Perpustakaan Digital ITB

This study investigates the potential for CO? mineral trapping in basaltic formations using geochemical equilibrium modeling. The simulation involves five main stages: initial brine characterization, surface CO? injection and mixing, temperature-pressure adjustment to reservoir conditions, and two sequential rock-fluid interactions. PHREEQC is utilized to track ion molality and saturation indices (SI) of potential secondary minerals. Results show that temperature significantly influences ion behavior and mineral formation, while pressure has negligible effects. Notably, Ca²? concentrations continue to increase at elevated temperatures, suggesting ongoing dissolution of calcium-bearing minerals. In contrast, Mg²? concentrations decrease, likely due to partial precipitation at intermediate temperatures. Among the carbonate minerals, calcite consistently shows positive SI values across all conditions, indicating it is the main carbonate phase contributing to CO? trapping. In addition, iron-bearing and sulfate minerals such as hematite, magnetite, and anhydrite also exhibit high SI values and may play a complementary role in long-term mineral sequestration. The findings highlight the viability of basaltic systems for geologically secure CO? storage via mineralization.