Storing Hydrogen: Harnessing the Power of Magnetic Materials to Boost Hydrogen Liquefaction Efficiency

• Carbon Neutrality
• Hydrogen Materials
• Hydrogen Society
• Magnetic Materials
• Magnetic Refrigeration
• Research Center for Magnetic and Spintronic Materials (CMSM)
• Women Researchers

To liquefy hydrogen for large-scale transportation and storage, NIMS is developing a magnetic refrigeration system. Akiko Saito and her materials development team are actively involved in the research and development of magnetic materials—core components with the potential to significantly enhance liquefaction efficiency.

Where the Magnetic Refrigeration Project Stands Today

Magnetic refrigeration technology is drawing attention as a promising way to reduce the cost and energy required to produce liquid hydrogen. This method utilizes the magnetocaloric effect—a phenomenon in which magnetic materials absorb or release heat when exposed to a magnetic field—to control temperature.

To liquefy hydrogen, it must be cooled from room temperature down to 20 K (–253°C), a broad and technically demanding temperature range. In response to this challenge, NIMS has adopted a method known as Active Magnetic Regenerative Refrigeration (AMRR) and is vigorously working on system development. This initiative began in 2018 as part of the JST-Mirai Project, and has been featured in previous issues of NIMS NOW.

NIMS’s target is to first cool hydrogen down to 77 K (–196°C) using liquid nitrogen, and then use the AMRR system to bring it further down to 20 K. By 2021, the team had already succeeded in cooling hydrogen from 34 K (–239°C) to 20 K, achieving the world’s first hydrogen liquefaction using an AMRR system (see page 9 for the related issue).

The remaining challenge lies in cooling the intermediate temperature range from 77 K to 34 K. To accomplish this, further system optimization—and, crucially, the advancement of magnetic materials—is essential.