Cathodic Protection Using Aluminum Metal in Chloride Molten Salts as Thermal Energy Storage Material in Concentrating Solar Power Plants

Abstract

The new generation of concentrated solar power (CSP) plants to be developed presents a great challenge related to the increase in maximum operating temperature since molten salt CSP technologies require alternative salt chemistries such as chloride. The cathodic protection strategy involves the addition of a sacrificial metal to prevent corrosion of the alloy tested as container material in a CSP plant. In this paper, aluminum (Al) metal was analyzed as a corrosion inhibitor in OCT and HR224 alloys, obtaining corrosion rates of 4.37 and 0.27 mm/y, respectively. It has been confirmed that the use of Al metal can reduce the anodic current which is directly related to the corrosion rate. The formation of protective alumina scales (Al2O3) was assessed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), confirming the corrosion model results from electrochemical impedance spectroscopy monitoring tests.

Bibliometric Map on Corrosion in Concentrating Solar Power Plants

“…Excluding reviews, the most cited document from the Chilean university was a study on the corrosion resistance of pretreated aluminaforming alloys to produce surface passivation that was tested against molten chlorides [5], The most recent publication from this author that is relevant in terms of number of citations was published in 2019 and was a study regarding the corrosion properties of nanoparticles included in molten salts on stainless steel [20]. This author has strong co-authorship with L.F. Cabeza [4,[21][22][23][24][25] and F.J. Pérez [19,[26][27][28]. T. Bauer from DRL accounts for 16 documents published on corrosion and has strong collaborations with A. Bonk [29][30][31][32][33][34][35][36][37][38] and W. Ding [29][30][31][32][33][34][35]39,40].…”