Studies evaluating the use of magnetic refrigeration to efficiently obtain liquid hydrogen are producing promising results.
Researchers at Tohoku University have been using a high-temperature superconductor magnet in combination with a gadolinium gallium garnet magnetic body to get a small quantity of liquid hydrogen.
The process provides a considerable potential to fulfil liquefaction efficiency of over 50 percent compared with the average efficiency rates of 20-40 percent achieved by the standard method of compressing and then freezing hydrogen gas. The magnetic refrigeration method entails cooling the hydrogen gas to roughly 20 K, after which latent heat is eliminated through condensation.
Several other entities are conducting similar research including Mitsubishi Heavy Industries and Canada's University of Victoria.