Sulfur–iodine cycle

The sulfuric acid -iodine process is a thermochemical process for the production of hydrogen. It consists of three chemical reactions whose reactant water and their products are hydrogen and oxygen.

The sulfur and iodine compounds can be reused, therefore the process is called cyclic. This process is endothermic and must be carried out at high temperatures, so it must be supplied energy in the form of heat.

Research

The Japan Atomic Energy Research Institute successfully carried out experiments on sulfuric acid -iodine method with the help of Generation IV high temperature nuclear reactors. Large-scale automated systems for hydrogen production are being planned. The French CEA and the U.S. Oak Ridge National Laboratory also conduct research on the sulfur -iodine process.

Hydrogen economy

The sulfuric acid -iodine method has been proposed as a method for producing hydrogen for the hydrogen economy. With an efficiency of 50 %, it is more effective than the electrolysis and does not require hydrocarbons such as the currently used method of steam reforming. There is still much research needed before the sulfuric acid -iodine method can be used as a reliable source of hydrogen. The first Generation IV reactors are predicted for around 2030.

See also

Hydrogen production

• Chemical- technical process
• Hydrogen production