Abstract
Geological CO2 storage involves a sophisticated hierarchy of trapping mechanisms, including structural, residual, solubility, and mineral trapping. For a large-scale economic deployment of CO2 storage, the injected CO2 streams typically contain various reactive impurities.
Consequently, the presence of impurities, such as SOx and NOx, must be carefully accounted for, as their reactive nature can significantly influence the geochemical stability of the storage reservoir
This work investigated batch geochemical reactions associated with impurities in CO2 stream. Most existing batch studies have primarily utilized low-salinity brines and relatively high impurity concentrations to simulate underground rock-fluid interactions.
This study addresses this knowledge gap by targeting some typical Danish storage conditions, specifically employing a high saline environment (20 wt% NaCl) to investigate the geochemical interactions triggered by the injection of a CO2 stream containing 1000 ppm impurity.
By employing various characterization techniques for rock and aqueous phases, including XRD, XRF, SEM, ICP-MS and OES, this research provides a more realistic assessment of how trace reactive compounds influence rock-fluid geochemical process in deep saline aquifers.