Performance of corrosion inhibitors on carbon steel in the geothermal environment of the Upper Rhine Graben (URG) depending on inhibitor concentration, temperature and hydrodynamic conditions—A laboratory study

Abstract The effectiveness of amine and imidazoline-based corrosion inhibitors on carbon steel was compared in CO2 saturated artificial geothermal water. Weight loss tests were carried out under the influence of the stirring speed in accordance with the conditions that exist on the production side (160 °C) and the injection side (80 °C) in geothermal power plants in the Upper Rhine Graben (URG). Corresponding to a possible two-phase flow, the corrosion behavior and inhibitor performance in the liquid and the gas phase was investigated. In addition, depending on the inhibitor concentration and various hydrodynamic conditions, electrochemical tests such as potentiodynamic polarization and electrochemical impedance spectroscopy (80 °C) were carried out.