Experimental study of CO2 hydrate formation under an electrostatic field

The hydrate-based CO2 capture and storage technique is cutting-edge and promising, but it exhibits slow formation rates and insufficient gas storage capacity, making commercialization challenging. In this work, the CO2 hydrate formation process in fresh water, memory water, and saltwater systems under the electrostatic field was studied, and the influence mechanism of the electrostatic field on the CO2 hydrate formation was discussed. Experimental results showed that the nucleation and growth of CO2 hydrate could be affected by the electrostatic field. The nucleation of CO2 hydrate could be promoted in the presence of an electrostatic field. In the fresh water system, the completion of hydrate formation was 54.5% faster with the 150 V application compared to the one without the electrostatic field. The introduction of an external electrostatic field causes a further reduction in the system's free energy. In the memory water system, the residual hydrate cage fragments could promote the reformation process of hydrate. Nevertheless, the presence of the electrostatic field could weaken the memory effect. In the salt water system, the electrostatic field could promote hydrate formation after the stage of dissolution. Due to the collision of ions with hydrate nuclei, however, the completion time of hydrate formation was increased. This study is anticipated to provide novel insights into the promotion of hydrate formation through the implementation of an electrostatic field.