Solvation structure of supercritical CO2 and brine mixture for CO2 plume geothermal applications: A molecular dynamics study

This study can help reveal the solvation structures of scCO2/brine mixture under different temperatures (373.15 K to 473.15 K) and ion concentrations (1 wt% to 10 wt%). Results show that H2O molecules bind more tightly to Na+ ion than Cl- ion while scCO2 molecules seem have a uniform distribution in the scCO2/brine mixture. Both the interaction of Na+-H2O pairs and that of Cl--H2O pairs become stronger under higher temperature conditions. Besides, the increase of ion concentration not only reduces the number of H2O molecules in the solvation shell of Na+ ion, but also weakens the interaction of hydrogen bonds. Moreover, it seems that the scCO2/brine mixture is heterogeneous in the CPG application.Graphical abstract

Source: The Journal of Supercritical Fluids - February 7, 2020 Category: Chemistry Source Type: research