(375a) Pd-Nanoparticle Enabled Optical Fiber Hydrogen Sensor for Subsurface Storage Conditions

Hydrogen is the center of attention as the hydrogen economy is expected to aid significantly in the decarbonization of the energy and transportation sectors. As more hydrogen is produced and utilized to decarbonize, more storage for surplus hydrogen will be required. One of the cost-effective methods to store hydrogen at large scale is to use underground resources such as salt caverns, aquifers, and depleted oil and gas fields. In those underground storage systems, it has been found that hydrogen concentration is subject to change due to microbial reactions and leakage through caprocks and wells. Therefore, it is critical to monitor hydrogen concentration in a real-time manner under humid and harsh subsurface conditions. We have developed an optical fiber sensor coated with palladium nanoparticle incorporated-silica composite layers to detect hydrogen over a wide range of hydrogen concentrations. The effects of palladium particle-loading and thickness of the composite layers on hydrogen sensing performance with optical fiber sensors will be discussed in the presentation. The hydrogen sensing response under different humidity and temperature conditions that simulate the subsurface hydrogen storage conditions will also be presented. The optical fiber sensor developed in this study would enable real-time hydrogen monitoring in the subsurface hydrogen storage systems in a safe and stable mode.