InterPore2026

Pore-Scale Reactive Transport Controls on Subsurface Hydrogen Production via Pyrolysis and Serpentinization

20 May 2026, 10:05

1h 30m

Poster Presentation (MS06) Interfacial phenomena across scales Poster

Speaker

Mr Elhadj Marwane Diallo (KAUST)

Description

Subsurface hydrogen production via organic matter pyrolysis and serpentinization is emerging as a promising geo-energy pathway for low-carbon energy systems. However, hydrogen generation, migration, and retention are strongly governed by pore-scale reactive transport and interfacial processes that remain insufficiently constrained under reservoir conditions. In particular, mineral and organic surface alterations induced by pyrolysis by-products and serpentinization reactions can significantly modify wettability, capillary forces, and hydrogen mobility.

In this study, we investigate the evolution of pore-scale interfacial properties that control hydrogen behavior in geological formations undergoing pyrolysis- and serpentinization-driven alterations. Experiments are conducted under representative subsurface conditions (5–20 MPa, 308–343 K, 10 wt.% NaCl brine). Equilibrium contact angles, solid–liquid interfacial tension, and solid–gas interfacial tension are quantified by combining Young’s equation with Neumann’s equation of state. Mica is used as a caprock proxy and systematically modified to simulate (i) pyrolysis-derived organic coatings through controlled aging with fatty acids of varying chain lengths and concentrations, and (ii) serpentinization-like mineral transformations via alumina nanoparticle aging at different loadings.

The results show that organic coatings formed during pyrolysis markedly enhance hydrogen-wet conditions, promoting hydrogen mobility and weakening capillary sealing efficiency. In contrast, serpentinization-induced mineral alterations exhibit non-monotonic wettability behavior, with nanoparticle concentration governing transitions between water-wet and hydrogen-wet regimes. These findings highlight the strong coupling among reactive transport processes, surface chemistry, and pore-scale hydrogen flow. A comparison with carbon dioxide systems further reveals that hydrogen exhibits systematically lower wettability under similar conditions, implying a higher propensity to leak if interfacial effects are not adequately accounted for.

Overall, this work provides new pore-scale insights into reactive interfacial mechanisms critical for evaluating subsurface hydrogen production, containment, and the performance of geo-energy systems.