{"title":"Numerical evaluation of fingering behavior for hydrogen in aquifers","authors":"Cunqi Jia , Jinchuan Hu , Kamy Sepehrnoori","doi":"10.1016/j.jgsce.2025.205667","DOIUrl":"10.1016/j.jgsce.2025.205667","url":null,"abstract":"<div><div>Underground hydrogen storage emerges as a strategy to address the challenge of large-scale, long-term, and economically viable hydrogen preservation, fulfilling energy demands and balancing supply discrepancies in renewable energy frameworks. This study is motivated to investigate and evaluate the fingering behavior during the hydrogen injection process. Numerical cases are performed to evaluate different simulation scenarios and sensitive influencing factors, such as fluid-rock interaction parameters and formation heterogeneity cases, on the influence of fingering flow. Different mesh upscaling schemes are compared to computational efficiency in the scale-up hydrogen injection process. Results show that fingering flow can indeed be induced during the hydrogen injection process due to the difference in flow capability between hydrogen and saline water. The characteristics of fingering flow significantly impact the performance of hydrogen displacement in saline aquifers. The hydrogen displacement path in the saline aquifer is highly sensitive to variations in the autocorrelation length. Compared to the averaging upscaling scenario, the same-statistic upscaling scenario can prevent a significant loss of numerical simulation characteristics.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205667"},"PeriodicalIF":0.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analysis of the freezing circle and energy consumption for underground LNG storages in fractured rocks","authors":"Zipeng Zhang, Yun Chen, Yuliang Zhang, Guowei Ma","doi":"10.1016/j.jgsce.2025.205670","DOIUrl":"10.1016/j.jgsce.2025.205670","url":null,"abstract":"<div><div>Accurate prediction of the freezing process in underground liquefied natural gas (LNG) storages plays an important role in enhancing the sealing effect of surrounding rocks and the economic benefits of the storage system. This study established a freezing circle extension model of underground refrigerated storage based on the hydrothermal coupled method with nonlinear seepage effects in fracture networks. A novel method for analyzing energy consumption during the storage process is then presented. The effects of cavern parameters, seepage in the fracture network, and grouting on the freezing circle expansion process and energy consumption are further investigated. The results show that the proper expansion of the cavern is conducive to accelerating the growth of the freezing circle and reducing the energy consumption per unit volume of LNG storage. Setting the thickness of the polyurethane insulation layer up to 50 mm can effectively reduce energy consumption and ensure the emergence of freezing circles in a short time. The seepage within the fracture network inhibits the expansion of freezing circles and increases the energy consumption of the storage system. The increase in the groundwater pressure gradient and the connectivity of the fracture network will exacerbate the adverse effects of seepage on freezing circles. However, a grouting depth that matches the storage cycle allows the freezing circle expansion process and energy consumption to be virtually unaffected by fracture seepage.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205670"},"PeriodicalIF":0.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Minghan Li , Ze Deng , Erfan Mohammadian , Mehdi Ostadhassan , Yubin Ke , Zhejun Pan , Mengdi Sun
{"title":"Pore-scale distribution of primary water in deep coal reservoirs: Implications for methane recovery and CO2 sequestration","authors":"Minghan Li , Ze Deng , Erfan Mohammadian , Mehdi Ostadhassan , Yubin Ke , Zhejun Pan , Mengdi Sun","doi":"10.1016/j.jgsce.2025.205665","DOIUrl":"10.1016/j.jgsce.2025.205665","url":null,"abstract":"<div><div>The distribution of formation water in the pore system of deep-coal reservoirs significantly influences natural gas adsorption, transport, and its production in coalbed methane (CBM). However, previous studies primarily relied on simulation or experiments of water core flooding, neglecting the initial state of the samples, specifically formation (primary) water distribution. Therefore, to fill this knowledge gap, this study characterizes the initial distribution of formation water in coal samples through a comprehensive experimental analysis of both dried and undried (natural as received) coal samples retrieved from two different wells. To do so, small angle neutron scattering (SANS), N<sub>2</sub> and CO<sub>2</sub> physisorption, and contrast-matching SANS (CM-SANS) were employed to assess pore structure and accessibility to toluene under ambient conditions. Results indicate that formation water that is occupying pore spaces, reduces toluene accessibility in natural samples compared to dried ones. Furthermore, formation water is predominantly occupying pores of 1–10 nm in size, with water saturation inversely correlated with the pore size. Water saturation is also influenced by clay minerals and the organic matter content of the samples, particularly the vitrinite maceral group in comparison to inertinite. Collectively, these findings provide critical insights for better optimization of coalbed methane recovery and assessing coal reservoirs for CO<sub>2</sub> sequestration through a better understanding of water-hydrocarbon-pore interactions.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205665"},"PeriodicalIF":0.0,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stella I. Eyitayo , Talal Gamadi , Oladoyin Kolawole , Marshall C. Watson
{"title":"Experimental study of scCO2 injection strategies: Effects on geochemical reactions and reservoir properties in sandstone and carbonate formations","authors":"Stella I. Eyitayo , Talal Gamadi , Oladoyin Kolawole , Marshall C. Watson","doi":"10.1016/j.jgsce.2025.205660","DOIUrl":"10.1016/j.jgsce.2025.205660","url":null,"abstract":"<div><div>Carbon dioxide (CO<sub>2</sub>) storage in geological formations is a promising strategy for mitigating greenhouse gas emissions. However, the injection of supercritical CO<sub>2</sub> (scCO<sub>2</sub>) induced a geochemical reaction in the host rock. While the different causes of these reactions have been studied, the effects of different injection strategies are understudied. This study uses core-flooding equipment to investigate the effects of three different scCO<sub>2</sub> injection strategies-continuous scCO<sub>2</sub> injection (CCI), Water or Brine alternating scCO<sub>2</sub> injection (WAG), and Simultaneous brine or water and scCO<sub>2</sub> Aquifer injection (SAI)- on the petrophysical, mineralogy, and microstructural properties of the Gray Berea sandstone and Indiana limestone sample using X-ray diffractometer (XRD), CoreLab UltraPore<sup>TM</sup>300 Ultra K 500<sup>+</sup> and Scanning Electron Microscope-Energy-Dispersive X-ray Spectroscopy (SEM-EDS). Core-flooding experiments were conducted under dynamic flow conditions at 75, 225, and 525 pore volumes (PV) to simulate short-, intermediate-, and long-term CO<sub>2</sub> storage scenarios. Sandstone permeability dropped most under WAG and SAI (∼35 %), with CCI showing a 6.8 % reduction. Carbonate porosity showed an overall gain of 2.5 %–3.3 %, increased permeability under CCI (20.3 %), WAG (4.8 %), and declined under SAI. Elemental analysis showed up to a 50 % increase in Ca and 40.6 % in C in sandstone (CCI), indicating significant carbonate precipitation, while limestone samples exposed to SAI exhibited Al and Si increases of up to 550 % and 322.2 %, respectively, highlighting more intense silicate mineral formation compared to sandstone with microstructural changes observed across all injection methods, especially at extended exposure durations.</div><div>These changes are primarily driven by the dissolution of the host rock, acidification, saturation effects, fluid-rock interaction dynamics, etc. The sequence of the dissolution, precipitation, formation of new minerals, and fine migrations also contributes to alterations in pore structures and fluid flow pathways. WAG indicates a balanced approach to the other two injection strategies. However, the reduction in permeability is not desirable.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205660"},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Siyu Chen , Xi Li , Guangyou Zhu , Zhiyuan Lu , Ruilin Wang , Yue Huang , Wanyan Lan , Fanchen Jia , Yanqing Zhu
