MIT Seems Forward to Hydrogen’s Aviation Future

This text is a part of our unique IEEE Journal Watch series in partnership with IEEE Xplore.

As funding in hydrogen-powered flight expands, airports and air carriers at the moment are realizing that it’s not sufficient to retrofit or design new planes for hydrogen energy. So whereas researchers and corporations giant and small spend money on the zero-carbon way forward for the sector, others are starting to review what provides and infrastructure on the bottom would even be wanted to make hydrogen aviation a actuality.

“Hydrogen could also be a superb factor, however you gotta have a look at it from the total system degree, proper?,” asks Professor R. John Hansman, an aeronautics and astronautics professor at MIT and director of the college’s International Center for Air Transportation. “As a result of it received’t work until you could have all of the items to make it work as an working system. There’s a number of expertise that must be developed.”

Chicago O’Hare would demand the equal of 719 tonnes of liquid hydrogen per day.

The primary problem is hydrogen manufacturing. A paper co-authored by Hansman and a number of other MIT college students—and introduced this summer time on the IEEE International Conference on Future Energy Solutions on the College of Vaasa in Finland— thought-about the case of supplying sufficient liquid hydrogen for 100 airports worldwide, every with long-haul flights. (Just a few hundred airports help flights that journey greater than 4,800 kilometers globally.)

The concept, Hansman says, was to give attention to a smaller set of airports and, theoretically, restrict the potential new infrastructure that could be required by hydrogen-powered flight. However simply supporting liquid hydrogen-powered long-haul flights at these airports would quantity to greater than 30 p.c of present world nuclear energy manufacturing per day, in line with the researchers’ calculations. Chicago O’Hare, as an illustration, would demand the equal of 719 tonnes of liquid hydrogen per day.

And the hydrogen must both be produced via clear or nuclear vitality to offer actual local weather advantages, the paper famous.

The analysis hinted at different logistical challenges, too, together with transporting and storing hydrogen in an environment friendly means. For instance, in line with the researchers, sustaining two days’ price of liquid hydrogen for long-haul flights at Chicago O’Hare would require 5 storage tanks equal to the dimensions of the liquid hydrogen storage tank at the NASA Kennedy Space Center—the biggest on the planet as of 2021.

It’s doable that some airports may produce hydrogen onsite, the researchers added, however others may not have the room.

Liquid hydrogen may require a brand new loading course of, too. Fueling hydrogen in a means that’s just like customary jet gas may require cryogenic equipment, because the liquid hydrogen would have to be transported at extraordinarily low temperatures, in line with Arnaud Namer, the chief working officer at Universal Hydrogen, a hydrogen-focused transportation startup. This equipment could possibly be costly and heavy, he famous, and transporting hydrogen on this means may additionally create the danger of loss, creating less-than-ideal security and local weather impacts.

One firm is creating modular hydrogen capsules, which may every carry round 200 kilograms of liquid hydrogen—the “Nespresso mannequin.”

In an analogous vein, a 2022 paper from researchers in Germany analyzing hydrogen refueling logistics thought-about the potential advantages of a number of completely different refueling programs, resembling vehicles and pipelines and hydrants. The first methodology anticipated by Julian Hölzen, one of many authors of that challenge, are vehicles.

“These are almost out there [and] commercialized at the moment, simply scalable, include comparatively low capital prices, and at airports with no site visitors constraints they’re an ideal first step for LH2 plane refueling,” Hölzen mentioned in an e-mail. “The pipeline-and-hydrant possibility is the best choice from an engineering perspective. However may not supply the economics for medium-sized airports and comes with much less flexibility.”

Refueling raises one other open query. Hydrogen, Hansman provides, is extraordinarily flammable, which implies gas traces would have to be cleared. Whereas NASA usually depends on helium, a brand new method to purge gas traces could also be wanted to work for a business aviation setting.

“Let’s simply say you need to refuel the airplane in an hour or two, proper? Effectively, so it seems, it’s difficult to do this,” he mentioned.

Proper now, there are different concepts, however they could not work for every kind of flights. Common Hydrogen is creating modular hydrogen capsules, which may every carry round 200 kilograms of liquid hydrogen. Whereas Hansman notes this strategy may not be workable for long-haul flights, Namer says this expertise could possibly be used on any sized plane.

“That’s just like the Nespresso model. You really use capsules, the place you fill the hydrogen on the manufacturing website with these capsules,” explains Namer. “In that sense, there’s no infrastructure growth to be completed on the airports or on the bottom dealing with since you’re transferring your gas such as you’re transferring cargo with the identical type of gear.”