Use of LIBS Technology for CO₂ Leak Detection in Carbon Sequestration

In this study, the in-situ measurement capability of Laser-Induced Breakdown Spectroscopy (LIBS) to detect CO₂ leakage in geological carbon storage (GCS) was evaluated. As LIBS is an optics-based (contains no electronics) spectroscopic technique, it can perform contamination-free analysis in extreme conditions of underground environment. During the leakage, the interaction of CO₂ with carbonate rocks at elevated pressures can release various metals which can potentially contaminate the drinking water sources above storage sites. Therefore, we evaluated the underwater LIBS technique for studying the carbonate dissolution with increased CO₂ pressure. Dissolution experiments using four carbonates (CaCO₃, SrCO₃, MnCO₃, and MgCO₃) at the elevated CO₂ pressure (ranging from ambient to 250 bars) were carried out by analyzing LIBS spectra obtained from aqueous solutions containing these carbonates. The results indicated the dissolution of all carbonates. However, the rate of dissolution varied from carbonate to carbonate. This study shows that in-situ monitoring of carbonate dissolution by underwater LIBS can be used for CO₂ leak detection in GCS.