EFFECT OF IMPURITIES ON CORROSION OF STEEL IN SUPERCRITICAL CO2

The differences in the geographical distribution of CO₂ emitters and potential geologic storage sites will necessitate commingling of captured and pressurized CO₂ from diverse sources using gathering lines and transporting it through transmission pipelines to the storage sites. The transportation of large quantities of super critical CO₂ over long distances from carbon capture facilities to carbon storage sites will create fracture and corrosion risks. Specifically, the effects of various incidental impurities arising from diverse sources of CO₂ on corrosion of pipelines have not been thoroughly evaluated. Corrosion of carbon steel associated with water and impurities in supercritical CO₂ was studied by Electrochemical Impedance Spectroscopy in autoclaves. The impurities studied included SO₂, NO₂ and O₂. Results are presented in terms of the phase behavior and speciation.