An Electrochemical Investigation on the Effect of Heat-Stable Salts on the Corrosion Resistance of Carbon Steel in MDEA Solution

The purpose of this study is to identify the influence of different concentrations of heat-stable salts (oxalate, acetate, formate, succinate, glycolate) on the carbon steel corrosion in MDEA solution. Natural gas usually contains acidic gases like CO2 and H2S along with other sulphur components. These acidic gases have to be scrubbed off from the gas for environmental, operational, and economic reasons. A long-term experiment was conducted to investigate the corrosion behavior of carbon steel in HSS+MDEA solutions and surface analysis techniques (SEM, EDS) were carried out to characterize the morphologies and compositions of the surface layers. To obtain the corrosion behavior of carbon steel in different concentrations of HSS+MDEA solutions the potentiodynamic polarization tests were used. The result showed that the acetate had less corrosion effect and the oxalate had the greatest impact on corrosion of the carbon steel. According to the electrochemical results, these five heat stable salts didn’t have a significant corrosion effect on carbon steel till 5000 ppm concentration.