抄録
Hydrogen promises to be one of the most important energy sources in the near future. Liquid hydrogen can be utilized for infrastructure construction consisting of storage and transportation. The figure of merit (FOM) must be larger than 0.57 for a hydrogen liquefier when comparing the consuming energy of hydrogen liquefaction with high-pressure (70 MPa) hydrogen gas. Magnetic refrigeration using the magneto-caloric effect has the potential to realize not only a higher liquefaction efficiency >50%, but also to be environmentally friendly and cost effective. Our hydrogen magnetic refrigeration system consists of a Carnot cycle for the liquefaction stage and active magnetic regenerators (AMR) for the precooling stages. Various magnetic materials were studied for candidate refrigerants. We developed a highly efficient liquefaction stage with >80% liquefaction efficiency and confirmed the AMR effect for the precooling stage.
