Theoretical investigation of graphene kirigami membrane for natural gas processing

Abstract

Membrane separation technology plays a vital role in natural gas processing due to its cost-effectiveness, excellent efficiency and low energy consumption. In this study, we demonstrate the superior permeability and selection capability of the graphene kirigami (GK) membrane for natural gas purification via molecular dynamics insights. The results indicate that the separation rate of the GK membrane can reach up to 4.1 × 106 GPU (gas permeance unit) with nearly 100% selectivity of the permeating gases mixture (H2S, CO2 and N2) over the non-permeating gas (CH4). Furthermore, the Monte Carlo simulation reveals that the unique geometry of the GK structure introduces a funnel-shaped adsorption channel to guide specific molecules’ separation and enhance the efficiency of the membrane. Compared with the nano-porous graphene (NPG) membrane, the gas separation rate of the GK membrane can be increased by more than four times. Moreover, the GK membrane does not require the modification of functional groups in natural gas purification, which provides great convenience for future applications in practical projects. The considerable potential of the GK membrane underpinned by the findings of this study will attract broad interest in the field of separation and purification.