This chapter evaluated the performance of environmentally friendly organic corrosion inhibitors on carbon steel in the amine-based carbon dioxide (CO2) absorption process. The evaluation was experimentally conducted using electrochemical techniques in 5.0 kmol/m3 monoethanolamine (MEA) solutions in the absence and presence of process contaminants, namely formate and chloride, at 80°C and 0.55 mol/mol CO2 loading. The results show, in the absence of process contaminants, that 2-aminobenzene sulfonic acid, 3-aminobenzene sulfonic acid, 4-aminobenzene sulfonic acid, sulfapyridine, and sulfolane yielded 85–92% corrosion inhibition efficiencies, while sulfanilamide yielded the lowest efficiency of 20–42%. Sulfolane was the only tested inhibitor whose performance could be maintained in chloride- and formate-containing MEA solutions. On the contrary, the performance of 3-aminobenzene sulfonic acid and sulfapyridine was decreased by chloride. The performance of all the tested aminobenzene sulfonic acids was compromised by formate.
Part of the book: Corrosion Inhibitors, Principles and Recent Applications