Magnetocaloric materials for hydrogen liquefaction

Abstract

<p>The expected energy transition to hydrogen gas as a greener energy vector has revived the interest in magnetic refrigeration at the cryogenic range, specifically between 20 and 80 K, with the vision to develop a new generation of hydrogen gas liquefiers. From the materials science point of view, the search for magnetocaloric materials containing mainly non-critical elements with a significant response in that temperature range, together with good cyclability and stability, is a challenging task. Given the increasing interest of the research community on this topic, we aim to establish a comprehensive catalog of the magnetocaloric compounds characterized so far, to be used as a starting point for further research. For this purpose, a systematic outlook of the state of the art is presented here, with the analysis and classification of more than 400 cryogenic magnetocaloric materials, divided into five large families according to their physicochemical properties. Moreover, we provide detailed information about their magnetocaloric properties, magnetic behavior, and transition characteristics together with criticality, which will facilitate the future search for optimal compounds.</p>

A full solid-state conceptual magnetocaloric refrigerator based on hybrid regeneration

“…With high efficiency, solid-state caloric refrigeration, including magnetocaloric (MC), electrocaloric, elastocaloric, and barocaloric refrigeration, 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 is acknowledged as a promising candidate to substitute traditional VC cooling. The refrigerants used in these types of caloric refrigeration are solid caloric materials, which exhibit a reversible entropy change during a phase transition triggered by an external field, introducing zero ozone depletion potential and an extremely low global warming potential.…”

Choosing a cool magnetic material for H₂ liquification

“…Last year, an AMR refrigerator using a superconducting solenoid by a Japanese group and hydrogen liquefaction was successfully demonstrated. 3 They achieved a theoretically high liquefaction efficiency, which is twice that of conventional gas expansion refrigerators, as illustrated in Figure 1. This year, a Horizon Europe project called HyLI-CAL was launched to developed an industrial hydrogen liquefier prototype based on magnetic cooling, which aims to reach an energy demand of 8 kWh/kg and a liquefaction cost of <1.5 €/kg by the prototype for the cryogenic region (< 120 K).…”

Opportunities and challenges of additive manufacturing toward magnetic refrigeration

“…Till now, the systems are designed by the Astronautics Technology Center (USA) attaining 3024 W cooling power at zero temperature span and Toshiba Corporation achieving 42 K temperature span under no load condition, underscoring the efficacy of this technology. 1 Moreover, magnetic refrigeration finds potential application in nitrogen and hydrogen liquefaction, exhibiting higher thermal efficiency and entropy density relative to conventional liquefaction techniques involving Joule-Thomson valve. 2 These room/low-temperature prototypes employ either packed particle beds or stacked plane plates separated by spacers to provide channels for heat exchange fluid.…”

“…Additive manufacturing (AM) emerges as an innovative solution for the preparation of microchannels as shown in Figure 1, leveraging its capacity to digitally construct three-dimensional objects layer by layer. Kitanovski 1 has pointed out that AM would eventually represent the basis for the mass production of magnetic refrigerants. Also known as 3D printing, AM affords a unique advantage in optimizing geometries for enhanced thermal efficiency, concurrently reducing lead time and material wastage.…”