Corrosion in CO{sub 2} 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{sub 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{sub 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{sub 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{sub 2}), while acetate is the most corrosive salt followed by formate, oxalate, and thiosulfate in the presence of O{sub 2}.