# Development of an active magnetic refrigerator for hydrogen liquefaction https://mdr.nims.go.jp/datasets/d8d841b0-93e7-4e06-a6e1-0a6587d54eb7 ## File - [REPM2025_O6-4_Kamiya.pdf](https://mdr.nims.go.jp/filesets/71a7c068-a35f-44b6-b751-c8c993b08298/download) ([Detail](https://mdr.nims.go.jp/filesets/71a7c068-a35f-44b6-b751-c8c993b08298.md)) ## Id d8d841b0-93e7-4e06-a6e1-0a6587d54eb7 ## Local identifier ## Visibility open_to_public ## State published ## Created at 2025-08-31T07:19:29.738641Z ## Updated at 2025-09-11T07:31:37.657970Z ## Published at 2025-09-11T07:20:21.717847Z ## Doi https://doi.org/10.48505/nims.5689 ## First published url ## Date published ## Recorded date published ## Resource type conference_presentation ## Manuscript type na ## Collection - id: d28f086a-61aa-4bc7-bcae-5a1078cbc6c7 identifier: https://mdr.nims.go.jp/pid/d28f086a-61aa-4bc7-bcae-5a1078cbc6c7 title: The 28th International Workshop on Rare Earth and Future Permanent Magnets and Their Applications (REPM2025) ## Title - title: Development of an active magnetic refrigerator for hydrogen liquefaction title_type: original lang: en ## Description - description: "In Japan, hydrogen has been recognized as one of the key elements in the Green Growth Strategy formulated in December 2020 by the Ministry of Economy, Trade, and Industry, in response to the Carbon Neutral Declaration. The strategy aims to achieve a maximum hydrogen demand of 3 million tons by 2030 and 20 million tons by 2050, while also reducing the current hydrogen supply price from 100 yen/m3 to 30 yen/m3 by 2030 and to 20 yen/m3 or less by 2050.\r\nTo make hydrogen usable as an energy source for consumers, it is necessary to convert it into a compact and manageable form for distribution. Various forms of hydrogen, such as liquid hydrogen, ammonia, and methylcyclohexane, have been considered, and ongoing research and development are focused on overcoming technical challenges, considering the advantages and disadvantages of each option. Among these forms, liquid hydrogen offers the advantage of significantly reducing the volume of hydrogen gas to 1/800th, but its higher cost compared to other forms has been a drawback. To liquefy hydrogen, hydrogen gas needs to be cooled to cryogenic temperatures of around 20 K at a pressure of 1 atmosphere, which requires a considerable amount of electricity by conventional gas refrigeration.\r\nOne method that has the potential to greatly enhance liquefaction efficiency and reduce amount of electricity is magnetic refrigeration. Magnetic refrigeration is a refrigeration method based on the \"magnetocaloric effect,\" which generates temperature changes by ordering or disordering the magnetic moment (spin entropy) of magnetic refrigerants by changing the magnetic fields. Magnetic refrigeration can theoretically achieve liquefaction efficiencies of 50% or more, which is about twice that of the conventional gas expansion refrigerators.\r\nThis talk will introduce Active Magnetic Refrigerator (AMR) for hydrogen liquefaction being developed under the Japan Science and Technology Agency (JST) Mirai Project.1) The JST Mirai project has two goals: POC1 (Proof of Concept 1) and POC2. In POC1, efficient hydrogen liquefaction is performed, while POC2 involves the efficient re-condensation of liquid hydrogen. POC1 requires a relatively large amount of hydrogen, which necessitates significant refrigeration capacity. For this reason, a 5T magnetic field is necessary for magnetic refrigeration, and therefore a superconducting magnet is used. On the other hand, the re-condensation of liquid hydrogen in POC2 does not require as much capacity as POC1, allowing the use of permanent magnets to drive magnetic refrigeration.\r\nIn this talk, I will first introduce the AMR (Active Magnetic Regenerator) system used for hydrogen liquefaction in POC1 and report on the world's first hydrogen liquefaction experiment using AMR. Then, I will describe the magnetic refrigeration system using permanent magnets implemented in POC2 and report on the development status of the newly developed permanent magnets at NIMS for this JST Mirai project2).\r\n\r\nReference\r\n1) Koji Kamiya et al. Appl. Phys. Express 15 (2022) 053001\r\n2) X. Tang, J. Lai, H. Sepehri-Amin et al. Scripta Mater. 194 (2021) 113648." description_type: abstract lang: en ## Creator - name: Koji Kamiya role: author organization: National Institute for Materials Science, Japan - name: Kyohei Natsume role: author organization: National Institute for Materials Science, Japan - name: Akira Uchida role: author organization: National Institute for Materials Science, Japan - name: Tsuyoshi Shirai role: author organization: National Institute for Materials Science, Japan - name: Akiko T. Saito role: author organization: National Institute for Materials Science, Japan - name: Takenori Numazawa role: author organization: National Institute for Materials Science, Japan - name: Xin Tang role: author organization: National Institute for Materials Science, Japan - name: Hossein Sepehri-Amin role: author organization: National Institute for Materials Science, Japan - name: Koichi Matsumoto role: author organization: Kanazawa University, Japan ## Contact agent ## Publisher organization: National Institute for Materials Science (NIMS) ## Managing organization ## Keyword - subject: REPM2025 schema: not_defined - subject: Magnetic refrigeration schema: not_defined - subject: AMR schema: not_defined - subject: hydrogen schema: not_defined ## Rights - identifier: https://creativecommons.org/licenses/by/4.0/ ## Other identifier(s) ## Data origin - data_origin_type: other ## Embargo ## Journal ## Conference name: REPM2025 start_date: 2025-07-27 end_date: 2025-07-31 identifier: https://www.nims.go.jp/mmu/repm2025/ ## Related item ## Funding ## Instrument ## Instrument operator ## Instrument managing organization ## Measurement method ## Specimen ## Chemical composition ## Structure for specimen ## Structural feature for specimen ## Specific property for specimen ## Process for specimen treatment ## Computational method ## Energy level/transition state ## Software ## Custom property ## Fileset - id: 71a7c068-a35f-44b6-b751-c8c993b08298 filename: REPM2025_O6-4_Kamiya.pdf content_type: application/pdf size: 6290091 md5: 5cf4e8f9e8d081f06456d21eca9fa6f5 ## Thumbnail fileset_id: 71a7c068-a35f-44b6-b751-c8c993b08298 filename: REPM2025_O6-4_Kamiya.pdf