• Corrosion of Commercial Nickel Based Hastelloys Exposed to Molten ZnCl2 based Salt Systems

      Lucas, Pierre; T Devaadithya Gardiya Wasam Lidamulage, Chrishani Maheswari; Lucas, Pierre; Deymier, Pierre; Muralidharan, Krishna (The University of Arizona., 2017)
      Concentrating solar power (CSP) systems are a promising technology which helps to reduce greenhouse gas emissions linked with electricity generation. Molten salt systems such as nitrides, nitrates and are widely used as heat transfer fluids (HTF) in CSP plants. HTF is one of the most important components for overall performance and efficiency of the CSP system. The heat transfer fluids currently used in CSP systems are either hydrocarbon oils or alkali- nitrate based eutectic slat mixtures. Both nitrate based salts and hydrocarbon oil have limited operating temperature and thermal. Hence there is a need to come up with a new heat transfer fluids made from inexpensive naturally abundant materials, which are stable up to 1000ᵒC. The Multidisciplinary University Research Initiative (MURI) team based at U of A has proposed molten chloride eutectic salt systems (NaCl,KCl, ZnCl2) as a commercially viable HTFs. Indeed molten chloride eutectic salt systems increase the efficiency of the CSP systems at high temperatures while remaining stable and producing low vapor pressure. However, they raise the risk of potential corrosion in piping / container alloys. The main objectives of this work is to understand the corrosion mechanisms of metal alloys in contact with ZnCl2 based salt systems, purify low purity grade ZnCl2 salts in cost effective way and to investigate the alternative alloys, which are resistant to corrosion by ZnCl2.