Technical Committee Underground Storage Technology

Influence of Hydrogen on Underground Gas Storage - Literature Study

Conventionally produced and transported natural gas is commonly free of hydrogen. However, gases produced from renewable energy sources and fed to natural gas transportation networks can contain hydrogen. The objective of this study is to summarize available knowledge on the behavior of gases containing hydrogen from the assessed published literature with special focus on the issue of underground gas storage.

This report outlines the aspects related to the technical and geological integrity of the underground reservoir and cavern gas, and reflects on issues and solutions for the underground storage of natural gas with added hydrogen. The issues related to the influence of added hydrogen on the capacity and energy efficiency of such underground gas storages in Germany, and the safety aspects are also outlined.

It can be conclusively stated that in particular cases the down hole equipment of the underground storage of natural gas with added hydrogen should be adapted to the new hydrogenous environment. Here, the high hydrogen diffusivity poses a risk of hydrogen-induced corrosion and imposes special requirements on the materials used. The hydrodynamic behavior of storage and the sealing ability of cap rock could also be altered because of the effect of the hydrogen present. In addition microbiological activity provides a particular risk.

Most of the issues indicated in this report are insufficiently studied. Therefore more detailed research on the technical and geological issues of the underground storage of natural gas with added hydrogen is recommended.