Aircraft

Ultra-light liquid hydrogen tanks promise to make jet fuel obsolete

HyPoint and GTL are developing ultra-lightweight cryogenic hydrogen tanks that the partnership promises will radiacally boost the range of clean hydrogen-electric aircraft
Gloyer-Taylor Laboratories
HyPoint and GTL are developing ultra-lightweight cryogenic hydrogen tanks that the partnership promises will radiacally boost the range of clean hydrogen-electric aircraft
Gloyer-Taylor Laboratories

A revolutionary cryogenic tank design promises to radically boost the range of hydrogen-powered aircraft – to the point where clean, fuel-cell airliners could fly up to four times farther than comparable planes running on today's dirty jet fuel.

Weight is the enemy of all things aerospace – indeed, hydrogen's superior energy storage per weight is what makes it such an attractive alternative to lithium batteries in the aviation world. We've written before about HyPoint's turbo air-cooled fuel cell technology, but its key differentiator in the aviation market is its enormous power density compared with traditional fuel cells. For its high power output, it's extremely lightweight.

Now, it seems HyPoint has found a similarly-minded partner that's making similar claims on the fuel storage side. Tennessee company Gloyer-Taylor Laboratories (GTL) has been working for many years now on developing ultra-lightweight cryogenic tanks made from graphite fiber composites, among other materials.

GTL claims it's built and tested several cryogenic tanks demonstrating an enormous 75 percent mass reduction as compared with "state-of-the-art aerospace cryotanks (metal or composite)." The company says they've tested leak-tight, even through several cryo-thermal pressure cycles, and that these tanks are at a Technology Readiness Level (TRL) of 6+, where TRL 6 represents a technology that's been verified at a beta prototype level in an operational environment.

HyPoint's lab validation prototype for its turbo air-cooled fuel cell
HyPoint

This kind of weight reduction makes an enormous difference when you're dealing with a fuel like liquid hydrogen, which weighs so little in its own right. To put this in context, ZeroAvia's Val Miftakhov told us in 2020 that for a typical compressed-gas hydrogen tank, the typical mass fraction (how much the fuel contributes to the weight of a full tank) was only 10-11 percent. Every kilogram of hydrogen, in other words, needs about 9 kg of tank hauling it about.

Liquid hydrogen, said Miftakhov at the time, could conceivably allow hydrogen planes to beat regular kerosene jets on range.

"Even at a 30-percent mass fraction, which is relatively achievable in liquid hydrogen storage, you'd have the utility of a hydrogen system higher than a jet fuel system on a per-kilogram basis," he said.

GTL claims the 2.4-m-long, 1.2-m-diameter (7.9-ft-long, 3.9-ft-diameter) cryotank pictured at the top of this article weighs just 12 kg (26.5 lb). With a skirt and "vacuum dewar shell" added, the total weight is 67 kg (148 lb). And it can hold over 150 kg (331 lb) of hydrogen. That's a mass fraction of nearly 70 percent, leaving plenty of spare weight for cryo-cooling gear, pumps and whatnot even while maintaining a total system mass fraction over 50 percent.

If it does what it says on the tin, this promises to be massively disruptive. At a mass fraction of over 50 percent, HyPoint says it will enable clean aircraft to fly four times as far as a comparable aircraft running on jet fuel, while cutting operating costs by an estimated 50 percent on a dollar-per-passenger-mile basis – and completely eliminating carbon emissions.

HyPoint gives the example of a typical De Havilland Canada Dash-8 Q300, which flies 50-56 passengers about 1,558 km (968 miles) on jet fuel. Retrofitted with a fuel cell powertrain and a GTL composite tank, the same plane could fly up to 4,488 km (2,789 miles).

"That's the difference between this plane going from New York to Chicago with high carbon emissions versus New York to San Francisco with zero carbon emissions," said HyPoint co-founder Sergei Shubenkov in a press release.

There's not a sector in the aviation world that shouldn't be pricking up its ears at this news. From electric VTOLs to full-size intercontinental airliners, there aren't a lot of operators that wouldn't want to dramatically boost flight range, reduce costs, eliminate carbon emissions or simply just reduce weight to increase cargo or passenger capacity.

