Evaluation of Singrauli Coals for Sustainable Energy Utilisation: Insight From Geochemical and Petrographic Perspectives
P. Gopinathan, Abhishek Mahato, Om Prakash Kumar, Alok Kumar, T. Subramani, Amit Karmakar, Bodhisatwa Hazra, Pradip Banerjee, Manoj Saini, Manoj Sethi
Abstract
ABSTRACT The study investigated 50 Permian coals from the Singrauli Coalfields in the Son Valley Basin, India, using advanced petro‐geochemical techniques to assess their source rock properties, energy and utilisation potential and to reconstruct the paleodepositional environment. Petrological analysis indicated vitrinite reflectance values between 0.39% and 0.49%, classifying the Singrauli coals as sub‐bituminous to high volatile bituminous rank and indicating a thermally immature state. The results of geochemical analysis (volatile matter: 36.8%–46.5% and T max : 420°C–425°C) further support the above contention. High carbon content (average 77.89%), low sulphur content (average 0.46%) and varying nitrogen and oxygen levels in studied coal enhance its environmental suitability. The hydrogen index (HI: 163–279 mg HC/g TOC) values suggest a predominance of type‐III kerogen with mixed type‐II–III kerogen, further supported by petrographic data. Moreover, geochemical and petrographic data suggested the suitability of Singrauli coals for gasification. The high total organic carbon (TOC ≥ 38 wt%) indicated admirable potential as a source rock for hydrocarbon generation, particularly within the gas‐source rock zone, highlighting their suitability for energy production. Petrographic indices indicated a wet forest swamp origin with a telmatic source and bog region under ombrotrophic to mesotrophic hydrological circumstances. The association of macerals and total sulphur content further supported the conclusion of a freshwater environment during peat deposition.