Iron oxide cycle
Encyclopedia
The iron oxide cycle is a two-step thermochemical cycle
proposed for use for hydrogen production
.
process uses redox
systems. The two iron oxide
cycles under research are:
The temperature level is realized by using a solar power tower
and a set of heliostat
s to collect the solar thermal energy
.
Thermochemical cycle
Thermochemical cycles combine solely heat sources with chemical reactions to split water into its hydrogen and oxygen components . The term cycle is used because aside of water, hydrogen and oxygen, the chemical compounds used in these processes are continuously recycled.If work is partially used...
proposed for use for hydrogen production
Hydrogen production
Hydrogen production is the family of industrial methods for generating hydrogen. Currently the dominant technology for direct production is steam reforming from hydrocarbons. Many other methods are known including electrolysis and thermolysis...
.
Process description
The thermochemical two-step water splittingWater splitting
Water splitting is the general term for a chemical reaction in which water is separated into oxygen and hydrogen. Efficient and economical water splitting would be a key technology component of a hydrogen economy. Various techniques for water splitting have been issued in water splitting patents in...
process uses redox
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
systems. The two iron oxide
Iron oxide
Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides.Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, and are widely utilized by humans, e.g.,...
cycles under research are:
- Mn0.5Zn0.5Fe2O4 + yH2O→Mn0.5Zn0.5Fe2O4+y + yH2
- Mn0.5Zn0.5Fe2O4+y→Mn0.5Zn0.5Fe2O4 + y/2O2
The temperature level is realized by using a solar power tower
Solar power tower
The solar power tower is a type of solar furnace using a tower to receive the focused sunlight. It uses an array of flat, movable mirrors to focus the sun's rays upon a collector tower...
and a set of heliostat
Heliostat
A heliostat is a device that includes a mirror, usually a plane mirror, which turns so as to keep reflecting sunlight toward a predetermined target, compensating for the sun's apparent motions in the sky. The target may be a physical object, distant from the heliostat, or a direction in space...
s to collect the solar thermal energy
Solar thermal energy
Solar thermal energy is a technology for harnessing solar energy for thermal energy . Solar thermal collectors are classified by the United States Energy Information Administration as low-, medium-, or high-temperature collectors. Low-temperature collectors are flat plates generally used to heat...
.
See also
- Cerium(IV) oxide-cerium(III) oxide cycleCerium(IV) oxide-cerium(III) oxide cycleThe cerium oxide–cerium oxide cycle or CeO2/Ce2O3 cycle is a two step thermochemical process based on cerium oxide and cerium oxide for hydrogen production...
- Copper-chlorine cycleCopper-chlorine cycleThe copper–chlorine cycle is a four-step thermochemical cycle. It has a maximum temperature requirement of about 530 degrees Celsius. The Cu–Cl cycle is one of the prominent thermochemical cycles under development within the Generation IV International Forum...
- Hybrid sulfur cycleHybrid sulfur cycleThe hybrid sulfur cycle is a two-step water-splitting process intended to be used for hydrogen production. Based on sulfur oxidation and reduction, it is classified as a hybrid thermochemical cycle because it uses an electrochemical reaction for one of the two steps...
- Hydrosol-2Hydrosol-2HYDROSOL is series of European Union funded projects for the promotion of renewable energy...
- Sulfur-iodine cycleSulfur-iodine cycleThe sulfur–iodine cycle is a three-step thermochemical cycle used to produce hydrogen.The S–I cycle consists of three chemical reactions whose net reactant is water and whose net products are hydrogen and oxygen. All other chemicals are recycled...
- Zinc zinc-oxide cycle