Presentation Information
[U05-P03]Thermal and Mechanochemical Approaches for Hydrogen Generation from Water–Rock Reactions in Peridotite
*Ryota Gemma1, Haru-Hisa Uchida1 (1.Tokai University)
Keywords:
Natural hydrogen,White hydrogen,Mechanochemistry
As global demand for hydrogen as a carbon-free fuel increases, naturally generated underground hydrogen is gaining significant attention as a potentially large hydrogen resource. Previous research has suggested that the primary formation mechanism of natural hydrogen is serpentinization of iron-bearing lithologies, such as peridotites, through interaction with water under high-pressure and high-temperature subsurface conditions. Hydrogen gas can be generated in the subsurface or even from the ocean floor as long as these conditions are satisfied. However, the controlling factors governing hydrogen generation through such water–rock reactions have not yet been fully understood.
Mechanochemical treatments, such as ball-milling processes, are often used to promote various chemical and metallurgical reactions rapidly or to achieve far-from-equilibrium conditions by locally generating high pressure and temperature at impact points. In other words, the hydrogen-generation conditions described above may also be reproduced using mechanochemical processes in the presence of water and peridotites. Considering the dynamic activity of subsurface geological layers, mechanical driving forces should also be taken into account when investigating natural hydrogen generation behavior.
In this study, we conducted preliminary investigations of water–rock reactions and the accompanying hydrogen generation induced by mechanochemical treatment, together with additional external heating to accelerate the reactions and investigate the reaction mechanisms under such conditions. The resulting hydrogen-generation behavior is compared and discussed with that obtained solely from thermal reactions.
Mechanochemical treatments, such as ball-milling processes, are often used to promote various chemical and metallurgical reactions rapidly or to achieve far-from-equilibrium conditions by locally generating high pressure and temperature at impact points. In other words, the hydrogen-generation conditions described above may also be reproduced using mechanochemical processes in the presence of water and peridotites. Considering the dynamic activity of subsurface geological layers, mechanical driving forces should also be taken into account when investigating natural hydrogen generation behavior.
In this study, we conducted preliminary investigations of water–rock reactions and the accompanying hydrogen generation induced by mechanochemical treatment, together with additional external heating to accelerate the reactions and investigate the reaction mechanisms under such conditions. The resulting hydrogen-generation behavior is compared and discussed with that obtained solely from thermal reactions.