Spectral narratives of microstructural restyling and their controls on hydrocarbon generation potential from coal
Tushar Adsul1
Santanu Ghosh2
Anwita Ojha1
Sudip Bhattacharyya3
Atul Kumar Varma1
1.Coal Geology and Organic Petrology Laboratory,Department of Applied Geology,Indian Institute of Technology(Indian School of Mines),Dhanbad,Jharkhand 826004,India2.Coal Geology and Organic Petrology Laboratory,Department of Applied Geology,Indian Institute of Technology(Indian School of Mines),Dhanbad,Jharkhand 826004,India;Department of Geology,Mizoram University,Aizawl,Mizoram 796004,India3.Specialized Coal Petrography Laboratory,Natural Energy Resources,Mission Ⅱ-B,Geological Survey of India,DK-6,Sector-Ⅱ,Salt Lake City,Kolkata,West Bengal 700091,India
摘要：The low to medium-rank Tertiary coals from Meghalaya,India,are explored for the first time for their comprehensive micro-structural characterization using the FTIR and Raman spectroscopy.Further,results from these coals are compared with the Permian medium and high-rank coals to understand the microstructural restyling during coalification and its controls on hydrocarbon generation.The coal samples are grouped based on the mean random vitrinite reflectance values to record the transformations in spectral attributes with increasing coal rank.The aliphatic carbon and the apparent aromaticity respond sharply to the first coalification jump((R)r:0.50％)during low to medium-rank transition and anchizonal metamorphism of the high-rank coals.Moreover,the Raman band intensity ratio changes during the first coalification jump but remains invari-able in the medium-rank coals and turns subtle again during the onset of pregraphitization in high-rank coals,revealing a polynomial trend with the coal metamorphism.The Rock-Eval hydrogen index and genetic potential also decline sharply at the first coalification jump.Besides,an attempt to comprehend the coal microstructural controls on the hydrocarbon poten-tial reveals that the Tertiary coals comprise highly reactive aliphatic functionalities in the type Ⅱ-S kerogen,along with the low paleotemperature(74.59-112.28 ℃)may signify their potential to generate early-mature hydrocarbons.However,the presence of type Ⅱ-Ⅲ admixed kerogen,a lesser abundance of reactive moieties,and overall moderate paleotemperature(91.93-142.52 ℃)of the Permian medium-rank coals may imply their mixed hydrocarbon potential.Meanwhile,anchizonal metamorphism,polycondensed aromatic microstructure,and high values of paleotemperature(～334.25 to～366.79 ℃)of the high-rank coals indicate a negligible potential of producing any hydrocarbons.
机标关键词：generationfromcoalcontrolshydrocarbonmicrostructuralnarrativespotential
论文发表日期：2023-06-28
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：23( 167-189 )
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