Solar Salt corrosion : Oxide ions and Impact on corrosion

Kurzfassung

This study investigates the corrosion behavior of SS316L steel in Thermal Energy Storage (TES) systems using molten Solar Salt as a storage medium and heat transfer fluid. The focus is on the influence of oxide ion concentrations in the salt, particularly Na2O impurities, on corrosion rates. The research reveals a significant correlation between increasing Na2O concentrations and higher corrosion rates, indicating the critical role of oxide ions in corrosion. The study employed a systematic approach, including weight change measurements, SEM-EDX analysis, and ion chromatography, to assess the corrosion impact. The findings have important implications for estimating the durability of metal components in TES systems, Concentrated Solar Power plants, Carnot Batteries, and industrial process heating applications. The presented data supports the understanding that oxide ion concentrations in molten nitrate salts play a crucial role in corrosion mechanisms, contributing to advancements in renewable energy storage technologies.