Submitted by yourSAS t3_z7t0sf in technology
Isn't hydrogen very scarce?
*Pretty sure I'm thinking about helium. Thanks everyone!
>hydrogen
It's the most abundant chemical element. It's just expensive (energy wise) to extract.
Helium is somewhat but hydrogen is everywhere.
Like Water
Nope, just run an electric current through water and it will separate it into oxygen and hydrogen. Super easy to generate if you have enough electricity.
It's the most abundant element in the entire universe.
[removed]
That's the same with any fuel.
Nuclear say hi.
Great for generating electricity. Not so great for planes.
Exactly what this should be for now. Who know what nuclear can do if allow to advance.
There is no replacement for gasoline in commercial flight. Even if such technology exist, it probably won't implemented due to the cost of building an aircraft ($10 to $20B).
No company will be taking such as risk. Politicians will do it, because it is not their money and a big payout for their buddies.
This is literally about replacing gasoline with hydrogen.
Maybe don't embarrass yourself.
Aircraft don't run on gasoline
You don't need to design a plane from scratch for a new engine. BROADLY speaking it's mainly the horizontal tail that needs to be redesigned to account for the pitching moment from the engines. The problem with hydrogen is its lower energy density than aircraft fuel. It's the reason why electric jets don't exist
This would probably be for future aircraft not retrofits.
You clearly have no idea what you're talking about.
Unless they are forced to do it. Via legislation,
Hello. Where do you put your waste?
Preferably it's recycled. Then the unusable waste is stored. Not to mention most waste is only dangerous for around 10-20 years. Nuclear energy is really the best stop gap we have to fight climate change.
Let’s see: every single known nuclear reactor has leaked dangerous radiation/particles into its surrounding environment, there’s waste that is dangerous for much more that 10-20 years, there’s been major accidents across the globe (not limited to one or two nations), none have ever been “profitable” and all have needed to be subsidized by the nations they are in to make the energy affordable to the consumer, has to be along a major water source (which they’ve almost universally leaked into), and is growing exponentially more expensive than renewables which are rapidly growing less expensive. They do not allow for micro grids only large, centralized grids, and you can make nuclear weapons from them. Not to mention solar generation plants and windmills can’t have “meltdowns” (oh I know, that NEVER happens right? Except for a couple of times). With the money it would take to build new “modern” reactors you can build tons of windmills and solar farms.
This is such a spent and fictitious talking point I don’t know why people still say it. The fake “green nuclear” argument has always just been propaganda and it sucks people fall for it.
[removed]
Why would we want to commit to climate change? Isn't climate change bad?
Not a "first". In the 50's the US government through Lockheed was developing a replacement for the U2. It was going to be bigger, faster and powered by hydrogen. Pratt & Whitney developed the engine for the project. Project 304.
Problem was they couldn't figure out how to store enough cryogenic hydrogen and keep it cryogenic to make it work.
https://en.wikipedia.org/wiki/Lockheed_CL-400_Suntan
EDIT: Pratt got the engine working pretty well. Lockheed couldn't get the CL-400 figured out. Pratt's work with hydrogen ended up helping them develop the RL-10 upper stage rocket engine.
>Problem was they couldn't figure out how to store enough cryogenic hydrogen and keep it cryogenic to make it work.
That's still an unsolved problem. Liquid hydrogen only has 1/4 the energy density of gasoline, although it is significantly lighter per joule of energy. Some more research is also needed to figure out a way to efficiently split water, IIRC current methods lose a significant amount of energy to heat. Long term, I think battery technology will be the best bet for cars and airplanes and we might see hydrogen in use for grid balancing.
If I had to guess, I'd think the majority of hydrogen research funding comes from fossil fuel companies as they'll be entirely obsolete if the planet shifts away from liquid fuel.
I was just looking at the Google server building here in my area and it’s really too bad we can’t build something next to it to take advantage of the heat it generates to cool the servers. The same would be useful for hydrogen, if we could just put a useful business next door that needs the heat, we could start being more efficient.
