Effect of iron carbonate on the corrosivity of amine solutions in CO2 removal unit

This paper describes the corrosion behavior of carbon steel in two, different amine solutions intended for use in a new Acid-gas Removal Unit (AGRU) being developed for use in carbon dioxide capture and storage (CCS) processes.  The corrosion rate in both amine solutions was affected by CO₂ loading and temperature.  The corrosion was also inhibited by the formation of FeCO₃ scale.  The FeCO₃ solubility appeared to be affected by amine complex formation with Fe²⁺ in CO₂ loaded amine solutions.  When selecting an amine solution for the AGRU, an amine solution in which FeCO₃ is less soluble is important in terms of its effect on the corrosion rate.