A hierarchical multi-scale method to simulate reactive–diffusive transport in porous media

A time-dependent, hierarchical multi-scale model to simulate reactive–diffusive transport in a 3-dimensional, porous structure, using a combination of molecular dynamics (MD), kinetic Monte-Carlo (KMC) and Monte-Carlo diffusion (MCD) methods has been developed. The parameters that are passed from the models at the lower spatial and temporal scales (MD, KMC) to those at the higher scales (KMC, MCD respectively) are identified. The advantages and disadvantages of the different methods are discussed with respect to reactive–diffusive transport simulations of atoms in porous 3D structures. The model is illustrated by simulating hydrogen transport, reactions, inventory and re-emission from a porous hydrocarbon layer.