Investigation of low-toxic organic corrosion inhibitors for CO₂ separation process using aqueous MEA solvent

This work investigated the possibility of using low-toxic corrosion inhibitors, instead of heavy-metal inhibitors, for CO₂ separation using aqueous solutions of monoethanolamine (MEA). The performances of eight low-toxic organic inhibitors (amines, carboxylic acid, and sulfoxide) were evaluated by conducting electrochemical corrosion experiments with carbon steel-1020 specimens immersed in 3.0 kmol/m³ MEA solutions under CO₂ saturation at 40 and 80 °C. The experimental results showed that carboxylic acid had the best inhibition performance (as high as 92%), followed by sulfoxide and long-chain aliphatic amine. Their performances depended on inhibitor concentration and temperature.