“The Japan Steel Works, a Japanese major specialty steel manufacturer, has developed a 300 liter type steel pressure accumulator for use at 70MPa hydrogen stations. The company became fully involved in the market for pressure accumulators for merchant hydrogen stations this year.

The Japan Steel Works has been involved in research and development of hydrogen storing alloys and hydrogen storage tanks since the late 1970’s. The company will expand its hydrogen business using steel pressure accumulators to give it a foothold in the market. Since 2009 The Japan Steel Works had undertaken a project called, “Research and Development for Low Cost Type 70 MPa Hydrogen Filling Stations” sponsored by the New Energy and Industrial Technology Development Organization (NEDO) until 2012, and it has already developed a large 450 liter steel accumulator. A sales of 2 accumulators has been recorded to the technology institute of Toho Gas.

In Japan, this year 19 hydrogen stations will be installed under the auspices of the government. The Japan Steel Works aims to ship its steel pressure accumulator to these stations.

At the hydrogen station, the pressure accumulator plays the roll of a storage tank for gaseous hydrogen. They are made of two types of material, steel or CFRP (carbon fiber reinforced plastic) which is an aluminum container wrapped in carbon fiber. The Japan Steel Works estimated that demand for small type pressure accumulators with a capacity of 300 liters would be greater than for larger ones for the 19 hydrogen stations to be installed. In August of this year the company expanded its Muroran works in Hokkaido by constructing a new dedicated production line with a capacity of 50 units a year. By mass producing the steel pressure accumulators, Japan Steel Works aims to reduce cost and promote its sales.

The company will expand its production in accordance with orders from the 19 stations. The price has not been disclosed but it is expected to be the same as that of a CFRP pressure accumulator.

A feature of the accumulator is that it can implement ultrasonic flaw detection (UT), which can detect internal flaws by using ultrasonic waves from outside of the accumulator.

In addition, while CFRP pressure accumulator for use with hydrogen station is limited in product cycle, ruggedization made steel pressure accumulator be not limited in usable life, and it can be used 100,000 times or more.

Steel pressure accumulator is heavier than CFRP pressure accumulator. However, The Japan Steel Works is planning to market new steel type pressure accumulator in the future, which was made be light after undergoing safety and reliability tests and accumulating these results. Further more, hybrid container which was wrapped by mixed liner of steel and FRP has been under development.”