Review of gas mixing processes in underground hydrogen storage (UHS)

The growing interest in hydrogen as a clean energy carrier has increased the significance of safe and efficient storage solutions. Underground storage has emerged as a key strategy. Understanding gas mixing processes, primarily diffusion and dispersion, is crucial to the success of underground hydrogen storage. These processes are essential for determining the hydrogen distribution within the storage reservoir, which impacts safety, efficiency, and overall storage performance.

This is literature review about the mixing processes occurring in underground hydrogen storage. The different processes should be identified and described. The focus is on molecular diffusion and mechanical dispersion. Furthermore, it should be analysed how these mixing processes impact the storage process.

• Ho, C.K. and Webb, S.W. (2006), Gas Transport in Porous Media, Vol. 20, Springer Netherlands.
• Heinemann, Niklas; Alcalde, Juan; Miocic, Johannes M.; Hangx, Suzanne J. T.; Kallmeyer, Jens; Ostertag-Henning, Christian et al. (2021): Enabling large-scale hydrogen storage in porous media – the scientific challenges. Energy & Environmental Science 14 (2), pp. 853–864.