CO2 Transport - Corrosion of Carbon Steel Exposed to Inhibited Water Pools Present after Commissioning

Abstract Water pools might remain in CO2 transport pipelines after installation and commissioning or be present due to accidental ingress of water. The pipelines are normally made of carbon steel and the corrosion rate of the exposed steel will depend on a number of parameters including CO2 partial pressure (pCO2), flow velocity, temperature, water volume to steel surface ratio (Vaq/S ratio), water composition, presence of impurities (SOx, NOx, H2S, O2) in the CO2 stream, and corrosion and hydrate inhibiting chemicals. A corrosion inhibitor testing program was performed under simulated commissioning and start-up conditions. Two inhibitors were tested. The experiments were performed in static autoclaves and transparent test cells at CO2 pressures up to 100 MPa. Impurities (SOx, NOx, H2S, O2) and reaction products (H2SO4, HNO3) were injected/present at various concentrations.