{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:13:01Z","timestamp":1788221581939,"version":"build-2803163510"},"reference-count":38,"publisher":"American Chemical Society (ACS)","issue":"33","license":[{"start":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T00:00:00Z","timestamp":1786579200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["52074104"],"award-info":[{"award-number":["52074104"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["52074107"],"award-info":[{"award-number":["52074107"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006407","name":"Natural Science Foundation of Henan Province","doi-asserted-by":"publisher","award":["252300420030"],"award-info":[{"award-number":["252300420030"]}],"id":[{"id":"10.13039\/501100006407","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,25]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Gas injection pressure is a key parameter controlling enhanced coalbed methane (ECBM) recovery, as it directly influences gas adsorption\u2013desorption, diffusion-seepage, and the dominance of replacement-displacement mechanisms. In this study, carbon dioxide (CO2) and nitrogen (N2) were selected as injection media, and gas-injection simulation experiments were conducted under injection pressures of 0.6, 1.0, and 1.4 MPa. Real-time monitoring of inlet and outlet flow rates, outlet gas composition, and gas-content variations in coal enabled quantitative analysis of gas breakthrough timing, replacement-displacement transition characteristics, and injection efficiency. Increasing injection pressure significantly shortened gas breakthrough time, accelerated outlet gas-concentration evolution, and enhanced gas transport capacity within the coal. When injection pressure increased from 0.6 to 1.4 MPa, the breakthrough time decreased from 406 to 128 min for CO2 and from 16 to 6 min for N2, corresponding to reductions of 68.5% and 62.5%, respectively. During CO2 injection, replacement remained the controlling mechanism, although the cumulative displacement ratio increased from 6% to 24% as pressure increased. In contrast, N2 injection changed rapidly from replacement-dominated behavior to displacement-dominated behavior, with cumulative displacement ratios of 69%, 83%, and 76% at 0.6, 1.0, and 1.4 MPa, respectively. The maximum final injection efficiency was 23% for CO2 at 0.6 MPa and 64% for N2 at 0.6 MPa; CO2 injection efficiency followed a decrease-then-increase pattern with increasing pressure, whereas N2 injection efficiency decreased monotonically from 64% to 17%. These findings clarify the pressure-dependent evolution of replacement-displacement dominance for different injection gases and provide experimental guidance for ECBM injection-pressure optimization.<\/jats:p>","DOI":"10.1021\/acsomega.6c00827","type":"journal-article","created":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T20:02:17Z","timestamp":1786651337000},"page":"49054-49066","source":"Crossref","is-referenced-by-count":0,"title":["Pressure-Controlled\nDynamic Conversion of Replacement\u2013Displacement\nMechanisms During ECBM Recovery"],"prefix":"10.1021","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-7179-3386","authenticated-orcid":true,"given":"Danhui","family":"Wang","sequence":"first","affiliation":[{"name":"Henan Polytechnic University , , ,","place":["Jiaozuo, China, 454003"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9337-7664","authenticated-orcid":true,"given":"Hongmin","family":"Yang","sequence":"additional","affiliation":[{"name":"Henan Polytechnic University , , ,","place":["Jiaozuo, China, 454003"]},{"name":"State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization , ,","place":["Jiaozuo, China, 454003"]},{"name":"Engineer Research Center of Minister of Education for Coal Mine Disaster Prevention and Emergency Relief , ,","place":["Jiaozuo, China, 454003"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liwei","family":"Chen","sequence":"additional","affiliation":[{"name":"Henan Polytechnic University , , ,","place":["Jiaozuo, China, 454003"]},{"name":"State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization , ,","place":["Jiaozuo, China, 454003"]},{"name":"Engineer Research Center of Minister of Education for Coal Mine Disaster Prevention and Emergency Relief , ,","place":["Jiaozuo, China, 454003"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-6610-3138","authenticated-orcid":true,"given":"Xiaotong","family":"Lu","sequence":"additional","affiliation":[{"name":"Henan Polytechnic University , , ,","place":["Jiaozuo, China, 454003"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ke","family":"Zhang","sequence":"additional","affiliation":[{"name":"Henan Polytechnic University , , ,","place":["Jiaozuo, China, 454003"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,8,13]]},"reference":[{"key":"2026083119125861900_cit1","doi-asserted-by":"publisher","first-page":"104796","DOI":"10.1016\/j.jngse.2022.104796","article-title":"Multi-field coupling theory and research progress of\nmethane extraction in deep coal seams: A review","volume":"107","author":"Xu","year":"2022","journal-title":"J. 