Molecular simulation of CO2 and H2O adsorption/deformation on model cement materials

Carbon capture and storage (CCS) is a critical technology for mitigating atmospheric CO2 levels and achieving carbon neutrality, with the potential to capture billions of tons of CO2 annually. To ensure secure geological storage, it is essential to deeply understand well cement degradation, car-bonation processes, and wellbore integrity under CO2 injection conditions. This study employs Monte Carlo simulations to investigate the interactions between CO2 and H2O in cement materials (portlandite and tobermorite) at 66°C and 100 bar, focusing on thermodynamic mechanisms pre-ceding chemical degradation. Model validation was conducted by comparing the heat of water ad-sorption (Qst) with literature values, which confirmed the accuracy of the simulations and empha-size the role of surface water in CO2 adsorption. The analyses reveal CO2 enrichment at water in-terfaces and demonstrate the significant impact of water content on material interactions. These findings provide valuable insights for refining predictive models and guiding future research on cement integrity under CO2 exposure.