Originally published at: ZeroAvia Secures Grant Supporting Hydrogen-Power Development - AVweb
Solving the storage and delivery dilemma is key to promoting liquid hydrogen as an energy source for aviation.
“A large part of the challenge……..to store and dispense the fuel”. Exactly! Hydrogen is a tricky fuel. Having a boiling point of -423°F at atmospheric pressure it is very difficult to hold in quantity, at least for very long. Of course, raising pressures raises that boiling point, but that produces its own issues. Using mechanical refrigeration (cascade system) to hold quantities soon negates the efficiency factor of the fuel system. Hopefully, this company will reach a breakthrough in technology for production, storage, and handling.
Since there are no “hydrogen mines” in the UK, how does this zero-emission fuel become there?
Since hydrogen is, by far, the most plentiful atom in the universe, surely they can find some. And perhaps with a bottle of the stuff in the back of your Cherokee, you won’t have to worry about air conditioning!
“Since hydrogen is, by far, the most plentiful atom in the universe, surely they can find some”
Since H2 is also the lightest molecule, you can find it all you want (at the top of the atmosphere).
Point is that they have to use processes/synthesize H2 gas, then chill/compress it, and then transport it to the UK, transfer it, and store it. Also being one of the smallest molecules means it’s guaranteed to leak out at fittings and/or self-vents until it’s all gone over time.
The process is a NET ENERGY LOSS.
It’s not sustainable. It’s actually adds to the problem.
Pretty sure no one needs to go to “the top of the atmosphere” to find Hydrogen. In elementary school, most of us learned “another” name for water is H2O. And, of course that means that the cup of coffee, or that shower, or the stuff inside the garden hose at the airport has approx 2 times more hydrogen atoms than everything else combined.
Don’t know about you, but as a kid, I put two wires in a glass of water, hooked it to a battery and watched the H2 and O2 bubbles – even arranged a few not-so-controlled fires and small explosions from them…
And – yes getting H2 from water costs energy, but because of solar and wind, even without subsidies, electricity is getting cheaper every year. And for H2, it can all be local – with minimal transportation required. Don’t forget that the cost of drilling, pumping, transporting, refining, transporting again, formulating, transporting again and delivering AvGas is also a huge “ENERGY LOSS”.
The difference is, that with H2, even now, producing and then converting H2 to electricity and then power is wildly more efficient than the 20-something percent efficiency of AvGas producing power in my Lycomings… and over time, the cost of every other step will drop and keep dropping – and the market (including probably you) will most certainly prefer to pay less than more. (And there may be a few other benefits too!)
Turns out that production of pure H2 might become much easier in the near future. Scientists have discovered certain natural processes in the earth’s crust that produce hydrogen, just like the processes that formed oil, natural gas and coal. According to the USGS and some oil companies, they have identified huge underground reservoirs of hydrogen beneath the USA that could supply much of our energy needs for over a thousand years. Other parts of the world have similar formations. Several companies are now in the process of working out the drilling and production systems.
Production aside, the storage and distribution of hydrogen is well understood and can be implemented with no new breakthroughs needed. However, due to its extreme low temperature, storage, handling and transfer is definitely not something your average line boy is qualified to perform. Strict adherence to transfer procedures is an absolute must. The trick will be how to design the on-board tankage and vaporization systems. Jet fuel can be stored in irregular shaped tanks nestled in the wings. Cryo tanks really need to be cylindrical and heavily insulated or double-wall vacuum bottles (or both). Used as a rocket fuel, the rocket is already just a big round tank anyway. Planes, not so much.
I seem to remember that Toyota looked into this as well and learned that the energy extracted resulted in very poor mileage compared to conventional fuels. While we have hybrid vehicles and E.V.'s, even the transit people have moved away from hydrogen fuelled busses. Might be a source of OPM for the blue-eyed optimists though.
Actually, I would like any plane I am flying to have as little in common with any rocket as possible. There are plenty of ways to make synthetic fuels if you have abundant, cheap power available. Hydrogen sounds like a real longshot to me.
Conservation of energy: Using electricity to break the bonds in water to free up Hydrogen takes MORE energy than you get from of the fuel you produce. Period.
Solar and wind are already being used so ADDING a 24/7 demand process to the grid to generate H2 means takes away from that capacity so oil & natural gas generators will need to expand.
As said, the process is a NET ENERGY LOSS.
It’s not sustainable. It’s actually adds to the problem.
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