I used to build smart homes with automation etc. I once ducted the waste heat from the server racks into the elevator shaft in the middle of the house to capture some heat in the winter with a vent to switch the exhaust outside in the summer (this was in Canada)
A home with a server rack? Sounds expensive. Pretty good idea though. I was thinking about our dryer vent and how to capture that wasted heat in the colder months.
The clientele I worked for typically spent anywhere from 2-20 million dollars on their homes with our contracts ranging anywhere from $50000 to a million for all the A/V, lighting control, security, surveillance, and full systems integration with HVAC and gates, garage doors, hot tubs, self playing pianos, etc. Whatever they wanted. This was the high end of home automation, mind you.
Yeah, a bit out of my price range. Haha
I always thought jet engines would eat every combustible liquid or gas you give em. Another problem but the storage would be that hydrogen is manyfold worse than CO/2 for the climate when it escapes, and that is the mature problem with it, it's atomic weight is just to light and it crawls out of almost everything.
Edit: Sry but the stuff with the to light of an atomic weight to crawl out of contaiers was helium I guess, but put the production of hydrogen into an industrial scale it could still get messy.
They did test hydrogen with a standard j-57. The 304 was a highly optimized configuration. It had a massive heat exchanger after the cumbustors and it looked more like a steam turbine inside. Lots of tiny bladed compressor stages
Combusting hydrogen that starts in the liquid state is tricky. At 1 atmosphere, hydrogen evaporates into a gas at 33K, but oxygen freezes at 54K. On top of that, combustion occurs at much higher pressures in a jet engine. So, while it's definitely possible to make it work, you need an engine design that significantly pre-heats the incoming fuel. The space shuttle main engines do this by scavenging heat from the exhaust and are a marvel of engineering.
you guys on bikes driving the fan better keep peddling, if that flame reaches the fuel supply we're in trouble
You say that like jet fuel catching on fire wouldn’t be a problem
Everyone knows jet fuel isn’t hot enough to melt steel /s
but the plane is made of aluminium!
This might be a stupid question, so I apologize in advance. But let's say that engine caught fire somehow/blew up for some reason - would it be any more dangerous than a regular engine fire?
Or am I just totally misunderstanding the risks involved with hydrogen because I once heard the phrase "hydrogen bomb"..? (Probably, but idk what I don't know)
Hydrogen bombs are a type of nuke that uses hydrogen to create a fusion reaction (more powerful than fission) not entirely sure but I think you still need a regular fission (think uranium) bomb to create enough energy for that. Hydrogen on its own burns, but not nuclear bomb kinda burns. Think about the Hindenburg, the hydrogen caught fire and it burned, but it wasn’t going off like a nuke.
Yes, you’re correct. They’re a 2-stage bomb more or less. A small fission reaction is used to trigger the hydrogen fusion reaction.
a set of small fission bombs all denoated simultaneously to create a compression wave to super-compress the hydrogen target.
Oh the humanity!
Bringing up hydrogen bombs when discussing hydrogen engines is pretty disingenuous and fear mongery. Hydrogen itself is very flammable and dangerous in it's own right but is very different and much less dangerous than a hydrogen bomb.
My point exactly
Ahhh sorry, I didn't see that the previous person mentioned hydrogen bombs themselves.
One benefit of hydrogen in the safety side that I heard when talking about hydrogen powered cars is that if there's a puncture in the fuel line that catches fire, it is more contained, because the hydrogen is a gas in our atmosphere at normal temperatures and lighter than air, so it rises and doesn't spread. By comparison, a liquid fuel will pool and the fire will spread over a large area.
Oh, great point, I didn't think about that!
> would it be any more dangerous than a regular engine fire?
Not exactly what you were asking for, but it was already tested long ago : Difference between a hydrogen and a petrol car on fire
I forgot which YouTube video talked about the bad perception of the Hindenburg disaster. People saw it in flames, as one of the first video news stories. But what they didn't see is that it burned out very quickly.
This was so helpful, thank you! So it wouldn't necessarily be any worse, it would just be faster and very different.
