Thermochemical generation of hydrogen

摘要

The direct fluid contact heat exchange with H2SO4 at about 330 DEG C. prior to high temperature decomposition at about 830 DEG C. in the oxygen release step of several thermochemical cycles for splitting water into hydrogen and oxygen provides higher heat transfer rates, savings in energy and permits use of cast vessels rather than expensive forged alloy indirect heat exchangers. Among several candidate perfluorocarbon liquids tested, only perfluoropropylene oxide polymers having a degree of polymerization from about 10 to 60 were chemically stable, had low miscibility and vapor pressure when tested with sulfuric acid at temperatures from 300 DEG C. to 400 DEG C.