Molecular dynamics simulation of methane and carbon dioxide permeation through a layered inorganic membrane

Molecular dynamics simulations are performed to investigate the permeation and separation of methane and carbon dioxide mixture through a layered inorganic membrane at high temperature to circumvent carbon dioxide adsorption on membrane surface. The simulations show that a single layer membrane with narrow cylindrical-pore favors methane permeation over carbon dioxide.When a slit-space is present along with the cylindrical-pore in a layered inorganic membrane, the membrane can be tailored to favor carbon dioxide over methane. The comparison of the permeation rates obtained directly from simulation and those from Knudsen flow calculation highlights the prominence of molecular sieving mechanism in determining the permeation behaviors of methane and carbon dioxide through a narrow opening.