Review of researches on H2S splitting cycle for hydrogen production via low-temperature route

This paper presents an overview of the research and development of the H2S splitting cycle for hydrogen and sulfuric acid production via the low-temperature route of using iodine-toluene solution for Bunsen reaction and direct electrolysis of the mixed hydroiodic acid and sulfuric acid for hydrogen production. The use of I2-toluene solution makes low-temperature Bunsen reaction possible such that many drawbacks including side reactions, iodine vapor deposition, and corrosion have been eliminated or eased. The use of the Corning® Advanced-FlowTM Reactors to carry out multiphase Bunsen reaction allows not only the corrosion-free operation but also enhances mass transfer rate. The direct electrolysis of the product solution from the Bunsen reaction enables the production of hydrogen and separation of sulfuric acid from hydroiodic acid to occur in a single step. A customer-made continuous electrolysis cell was used for the direct electrolysis of Bunsen reaction products, which makes the scale up possible. © 2021 The Authors