In-situ infrared spectroscopy as a non-invasive technique to study carbon sequestration at high pressure and high temperature

Storage of carbon dioxide in geological formations involves changes in wettability to the host forma-tion during injection and ultimately the formation of inorganic carbonates through mineral trapping.Sequestration locations will be at high pressure and high temperature, thus providing a challengingenvironment for in-situ study. However, infrared spectroscopy (FTIR) with the use of photons is notlimited in temperature or pressure and therefore is applicable to study chemical changes to mineralsoccurring during carbon sequestration. Through the commission of a high pressure/high temperaturein-situ FTIR cell and the subsequent spectroscopic following of carbonation reactions in synthesised sili-cate mineral analogues, we document fundamental chemical changes occurring at the nanoscale duringcarbon storage. Speciation, coordination of carbonate ions to the surface of silicate mineral analoguesand changes in surface hydroxyl coverage are observed and discussed, in the context of CO2injection anddissolution/mineralisation reactions of reservoir silicate minerals.