{"title":"Classification, controlling factors, and multi-scale characterization techniques in shale reservoir pores: A comprehensive review","authors":"Siyu Chen , Xi Li , Guangyou Zhu , Zhiyuan Lu , Ruilin Wang , Yue Huang , Wanyan Lan , Fanchen Jia , Yanqing Zhu","doi":"10.1016/j.jgsce.2025.205662","DOIUrl":"10.1016/j.jgsce.2025.205662","url":null,"abstract":"<div><div>The size, distribution, and connectivity of pores play a critical role in determining the characteristics and formation of shale reservoirs. Therefore, pore analysis is critical for the reservoir evaluation. Considering the lack of a comprehensive overview, this paper reviews advancements in pore classification schemes, the factors and mechanisms controlling pore occur, and multi-scale characterization methods. We present an integrated analysis of pore classifications based on various criteria, including pore size, occurrence, connectivity, genesis, distribution, morphology, and their relationship with pore fluids. Thermal maturity, organic matter abundance, mineral composition, diagenesis, and tectonic processes are identified as key geological factors that govern pore formation and development. This study also highlights the evolution of experimental techniques, which have greatly enhanced the ability to characterize shale pores accurately. However, a unified classification system for shale reservoir pores is still lacking. A precise quantitative analysis of the influence of each geological factors on shale pore development remains absent. Each pore characterization method, while offering distinct advantages, also has its own limitations in terms of range and accuracy. When integrating multiple methods for comprehensive shale reservoir characterization, issues like poor data compatibility and difficulties in integration still exist. Future research should prioritize the standardization of shale pore classification, the quantitative assessment of geological factors influencing pore development, and the establishment of a comprehensive pore characterization framework and set of standards. This paper seeks to advance the understanding of shale reservoir pores, providing valuable insights and references for subsequent studies.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205662"},"PeriodicalIF":0.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ruichang Guo, Hongsheng Wang, Jianqiao Leng, Seyyed A. Hosseini
{"title":"Evaluation of hydrogen leakage through abandoned wells to overlaying saline aquifers during underground hydrogen storage in depleted natural gas reservoirs","authors":"Ruichang Guo, Hongsheng Wang, Jianqiao Leng, Seyyed A. Hosseini","doi":"10.1016/j.jgsce.2025.205659","DOIUrl":"10.1016/j.jgsce.2025.205659","url":null,"abstract":"<div><div>Underground Hydrogen (H<sub>2</sub>) storage (UHS) plays a critical role in the low-carbon hydrogen economy, which aims to mitigate global warming by replacing carbon-emitting fossil fuels. Depleted natural gas reservoirs, along with saline aquifers and engineered salt caverns, are primary options for UHS. Depleted natural gas reservoirs often contain numerous abandoned wells, and the potential leakage of H<sub>2</sub> through these wells is a significant concern for UHS. However, research on H<sub>2</sub> leakage through abandoned wells remains limited. In this study, a geological model comprising a natural gas reservoir, two saline aquifers, and a leaking well was developed. Systematic numerical simulations were performed to evaluate the potential H<sub>2</sub> leakage through the abandoned well under varying geological conditions. The integrity of the abandoned well, as the primary factor of interest, was modeled as a channel with high equivalent permeability. The influencing factors include permeability of the abandoned well, thickness of the confining zone, distance between the abandoned well and the injection/production well, permeability of the reservoir, and shut-in time of the natural gas reservoir. The influence of these key factors on H<sub>2</sub> leakage was quantified. The results indicated that the failure of the abandoned well was the primary factor contributing to significant H<sub>2</sub> leakage. H<sub>2</sub> leakage resulting from severe failure of the abandoned well can be three orders of magnitude greater than that in the base case with a mild failure of the abandoned well. An increase in the thickness of the confining zone or a greater distance between the injection/production well and the abandoned well leads to a linear reduction in H<sub>2</sub> leakage. Reservoir permeability and the shut-in time of natural gas reservoirs have a nonlinear impact on H<sub>2</sub> leakage and converged to a limit. Scaling relations between H<sub>2</sub> leakage and the influencing factors were fitted to quantify their effects. These findings contribute to improved site selection and safety assessments for UHS projects.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205659"},"PeriodicalIF":0.0,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yulin Zhang, Shanchao Liu, Kaiyue Ding, Jun Yao, Hai Sun, Yongfei Yang, Lei Zhang, Junjie Zhong
