Anders Malthe-Sørenssen: Fracturing-assisted reactive transport - a natural mechano-chemical process of relevance to CO2 storage

The slow growth of a crack in windshield represents a mechano-chemical process: The stress at the tip of the fracture is not high enough to cause rapid fracture motion. Instead, fracture motion is determined by the diffusion of hydrogen to the crack tip, where it weakens the material, leading to crack tip propagation. The velocity of the fracture depends on the coupling between deformation, transport, and reactions. Similar coupled processes determine the rate of many reaction processes of geological relevance, such as weathering and carbonation during mineralogical CO2 sequestration. We have developed numerical model that allow us to address mechano-chemical processes during fluid infiltration. The model demonstrates that fracturing assisted reaction fronts in shrinking materials propagate with a constant velocity and width, and that the reaction rate in volume increasing reactions may be accelerated by feedback processes between fluid flow, mechanical deformation, and reactions.

Anders Malthe-Sørenssen is professor at the Department of Physics, working at the center for Physics of Geological Processes