  Molecular dynamics simulations have been performed for CO2 capture and
separation from CO2/N2/H2O gaseous mixtures in bilayer graphtriyne. The gas
uptake capacity, permeability as well as selectivity of the layers were
simulated based on an improved formulation of force fields tested on accurate
ab initio calculations on specific systems for mixture separation in
post-combustion process. The effect of pressure and temperature on the
separation performances of graphtriyne layers was investigated. Compared with
the single layer graphtriyne, bilayer graphtriyne can adsorb more molecules
with relatively good selectivity, due to the action of the interlayer region as
an adsorption site. The interlayer adsorption selectivity of CO2/N2 and CO2/H2O
at a temperature of 333 K and a pressure of 4 atm have been found to be equal
to about 20.23 and 1.85, respectively. We also observed that the bilayer
graphtriyne membrane has high CO2 and H2O permeances compared to N2 with
permeance selectivity ranging from 4.8 to 6.5. Moreover, we found that
permeation and adsorption depend on the applied temperature; at high
temperatures permeation and adsorption tend to decrease for all molecules.
