Adsorption and Transport of CH4, CO2, H2 Mixtures in a Bio-MOF Material from Molecular Simulations

Accurate description of gas adsorption and diffusion in nanoporous materials is crucial in envisioning new materials for adsorption-based and membrane-based gas separations. This study provides the first information about the equilibrium and transport properties of different gas mixtures in a bio-metal organic framework (bio-MOF). Adsorption isotherms and self-diffusivity coefficients of CH 4, CO 2, H 2, and their binary mixtures in bio-MOF-11 were computed using grand canonical Monte Carlo and equilibrium molecular dynamics simulations. Results showed that bio-MOF-11 exhibits significantly higher adsorption selectivity for CO 2 over CH 4 and H 2 than the widely studied MOFs. Bio-MOF-11 outperforms several isoreticular MOFs, traditional zeolites, and zeolite imidazolate frameworks in membrane-based separations of CH 4 /H 2, CO 2 /CH 4, and CO 2 /H 2 mixtures due to its high gas permeability and permeation selectivity. The methods used in this work will assess the potential of bio-MOFs in gas separations and accelerate development of new bio-MOFs for targeted applications by providing molecular insights into adsorption and transport of gas mixtures.