(280g) Study of Vapor-Liquid Phase Equilibrium in High-Pressure CO2-H2O System Using Molecular Simulations

Carbon dioxide (CO₂) capture and sequestration (CCS) is a way of mitigating anthropogenic climate change. In CCS, the captured CO₂ is transported in supercritical or dense phase conditions from the source to the storage via pipelines. Corrosion of these pipelines, which occurs in the presence of free water and impurities, is a major concern. As CCS technologies achieve wider adoption in the near future, it has become imperative that safe operating conditions for these pipelines are established. We need to identify conditions that result in the precipitation of dissolved water from the CO₂ phase, thereby creating corrosive conditions. Many experimental studies have been done on the phase behavior of the water-CO₂ system. But most research has focused on low-pressure and temperature conditions. It is challenging to experimentally determine the solubility of water in dense phase CO₂. Furthermore, role of impurities and metallic interfaces on the nucleation of free water has remained unexplored.

In this work, I will discuss results obtained from fully atomistic simulations to study the phase behavior of water in dense phase CO₂ and will discuss the role of impurities.