Innovative Approach to Carbon Capture: Utilizing Calcium and Iron Rich Minerals

Abstract This study investigates the carbon capture potential of dolomite, gypsum, and limonite, focusing on their ability to sequester carbon dioxide (CO2) through mineral carbonation under atmospheric conditions. The research examines how different aqueous environments influence carbon uptake, with particular emphasis on the role of water composition in enhancing mineral reactivity. Three experimental scenarios were applied: (1) dry heating, (2) wet heating with distilled water, and (3) wet heating with formation water containing high total dissolved solids (TDS) from hydraulic fracturing activities in the Permian Basin. To quantify carbon uptake and mineral transformations, thermogravimetric analysis (TGA) combined with differential scanning calorimetry (DSC) was used to monitor thermal reactions. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) was employed to analyze surface changes and elemental composition before and after CO2 exposure, providing detailed insights into carbonation processes. The results revealed that limonite exhibited the highest carbon uptake across all experimental conditions, particularly in the presence of an aqueous phase. Limonite demonstrated superior reactivity compared to dolomite and gypsum when exposed to distilled water, and it surpassed dolomite in carbon uptake when exposed to formation water with high Total Dissolved Solids (TDS). Dolomite also showed enhanced carbon capture in formation water, while gypsum exhibited minimal carbon uptake under both aqueous conditions. Additionally, this study established the necessity of an integrated analytical approach for evaluating mineral-based carbon capture. Given that carbonation primarily occurs on mineral surfaces, X-ray Diffraction (XRD) was found to be inadequate for detecting newly formed carbonate phases. Instead, a combination of SEM-EDS, Fourier Transform Infrared Spectroscopy (FTIR), and TGA/DSC provided a more comprehensive assessment of carbonate formation. These findings highlight the significance of water composition in optimizing mineral carbonation reactions and demonstrate the variability in mineral reactivity. The study provides valuable insights into the potential of dolomite, gypsum, and limonite as candidates for carbon capture, contributing to the development of more effective and sustainable carbon capture and storage technologies.