Rise speed of supercritical carbon dioxide spheres in aqueous surfactant solutions

Abstract

The rise speed of supercritical carbon dioxide spheres in aqueous surfactant solution was investigated experimentally. Decanonic acid was added to water as a surfactant, and then the rise speed of the CO$_{2}$ spheres was measured at pressures 5 MPa to 10 MPa and at temperatures 28 $^{\circ}$C to 40 $^{\circ}$C generating different phases of spheres, namely gas, liquid, and supercritical. The results revealed that gas bubbles and liquid droplets showed the same behaviour as a rising rigid sphere due to the adsorption of surfactant onto the surface of the spheres. In contrast, due to the absorption of surfactant into the spheres, the drag coefficient of spheres of supercritical fluid was lower than that of a rigid sphere and was similar to that of a fluid sphere with a moving boundary. This behaviour mainly occurred in the rising process of the spheres composed of supercritical CO$_{2}$.

Dynamics of droplets and bubbles coated with magnetic particles

“…A bubble released in the liquid will rise, accelerating to a point where its buoyancy force is balanced by the drag force, and obtain a constant velocity. The study of rising bubbles is driven by its importance in numerous industrial processes, such as flotation tanks and stirred gas-liquid hydrogenation reactors, etc [83][84][85][86][87][88][89][90]. A large amount of work has been done in various gas-liquid systems in this subject.…”