| Summary: | Introduction Many of India’s large emission sources are located far from sedimentary basin settings where CO2 storage might otherwise be considered. Continental flood basalts of the Deccan Traps cover an estimated 500,000 km3 in west-central India, and there is much interest in their potential to permanently store and trap CO2 through mineral carbonation processes. The Deccan Traps consist of layers of solidified flood basalt more than 2,000 m in thickness. The volume of basalt exceeds 1,000,000 km3 and provides a significant theoretical potential for high-volume storage of CO2. Carbon capture and storage by mineralization (CCSM) has been studied in several regions, including the Wallula Basalt Project in Columbia River, USA, and the Carbfix project in Iceland. Although some previous studies on the trapping potential of basalts have shown promising results, there remains significant uncertainty as to the practicality of storing CO2 volumes at industrial scale in the Deccan Traps. Theory and/or Method To gain a preliminary insight into the types of reactions that may be expected during CCSM in Deccan Trap basalts, a core sample taken from the Killari borehole was reacted with CO2-rich water. Prior to reaction the sample was crushed to produce a 125 to 250 μm fraction, which increases the mineral surface area and enhances the rate at which the reactions occur. Future experiments using whole-rock samples will provide more realistic reaction rates, requiring the experiments to be run over a longer period of time to produce detectable mineralogical reactions. To produce basalt-equilibrated fluid for the experiment, this powder was placed in a 1 liter container of deionized water at 70°C for one week. A preliminary study was conducted using three batch vessels containing crushed starting material and the equilibrated fluid pressurized first with nitrogen, and then with CO2 to 90 bar. Each vessel was subjected to a different temperature (50, 100, and 150°C), and reacted for up to 43 days. The selected temperature range ...
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