Experimental Studies on Liquid CO2 Injection with Hydrate Film and Highly Turbulent Flows Behind the Releasing Pipe

Publisher Summary CO 2 ocean sequestration is considered to be an effective global warming countermeasure. One of CO 2 ocean sequestration methods is releasing liquid CO 2 droplets in intermediate depth of ocean, which leads to direct dissolution of CO 2 in seawater. To discuss implementation of CO 2 ocean sequestration, it is necessary to evaluate dissolution process of CO 2 in seawater. Released liquid CO 2 droplets from a towed pipe are dispersed into the sea vertically due to buoyancy effect and horizontally due to turbulent mixing behind the pipe. In terms of vertical dispersion of CO 2 , initial droplet size is of importance because velocity of droplet rising due to buoyancy and surface area of dissolve droplet are dominated by droplet size, while in horizontal dispersion, turbulent mixing behind the pipe have a key role. This chapter presents two different types of experiments related to releasing CO 2 into the ocean by a towed pipe: (1) investigation of injection behaviors of liquid CO 2 with hydrate, varying injection velocity, and surrounding temperature, and (2) visualization of highly turbulent flow over the critical Reynolds number around a circular cylinder simulating the towed pipe.