Advanced Solvents for Mineral Dissolution and CO₂ Capture Application

The rising concentration of atmospheric CO₂ poses a serious threat to global ecosystems, requiring the development of sustainable and efficient carbon capture and storage (CCS) strategies. This thesis investigates the potential of choline-based amino acid ionic liquids (ChoAAILs) as environmentally friendly solvents for CO₂ capture and mineral dissolution processes. Two ionic liquids—choline prolinate ([Cho][Pro]) and choline lysinate ([Cho][Lys])—were synthesized via metathesis reactions and characterized through ATR-IR, TGA-IR, XRD, and Raman spectroscopy. Experimental analyses revealed that [Cho][Lys], in particular, significantly enhanced the dissolution of olivine (Mg₂SiO₄) and facilitated the formation of magnesium carbonate hydrates under mild carbonation conditions (25–50 °C, 1–5 bar CO₂). X-ray diffraction confirmed the precipitation of carbonate phases, while Raman spectra highlighted vibrational shifts associated with CO₂ uptake. TGA-IR analyses indicated thermal stability for both ILs up to approximately 185 °C. These findings suggest the suitability of ChoAAILs for CCS applications under relatively low-energy conditions. In addition, computational simulations using HyperChem were conducted to evaluate the reaction kinetics. The activation energy for olivine dissolution was reduced from 25.21 to 11.81 kcal/mol upon CO₂ introduction, confirming its catalytic role in enhancing mineral reactivity. Overall, the study demonstrates that choline-based amino acid ionic liquids, especially [Cho][Lys], represent promising alternatives to conventional solvents due to their low toxicity, biodegradability, and tunable physicochemical properties. The synergy between ILs and CO₂ opens new opportunities for scalable mineral carbonation routes, aligning with green chemistry principles and offering potential for integration into industrial CCS technologies.