(614f) Investigation of the Separation of Carbon Dioxide from Methane Using Confined Deep Eutectic Solvents and Ionic Liquids: A Molecular Dynamics Study

Molecular dynamics (MD) simulations were performed to study the separation of carbon dioxide from methane utilizing deep eutectic solvents (DESs) or ionic liquid (ILs) in the bulk and inside slit-like nanopores. Two choline chloride-based DESs and one IL are considered in our study: ethaline and levuline (with ethylene glycol and levulinic acid as the hydrogen bond donor respectively), and [bmim⁺][NTf2^-]. The DESs/ILs partially fill slit graphite or rutile nanopores that are in contact with a bulk gas mixture of CO₂/CH₄. This study was motivated by the development of gas separation techniques using supported IL membranes and supported IL phase materials, in which small amounts of ILs are contained inside micron-thick membranes or nanoporous materials. Furthermore, DESs share many of the physical and chemical properties of ILs and have been investigated as potential alternatives for CO₂ separations. Our results show that the amounts of CO₂ retained in our confined systems depend on variables such as the CO₂ solubility in the IL or DES, the affinity of CO₂ with the gas-IL/DES interface, the chemistry of the pore walls, and the amount of nanoconfined DESs/ILs. Detailed comparisons of the properties of all systems will be presented and discussed.