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Eng. J."},{"issue":"4","key":"2026083119125861900_cit5","doi-asserted-by":"publisher","first-page":"1959","DOI":"10.1021\/acs.energyfuels.4c05241","article-title":"Differences\nin CH4 Displacement Efficiency by CO2\/N2 Injection in Anthracite under Isobaric and High Pressures:\nMolecular Dynamics Insights","volume":"39","author":"Wang","year":"2025","journal-title":"Energy Fuels"},{"issue":"5","key":"2026083119125861900_cit6","doi-asserted-by":"publisher","first-page":"792","DOI":"10.13225\/j.cnki.jccs.2010.05.023","article-title":"Experimental study\non nitrogen injection into coal seams to displace methane and promote\ngas drainage","volume":"35","author":"Yang","year":"2010","journal-title":"J. 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Methods\nGeomech."},{"issue":"45","key":"2026083119125861900_cit15","doi-asserted-by":"publisher","first-page":"29416","DOI":"10.1021\/acsomega.0c04352","article-title":"Molecular simulation study on adsorption\nand diffusion\nbehaviors of CO2\/N2 in lignite","volume":"5","author":"Zhu","year":"2020","journal-title":"ACS Omega"},{"key":"2026083119125861900_cit16","doi-asserted-by":"publisher","first-page":"138876","DOI":"10.1016\/j.energy.2025.138876","article-title":"Computed\ntomography imaging-based quantification of microstructural heterogeneity\nin coal under uniaxial loading: Insights into pore-scale gas flow\nbehavior","volume":"338","author":"Fan","year":"2025","journal-title":"Energy"},{"key":"2026083119125861900_cit17","doi-asserted-by":"publisher","first-page":"4942","DOI":"10.3390\/en18184942","article-title":"Geological\nStructure Control on Pore\nStructure of Coal Reservoirs: A Case Study in Erdaoling Mining Area,\nInner Mongolia, NW China","volume":"18","author":"Li","year":"2025","journal-title":"Energ."},{"key":"2026083119125861900_cit18","doi-asserted-by":"publisher","first-page":"086618","DOI":"10.1063\/5.0284039","article-title":"Full-scale\npore structure and its impact on methane adsorption in deep coal reservoirs\nof the Zijinshan area, Eastern Ordos Basin","volume":"37","author":"Li","year":"2025","journal-title":"Phys. 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Ph.D. Thesis, Northeastern\nUniversity, Shenyang, China, 2019."},{"issue":"2","key":"2026083119125861900_cit22","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1016\/j.coal.2007.11.001","article-title":"Differential swelling\nand permeability change of coal\nin response to CO2 injection for ECBM","volume":"74","author":"Mazumder","year":"2008","journal-title":"Int. J. Coal Geol."},{"issue":"1","key":"2026083119125861900_cit23","doi-asserted-by":"publisher","first-page":"56","DOI":"10.1016\/j.coal.2010.09.010","article-title":"Coal swelling strain\nand permeability\nchange with injecting liquid\/supercritical CO2 and N2 at stress-constrained conditions","volume":"85","author":"Kiyama","year":"2011","journal-title":"Int.\nJ. 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World J."},{"key":"2026083119125861900_cit34","doi-asserted-by":"publisher","first-page":"133437","DOI":"10.1016\/j.fuel.2024.133437","article-title":"Mechanism\nof pore pressure and adsorption swelling effect on permeability during\ngeological storage of carbon dioxide in coal seams","volume":"381","author":"Li","year":"2025","journal-title":"Fuel"},{"key":"2026083119125861900_cit35","unstructured":"Ministry of Commerce China.\n          .  Measurement Method\nof Methane Adsorption\nof Coal (High Pressure Capacity Method); Standards Press of China: Beijing, 1998."},{"key":"2026083119125861900_cit36","unstructured":"China National Offshore Oil Corporation.\n          .  Industrial Analysis Method\nof Coal; Standards Press of China: Beijing, 2008."},{"key":"2026083119125861900_cit37","unstructured":"China National Offshore Oil Corporation.\n          .  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