An experimental investigation of trace element dissolution in carbon dioxide: Applications to the geological storage of CO2

Abstract

This paper presents the first experimental data for the fractionation of Fe, Cu and Zn between brine and carbon dioxide at pressure-temperature conditions applicable to the saline aquifers used for the geological storage of CO2, in order to evaluate the potential for trace element remobilization within the injected CO2 plume. The study was carried out at 6.5-16 MPa and 60 °C in a large-volume autoclave, which was loaded with pressurized CO2 and a 20 wt% NaCl solution having a known concentration of Fe, Cu or Zn. Paired samples of brine and CO2 were extracted from separate capillary lines and analyzed for metal concentrations.