CCS Technologies for low carbon society

[1601-04-01] Molecular Dynamics Study on the Effect of CO₂ Dissolution on CO₂/Water Interfacial Tension

○Masashige Shiga¹, Weiren Lin¹, Yungfeng Liang² (1. Kyoto University, 2. The University of Tokyo)

Chairman: Tetsuya Suekane (Tokyo Institute of Technology)

Keywords:CCS, Interfacial Tension, Molecular Dynamics Simulation

CCS is considered as the effective way of reducing the amount of CO₂ emission to the atmosphere. Interaction at the interface has important roles in the behavior of the fluid in the pore space which consists of caprock and reservoir rock. In addition to the experimental work, molecular dynamics study, which based on the interaction between atoms or molecules, has been conducted actively (da Rocha, SRP, et al. 21). This method is useful to know the microscopic view of the interfacial phenomena.
The impact of CO₂ dissolution, however, cannot be treated easily in this approach, because chemical reaction in aqueous solution is involved. In this study, we reproduce the effect of solvation by the model of carbonic acid which is used by Javanbakht et al. (215). The concentration of carbonic acid is determined based on the chemical equilibrium using experimental solubility data. Then, we conduct the calculation of the interfacial tension between CO₂–Water + carbonic acid. By comparison with experimental work and the previous MD research, we investigate the validity of the model and the role of carbonic acid.