Influence of organic molecules on wetting characteristics of mica/H2/brine systems: Implications for hydrogen structural trapping capacities

Muhammad Ali; Nurudeen Yekeen; Nilanjan Pal; Alireza Keshavarz; Stefan Iglauer; Hussein Hoteit

doi:10.1016/j.jcis.2021.10.080

Influence of organic molecules on wetting characteristics of mica/H₂/brine systems: Implications for hydrogen structural trapping capacities

J Colloid Interface Sci. 2022 Feb 15;608(Pt 2):1739-1749. doi: 10.1016/j.jcis.2021.10.080. Epub 2021 Oct 18.

Authors

Muhammad Ali¹, Nurudeen Yekeen², Nilanjan Pal³, Alireza Keshavarz⁴, Stefan Iglauer⁴, Hussein Hoteit⁵

Affiliations

¹ Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia; Western Australia School of Mines, Minerals, Energy and Chemical Engineering, Curtin University, Kensington 6151, Western Australia, Australia. Electronic address: Muhammad.ali.2@kaust.edu.sa.
² Department of Chemical & Petroleum Engineering, Faculty of Engineering, Technology and Built Environment, UCSI University, 56000 Kuala Lumpur, Malaysia.
³ Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia.
⁴ School of Engineering, Edith Cowan University, Joondalup 6027, WA, Australia.
⁵ Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia. Electronic address: Hussein.hoteit@kaust.edu.sa.

PMID: 34742087
DOI: 10.1016/j.jcis.2021.10.080

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 (θ_a= 106.2°) and receding (θ_r=97.3°) contact angles. The order of increasing θ_a and θ_r 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.

Keywords: Caprock formation; Hydrogen geo-storage; Organic acids; Wettability.

MeSH terms

Aluminum Silicates
Hydrogen*
Salts
Wettability

Substances

Aluminum Silicates
Salts
brine
Hydrogen
mica