Séminaire 06.03.2015 – 11h00

Publié le : 06/03/2015

Alexandru Botan (Université d’Oslo), présentera un séminaire le 6 mars à 11h dans la bibliothèque du laboratoire PHENIX (7e étage, bâtiment F, porte 754) intitulé :

A bottom-up model of adsorption and transport in multiscale porous media


The accurate description of fluid transport in natural porous media is usually difficult to achieve because of its multiscale structure (ranging from nm to mm). Mass transfer in subnanopores (< 1 nm), nanopores (1 nm to 100 nm), and macropores (> 100 nm) is of different nature ; while transport in subnanopores is always diffusive, transport in nanopores and macropores, depending on pressure, can either follow the diffusive or viscous regime. The situation is even more puzzling since transport in nanopores (where the surface to volume ratio is far from negligible) must be corrected for the Knudsen diffusion or the Klinkenberg effect, which consists of taking into account possible slippage of the fluid at the pore surface.

In this talk I present a novel bottom-up approach of multiscale adsorption and transport in porous media which captures the effects of adsorption and changes in the confined fluid state. This model employs a lattice model in which accurate molecular simulations are upscaled to predict transport on larger scales. The methodology can be upscaled several times from molecular to engineering scales without losing information at the lower scale. By relying on molecular dynamics simulations, which capture the changes in transport with temperature T, pressure P, concentration c, pore size D, our approach does not require assuming any flow type (Darcy, diffusive, Knudsen, etc.). Moreover, by relating the local chemical potential μ(r) and density ρ(r) using Grand Canonical Monte Carlo simulations, the present model accounts for adsorption and possible changes in the confined fluid state which occur upon transport.