Molecular study on the behavior of CO2 hydrate growth promoted by the electric field

Carbon dioxide capture and storage (CCS) is a hot spot of current research. The use of hydrates to store carbon dioxide has the advantage of being non-polluting. However, the current problems, such as slow and inefficient CO 2 hydrate formation, limit its industrial application. In this study, the growth of CO 2 hydrate in electric fields was investigated by molecular dynamics simulations. We examined the effects of different electric field strengths on the rate and amount of CO 2 hydrate formation. The simulation results show that the growth of CO 2 hydrate is significantly promoted under the intensity window. It is mainly attributed to the addition of electric fields to promote the formation of cage-like structures in the system. We investigated the effect of electric fields on the solubility of the guest molecule in the CO 2 -H 2 O two-phase system. It was observed that the solubility of the guest molecule was enhanced under the intensity window. This study demonstrates the feasibility of the applied electric field to promote the growth of CO 2 hydrate and provides a molecular-scale view to explain the phenomenon. It provides some theoretical basis to encourage the capture and sequestration of CO 2 . • Specific intensity electric fields can effectively promote the growth of CO 2 hydrate. • The electric field can change water molecules' steering and reduce cage formation difficulty. • The solubility of CO 2 molecules in water can be enhanced by 4%–22% under the intensity of electric fields. • Some of the water molecules in hydrate cages can be replaced by free water during hydrate formation.