Thermodynamic modeling and rational design of ionic liquids for pre-combustion carbon capture

Although ionic liquids (ILs) have been widely explored as promising solvents for carbon capture, system-atic study on the rational selection and design of ILs for carbon capture processes is still scarce. In this contribution, a comprehensive literature survey is first performed to provide an up-to-date database comprising 10,116 CO2 solubility data and 463 H-2 solubility data measured in a large number of ILs at various temperatures and pressures. Using this dataset, the UNIFAC-IL model for predicting the vapor- liquid equilibrium of the CO2-H-2-IL ternary system is developed, where 42 main groups and 53 subgroups are specified and 220 group interaction parameters are fitted. With this model, an optimization-based computer-aided ionic liquid design problem is finally formulated and solved to identify the best ILs for the pre-combustion carbon capture process. It is found that the hydroxyl-ammonium and hydroxylimidazolium bis(trifluoromethylsulfonyl)amide ILs are the most promising solvent candidates. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

A systematic study was conducted to develop a model for predicting the vapor-liquid equilibrium of the CO2-H2-IL ternary system, and an optimization-based computer-aided ionic liquid design problem was formulated and solved to identify the best ILs for pre-combustion carbon capture processes. The hydroxyl-ammonium and hydroxylimidazolium bis(trifluoromethylsulfonyl)amide ILs were found to be the most promising solvent candidates.