Computational insights from GCMC, MD and DFT simulations of propane separation in Mg-based MOFs: Binary selectivity toward methane, ethane, and nitrogen

Abstract

The separation of light hydrocarbons represents a critical challenge in both industrial and environmental contexts. The binary separation of propane from ethane, methane, and nitrogen was investigated, and selected MOF structures containing Mg atoms were evaluated using GCMC and MD simulations. For Mg-MOF-74, propane uptake was found to be in the range of 297.5-378.7 mg/g at pressures 0.1, 1 and 10 bar. Adsorption properties were specifically examined at 1 bar and 298 K, and isotherm fitting (Langmuir/Freundlich) confirmed the strong affinity of propane toward the MOF surface. Key transport and separation parameters, including diffusion selectivity, permeability, and membrane selectivity, were calculated, showing that propane exhibited significantly higher selectivity compared to other gases. DFT calculations revealed adsorption energies of -6.1 kJ. mol- 1 (without dispersion correction) and - 41.4 kJ.mol- 1 (including dispersion effects) for propane binding to the MOF framework. These findings highlight the promise of Mg-based MOFs for the selective adsorption of propane.