Document Type
Journal Article
Publication Title
Journal of Colloid and Interface Science
Volume
608
First Page
1739
Last Page
1749
Publisher
Elsevier
School
School of Engineering / Centre for Sustainable Energy and Resources
RAS ID
45361
Abstract
Hypothesis:
Actualization of the hydrogen (H2) economy and decarbonization goals can be achieved with feasible large-scale H2 geo-storage. Geological formations are heterogeneous, and their wetting characteristics play a crucial role in the presence of H2, which controls the pore-scale distribution of the fluids and sealing capacities of caprocks. Organic acids are readily available in geo-storage formations in minute quantities, but they highly tend to increase the hydrophobicity of storage formations. However, there is a paucity of data on the effects of organic acid concentrations and types on the H2-wettability of caprock-representative minerals and their attendant structural trapping capacities.
Experiment:
Geological formations contain organic acids in minute concentrations, with the alkyl chain length ranging from C4 to C26. To fully understand the wetting characteristics of H2 in a natural geological picture, we aged mica mineral surfaces as a representative of the caprock in varying concentrations of organic molecules (with varying numbers of carbon atoms, lignoceric acid C24, lauric acid C12, and hexanoic acid C6) for 7 days. To comprehend the wettability of the mica/H2/brine system, we employed a contact-angle procedure similar to that in natural geo-storage environments (25, 15, and 0.1 MPa and 323 K).
Findings:
At the highest investigated pressure (25 MPa) and the highest concentration of lignoceric acid (10−2 mol/L), the mica surface became completely H2 wet with advancing (θa= 106.2°) and receding (θr=97.3°) contact angles. The order of increasing θa and θr with increasing organic acid contaminations is as follows: lignoceric acid > lauric acid > hexanoic acid. The results suggest that H2 gas leakage through the caprock is possible in the presence of organic acids at higher physio-thermal conditions. The influence of organic contamination inherent at realistic geo-storage conditions should be considered to avoid the overprediction of structural trapping capacities and H2 containment security.
DOI
10.1016/j.jcis.2021.10.080
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Comments
Ali, M., Yekeen, N., Pal, N., Keshavarz, A., Iglauer, S., & Hoteit, H. (2022). Influence of organic molecules on wetting characteristics of mica/H2/brine systems: Implications for hydrogen structural trapping capacities. Journal of Colloid and Interface Science, 608(Part 2), 1739-1749.
https://doi.org/10.1016/j.jcis.2021.10.080