Energy storage in the geological subsurface: impact of salt precipitation in porous media

01 January 2020 → Ongoing
Research Foundation - Flanders (FWO)
Research disciplines
  • Natural sciences
    • Hydrogeology
energy storage salt porous media
Project description

Renewable energy sources such as wind and solar are important to
combat climate change. Because their output is variable over time,
storing energy when there is a surplus to use at times of high
demand would be very valuable. A promising technology to do this at
large scale is to pump compressed air or hydrogen in the pores of
subsurface rock formations. However, salts from the brine originally
present in these pores may crystallize out and block the flow of
storage gas. Despite its large impact on storage operations, it is
currently poorly understood where and in which circumstances this
takes place, due to the interplay between the physics of the process
and geological heterogeneity.
Here, we propose to investigate this from the scale of pores up to
storage reservoirs (km-scale). We will contribute a better
fundamental understanding of salt blockage by tracking salt
precipitation on a pore-by-pore basis with high-resolution X-ray
imaging, and directly linking this to gas flow. We hypothesize that
successful upscaling of this pore-scale model has to take small-scale
heterogeneity (e.g. mm-scale “layering”) into account. We will do this
through a combined experimental-numerical approach. Finally, we
will test the impact of the newly developed models by implementing
them in reservoir-scale simulations. This will give novel and accurate
insights on the impact of salt crystallization on these promising
energy storage technologies.