32 and H 2 S/CO 2 /CH 4 /C 2 H 6, 33 but there are no relevant studies on C 2 H 2 /C 2 H 4 separation.…”