Identification of oxidizing agents in aqueous amine-CO2 systems using a mechanistic corrosion model

The purpose of this paper was to perform studies in order to obtain a better understanding of corrosion in an aqueous amine-CO₂ environment. A mechanistic corrosion model, built as a fortran-90 program, is established to identify the oxidizing agents responsible for corrosion reactions. The model incorporates the rigorous electrolyte nonrandom two-liquid (NRTL) equilibrium model and mixed potential theory in order to simulate the concentrations of chemical species and polarization behavior taking place at a metal-solution interface. The simulation results, based on monoethanolamine (MEA) system, indicates that bicarbonate ion (HCO₃⁻) and water (H₂O) are the primary oxidizing agents and hydrogen ion (H⁺) or hydronium ion (H₃O⁺) plays an insignificant role in the reduction reaction.