Authors: Riza A. Magbitang, Rheo B. Lamorena-Lim,
Carbon capture and storage (CCS) is a key strategy to reduce anthropogenic carbon dioxide (CO2) emissions to the atmosphere. Ophiolite formations are known to be reactive with CO2 and are very abundant in the Philippines, thus making it a significant rock type in carbon mineralization studies. Baseline studies were conducted by exposing powdered rock samples in (hyperalkaline) ground water purged with CO2. Carbonation reaction was monitored every 20 days for 60 days. Low pH (~1) and high pH (~13) set-ups were also studied to evaluate the effect of pH in carbon mineralization. Concentration of metals (Na, Mg, Al, Ca, and Fe) that could participate in the mineralization reaction was measured. Decrease in the metal concentration was observed with longer exposure to CO2, and this could be an indication that the metals were precipitated with CO32- (dissolved form of CO2). Rapid decrease of the metal concentration in the pH-controlled set-ups could be attributed to faster carbonation reaction. This study is an initial attempt to study CO2 storage in the Philippines through reaction kinetics perspective.
Keywords: carbon mineralization, CO2 sequestration, ophiolite formations