Corrosion Resistance of CRA for CCS Applications under O2, SO2 and Practical Mixed Gas Conditions at Different Chloride Levels

Paper ID: C2025-00004 ABSTRACT: The CO2 which contains impurities and is emitted from various, is captured and injected underground in dense or supercritical phase through a pipe. To evaluate the corrosion resistance of CRA materials in supercritical CO2 with O2, SO2, and practical mixture of gases, corrosion tests were performed under the conditions of 5 and 25 wt% NaCl in equilibrium with CO2. Super Martensitic Stainless Steel (UNS S41426), Duplex Stainless Steel (UNS S82551), Super Duplex Stainless Steel (UNS S39274) and Ni-based alloy (UNS N06255) were evaluated.Each material had applicable limit with O2 amount in 5% NaCl. However, only S39274 showed good resistance up to 100ppm O2 in a 25%NaCl condition.In the case of SO2, S41426 showed no applicability even in a 5%NaCl condition due to its de-passivation. In addition, there is no suitable material in a 25%NaCl condition in terms of crevice corrosion.In the case of mixed gas, S39274 showed good corrosion resistance in most of the test conditions. These results would be highly dependent on the chloride concentration levels and also the total pressure of CO2, in other words, the partial pressure of various impurities. Moreover, the effect of oxidants such as NO2 and O2 would decrease with mixed gas conditions.