Jul. 4, 2006

JAEA (Japan Atomic Energy Agency, President: Yuichi Tonozuka) has succeeded in test-fabrication of a sulfuric acid decomposer, which features ceramic heat exchanger that exhibits excellent resistance against pressure and corrosion, for nuclear production of hydrogen by IS process. Hydrogen is expected to serve as a clean energy carrier in future and JAEA has been conducting R&D on IS process from the view points of energy security and protection of the global environment.

IS process produces hydrogen from water by combining thermochemical reactions of sulfur- and iodine-compounds. The process environments are very corrosive in nature, which makes the development of corrosion-resistant chemical reactors an R&D subject of high priority. Especially, that of sulfuric acid decomposer is a big technical issue, which vaporizes concentrated sulfuric acid and decomposes H₂SO₄ into SO₃ and H₂O using the heat of high temperature helium gas supplied from High Temperature Gas-cooled Reactor. JAEA, in collaboration with Toshiba Corp., devised a simple pressure-resistant structure for the decomposer, which features multi-hole block heat exchanger made of silicon carbide that exhibits excellent corrosion resistance in the concerned environment. Furthermore, JAEA successfully test-fabricated the block ceramic heat exchanger for the hydrogen production plant of 30m³/h class, and confirmed its anti-seismic sealing performance, as well.

The result is a leading technical achievement in the R&D on IS process being carried out in many countries. It also has many potential applications in industries that handle corrosive chemicals.

The R&D was partly entrusted from the Ministry of Education, Culture, Sports, Science and Technology in Japan.

•Development of Sulfuric Acid Decomposer featuring Ceramic Heat Exchanger for Iodine-Sulfur Hydrogen Production Process