Corrosion Behavior of Carbon Steel in the Monoethanolamine−H2O−CO2−O2−SO2 System: Products, Reaction Pathways, and Kinetics

This work investigates the effect of operating parameters on corrosion products, reaction pathways, and kinetics for the corrosion of carbon steel in the monoethanolamine−H2O−CO2−O2−SO2 system. Corrosion experiments were conducted using a 273A potentiostat unit under conditions in which monoethanolamine (MEA), O2, and SO2 concentrations and CO2 loading were in the range of 1−7 kmol/m3, 0−100%, 0−204 ppm, and 0−0.5 mol CO2/mol MEA, respectively, at corrosion temperatures of 303−353 K to mimic the absorption−regeneration sections. Analysis, performed for this system for the first time, shows that corrosion products generated from the effect of SO2 include FeSO4 and Fe2O3·H2O. Also, a higher concentration of SO2 in simulated flue gas stream induces a higher corrosion rate because of the increase in the hydrogen ion concentration generated by reactions of SO2 and H2O as well as SO2, O2, and H2O. A power-law model developed to correlate corrosion rate with the parameters in the MEA−H2O−CO2−O2−SO2 system shows ...