Maturity-controlled competitive adsorption of CO2-H2 and CH4-H2 gas mixtures in shale kerogen nanopores

Authors

  • Zhikai Liang Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan 430100, P. R. China;School of Geosciences, Yangtze University, Wuhan 430100, P. R. China; State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing 102249, P. R. China https://orcid.org/0000-0002-8255-8475
  • Zhenxue Jiang State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing 102249, P. R. China (Email: jiangzx@cup.edu.cn) https://orcid.org/0000-0002-2553-4573
  • Mehdi Ostadhassan Institute of Geosciences, Marine and Land Geomechanics and Geotectonics, Christian-Albrechts-Universitat, Kiel 24118, Germany https://orcid.org/0000-0001-9235-4399
  • Guangyou Zhu Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan 430100, P. R. China; School of Geosciences, Yangtze University, Wuhan 430100, P. R. China
  • Zhuo Li State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing 102249, P. R. China https://orcid.org/0000-0001-9635-9840
  • Muhammad Arif Department of Chemical & Petroleum Engineering, Khalifa University, Abu Dhabi 127788, United Arab Emirates https://orcid.org/0000-0001-7035-6000

Abstract

Organic-rich shales present significant potential for underground hydrogen storage, yet our understanding of the interactions of H2 with CH4 and CO2 in kerogen-hosted nanopores remain insufficient. This study constructs and validates macromolecular models of high-maturity and overmature kerogens via combining solid-state carbon-13 nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Grand canonical Monte Carlo and molecular dynamics simulations are performed, which reveal that kerogen maturity controls the competitive adsorption and diffusion of methane/hydrogen and carbon dioxide/hydrogen mixtures by regulating nanopore structure and surface chemical heterogeneity. Compared with high-maturity kerogen, overmature kerogen shows stronger confinement and a more pronounced near-surface enrichment of CH4 and especially CO2, which reduces the effective storage space available for H2. Mechanistically, CH4/H2 competition is driven by van der Waals interactions, whereas CO2/H2 competition is dominated by stronger electrostatic and inductive interactions, establishing a thermodynamic affinity order of CO2 > CH4 > H2. The radial distribution functions and interaction energies are measured, which confirm that CH4 and CO2 monopolize high-energy surface sites, relegating H2 to a weakly adsorbed, bulk-like state. Furthermore, molecular mobility follows the order of H2 > CH4 > CO2. Although H2 exhibits the weakest adsorption affinity, its high mobility suggests a stronger migration tendency and potential leakage risk, which should be considered when evaluating long-term containment security during UHS. Overall, this study reveals that maturity-controlled coupling exists between kerogen structure, competitive adsorption and gas transport, providing molecular-scale insights into hydrogen storage security, injectivity, leakage risk, and recovery in organic-rich shale reservoirs.

Keywords:

Longmaxi shale, 3D molecular structure reconstruction, underground hydrogen storage, competitive adsorption, kerogen, molecular simulation

Author Biographies

Zhikai Liang, Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan 430100, P. R. China;School of Geosciences, Yangtze University, Wuhan 430100, P. R. China; State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing 102249, P. R. China

Liang Zhikai, is a member of the  specially appointed associate professor. His research mainly focuses on unconventional reservoir evaluation and hydrocarbon accumulation mechanisms, with particular interests in shale reservoir pores and heterogeneity, shale gas accumulation mechanisms, macromolecular structure of kerogen, and gas-water occurrence states. He has participated in 2 projects supported by the National Natural Science Foundation of China and 2 projects commissioned by oilfield enterprises. In recent years, he has published 18 academic papers as first author or corresponding author in journals including: International Journal of Rock Mechanics and Mining Sciences, Fuel, Geoenergy Science and Engineering, and Gas Science and Engineering. He has been granted 4 invention patents. He was awarded the AAPG Global Research Grant in 2022 and 2025 by the American Association of Petroleum Geologists.

Zhenxue Jiang, State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing 102249, P. R. China (Email: jiangzx@cup.edu.cn)

Jiang Zhenxue. He is a Professor and PhD Supervisor at the Institute of Unconventional Oil and Gas Science and Technology, China University of Petroleum (Beijing), and formerly served as Vice President of the Institute. He is Director of the Oil and Gas Accumulation Mechanism Laboratory, a Key Laboratory of CNPC. He is a member of the Petroleum Geology Committee of the Geological Society of China, a member of the Unconventional Oil and Gas Geology Committee of the Geological Society of China, and Secretary-General of the Petroleum Geology Committee of the China Energy Society.

 

Mehdi Ostadhassan, Institute of Geosciences, Marine and Land Geomechanics and Geotectonics, Christian-Albrechts-Universitat, Kiel 24118, Germany

Mehdi Ostadhassan is affiliated with Kiel University in Germany and has contributed extensively to the field of engineering, with a focused expertise in hydrocarbon exploration and reservoir analysis. Their research spans multiple interconnected domains, reflecting a multidisciplinary approach combining engineering principles with geological and chemical analyses.

