Project Name: Comparison of Protecting Layer Performance for Corrosion Inhibition in Molten Chloride Salts through Interfacial Studies at the Molecular Scale
Funding Opportunity: Generation 3 Concentrating Solar Power Systems Lab Call
SETO Subprogram: Concentrating Solar-Thermal Power
Location: Oak Ridge, TN
SETO Award Amount: $955,000
Awardee Cost Share: N/A

In concentrating solar power (CSP) plants, high-temperature molten chloride salts could increase plant efficiency by increasing the temperature of the thermal energy delivered to the turbine. But chloride salts can cause significant corrosion, which damages plant components and limits their lifetime. This project will examine how molten chloride salts interact with the surfaces of metal alloy components in CSP plants and attempt to track the corrosive changes as they occur.


The research team will use X-ray absorption, reflection, and diffraction measurements as well as neutron scattering techniques to examine the properties of the surfaces of metal alloys when they are exposed to molten chloride salts. These techniques are sensitive to depth in the material, allowing the team to identify changes only on the surface, which is the part that gets exposed to molten salt, and the mechanism that causes corrosion. To complete these measurements, the team will use facilities at SLAC National Accelerator Laboratory, Argonne National Laboratory, and the Spallation Neutron Source at Oak Ridge National Laboratory.


Most corrosion studies have examined how much mass is lost or bulk chemical changes after corrosion has occurred. But by using cutting-edge X-ray and neutron techniques, this team will be able to identify what happens to the alloy and salt during corrosion by studying the detailed changes occurring on the metal surface. These techniques will also show how impurities and additives in the salt affect the CSP plant components. The results of this project will provide information needed to prevent alloy corrosion, which can lead to developing more reliable, longer-lasting plant components.