After nearly two years of laser-focused design and development, a device that converts hydrogen gas into liquid hydrogen was completed by Washington State University researchers in April. Their Mobile Hydrogen Generation Unit (MHGU, pronounced magoo) – also known as a deployable hydrogen liquefier – will be tested later this year with the intent to provide cryogenic hydrogen fuel for army drones.

“One kilogram of liquid hydrogen has the same energy as a gallon of gasoline but is much more efficient than burning gasoline,” said Jacob Leachman, the lead researcher for the U.S. Army-funded project and an associate professor in the WSU School of Mechanical & Materials Engineering. “It’s environmentally friendly, green energy. Water is its byproduct which falls out of the sky as rain.”

For decades, Leachman has been committed to developing a process to convert hydrogen gas into liquid hydrogen. He explains while the equation to produce hydrogen gas is relatively simple, the process to produce liquid hydrogen is not. Though it has potential as a vital green energy source, production of liquid hydrogen has long proved elusive for researchers and energy innovators.

In 2010, Leachman founded the Hydrogen Properties for Energy Research (HYPER) Laboratory on the WSU Pullman campus with a mission to bring this vision into reality.

One of the key challenges to this goal has been temperature requirements. Liquid hydrogen is actually cryogenic hydrogen. For hydrogen gas to become liquid, it must be cooled to a cryogenic temperature below -420 degrees Fahrenheit.

Closeup of Jacob Leachman
Jacob Leachman

From the development of equipment that will liquefy the hydrogen, to exploring materials that will safely store the liquid hydrogen, the process to realize Leachman’s goal has been exponentially complex.

He and a team of innovative students are now one monumental step closer to reaching this goal with the completion of the MGHU in April.

“With over 6,000 parts, this liquefier is the most incredible achievement I’ve seen by engineering students in my lifetime,” Leachman said. “Each student delivered something key and critical to the project.”

Sean Dimmer joined the MHGU group in early 2019 as the CAD and plumbing team lead.

“My work involved putting together system diagrams and determining locations for equipment, so project requirements were met,” said Dimmer, who was awarded his Bachelor of Science in mechanical engineering in fall 2020. “From there, we merged with the controls and electrical team as ‘the BUILD squad’ to put it all together.”

The hydrogen liquefier’s sophisticated computer mechanisms were all built into an unassuming, 8-by-8 tan cube of a mil-spec shipping container.

“The challenge was fitting all 6,000 components into the container,” Leachman said. “The students created an amazing CAD model of the liquefier to verify the parts would work together in the box.”

In fact, all of the students who collaborated on this project forged uncharted terrain throughout this undertaking.

“Building the MHGU was like solving one giant jigsaw puzzle,” said Hannah Gardner, a mechanical engineering student. “Learning how to pioneer a new technology in a developing field is hard to do.”

After completion in mid-April, a two-ton crane was used to lift the MHGU into its container for transport. This summer, the MHGU team will travel with the liquefier to site across the U.S. for testing.

“I don’t think the magnitude of what we were doing set in for me until we lifted the equipment cages into the container,” Dimmer said. “Seeing MHGU with all the equipment loaded in, after working on the CAD assembly for months, blew my mind.”

Gardner’s experience mirrored Dimmer’s.

“The most inspiring moment was when I saw the MHGU being pulled out of our indoor lab site onto a trailer and moved to our outdoor testing location,” she said. “Everything we’d been doing was preparing for this moment. As I saw it roll away, I knew it was going to work.”