Basalt-Based Enhanced Rock Weathering for Long-Term CO2 Storage: Insights from Mineral Carbonation Experiments

Abstract Enhanced Rock Weathering (ERW) using Rajmahal traps basalt from India was investigated as a sustainable pathway for permanent CO2 sequestration through aqueous mineral carbonation. Experiments were conducted in a high-pressure stirred tank reactor to optimize the operational parameters, including sample volume and initial CO2 pressure. The optimum conditions of 20 g of basalt and 10 bar pressure achieved a maximum CO2 uptake of 9.72 g/kg basalt, corresponding to 6.27% of the carbonation efficiency. Detailed mineralogical and morphological analyses using XRD, SEM-EDX, FTIR, and TGA confirmed the transformation of reactive silicate phases into stable carbonate minerals such as calcite and magnesite. BET surface area analysis revealed a 72% reduction after carbonation, indicating pore filling and mineral precipitation. The findings demonstrate the significant potential of Rajmahal traps basalt as an abundant and viable geomaterial for long-term carbon storage, highlighting ERW as a promising climate mitigation strategy for India’s decarbonization efforts.