{"title":"Review on laboratory studies of pore-scale salt precipitation during carbon storage","authors":"Yulin Zhang, Shanchao Liu, Kaiyue Ding, Jun Yao, Hai Sun, Yongfei Yang, Lei Zhang, Junjie Zhong","doi":"10.1016/j.jgsce.2025.205663","DOIUrl":"10.1016/j.jgsce.2025.205663","url":null,"abstract":"<div><div>Salt precipitation in saline aquifers during CO<sub>2</sub> sequestration significantly reduces formation porosity and permeability (reaching 40 % and 70 %, respectively), ultimately influencing CO<sub>2</sub> storage. This review explores recent experimental advances in understanding pore-scale salt precipitation, focusing on core-flooding and microfluidic experiments. We outlined the stages of salt precipitation and analyzed two crystalline forms: bulk crystals and polycrystalline aggregates. We also described two distribution patterns (local and homogeneous) and their occurrence conditions, and discussed key influencing factors including rock properties, fluid characteristics, gas injection rates, CO<sub>2</sub> phases and boundary conditions. Finally, we assessed current research limitations and proposed potential directions for future.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205663"},"PeriodicalIF":0.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohamed L. Malki , Hichem Chellal , K.C. Bijay , Axel Indro , Vamegh Rasouli , Mohamed Mehana
{"title":"Risk assessment of wellbore leakage during underground hydrogen storage","authors":"Mohamed L. Malki , Hichem Chellal , K.C. Bijay , Axel Indro , Vamegh Rasouli , Mohamed Mehana","doi":"10.1016/j.jgsce.2025.205661","DOIUrl":"10.1016/j.jgsce.2025.205661","url":null,"abstract":"<div><div>The expansion of renewable energy sources would require large-scale energy storage options to overcome the intermittent nature of these sources. Underground hydrogen storage (UHS) in depleted hydrocarbon reservoirs offers a scalable and practical energy storage solution. These reservoirs are chosen for their availability and large capacity, but the unique properties of hydrogen raise concerns about potential leakage pathways, particularly through wellbores. In this study, we develop and apply, for the first time, reduced-order models (ROMs) specifically designed for efficient leakage risk prediction in UHS systems operating in depleted hydrocarbon reservoirs. Using 3,000 high-fidelity simulation scenarios, we examine the influence of 11 key parameters, including reservoir and aquifer depths, wellbore permeability and porosity, initial saturations of water, oil and gas fractions (hydrogen, light, intermediate, and heavy hydrocarbons), reservoir pressure multiplier, and the aquifer-to-reservoir volume ratio, to simulate leakage behavior over a 1,000-year timescale. We train ROMs using a two-step classification-regression approach, achieving R<sup>2</sup> values exceeding 99 % across all targets. These ROMs effectively capture the leakage evolution and identify critical controls of leakage, guiding the design of mitigation strategies. Results indicate that gas leakage occurs in about 27 % of scenarios as early as five years post-operation, reaching volumes of up to 10<sup>6</sup> ft<sup>3</sup>. Oil leakage is less frequent (∼17 %) and typically begins decades later. Our findings also show that hydrogen often migrates first, owing to its smaller molecular size and higher buoyancy, followed by heavier hydrocarbons. Over time, these heavier components contribute significantly to the total leaked volume, reinforcing the need for targeted monitoring and remediation strategies. Our analysis highlights that deeper storage reservoirs, shallower aquifers, and low-permeability wellbores significantly reduce leakage risks. This work offers a robust framework for risk-informed UHS deployment, supporting energy security through reliable large-scale hydrogen storage while safeguarding environmental integrity.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205661"},"PeriodicalIF":0.