Inhibitor performance on carbon steel in the geothermal environment of the Upper Rhine graben (Central Europe) – A laboratory study

Abstract The corrosion behavior of carbon steel in CO 2 -saturated artificial geothermal brine was tested in the absence and presence of an amine-based inhibitor by weight loss tests and electrochemical measurements. Experimental conditions were adapted to the conditions existing on the re-injection sites of geothermal power plants located in the Upper Rhine Graben. The influence of Ca 2+ -ions on the corrosion behavior due to scale formation and its impact on inhibitor performance was investigated. Inhibitor adsorption was strongly dependent on inhibitor concentration, Ca 2+ concentration in the brine, reaction time, and pre-corrosion of the metal surface.