Comparison of corrosion behaviour for X-65 carbon steel in supercritical CO2-saturated water and water-saturated/unsaturated supercritical CO2

The corrosion behaviour of X65 carbon steel was evaluated in supercritical carbon dioxide (SC-CO2)-saturated water, water-saturated SC-CO2 and under-saturated SC-CO2 conditions at 80 bar and 50 degrees C to simulate conditions of CO2 transportation in carbon capture and storage applications. A detailed assessment of localised corrosion and corrosion product film morphology/chemistry was conducted. Localised corrosion is shown to be a fundamental consideration in all environments, particularly in water-containing CO2 systems. Corrosion was shown to occur when under-saturated water was present in the system, however, no dissolution of the steel was observed at water contents below 1600 ppm at the conditions considered. (C) 2014 Elsevier B.V. All rights reserved.