Compatibility of Carbonate Mixtures to Be Used as Molten Salts with Different Metal Alloys to Be Used as Container Materials

The energy transition can only be achieved if the global energy sector is transformed from a fossil-based system to a zero-carbon-based source system. To achieve this aim, two technologies have shown promising advances in high-temperature application. Concentrating solar power (CSP) plants are seen as a key technology to achieve the needed energy transition, and carbon dioxide (CO₂) capture and storage (CCS) is a promising technology for decarbonizing the industrial sector. To implement both technologies, molten carbonate salts are considered promising material. However, their corrosive behavior needs to be evaluated, especially at high temperatures, where corrosion is more aggressive in metal structures. This paper presents an experimental evaluation of the static corrosion of two molten carbonate salts, a Li₂CO₃-Na₂CO₃-K₂CO₃-LiOH∙H₂O (56.65-12.19-26.66-4.51wt.%) mixture and a Li₂CO₃ salt, under an air atmosphere with five corrosion-resistant metal alloys, including Alloy 600, Alloy 601, Alloy 625, Alloy 214, and Alloy X1. In this study, the corrosion rate and mass losses were quantified. In addition, in all the cases, the results of the experimental evaluation showed corrosion rate values between 0.0009 mg/cm²·yr and 0.0089 mg/cm²·yr.