Modeling of nanocomposite graphene membrane for hydrogen separation

In this study, nanocomposite graphene membrane for H2/N2 separation was simulated using molecular dynamic (MD) method. Regarding to graphene membrane nature, membrane performance can be controlled by membrane pore structures and sizes. For this reason, in this work, size and shape of graphene membrane pores effect was analysed on membrane performance. Regarding, to model results, it can be concluded that the molecular sieve mechanism was governed. The small nanopore (pore-11) can only allow the hydrogen molecules to permeate due to the size restriction. In the systems of bigger nanopores (e.g., pore-16, pore-20, etc.), where the pore size is big enough to allow nitrogen molecules to permeate without any restriction, it is observed more permeation events of nitrogen than that of hydrogen molecules. Probably, the reason is that the van der Waals interactions with the graphene membrane make the nitrogen molecules accumulate on the surface of graphene. When the pore size further increases, the flow of hydrogen molecules exhibits the linear dependence on the pore area, while there is no obvious correlation between the flow of nitrogen molecules and the pore area. Moreover, temperature effect in term of graphene membrane permeance was studied by MD model. The results indicated that temperature effect was negative

Keywords:

Graphene membrane , Hydrogen separation , MD simulation