High-efficient helium purification through a novel Si-PWN zeolite membrane: Insights from molecular simulations

Abstract

Zeolites are recognized as a proper nanoporous material for gas separation. In this study, we employed molecular dynamics simulations to investigate the performance of the pure silica PWN-type (Si-PWN) zeolite membrane for helium recovery from natural gas, which consists mainly of methane. The molecular simulations were done under different temperatures and applied pressures. The results indicated that the Si-PWN membrane could satisfy both the necessity of high permeance and selectivity by presenting the best helium permeance of 1.22 × 106 GPU and ultrahigh selectivity of helium over methane molecules. The vdW interactions and potential of the mean force calculations were also carried out to evaluate the molecules’ permeation through this membrane. The results revealed that adsorption favors methane molecules on the surface of the membrane, whereas diffusion prefers helium over methane across the membrane. All the obtained results indicate the considerable performance of the Si-PWN membrane in helium purification, making it a promising membrane in industrial applications.