Speaker
Description
Natural hydrogen, as a clean and carbon-free energy carrier, plays an important role in the global energy transition and the low-carbon development of modern industries. However, the location of natural hydrogen reservoirs is difficult to predict, due to the lack of a targeted theoretical framework for exploration. Peridotite serpentinization serves as the primary mechanism for natural hydrogen generation. Given the extremely low solubility of hydrogen in brine, a rock-hydrogen-brine three-phase system readily forms. Consequently, the generation, migration, and accumulation of natural hydrogen in formations are directly controlled by the wettability of the peridotite surface.
In this study, the contact angles of hydrogen bubbles onto peridotite in brine were measured. The impacts of brine compositions (i.e., NaCl, KCl and CaCl2 with different concentrations) and temperature in the range of 300-580 K are investigated. The results show that there is an alteration of wetting tendency in NaCl solution at temperatures ranging from 400 to 430 K: a maximum hydrophilicity is observed within this temperature range while showing less hydrophilicity below and above this temperature range. In DI water, this transition temperature occurs around 480 K. However, a monotonic trend is observed for the hydrogen wettability in CaCl2 and KCl solution as the temperature increases, separately. We propose a theoretical model, on the basis of Young-Laplace equation, to demonstrate the maximum accumulation/storage of the hydrogen under formation conditions of 5 MPa pressure, approximately 403 K temperature, and 5 wt% NaCl brine. The capillary resistance may prevent a hydrogen column with heigh of 224.8 m from migration and escaping from the formation. Within a 1 km × 1 km formation area, this corresponds to a hydrogen storage potential of approximately 1.33 × 10⁴ t. This study provides implications for the optimum formation environments (i.e., pressure, temperature, salinity and salt types) for the accumulation/storage of hydrogen in subsurface.
| Country | China |
|---|---|
| Student Awards | I would like to submit this presentation into both awards |
| Acceptance of the Terms & Conditions | Click here to agree |
