Theoretical evaluation of graphene membrane performance for hydrogen separation using molecular dynamic simulation

The main purposes of this study was to evaluate from a theoretical point of view the performance of graphene membranes in the separation/purification of hydrogen from nitrogen, using the molecular dynamic (MD) simulation method, presenting details about molecular mechanisms of selective gas diffusion through nanoscale pores of graphene membrane at the simulated set conditions. On the other hand, permeance and perm-selectivity are two significant parameters of such a membrane that can be controlled by several variables such as pressure gradient, pore density, pore layer angles etc. Hence, in this work, the hydrogen and nitrogen permeating fluxes as well as the H2/N2 ideal perm-selectivity are investigated from a theoretical point of view in a two-layer nanoporous graphene (NPG) membrane through classical MD simulations, wherein effects of pressure gradient, pore density and pore angle on the NPG membrane performance are evaluated and discussed. Simulation outcomes suggest that hydrogen and nitrogen permeating fluxes increase as a consequence of an increment of pressure gradient across the membrane and pore density.