Sulfur Iodine

sulfer
https://www.aiche.org/academy/videos/conference-presentations/hydrogen-production-through-modified-sulfur-iodine-thermochemical-water-splitting-cycle-hydrophobic Of the Sulfur based cycles, one of the simplest is the Sulfur-Iodine cycle, which uses sulfur dioxide, iodine, and a large excess of water to produce iodic acid and sulfuric acid, both of which can be further processed into hydrogen and oxygen gases, and regenerate the initial sulfur dioxide and iodine for reuse. Unfortunately, this process has been stalled due to difficulties separating the azeotropic iodic acid/water mixture.(paper from 2012). Issue solved by Japan https://www.youtube.com/watch?v=_uTZWaJU6ho https://en.wikipedia.org/wiki/Sulfur%E2%80%93iodine_cycle

youtube
https://www.youtube.com/watch?v=O8OuN0na-1M

links
solar

https://www.youtube.com/watch?v=AMmOGAju8GQ hydrogen out of air. present method is steam methane reforming, which is the most practical way to make hydrogen from natural gas for ammonia.