Affiliation:
1. *State Key Laboratory of Safety and Control for Chemicals, SINOPEC Research Institute of Safety Engineering Co., Ltd., No. 339, Songling RD, Qingdao, Shandong, 266071, People’s Republic of China.
Abstract
The CO2 stream in a carbon capture utilization and storage application generally includes impurities that could cause internal corrosion of CO2 pipelines. The general and localized corrosion behavior with a variety of O2 concentrations for X65 mild steel both in water-saturated CO2 and CO2-saturated water environments was evaluated using an autoclave. Corrosion tests were performed at 8 MPa and 25°C, 8 MPa and 35°C, and 4 MPa and 35°C to simulate the liquid, supercritical, and gaseous CO2 transportation. Results indicate that notably higher general corrosion rates were recorded at each O2 concentration in the CO2-saturated water phase than those in the water-saturated CO2 environment. The general corrosion rates did not show gradual rise at 0 ppm to 2,000 ppm of O2; instead, a maximum was measured at 1,000 ppm of O2 at 8 MPa and 25°C, and 50 ppm O2 at 8 MPa and 35°C in the water-saturated CO2 environment and 50 ppm at 8 MPa and 25°C, and 100 ppm at 8 MPa and 35°C in the CO2-saturated water environment. The general corrosion rate at 4 MPa and 35°C followed a different changing trend with O2 content from that in 8 MPa, and 25°C and 35°C both in the water-saturated CO2 and the CO2-saturated water environments. Localized corrosion or an average corrosion rate of beyond 0.1 mm/y was identified in each test in the CO2-saturated water environment. When O2 was introduced, a more porous corrosion product scale was detected on the coupon surfaces. A final series of corrosion tests with 100 ppm and 2,000 ppm O2 and 60% and 80% relative humidity in a CO2 environment did not show any sign of localized corrosion attack, and the average corrosion rates were below 0.1 mm/y at 8 MPa, 25°C and 35°C, and 4 MPa and 35°C.
Publisher
Association for Materials Protection and Performance (AMPP)
Subject
General Materials Science,General Chemical Engineering,General Chemistry
Reference25 articles.
1. Dynamis CO2 quality recommendations
2. State-of-the-Art Overview of CO2 Pipeline Transport with Relevance to Offshore Pipelines;Oosterkamp,2008
3. Critical water content for corrosion of X65 mild steel in gaseous, liquid and supercritical CO2 stream
4. State of the aqueous phase in liquid and supercritical CO2 as relevant to CCS pipelines
5. Effect of Water Cntent on the Corrosion Behavior of Carbon Steel in Supercritical CO2 Phase with Impurities;Choi,2011