Measurements and modelling of FeCO3 solubility in water relevant to corrosion and CO2 mineralization
Randi Neerup, Isaac Appelquist Løge, Georgios M. Kontogeorgis, Kaj Thomsen, Philip Loldrup Fosbøl
Abstract
FeCO3 is present as a CO2 corrosion product in many industrial processes and takes part in the natural CO2 mineralization process. This work presents the solid–liquid equilibrium of the system FeCO3-H2O at 5–120 °C. The FeCO3 solubility showed little temperature dependence. However, temperature affected kinetics as the rate constants for FeCO3 dissolution increased with temperature. The activation energy of FeCO3 dissolution in water was determined to 1.55 kJ mol−1. Gibbs energy of formation was found to be −653.27 kJ mol−1, and the enthalpy of formation for FeCO3 was −710.01 kJ mol−1 using the Extended UNIQUAC model. Extended UNIQUAC could predict the experimental solubility data of FeCO3 in water within an average absolute relative deviation of 0.08. The data obtained in this study creates the basis for reducing the consequences of CO2 corrosion and increasing knowledge of the CO2 mineralization process.