SHI uses cryocooler technology to avoid losses of liquid hydrogen during storage ~ prevents the release of hydrogen gas to the atmosphere and promotes a Hydrogen Society ~
May 27, 2025
Sumitomo Heavy Industries, Ltd. (SHI, Head office: Shinagawa-ku, Tokyo, Representative Director and President and CEO: Shinji Shimomura) is pleased to announce the development of a cryocooler capable of liquefying and recondensing hydrogen, and the verification of its safety and effectiveness.
Stored liquid hydrogen vaporizes in the container and generates hydrogen gas known as Boil Off Gas (BOG). This must be released to prevent pressure from rising in the container. Small containers of less than 100 m3 capacity lose 0.5 to 1% per day of their liquid hydrogen in this way. Therefore, it is important to suppress the generation of BOG in equipment that stores and supplies liquid hydrogen.
SHI has succeeded in collecting all the BOG using a new cryocooler for condensing liquid hydrogen developed by our Technology Research Center and Precision Equipment Group. As a result, hydrogen gas does not need to be released and the losses are completely avoided. We will continue development to increase the efficiency of cryocoolers towards even more cost-effective BOG collection, and are looking into acquiring IEC-Ex certification for the cryocoolers as explosion-proof electrical devices. Already a leading global supplier of cryocoolers, SHI is opening up new possibilities in this field and contributing to the realization of a carbon neutral society.
[Development Background]
The utilization of hydrogen to help realize a carbon neutral society is gaining traction both in Japan and overseas. As a source of very pure hydrogen, liquid hydrogen is attracting particular attention for use in fuel cells. However, the boiling point of minus 253°C makes it difficult to avoid the generation of BOG. For safety reasons the BOG is often released to the atmosphere but this measure is uneconomic due to the cost of replenishing the hydrogen.
[Merits of the new cryocoolers]
・Based on our GM cryocoolers (*1), the new device uses an in-house developed heat exchanger to efficiently transmit the cooling effect generated by the cryocoolers to the hydrogen gas in the storage container.
・It efficiently generates a cryogenic atmosphere of minus 253°C and completely prevent
the generation of BOG from liquid hydrogen. The amount of (previously lost) hydrogen collected by re-condensation in the storage container covers the cost of the electricity needed to operate the cryocoolers (*2).
・The newly designed explosion-proof construction considers possible leaks of flammable gas and complies with legal requirements.
(*1) Abbreviation for Gifford-McMahon cryocoolers. A mechanically driven refrigerator that generates cooling by reciprocating the coolant gas for the heat exchanger in the cylinder and repeating the expansion of the coolant gas. SHI has a track record as the world’s leading supplier of this type of device for use in MRI medical equipment.
(*2) Note on the cost of hydrogen. Calculated using 30 yen/Nm3, the target price in Japan for 2030. The current price in Japan is 150 yen/Nm3.