Numerical simulation on mesoscale diffusion of CO₂ sequestrated in the deep ocean in practical scenario

Among possible carbon capture and storage (CCS) methods to mitigate the global warming, the direct injection of carbon dioxide (CO₂) into the deep ocean by the moving ship method, is considered to be a feasible way and expected to minimize its environmental impacts on marine organisms in the vicinity of the injection points. In this study, a simple but effective numerical model for the given practical scenario of very large system was developed with adopting moving and nesting grid technique and low-wavenumber forcing technique. The calculated results show that the maximum change of PCO₂ (APCO₂) is lower than a given criteria, +5,000 µatm, in the both small- and mesoscale domains. This indicates that the scenario of 30 ships with different length of injection pipes injecting total CO₂ of 50 million t/yr and moving in the 110 x 330 km operation area is efficient and effective. The developed techniques demonstrated its efficiencies and applicability to give an outline for the optimization of the CO₂ ocean sequestration system, by which biological impacts should be minimized and insignificant. ©2008 IEEE.