Experimental evaluation of the thermal degradation of solar salt under different gas covers

Abstract

Commercial concentrating solar power (CSP) plants use solar salt (60–40 wt% NaNO3-KNO3) as thermal energy storage media due to its proven performance. Nevertheless, at high temperatures its decomposition can become a problem, hindering the possibility to rise operating temperatures. Therefore, this paper studies the decomposition of solar salt using different cover gases, dry air and oxygen. Results show that the use of oxygen as cover gas, instead the commercially used dry air, slows down the thermal decomposition of solar salt, reducing the amount of NOx and nitrites formation.