Integrated Insights into CO 2 Storage, Trapping Mechanisms, and Hydrocarbon Recovery in Coal and Shale from the Damodar Valley Basin, India

This study investigates the CO 2 storage potential, trapping mechanisms, and hydrocarbon recovery in coal and shale samples from the Damodar Valley Basin, India. Techniques such as proximate and ultimate, petrography, Rock-Eval and total organic carbon (TOC), nitrogen adsorption/desorption, and X-ray diffraction (XRD) and high-pressure CO 2 and CH 4 adsorption were employed. The results, integrated with stratigraphic and lithological data, provide insights into the burial history, basin structure, thermal maturity, kerogen type, pore characteristics, mineralogical composition, and CO 2 trapping mechanisms. The findings revealed thermally mature and carbon-rich coal and shale with TOC ranging from 3.07 to 62.54 wt % and carbon content of 1.85–57.76 wt %. Coal samples are vitrinite-rich (44.65–61.84 vol %), and shale samples are dominated by mineral matter (29.80–62.80 vol %). The presence of type II, III, and IV kerogens supports hydrocarbon generation. The mesoporous nature of samples (2.97–4.23 nm) is conducive to CO 2 storage and hydrocarbon extraction. The CO 2 adsorption capacities of 16.90–30.30 cm 3 /g are significantly higher than the CH 4 adsorption capacities of 6.20–11.30 cm 3 /g, favoring the scope for CO 2 injection for CH 4 displacement. Also, the findings of this study indicate that TOC, moisture, mineral matter, maceral composition, and pore size distribution have a combined influence on the CO 2 adsorption capacity. The basin’s geological and reservoir parameters, including depth, temperature, pH, and formation water chemistry, with the reactive mineralogy comprising clays and minerals like kaolinite, Illite, albite, and siderite, collectively help in structural, capillary, solubility, and mineral trapping of CO 2 . Overall, this study provides a simultaneous evaluation of both coal and shale samples for CO 2 storage and hydrocarbon recovery, unlike many prior studies that address them separately, and the findings of this study demonstrate that the Damodar Valley Basin offers a promising potential for CO 2 storage, presenting a dual solution for energy resource utilization and greenhouse gas mitigation.