Selective Removal of Sulfur Dioxide from Oxygen Using Porous Iron: A Molecular Dynamics Study

Sulfur dioxide (SO₂) is a toxic pollutant generated primarily by the combustion of sulfur-containing fossil fuels, and its removal is crucial for sustainable industrial development. In this computational study, molecular dynamics (MD) simulations were employed to evaluate a porous iron membrane for separating oxygen from a SO₂ gas stream. The Fe membrane was modeled with the Embedded Atom Method (EAM), while the O₂–SO₂ mixture was described using the DREIDING force field. Equilibration confirmed the structural stability of the atomic models, reflecting appropriate MD settings and carefully chosen initial conditions. To characterize separation performance, we report SO₂ and O₂ sorption coefficients, gas–membrane interaction energies, and the membrane’s post-separation mechanical properties. The simulations further show that the initial conditions (e.g., temperature and pressure) govern the perm-selective behavior of the porous iron membrane throughout the simulation campaign. Under optimized conditions, the membrane achieved an O₂ purity of ~81% and an O₂ recovery of 96.7% in the designed atomic-scale purification system. This performance arises from optimum interaction between the porous iron membrane and target gas molecules. Numerically, the magnitude of the interaction energy between these modeled samples increased to -83.14 eV. This described procedure did not disturb the mechanical performance of the designed porous membrane, and the ultimate strength and Young’s modulus of them reached 212.39 MPa and 6.00 GPa (respectively) after the gas molecules selective removal process was fulfilled.