Corrosion in CO₂ Capture Process Using Blended Monoethanolamine and Piperazine

This work explores the promise of aqueous solutions of blended monoethanolamine (MEA) and piperazine (PZ) as a cost-effective solvent for carbon dioxide (CO 2 ) capture from industrial flue gas streams with respect to corrosion, which is regarded as one of the most severe operational problems in typical CO 2 capture plants. Electrochemical corrosion experiments were carried out using the potentiodynamic polarization technique for corrosion measurements. The results show that the blended MEA/PZ solutions are more corrosive than the MEA solutions. The corrosion rate of carbon steel increases with concentration of PZ, total amine concentration, CO 2 loading of solution, solution temperature, and the presence of heat stable salts. Among the tested heat-stable salts, formate is the most corrosive salt, followed by acetate, oxalate, and thiosulfate in the absence of oxygen (O 2 ), while acetate is the most corrosive salt followed by formate, oxalate, and thiosulfate in the presence of O 2 .