Molecular simulation of CO2 adsorption behavior by different stratigraphic conditions in geological storage

Abstract

CO₂ emissions and their contribution to global climate change become a critical issue. Geological storage of CO₂ in subterranean reservoirs, particularly in carbonate rocks, is one of the promising methods proposed to mitigate atmospheric CO₂ levels. The research specifically explores the molecular-level interactions of CO₂ with calcite, anorthite, and albite, which are key components of carbonate rock formations. Using a combination of Grand Canonical Monte Carlo (GCMC), molecular dynamics simulations (MDs), and density functional theory (DFT) methods, the study investigates CO₂ adsorption behaviors within the slit nanopores of these minerals under varying conditions. The findings demonstrate that anorthite exhibits the highest CO₂ adsorption capacity at lower pressures, although this advantage diminishes as pressure increases, leading to a more uniform adsorption capacity across the three minerals. The study also reveals that the presence of water significantly impairs CO₂ adsorption, with higher water content further reducing adsorption efficiency.