Numerical simulation of the leakage and diffusion of CO2 in CCS transportation pipelines

This paper aims to develop a CFD model to calculate the leakage and unsteady atmospheric diffusion of CO2 from the transport pipelines in Carbon Capture and Storage (CCS) system. The influences of wind profiles, wind speeds, atmospheric stabilities and ground surface roughness on the diffusion of CO2 are numerically investigated. Under different wind profiles, the mass fractions of CO2 in the horizontal and vertical directions are different. As the wind speed increases, the time to reach the stability of CO2 diffusion and the mass fraction of CO2 in the vertical direction both decrease. The strong atmospheric instability is not useful for the diffusion of CO2 in the horizontal direction. The tougher ground surface is advantageous to the formation of the vertical turbulent fluctuation. However, the horizontal diffusion of CO2 is blocked and the time to achieve the diffusion stability increases.