Hydrogen production using thermochemical water-splitting Iodine-Sulfur process test facility made of industrial structural materials: Engineering solutions to prevent iodine precipitation

摘要

A thermochemical water-splitting iodine-sulfur process offers the potential for mass-producing hydrogen at high-efficiency levels, and it uses high-temperature heat sources, including high-temperature gas-cooled reactors, solar heat, and waste heat of industries. The raw material (H2O) is split into H-2 and O-2 by combining three chemical reactions using sulfur and iodine. Currently, R&D tasks are essential to confirm the integrity of the com-ponents that are made of practical structural materials and the stability of hydrogen production in harsh working conditions. A test facility for producing hydrogen was con-structed from corrosion-resistant components that are developed using industrial mate-rials. In addition, for stable hydrogen production, technical issues for instrumental improvements (i.e., stable pumping of the hydrogen iodide (HI)-I-2-H2O solution without locking the shaft seal, prevention of leakage by improving the quality control of glass-lined steel, prevention of I-2 precipitation using a water removal technique in a Bunsen reactor) were solved. The entire process was successfully operated for 150 h at the rate of ca. 30 L/h. The integrity of components made of practical structural materials and the operational stability of the hydrogen production facility in harsh working conditions were demonstrated. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.