TY - JOUR
T1 - Influence of organic molecules on wetting characteristics of mica/H2/brine systems: Implications for hydrogen structural trapping capacities
AU - Ali, Muhammad
AU - Yekeen, Nurudeen
AU - Pal, Nilanjan
AU - Keshavarz, Alireza
AU - Iglauer, Stefan
AU - Hoteit, Hussein
N1 - KAUST Repository Item: Exported on 2021-11-05
Acknowledgements: The authors acknowledge Mr. Antonio García, a scientific illustrator from King Abdullah University of Science and Technology, Saudi Arabia for producing the graphical abstract.
PY - 2021/10/19
Y1 - 2021/10/19
N2 - 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 106.2°) and receding 97.3°) contact angles. The order of increasing and 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.
AB - 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 106.2°) and receding 97.3°) contact angles. The order of increasing and 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.
UR - http://hdl.handle.net/10754/673114
UR - https://linkinghub.elsevier.com/retrieve/pii/S0021979721017574
U2 - 10.1016/j.jcis.2021.10.080
DO - 10.1016/j.jcis.2021.10.080
M3 - Article
C2 - 34742087
SN - 0021-9797
VL - 608
SP - 1739
EP - 1749
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
ER -