Separation of Water Vapor From Methane by Nanoporous Graphene Membrane

We study the separation process of gaseous H₂O/CH₄ mixtures using nanoporous graphene membranes via molecular dynamics simulations. We run the simulation in an equilibrium system 10 times with different initial atomic velocities to overcome the inefficiency brought by the low pressure of the system. The results show that the H₂O molecules can permeate the graphene membrane with a linearly time-dependent crossing number. The permeance of the H₂O molecules reaches to 9.5×10⁻⁴ mol/m²sPa, far exceeding that of the polymer gas separation membranes. High selectivity of H₂O over CH₄ is also observed. In summary, this study demonstrates that the specific NPG cloud be adopted as an efficient membrane in natural gas dehydration.