Carbon Dioxide Sequestration through Carbon Mineralization Using pH-Swing Treatment: A Case Study of Mae Tha Basalt

Summary Transforming carbon dioxide (CO2) into stable solid carbonate phases through carbon mineralization offers a promising pathway for long-term CO2 sequestration and climate change mitigation. This study emphasizes the permanent storage of CO2 by enabling its conversion into solid carbonates via the mineralization of basaltic rocks under low-energy, ambient conditions. The process is enhanced by a pH-swing treatment, where the acidic phase (HCl) promotes the dissolution of target minerals, releasing magnesium, calcium, and iron cations. Subsequently, the basic phase (NaOH) induces carbonate precipitation in the presence of dissolved CO2. XRF analysis of materials from each stage reveals that silicon remains largely unreacted in the original rock, while magnesium effectively dominates the combination with CO2 to form magnesium carbonate compounds. Iron, in contrast, precipitates distinctly when the solution pH is increased to 5–9. These findings deepen the understanding of CO2 interactions with natural basaltic minerals, paving the way for more efficient carbon mineralization processes that could significantly advance carbon capture and sequestration technologies.