A discussion on hydrogen migration in rock salt for tight underground storage with an insight into a laboratory setup

Hydrogen is being regarded as a primary vector in the energy transition process towards a less polluted planet. The tremendous and increasing energy demands necessitate finding large-scale storage techniques. Underground salt caverns seem to be promising. Nevertheless, the fast solicitations (thermal and mechanical) of these caverns, to reply to the fast demands, imply damage to the ambient rock salt. There is a general scientific ambiguity about the transport mechanisms taking place in the rock salt intact/damaged, particularly for hydrogen. In this paper we provide a detailed review about these transport mechanisms while the cavern undergoes cycling. This review helped us define a mathematical approach to simulate hydrogen migration in the rock salt around underground caverns. We ended up by presenting a patent laboratory setup that we are currently using to define any required model parameters experimentally.