Thermal and Kinetic Modeling of Microbial Reactions during Underground Hydrogen Storage

Underground Hydrogen Storage (UHS) is a promising form of clean energy storage that enables the sustainable use of Hydrogen-Powered Systems on a seasonally-consistent basis. Similar to Carbon Sequestration, a question that arises is how do underground microbial communities react to an increase in hydrogen concentration, as there is still no general consensus nor quantitative effect of the microbial activity on Hydrogen reaction rate. In this study, two models are developed using PHREEQC to observe the biotic redox reactions that occur underground. Specifically, the catalytic effects of bacterial activity in methanogenesis, acetogenesis and sulfate-reduction reactions are observed. The first model is controlled by kinetics and threshold energy thermodynamic constraints, and the second is controlled by a microbial kinetic model. These models are then applied to recorded cases of Underground Hydrogen Storage in literature in order to calibrate models for correct hydrogen reactivity. Through conducting these modeling studies, we can increase confidence in our ability to assess hydrogen reactivity in future Underground Hydrogen Storage (UHS) projects within aquifers or depleted reservoirs.