Iron-Rich Rocks for Hydrogen Geo-Storage: Induced Storage Capacity by Active Sorption

Countries and organizations globally are in a race to identify the most environmentally friendly alternative to replace fossil fuel, with hydrogen emerging as a leading candidate for a sustainable and clean energy future. However, one of the significant challenges associated with hydrogen utilization is its storage and retrieval for future use. Due to the requirement of substantial volume and high-pressure during storage, the concept of subsurface hydrogen storage has emerged. Additionally, there is a need to devise a retrieval strategy to minimize hydrogen gas losses and ensure security of underground storage. Given these considerations, concerns have been raised regarding the application of hydrogen both as a fuel and for underground storage. More significantly, there is currently no mechanism in place that ensures that hydrogen stored underground can be retrieved. This work presents the first assessment of iron minerals' potential as hydrogen storage media. The minerals assessed include magnetite, hematite, and pyrite. The process for retrieving hydrogen from the investigated iron minerals is also emphasized. The outcomes demonstrated that hydrogen can be stored in formations rich in iron minerals like magnetite and can be recovered by using chelating agents such as ethylenediaminetetraacetic acid (EDTA). Our findings suggest that there is a great deal of commercial potential because banded iron formations, which are widely distributed throughout the planet, can be utilized to store hydrogen. Thus, this work has addressed the issue of storing hydrogen underground─namely, how it may be retrieved─ensuring the security of hydrogen underground storage.