Hydrogen purification using nanoporous graphene membranes and its economic analysis

We show from molecular dynamics insights that the nanoporous graphene (NPG) is an efficient membrane in hydrogen purification for separating gaseous H₂/CH₄ mixtures with a high permeance and selectivity. The H₂ permeance is as high as 10⁶ GPU, extremely higher than those of polymer membranes; the selectivity of H₂ over CH₄ is up to 225, in the same order with those of polymer membranes. An economic analysis is performed from the aspects of compression energy consumption and required membrane area; it is shown that the NPG membrane requires less membrane area but a bit more compression energy compared with the polymer membranes. However, the slightly higher compression energy consumption can be totally offset by the remarkably smaller membrane area. In summary, the NPG membranes for hydrogen purification present an excellent separation performance with a high H₂ permeance, ultimately resulting in an impressive economic index comparing to the polymer membranes.