Scientists use magnets to make liquid hydrogen

A new, environmentally friendly cooling technology uses magnets to liquefy hydrogen, promising to completely change the game in energy-efficient hydrogen production.

The technique, called magnetocaloric coolinguses materials that heat up when exposed to a magnetic field and cool when the field is removed.

The approach of researchers at the University of Groningen could significantly reduce the economic and energy costs of hydrogen liquefactiona fundamental step for its industrial use.

Industries explore hydrogen as a key element in global carbon neutrality efforts, so the discovery is classified as extremely important by the study’s authors at Nature Communications on October 3rd.

Hydrogen must be cooled to an extremely low temperature, specifically -253°C or 20 Kelvin, to be stored as a liquid. Traditionally, cooling to such temperatures has been energy intensiveincreasing economic and environmental costs.

However, magnetocaloric cooling offers a more efficient alternative. The method works by exposing magnetocaloric materials to an external magnetic field, causing their atoms to align and the material to heat up. This heat is then transferred and, when the magnetic field is turned off, the material cools.

This cooling process can reach temperatures low enough to liquefy hydrogen, making it a tool with potential for industrial applications.

A critical component of the research is the use of abundant earth elements to create the magnetocaloric materials, as previous efforts have relied on rare earth elements.

Extracting these rare elements is expensive and energy-intensive, which goes against the environmental goals associated with hydrogen production. The researchers’ new materials were designed to be more sustainableminimizing the ecological footprint of hydrogen liquefaction.

“We show that the excellent magnetocaloric properties can be attributed to a second-order ferromagnetic phase transition,” the study reads.

“Our material, or a future variant of it, could likely reduce the cost and improve the environmental compatibility of this cooling technology”, also states the lead author, Graeme Blakecited by .

“We hope that there is still room to improve the magnetocaloric properties, for example, by incorporating transition metals with higher magnetic moments”, he reinforces.