Past research and future strategies for molten chlorides application in concentrated solar power technology

Abstract

This review summarizes past research and future strategies for the improvement of the pair heat transfer fluids (HTF) - containing material, used in concentrated solar power (CSP) plants, focusing on the most interesting and promising HTF, chloride molten salts. Indeed, their low cost and operating range temperature make them very strong potential candidates for future CSP plants, furthermore improvable by wisely adding nanoparticles. Nevertheless, their well-known aggressive behaviour entails selecting a long-lasting resistant alloy, which requires a better understanding of its associated corrosion mechanisms and the influences of its alloying elements. Mitigation strategy mechanisms that come from salt impurities implying purification processes are also reviewed. Finally, thermogravimetric analysis (TGA) coupled with differential scanning calorimetry (DSC) for salt preparation, and numerical simulations on Thermocalc software modelling elements activities of selected alloys and their interaction with molten chlorides are discussed.