Just as hydrogen fuel is gaining more attention as clean energy, a project that would produce liquid hydrogen by utilizing geothermal power is about to kick off on the volcanic island of Iojima (See below) in Mishima, Kagoshima Prefecture.
Kawasaki Heavy Industries, Ltd., along with Obayashi Corp., is set to start a drilling survey this fiscal year in preparation for building a demonstration plant there. Organizers for the 2020 Tokyo Olympics and Paralympics are planning to use hydrogen energy at the accommodation centre for athletes competing in the event. The companies initiating the hydrogen production project aim to put hydrogen energy into practical use by then.
Liquid hydrogen is mostly used in fuel cell vehicles and hailed as clean energy as it does not emit carbon dioxide. However, some critics point out it does not help in greatly reducing carbon dioxide emissions since fossil fuel is used as a power source to enable the electrolysis of water, the process often employed to produce hydrogen.
With this in mind, the companies came up with the idea of generating electricity to enable the process through the use of geothermal power. The 703-meter-high Mt. Iodake, an active volcano on the northeastern side of Iojima, was their choice as a venue. Many vents, where volcanic gas as hot as 900 C constantly pours out, can be found near the peak. Kawasaki Heavy Industries says Mt. Iodake is one of the few places in Japan where high-temperature volcanic gas can be obtained without digging deep into the earth.
According to the plan, volcanic gas will be used to generate the steam to activate the turbine, which in turn produces electricity. Desalinated seawater will be used to extract the hydrogen, which will then be liquefied at minus 253 C and kept in storage until it is shipped out of the island in a container.
Kawasaki Heavy Industries is the first Japanese company to have developed equipment to produce liquid hydrogen. They started gathering basic data at Iojima in fiscal 2013, and are now capable of producing 18 tons of liquid hydrogen per day, which is enough to supply 3,600 fuel cell vehicles. Boring surveys will be conducted this fiscal year in preparation for the construction of a demonstration plant on the island starting in fiscal 2016.
The eruption of Mt. Iodake, at the foot of which liquid hydrogen will most likely be manufactured, is a risk that needs to be anticipated. To ensure the safety of everyone involved, the company says production will be halted immediately if such a disaster should occur.
■ Iojima island
One of three inhabited islands in the village of Mishima, Kagoshima Prefecture, it is located in the East China Sea about 40 kilometers southwest from Cape Sata, the southernmost tip of Kyushu. With a 19.1-kilometer periphery, the island is 11.7 square kilometers in size and has a population of about 110. Sulfur mining had been its chief industry since the Meiji era until demand for sulfur abated and the mines were shut down in 1964. Thereafter, fishery and livestock have become their main industry. Not to be confused with the island of Iwoto, a fierce battleground during World War II, which is in Ogasawara village, Tokyo.