Molecular simulation of confined ethaline-based deep eutectic solvents
for separations of carbon dioxide from methane
Classical molecular dynamics simulations were used to study the
separation of carbon dioxide from methane by three formulations of the
deep eutectic solvent (DES) ethaline (choline chloride: ethylene glycol
at 1:2, 1:4 and 1:8 molar ratios), in the bulk and confined inside
carbon and titania slit pores of two different pore widths, 2 nm and 5
nm. The highest permselectivities (~20) are observed for
1:2 ethaline in a 5 nm carbon pore, followed by the 1:4 DES in a 5 nm
graphite pore, 1:2 ethaline in a 2 nm carbon pore and the 1:8 bulk DES.
Our results indicate that variations in the ratio of ethylene glycol,
which in turn affect the interactions of all DES species with the gas
molecules and the different pore walls, plus confinement effects
resulting from varying the pore sizes, can affect the gas separation
performance of these systems in complex ways.