Molecular mechanisms of hydrogen leakage and blockage in kaolinite nano-cracks for underground hydrogen storage

Physics of Fluids, Год журнала: 2025, Номер 37(1)

Опубликована: Янв. 1, 2025

Underground H2 storage in saline aquifers is critical for advancing the global energy transition through large-scale utilization. However, cyclic stress-induced nano-cracks caprocks may lead to leakage due small size and high diffusivity of H2. This study employed molecular dynamics simulations exploring occurrence states H2O near kaolinite surfaces, particularly focusing on when a nano-crack formed. We examined effects basal surfaces (gibbsite siloxane), water content, cushion gases (CH4 CO2). In gibbsite aquifers, formed adsorption layers; while siloxane it appeared as droplets or bridges. Upon formation, initial occurred but halted once number blocked crack. was generally higher than except at low content. Increased content significantly reduced by rapidly achieving number, whereas effect depended distribution. Cushion effectively mitigated leakage. CO2 outperformed CH4 their varied based hindering entry into crack, not only impeded also assisted blocking Our analysis density distributions, dynamics, configurations, excess chemical potentials provides insights blockage mechanisms aqueous environments caprock minerals, facilitating evaluation feasibility aquifers.

Язык: Английский

Experimental investigations on the dynamic transport characteristics of H2, CO2, and CH4 gas mixtures in shale: Implications for underground hydrogen storage

International Journal of Hydrogen Energy, Год журнала: 2025, Номер 138, С. 582 - 594

Опубликована: Май 21, 2025

Язык: Английский