Screening Tests on Materials of Construction for the Thermochemical IS Process

Abstract

Corrosion tests were conducted at two environments in an iodine-sulfur thermochemical water-splitting process. One is 50wt% sulfuric acid solution containing 0.1wt% hydriodic acid at 95°C and 120°C, and the other is gaseous mixture of HI/I₂/H₂O, the molar ratio of which is 1/1/6, at 200-400°C. In the former environment, Ta, Zr, Quartz glass, and Pb showed corrosion resistance. Although PFA showed corrosion resistance, iodine penetration was observed. In the latter environment, Ti and Hastelloy C-276 showed good corrosion resistance. Inconel 600 and 1Cr-1/2Mo also showed small corrosion rate. However, Inconel 600 suffered grain boundary corrosion.