Performance of 316 L and 304 L stainless steels in the APBS-CDRMax® solvent for CO2 capture processes: Insights into corrosion resistance and stability

This study focuses on investigating the corrosion performance of SS 304 L and SS 316 L stainless steels when exposed to the APBS-CDRMax® solvent, under various conditions, including CO 2 and presence of SO X /NO X contaminants. Electrochemical techniques, including potentiodynamic and cyclic polarization are employed, along with Inductively Coupled Plasma (ICP) analysis to evaluate both the short-term corrosion rate and the pitting tendency. Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-Ray (EDX) analysis provide insights into the underlying corrosion mechanism. Long term exposure tests are also carried out at temperatures up to 90°C to assess the long-term corrosion behavior of the stainless steels and stability of the solvent. Findings indicate that APBS-CDRMax® presents extremely low corrosion rates, even in the presence of high concentrations of sulfuric and nitric acid used to simulate the effects of SO X and NO X dissolution. The observed corrosion rates are multiple times lower than those of the benchmark monoethanolamine (MEA) solvent. Microscopic observation and EDX analysis identify the presence of black layers associated with amine byproducts and different types of corrosion precipitates, many of which are linked to the inherent properties of the solvent. Long-term exposure tests indicate a tendency for the stainless steels to form corrosion precipitates, confirming the solvent’s exceptional low corrosivity over time and reveal a stabilization of the corrosion process after 7–10 days of exposure to the solvent. Following extended exposure of the solvent to conditions causing thermal degradation, only minor signs of degradation are observed. The solvent’s CO 2 loading capacity remains virtually unaffected, whereas both density and viscosity remain stable. • APBS-CDRMax® showed very low corrosion rates, even with SO X /NO X contaminants present. • Electrochemical tests confirmed stable corrosion behavior after 7–10 days of exposure. • SEM/EDX analysis revealed minor corrosion layers linked to amine byproducts only. • Solvent maintained loading, viscosity, and density despite thermal degradation tests.