Visualization of the dissolution behavior of a CO₂ droplet into seawater using LIF

Sequestration of liquid CO₂ in the intermediate depth ocean has been considered as a means to reduce the atmospheric concentration of the greenhouse gas and to mitigate global warming. The dissolution behavior of CO₂ in pure or seawater was investigate under high-pressure and low-temperature conditions in the intermediate ocean. Under these conditions, the CO₂ clathrate hydrate film was formed at the interface between CO₂ and (sea) water. The hydrate film has been considered to affect and decrease the dissolution rate. The LIF technique was used in the experiments. LIF intensity showed the pH of CO₂ dissolved water, while the CO₂ droplet itself did not illuminate. Therefore, we could know the dissolution rate of CO₂ and the nonuniform two-dimensional CO₂ concentration distribution during the CO₂ dissolution, with or without the CO₂ hydrate film, in pure or seawater.