Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coal
Tar-rich coal in-situ pyrolysis (TCIP) is a green and low-carbon technology that extracts tar and gas from underground tar-rich coal seams. Overburden pressures are a crucial factor for TCIP that differs from conventional ground pyrolysis. This study investigated the impact of axial pressure on the...
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Elsevier
2025-03-01
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| Series: | Fuel Processing Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0378382024001450 |
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| author | Bingyang Kou Qingmin Shi Shuangming Wang Qiang Sun Shidong Cui Xiaolong Yang Xinyue Zhao Junwei Qiao |
| author_facet | Bingyang Kou Qingmin Shi Shuangming Wang Qiang Sun Shidong Cui Xiaolong Yang Xinyue Zhao Junwei Qiao |
| author_sort | Bingyang Kou |
| collection | DOAJ |
| description | Tar-rich coal in-situ pyrolysis (TCIP) is a green and low-carbon technology that extracts tar and gas from underground tar-rich coal seams. Overburden pressures are a crucial factor for TCIP that differs from conventional ground pyrolysis. This study investigated the impact of axial pressure on the pyrolysis of Xinjiang tar-rich coal using simulations. The variation of pore structure and volatiles was studied using low-field nuclear magnetic resonance and gas chromatography. Results indicated that pore structure and tar-gas composition evolved synergistically, and presented staged characteristics during pyrolysis under axial stress. 10.0–17.5 MPa, coals compressed to breakage, enhancing pore-fracture connectivity and convective heat transfer during pyrolysis. Pores continued to enlarge, porosity-permeability increased, promoting volatiles release and reducing secondary reactions, leading to increased tar-gas yield, particularly light and phenol oils, CO2, and C2+ gases proportion. Conversely, coals compacted at 20.0–25.0 MPa, pore-fracture connectivity worsened due to fracture closure, decreased convective heat transfer, and weakened pore enlargement phenomenon. The enhancement of matrix heat transfer formed many smaller pyrolysis pores within the coal matrix, but poor connectivity decreased porosity-permeability. This increased the release resistance of volatiles, strengthened secondary reactions, and reduced tar-gas yields. However, the proportion of light and naphthalene oils, CH4, H2, and CO is increasing. |
| format | Article |
| id | doaj-art-72bd4dcb31cc486283aeaa963078014b |
| institution | Kabale University |
| issn | 0378-3820 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | Elsevier |
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| series | Fuel Processing Technology |
| spelling | doaj-art-72bd4dcb31cc486283aeaa963078014b2025-01-15T04:11:33ZengElsevierFuel Processing Technology0378-38202025-03-01267108175Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coalBingyang Kou0Qingmin Shi1Shuangming Wang2Qiang Sun3Shidong Cui4Xiaolong Yang5Xinyue Zhao6Junwei Qiao7College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, ChinaCollege of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an University of Science and Technology, Xi'an 710054, China; Xi'an University of Science and Technology, the Belt and Road Energy Research Institute of Xinjiang, Urumqi 830000, China; Corresponding author at: College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China.College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an University of Science and Technology, Xi'an 710054, ChinaCollege of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an University of Science and Technology, Xi'an 710054, ChinaCollege of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, ChinaCollege of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, ChinaCollege of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, ChinaCollege of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an University of Science and Technology, Xi'an 710054, ChinaTar-rich coal in-situ pyrolysis (TCIP) is a green and low-carbon technology that extracts tar and gas from underground tar-rich coal seams. Overburden pressures are a crucial factor for TCIP that differs from conventional ground pyrolysis. This study investigated the impact of axial pressure on the pyrolysis of Xinjiang tar-rich coal using simulations. The variation of pore structure and volatiles was studied using low-field nuclear magnetic resonance and gas chromatography. Results indicated that pore structure and tar-gas composition evolved synergistically, and presented staged characteristics during pyrolysis under axial stress. 10.0–17.5 MPa, coals compressed to breakage, enhancing pore-fracture connectivity and convective heat transfer during pyrolysis. Pores continued to enlarge, porosity-permeability increased, promoting volatiles release and reducing secondary reactions, leading to increased tar-gas yield, particularly light and phenol oils, CO2, and C2+ gases proportion. Conversely, coals compacted at 20.0–25.0 MPa, pore-fracture connectivity worsened due to fracture closure, decreased convective heat transfer, and weakened pore enlargement phenomenon. The enhancement of matrix heat transfer formed many smaller pyrolysis pores within the coal matrix, but poor connectivity decreased porosity-permeability. This increased the release resistance of volatiles, strengthened secondary reactions, and reduced tar-gas yields. However, the proportion of light and naphthalene oils, CH4, H2, and CO is increasing.http://www.sciencedirect.com/science/article/pii/S0378382024001450Tar-rich coalAxial pressurePyrolysisPore structureTar fractionGas composition |
| spellingShingle | Bingyang Kou Qingmin Shi Shuangming Wang Qiang Sun Shidong Cui Xiaolong Yang Xinyue Zhao Junwei Qiao Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coal Fuel Processing Technology Tar-rich coal Axial pressure Pyrolysis Pore structure Tar fraction Gas composition |
| title | Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coal |
| title_full | Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coal |
| title_fullStr | Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coal |
| title_full_unstemmed | Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coal |
| title_short | Axial pressure impact on pyrolysis behavior of Xinjiang coal: An inspiration for in-situ pyrolysis of tar-rich coal |
| title_sort | axial pressure impact on pyrolysis behavior of xinjiang coal an inspiration for in situ pyrolysis of tar rich coal |
| topic | Tar-rich coal Axial pressure Pyrolysis Pore structure Tar fraction Gas composition |
| url | http://www.sciencedirect.com/science/article/pii/S0378382024001450 |
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