Revisiting Hydrogen Sorption-Desorption in Natural Rocks

Area of Science:

• Geochemistry
• Environmental Science
• Energy Science

Background:

• Hydrogen sorption/desorption in rocks is crucial for subsurface energy and environmental applications.
• Understanding these interactions is vital for applications like underground hydrogen storage and radioactive waste containment.
• Current knowledge on how these physical interactions affect hydrogen behavior in geological materials is limited.

Purpose of the Study:

• To review experimental and theoretical studies on hydrogen sorption and desorption in natural rocks.
• To evaluate sorption capacities, influencing parameters, and hysteresis across different lithologies.
• To identify the best-fitting isotherm models for hydrogen sorption data.

Main Methods:

• Literature review of experimental and theoretical studies.
• Atomistic simulations and isotherm modeling.
• Data analysis of sorption capacities, influencing parameters, and hysteresis.
• Modeling of available data using multiple isotherm models.

Main Results:

• Sorption capacities vary significantly across different rock types (lithologies).
• Key parameters influencing sorption and desorption, along with hysteresis, were identified.
• The study identified the most suitable isotherm models for describing hydrogen sorption data.
• The review delineates conditions where physical sorption-desorption is significant versus negligible.

Conclusions:

• Physical sorption-desorption plays a critical role in hydrogen transport and retention in specific geological settings.
• Understanding these processes is essential for effective hydrogen storage, exploration, and waste containment.
• Identified data gaps and proposed future research directions to improve hydrogen behavior understanding in geological formations.