Biogeochemical reactivity during underground hydrogen storage in a carbonate aquifer in Belgium
E001
Abstract
Underground hydrogen storage (UHS) in deep geological reservoirs is a promising technology for large-scale renewable energy storage. In this technology, hydrogen is injected into a geological reservoir during peak production times and withdrawn months later, when the demand for renewables exceed its production. However, hydrogen injection into the subsurface alters the chemical potential, resulting in a reducing environment that may trigger geochemical and microbial reactivity. This can lead to hydrogen conversion and loss, introduction of impurities, and pore clogging, impacting storage efficiency. Carbonate reservoirs, which make up a quarter of the potential UHS sites in Europe, are theoretically more susceptible to these types of reactivity. This is also true for pyrite-containing reservoirs, as the latter can react with hydrogen in redox reactions.
In my research, I investigate the extent and interactions of these reactive processes during underground hydrogen storage through a series of batch experiments conducted under both high- and low-pressure conditions. These experiments provide insights that support the interpretation of a hydrogen storage pilot test in a karstified carbonate aquifer located in Loenhout, Belgium.