Process Description
The thermochemical two-step water splitting process uses two redox steps. The steps of solar hydrogen production by iron baised two-step cycle are:
(1) M(II)Fe2(III)O4 → M(II)O + 2Fe(II)O + ½O2 (Reduction)
(2) M(II)O + 2Fe(II)O + H2O → M(II)Fe2(III)O4 + H2 (Oxidation)
Where M can by any number of metals often Fe itself, Co, Ni, Mn, Zn or mixtures thereof. The endothermic reduction step (1) is carried out at high temperatures greater than 1400 oC, though the "Hercynite cycle" is capable of temperatures as low as 1200 oC. The oxidative water splitting step (2) occurs at a lower ~1000 oC temperature which produces the original ferrite material in addition to hydrogen gas. The temperature level is realized by using a solar power tower and a set of heliostats to collect the solar thermal energy.
Read more about this topic: Iron Oxide Cycle
Famous quotes containing the words process and/or description:
“Because her instinct has told her, or because she has been reliably informed, the faded virgin knows that the supreme joys are not for her; she knows by a process of the intellect; but she can feel her deprivation no more than the young mother can feel the hardship of the virgin’s lot.”
—Arnold Bennett (1867–1931)
“I fancy it must be the quantity of animal food eaten by the English which renders their character insusceptible of civilisation. I suspect it is in their kitchens and not in their churches that their reformation must be worked, and that Missionaries of that description from [France] would avail more than those who should endeavor to tame them by precepts of religion or philosophy.”
—Thomas Jefferson (1743–1826)