Mineralization of CO2 in hydrated calcium Montmorillonite

• CO2 mineral carbonation in hydrated calcium Montmorillonite (Ca-MMT) is investigated.
• Ca-MMT clays were considered with H2O-CO2-H3O+-CO32− mixture.
• Radial distribution functions indicate that average CO32− distance is about 2.275 Å.
• Carbonation energy is calculated at different temperatures from 280 K to 460 K.

We perform here a theoretical study based on both Monte Carlo and Molecular dynamic simulations in order to investigate CO2 mineral carbonation in hydrated calcium Montmorillonite (Ca-MMT). Thermodynamical, structural and dynamical properties have been evaluated in order to understand the mineral carbonation characteristics of CO2 in Ca-MMT. To simulate the behavior of CO2 through mineral carbonation, we consider calcium Montmorillonite clays at equilibrium with H2O-CO2-H3O+-CO32− mixture under different hydration and different CO32− concentration. Radial distribution function results indicate that average calcium–oxygen (CO32−) distance is about 2.275 Å, which is rather short because of the charge attraction. These carbonation reactions produce the stable limestone. The carbonation energy for different CO32− concentrations is calculated at different temperatures varying from 280 K to 460 K, gradually with 20 K. The calculated diffusion coefficient indicates that the diffusion of calcium ions decreases with CO32− concentrations. Finally, the obtained mineralization energy was found in increase with carbonate concentration and burial depth.