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pore and chemical structure variation of tectonically deformed coal and their influences on methane adsorption","authors":"Huazhou Huang , Wenbing Zhou , Chuanxia Tong , Zhangchi Wen , Qiming Zhang","doi":"10.1016/j.jgsce.2025.205658","DOIUrl":"10.1016/j.jgsce.2025.205658","url":null,"abstract":"<div><div>Coal deformation involves the transformation of coal from its initial geometric state to its final state, encompassing rigid body translation, rotation, strain, distortion, and volume changes driven by factors such as embrittlement, fracturing, or ductile deformation. This study selected three types of tectonically deformed coal (TDC) from the Sanjiang-Mulinghe Basin Group—cataclastic, granulated, and mylonized—characterized by progressively increasing degrees of deformation, to evaluate their methane adsorption capacities and elucidate the underlying mechanisms driving the observed differences in adsorption capacity. The adsorption characteristics were examined using an isothermal adsorption apparatus employing the volumetric method. Nitrogen adsorption-desorption and CO<sub>2</sub> adsorption techniques were utilized to analyze the mesoporous and microporous structure. X-ray diffraction and Fourier-transform infrared spectroscopy were performed to determine the basic structural units and organic molecular structure parameters in coal. The findings indicated that methane adsorption capacity progressively enhances across the cataclastic → granulated → mylonized deformation sequence in the TDCs of the Sanjiang-Mulinghe Basin Group, which is attributed to the deformation-induced expansion of available adsorption spaces and the strengthening interactions between coal macromolecules and methane molecules. The deformation of coal prompts the polycondensation and depolymerization of its macromolecular structure, leading to an increase in both pore volume and specific surface area of TDCs. This enhancement is particularly significant with higher degrees of coal deformation, offering additional space and adsorption sites for methane, thereby improving methane adsorption capacity. Concurrently, parameters such as crystallite size and aromaticity were found to increase with more intense coal deformation. The increase in crystallite size is due to the growth in the number of crystallites per stack, the height of the stacks, and the diameter of crystallites within a stack, accompanied by a decrease in the distance between aromatic layers. The study enhances comprehension regarding the gas-bearing characteristics of tectonically deformed coals.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205658"},"PeriodicalIF":0.0,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lu Zhang , Chao Liu , Wende Yan , Zhiqiang Li , Jingang Fu , Shouyin Cai
{"title":"Influence of interaction strength on adsorption and transport properties of nanoconfined gas","authors":"Lu Zhang , Chao Liu , Wende Yan , Zhiqiang Li , Jingang Fu , Shouyin Cai","doi":"10.1016/j.jgsce.2025.205649","DOIUrl":"10.1016/j.jgsce.2025.205649","url":null,"abstract":"<div><div>The surface properties of nanostructures play a key role in the storage and development of underground complex fluids. The adsorption and transport mechanism resulting from surface-molecule interaction force plays a key role in graphite nano-slits. These mechanisms explain their characteristically weaker gas adsorption but superior transport capabilities when compared to organic and inorganic nano-slit counterparts. Understanding the relationship between gas adsorption and transport in nano-slits with varying interaction forces is crucial for elucidating the fluid properties of different material surfaces. In this work, the effects of interaction on gas adsorption and transport property in nano-slits are quantitatively accessed by using molecular dynamics simulations. We found that as the interaction energy parameter between gas molecules and nano-slits, the adsorption density of gas molecules increases, and the self-diffusion coefficient of gas also decreases. The gas molecule preferentially adsorbed at the center of the graphene circle, which is the strongest interaction site of nano-slits. Considering the confined effect, the quantitative relation between self-diffusion coefficient, adsorption density and the ratio of pore size to interface interaction parameters (H/α) are respectively acquired to describe the self-diffusion and adsorption characteristics. A revised theoretical model that integrates adsorption and self-diffusion equations to predict the apparent permeability of gas molecules in nano-slits is proposed, demonstrating strong agreement with molecular simulation results. This work can be further revealed in gas purification and chemical industry through the fluid molecules transport behavior across various materials systems.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"140 ","pages":"Article 205649"},"PeriodicalIF":0.0,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}