Dense gas dispersion modeling of CO2 released from carbon capture and storage infrastructure into a complex environment

Two scenarios for atmospheric dispersion relevant for consequence assessment associated with the loss of containment from carbon capture and storage related infrastructure were investigated using a physics-based mathematical model: namely, the leakage of carbon dioxide (CO2), which is a heavier-than-air (or, dense) gas, from storage tanks and transportation pipelines. Simulations of these two scenarios (viz., a storage tank release in the vicinity of a cubical obstacle and a pipeline rupture in a complex topography involving two axisymmetric hills) were performed using computational fluid dynamics, in which the density variations of the fluid (containing the dense gas) were simplified using the Boussinesq approximation. It is shown that the presence of an obstacle and/or complex terrain has a significant influence on the dispersion of the dense gas. Owing to the 'slumping' of the dense gas under the action of gravity, regions well upwind of the source of the gas release can also lie within the hazard zone. The research reported herein provides an improved model for analyzing hazards associated with the dispersion of dense gas clouds and their interaction with local building wakes and/or topographic (terrain) features and contributes to providing a sophisticated method for the assessment of safety and security related to the transportation and geological storage of CO2. (C) 2013 Elsevier Ltd. All rights reserved.