Hydrogen penetration in water through porous medium: application to a radioactive waste storage site

Abstract

Hydrogen penetration in water through porous medium was analyzed in the paper. A two-phase compositional model approach was considered. The first part of the work deals with the thermodynamic analysis of the hydrogen–water system. The thermodynamic model was calibrated using the experimental data of hydrogen solubility in water. The phase densities, viscosities and phase concentrations were presented in an analytical form. Moreover, the domain of validity of analytical laws—such as Henry’s, Raoult’s and Kelvin’s laws—for the estimation of phase properties was presented for the analyzed system. The second part deals with two-phase hydrodynamic behaviors. An analytical solution for the non-compressible flow was constructed. In general case, the influence of relative permeabilities on the flow regimes was analyzed numerically. The notion pseudo-saturation was introduced to define phase appearance. Actually, mobile gas created a time displaced front relatively slower than mobile gas flow. Diffusion becomes really important for low mobile gas case as the penetration accelerates for the large range of saturation. In contrast, the mass exchange phenomena have a small influence on the flow type. Thus, the regimes of hydrogen penetration in liquid were shown really sensitive to the relative permeability form.