Corrosion study of carbon steel in CO2 loaded solution of N-methyldiethanolamine and l-arginine mixtures

This study presents an electrochemical corrosion investigation of carbon steel in blends of methyldiethanolamine (MDEA) and arginine (ARG) at different molar concentrations and solvent proportions. The effects of three main parameters which are CO2 partial pressure, solution temperature and MDEA/ARG proportions ratio were studied. The selected temperatures range varied from 293 to 323K and the CO2 partial pressure was in the range of 49–98kPa. The results showed that the corrosion rate increased with increased CO2 partial pressure and solution temperature. However, when ARG was added to MDEA, it was found that ARG acts as an inhibitor, the higher ARG fraction in the mixture, the more inhibition effect was observed. SEM, XRD, and XPS techniques were used to characterize the corroded surfaces; analysis of the corrosion products of the specimen surface confirmed the formation of FeCO3 protective layer. •Corrosion behavior of carbon steel in a CO2 loaded MDEA solution was investigated using electrochemical methods•The effect of adding arginine in different proportions to MDEA on the corrosion of carbon steel was assessed•The temperature ranged from 293 to 323K while the CO2 partial pressure was varied from 49 to 98 kPa•X-ray power diffractometer, scanning electron microscopy and XPS analyses at different conditions are reported