Molten chloride technology pathway to meet the U.S. DOE sunshot initiative with Gen3 CSP
Third generation (Gen3) concentrating solar power (CSP) technologies require a thermally stable and inexpensive fluid to be used for heat transfer and thermal energy storage. For Gen3 CSP plants, a molten salt composed of MgCl2 KCl NaCl is a new candidate, but it is familiar enough to plants with existing molten salt systems. To determine the best composition for the heat transfer fluid, we mixed nine different ratios of the salts, dry/purified them following strict protocols, and tested them with a differential scanning calorimeter and a thermogravimetric analyzer. Our results showed that the lowest melting and solidification temperature of 385degC 1degC was determined for the eutectic composition 44.7 MgCl2 25.8 KCl 29.4 NaCl (mol. We determined that improper handling and preparation of the salt mixture highly affects its thermal properties because of moisture absorption. Preparation standards particularly the dehydration of hydrous MgCl2 merit further development.