U.S. Department of Energy

Fundamental Corrosion Studies in High-Temperature Molten Salt Systems for Next-Generation CSP Systems

Savannah River National Laboratory logo Image of a yellow strip with dark lines throughout.

SEM-EDS image showing Cr depletion at grain boundaries in Incoloy, a common high-temperature corrosion mechanism in molten salts. Image from SRNL

The Savannah River National Laboratory (SRNL), under the National Laboratory R&D competitive funding opportunity, is working with United Technology Research Center and the University of Alabama to understand corrosion when operating concentrating solar power (CSP) systems at high temperatures with advanced power cycles and to develop corrosion mitigation strategies to lengthen system lifetimes. By improving high-temperature operation, CSP systems can achieve greater efficiencies and thereby reduce the overall system cost.

Approach

The project team is characterizing the corrosion of advanced materials in high-temperature molten salt heat transfer fluids. The goal is to identify combinations of heat transfer fluids and materials that will maximize system lifetime while minimizing cost. By investigating operating temperatures over 800°C, the project will help to enable superheated Rankine or advanced Brayton power cycles.

The specific technical goals of this project are to:

  • Identify materials that can achieve corrosion rates of less than 3 milli-inches per year
  • Develop models that predict corrosion rates in high-temperature heat transfer loops
  • Provide standardized corrosion testing results that give industry a solid design basis.

Innovation

Most corrosion characterizations with molten salts have focused on lower temperature operation, typically at temperatures less than 600°C. The research team will investigate corrosion in heat transfer systems at temperatures above 800°C, which are needed to drive high-efficiency power cycles. Given that corrosion rates increase exponentially with temperature, identifying materials with the necessary mechanical strength and corrosion resistance will be critical to meeting SunShot Initiative targets.

Publications, Patents, and Awards

At this time, this project does not have published articles, patents, or awards.

SunShot logo

Learn about other DOE competitive awards for concentrating solar power research that are in progress.