Guangyou Zhu, Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan 430100, P. R. China; School of Geosciences, Yangtze University, Wuhan 430100, P. R. China

Zhu Guangyou, male, He serves as Director of the Energy Faculty, Dean of the School of Geosciences, Yangtze University, Director of Hubei Key Laboratory of Geology and Development of Complex Marine Shale Oil and Gas in South China, and Leader of the Deep and Unconventional Oil & Gas Research Team. He is a Level-2 Professor and doctoral supervisor.   He has been selected into the National High-Level Talent Special Support Program, the Leading Talent in Science and Technology Innovation for Young and Middle-Aged Scholars of the Ministry of Science and Technology, and is a Fellow of the China Invention Association, a Fellow of the Geological Society of China, and a recipient of the CNPC Model Worker and Craftsman Talent Innovation Studio.   He has received numerous awards, including the Qiushi Outstanding Youth Achievement Transformation Award by the China Association for Science and Technology, the Guanghua Engineering Science and Technology Award, the China Youth Science and Technology Award, the Hou Defeng Young Scientist Award, the Golden Hammer Award, and the Sun Yueqi Award. He has been honored with titles such as Contemporary Inventor, Beijing Great Inventor Artisan, Hubei May 1st Labor Medal, Top Ten Outstanding Young Persons of the 6th Session of CNPC, and Outstanding Young Post Expert of CNPC.   He has been consecutively listed among the World's Top 2% Scientists and Highly Cited Researchers, and was awarded the title of Influential Scientist of the 2022 Science and Technology Person of the Year, the Distinguished Scientist Award by Elsevier Gas Science and Engineering, and the Outstanding Contribution Award by the China Association for the Promotion of Science and Technology Industrialization.  

Zhuo Li, State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing 102249, P. R. China

Li Zhuo, male, Han nationality, born in July 1983 in Suihua, Heilongjiang Province, PhD, associate research fellow. He graduated from the College of Earth Sciences, Jilin University in 2006 with a bachelor’s degree in Resource Exploration Engineering. He obtained his master’s degree in Mineral Resource Prospecting and Exploration from China University of Petroleum (Beijing) in 2009, and his doctoral degree in Geological Resources and Geological Engineering from China University of Petroleum (Beijing) in 2013. In the same year, he joined the faculty of China University of Petroleum (Beijing). Research Interests: Unconventional reservoir evaluation and hydrocarbon accumulation mechanism - Petroleum-bearing basin analysis - Formation and distribution of conventional and unconventional oil and gas - Conventional and unconventional oil and gas resource assessment

 

Muhammad Arif, Department of Chemical & Petroleum Engineering, Khalifa University, Abu Dhabi 127788, United Arab Emirates

Dr. Muhammad Arif is working as an Assistant Professor in the Petroleum Engineering Department of Khalifa University. Previously, he worked at King Fahd University of Petroleum & Minerals (KFUPM), Saudi Arabia.

He holds a Ph.D. degree in Petroleum Engineering from Curtin University, Western Australia, and B.Sc. and M.Sc. degrees in Petroleum Engineering. His teaching interests include Well Testing, Well Stimulation, and Enhanced Oil Recovery.

Dr. Arif is currently leading two research projects as a principal investigator – and the key focus of these projects is to understand the rock/fluid interactions at multiple scales. He has published 90+ articles in reputable journals with a citation h-index of 26, including publications in the Top 1 percent ranked journals. His research interests include enhanced oil recovery, CO2 and H2 geo-storage, and unconventional reservoirs.

Furthermore, he currently holds the honor of working as an Associate Editor at the Journal of Petroleum Science & Engineering, Elsevier. He has also been a Guest Editor at Frontiers in Earth Science. He has chaired/co-chaired technical sessions at International conferences. Moreover, he is an active reviewer for several scientific journals. He has recently had the honor to be ranked in Stanford's list of the top 2 percent of scientists in the world in the field of Energy for two consecutive years (2021 and 2022). 

He also received the prestigious award for Research Excellence in the College of Engineering at Khalifa University. 

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Published

2026-06-21

How to Cite

Liang, Z., Jiang, Z., Ostadhassan, M., Zhu, G., Li, Z., & Arif, M. (2026). Maturity-controlled competitive adsorption of CO2-H2 and CH4-H2 gas mixtures in shale kerogen nanopores. Advances in Geo-Energy Research, 20(3). Retrieved from https://ager.yandypress.com/index.php/2207-9963/article/view/863

Issue

Vol. 20 No. 3 (2026): June (In progress)

Section

ARTICLES

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Copyright (c) 2026 Zhikai Liang, Zhenxue Jiang, Mehdi Ostadhassan, Guangyou Zhu, Zhuo Li, Muhammad Arif

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