The sponge iron reaction (SIR) is a chemical process based on

redox Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

cycling of an iron-based contact mass, the first cycle is a conversion step between

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

metal (Fe) and wuestite (FeO), the second cycle is a conversion step between wuestite (FeO) and

magnetite Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe2+Fe3+2O4. It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. With th ...

(Fe₃O₄). In application, the SIT is used in the reformer sponge iron cycle (RESC) in combination with a

steam reforming Steam reforming or steam methane reforming (SMR) is a method for producing syngas (hydrogen and carbon monoxide) by reaction of hydrocarbons with water. Commonly natural gas is the feedstock. The main purpose of this technology is hydrogen product ...

unit.

Process description

The process has two modes, a reduction mode and an oxidation mode.

Iron-wuestite

+ ↔ +

Magnetite-wuestite

+ ↔ 3 +

Application

The reformer sponge iron cycle is a two step cycle to produce

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

from

hydrocarbon fuel Hydrocarbon fuel is fuel that consists mostly of hydrocarbons. It may refer to: * Fossil fuel, derived from coal, oil, or natural gas * Biofuel, derived from plant or animal matter * Synthetic fuel, derived from synthesis gas * Electrofuel, derive ...

s based SIR and steam.

Reformer sponge iron cycle

In the first step the

is reformed to syngas in the reformer which is then used to reduce the iron oxide (

—Fe₃O₄) to iron (

wüstite Wüstite ( Fe O) is a mineral form of iron(II) oxide found with meteorites and native iron. It has a grey colour with a greenish tint in reflected light. Wüstite crystallizes in the isometric-hexoctahedral crystal system in opaque to translu ...

—FeO), in the second step steam is utilized to re-oxidise the iron into magnetite and hydrogen. The iron oxide pellets are placed in a pelletbed and have a

service life A product's service life is its period of use in service. Several related terms describe more precisely a product's life, from the point of manufacture, storage, and distribution, and eventual use. Service life has been defined as "a product li ...

of several thousand

cycles.First investigations of structural changes of the contact mass in the RESC process for hydrogen production
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References

External links

A thermodynamic analysis of the reformer sponge iron cycleInvestigations on mixed CO₂- and steam reforming of liquid hydrocarbons for the decentralized production of hydrogenSolid biomass gasification for fuel cells (sponge iron reactor SIR)
{{DEFAULTSORT:Sponge Iron Reaction Chemical processes Hydrogen production