CF4 Capture and Separation of CF4-SF6 and CF4-N2 Fluid Mixtures Using Selected Carbon Nanoporous Materials and Metal-Organic Frameworks: A Computational Study

The adsorption of pure fluid carbon tetrafluoride and the separation of CF4-SF6 and CF4-N-2 fluid mixtures using representative nanoporous materials have been investigated by employing Monte Carlo and molecular dynamics simulation techniques. The selected materials under study were the three-dimensional carbon nanotube networks, pillared graphene using carbon nanotube pillars, and the SIFSIX-2-Cu metal-organic framework. The selection of these materials was based on their previously reported efficiency to separate fluid SF6-N-2 mixtures. The pressure dependence of the thermodynamic and kinetic separation selectivity for the CF4-SF6 and CF4-N-2 fluid mixtures has therefore been investigated, to provide deeper insights into the molecular scale phenomena taking place in the investigated nanoporous materials. The results obtained have revealed that under near-ambient pressure conditions, the carbon-based nanoporous materials exhibit a higher gravimetric fluid uptake and thermodynamic separation selectivity. The SIFSIX-2-Cu material exhibits a slightly higher kinetic selectivity at ambient and high pressures.