It won't be simple – there's a ton of work to be done yet on green hydrogen production, transport and logistics, not to mention developing these tanks and aircraft fuel cells to the point where they're airworthy, certified and well-enough tested to be considered a no-brainer. But with these kinds of numbers on the table as carrots, and the aviation sector's enormous emissions profile acting as a stick, these tanks should surely get a chance to prove themselves.

Source: HyPoint/GTL

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35 comments
MarylandUSA
"Massively disruptive" indeed. We've all been wondering when jet fuel will be replaced by batteries. Wouldn't it be something if liquid hydrogen wins?
FB36
Just last week NASA had to cancel a rocket (SLS) test because of a hydrogen leak detected!
Hydrogen is not just flammable it is explosive!
Is it really hard to see the extreme danger, if hydrogen fuel is used for any land/sea/air transportation?
& by the way there is actually no need at all!
All existing large vehicles for land/sea/air transportation, just need to switch to biodiesel/biofuel!
noteugene
If it sounds too good to be true, it usually is. Always a catch. I agree with another poster concerning the explosive factor. If you don't think it'd bother you to ride a bomb, I say go for it.
Expanded Viewpoint
There must be something in the water they're drinking, and I don't think it's snake venom that is clouding their mental processes. From WHERE does all of this liquid Hydrogen come from?? Does it come from some kind of plant life no one has seen before? Or is it really just Unicorn pee?
Fuel cells are not batteries, they are expensive devices that require exotic metals and technology to make them. Evidently, chemistry and physics aren't taught in the public fool system these days.
CraigAllenCorson
FB36 There is a product that is about 1,000 times as explosive as hydrogen, and it is piped into more than half of American homes, as well as most businesses. It's called natural gas. Most people consider it a very safe fuel, and use it for winter heating, cooking, and domestic hot water. If we can learn to handle this highly explosive material safely, we can certainly learn to handle hydrogen safely. The only reason that you fear hydrogen is the Hindenburg, but most of the people who died in that disaster died from the fall, not from burns. Hydrogen, being the lightest gas, tends to rise, and this tendency increases with temperature. It rises UP AND AWAY from its source, unlike other fuels, which stay near the ground, burning whatever else is there. If I could heat my home with hydrogen, I would. It's far safer.
freddotu
Even if the technology is safe enough to avoid explosions and fire, I question the "green" component of hydrogen, regardless of how it's stored. Currently, creation of hydrogen is carbon intensive, especially when one considers the energy necessary to compress the gas and also to transport it. Will there be hydrogen powered compressors and hydrogen powered transport trucks and hydrogen powered pumps at the airport? If not, there's a strong possibility that the carbon footprint of all the above will remove the green. Certainly, all those things come into play with petroleum fuels and I'll concede that the overall figure may be better with hydrogen.
Ray6969
Well lets just jump right into rigging up these things and see how long it takes before one blows an airport into the heavens! Just like the morons that want 'everything electric' right now, but have no idea just what that entails or the damage it will cause if done wrong! I can understand a slow transition as things are made far more safe, far more dependable, but to try and make an immediate transition is just nothing short of ignorant.
vince
Zero carbon emissions at point of use but filthy Carbone generation in production of hydrogen gas from natural gas which make 95 percent of all hydrogen. Back to drawing board.
TechGazer
People really misunderstand the concept of 'explosive'. Hydrogen is not explosive. Hydrogen 'mixed with air at the correct ratio' is explosive. If the ratio is wrong, you'll get a 'wumph' of heat. Fire a bullet through a liquid hydrogen tank (and provide an ignition source) and you'll get a fire. I expect that jet fuel is actually a more powerful explosive (when mixed with air at the right ratio), but it's much harder to achieve that ratio. Handling hydrogen will require safety precautions, but so does natural gas, gasoline, jet fuel, wheat flour and any other substance that can potentially result in an explosion.

This new technique will probably find some use. Just how much use depends on a lot of factors, such as availability of green hydrogen, and the overall economics of all the steps and issues involved.
rpark
Although I'm not an aeronautic engineer, the numbers and verbiage in the article sound remarkable -> "At a mass fraction of over 50 percent, HyPoint says it will enable clean aircraft to fly four times as far as a comparable aircraft running on jet fuel while cutting operating costs by an estimated 50 percent on a dollar-per-passenger-mile basis – and eliminating carbon emissions." Although, hydrogen is exceedingly explosive (Hindenberg), so is jet fuel and its associated risks .. this technology, while unproven, seems to hold much promise for a more sustainable future.