Webinar: In-situ visualization of microbial hydrogen consumption using high-resolution PET-MRI

The Norwegian research school on hydrogen and hydrogen-based fuels (HySchool) at the University of Bergen invites for a webinar where the CSSR PhD students, Raymond Mushabe, will present his research topic. The webinar is open for all interested. 

Link to the webinar can be found at the bottom of the HySchool website!

Raymond Mushabe, CSSR PhD student, UiB

Abstract: In-situ visualization of microbial hydrogen consumption using high-resolution PET-MRI

The efficiency of short- and long-term underground hydrogen storage UHS in subsurface porous media is one of the limiting technical challenges facing the renewable energy industry. The stored H2 is one of the most important electron donors for many subsurface microbial processes, e.g., microbialinduced sulphate reduction and methanogenesis, which can convert H2 to H2S and CH4, causing permanent gas loss and H2 contamination. Therefore, understanding the microbial H2 metabolisms is essential for estimating the storage and withdrawal efficiency in UHS and improving the selection criteria for future storage sites. A halophilic sulfate-reducing stain was used as the model bacterium to quantitatively assess the consumption of H2 in in 6 cm x 1.5 cm sand and glass bead packs. The bacterium can utilize H2 as electron donor and sulfate as electron acceptor producing H2S, for growth. Besides, the high accumulation of bacteria can form biofilms and cause pore-clogging. In this study, state-of-the art visualization techniques were utilized to study hydrogen consumption and bacteria growth in 6 cm x 1.5 cm sand and glass bead packs. A multi-modal magnetic resonance imaging (MRI)- positron emission tomography (PET) scanner was used to study both static and dynamic phenomena, respectively. Sand and glass bead packs were saturated with bacteria solution (a sulphate-reducer oleidesulfovibrio alaskensis), both without and in the presence of hydrogen. The whole experiment was conducted under anaerobic conditions for the bacteria to survive and grow. In-situ visualization provided insight into the dynamics of bacterial growth and hydrogen consumption rates: MRI provided information on the spatial fluid saturation at micrometer scale. PET provided fluid displacement dynamics during injection. of brine, nutrients and bacteria at high temporal resolutions. We, hence, observed bacterial growth and fluid flow redistribution at resolutions not previously used to study these phenomena at the core scale.