Hm nice plan, but in Scandinavia there where exploding hydrogen petrol stations.
For those wondering, it was a plant in Norway that was preventable :
Yes, it can explode.just like natural gas/petrol stations/chemistry plants. Never refuted that. But hydrogen at least burns up, unlike oil spills,
And disperses since hydrogen floats upwards unlike the forever burning hole
When you are on a plane I don't really think it matters what the fuel source is if it catches fire midair
Lol I guess I meant whole it was on the runway or something like that. I remember watching a video a while back where people were evacuating a burning plane that hadn't taken off yet, and that's what my brain jumped to when I saw this post.
I just look at it like if the plane is going to crash it probably doesn't matter if it's hydrogen or jet fuel, you're gonna go boom either way.
But you make a good point about a plane that is still on the ground.
You can dump hydrogen pretty quickly and controlled.
People often quote the Hindenburg disaster showing that hydrogen in dangerous, but if you look carefully you can see that the hydrogen has floated up above the rest of the airship, and is burning well away from anything important.
It can mix with air to form an explosive, just like gas/petrol vapour or propane/butane - but when spilt, it's less likely to hang around and be a fire risk than a heavier fuel.
That's such a great point, I completely forgot how light it was. I guess in a way it would actually be a bit safer then!
Now all we need to do is create the fuel supply while taking care of our nuclear waste and debt currency problems at the same time. It’s time for a new economic age that recognizes the Nash Equilibrium like AlphaGo did, "Only if everyone has what they need, can anyone achieve their potential."
[removed]
How much thrust did it develop I wonder
OK, but I thought hydrogen didn't work well at low temperatures. How would they compensate for that in air travel? Not picking a fight, I'm fascinated to know.
I could be wrong, but I think that the last time that an aircraft flew on hydrogen fuel, there were some rather explosive results. https://en.wikipedia.org/wiki/Hindenburg_disaster
hindenburg 2
Maybe this is how it starts with hydrogen. If they can produce it on scale for the aerospace industry then hopefully the cost of producing it will drop and scale for cars easier.
Phew just in time for the climate lockdown, world leaders wont have to make excuses for G summit travel again
The problem is not 'burning' hydrogen. That's been done for ages. The problem with hydrogen powering aircraft is figuring out where to store the hydrogen. Hydrogen has an incredibly low energy density by volume. Because of this (and other) basic physics problem(s), hydrogen will not work to power planes on long duration flights. The most likely solution to decarbonizing intercontinental aircraft travel will be some form of liquid bio-fuel or even synthetic liquid fuel.
Because of the expense of hydrogen, medium and short haul flights will most efficiently be covered by some combination of an expansion of high speed rail and battery electric aircraft.
[removed]
As a gas turbine OEM, they're doing their part in ensuring that they can safely operate with hydrogen, ammonia or other vectors. It's on the major energy players to make sure that hydrogen is green, i.e. coming from electrolysis with renewable energy rather than NG.
I would add that jets in particular are difficult for a green transition.
High power and portability requirements really limit your options.
I recommend you give this a read then.
https://www.reddit.com/r/collapse/comments/xdytr0/the_renewable_energy_scam/
Yeah but we aren't gonna give up modern day life. Yes renewables take finite non renewable resources, but they result in much less damage than the melting of the planet through climate change.
Except it takes 7x the amount of energy to produce the same result, how is that even remotely effective?
What does this even mean? Over how long? Building the structures? Running it continuously? How does that energy equate to the amount it puts out?
In “moving on from oil” we would be walking away from a complex and often-violent and always critical supply and transport system, only to replace it with at least ten more. A world in which we “electrify everything” requires an order of magnitude more copper and lithium and nickel and cobalt and graphite and chromium and zinc and rare earths and silicon and more.
The future is darker, and less green, than you think.
What point are you arguing? I asked about energy amounts and you bring up rare earth metals.
Yes. I agreed that finite resource materials are required.
I suppose what your definition of "green" is required. I'm thinking of carbon emissions resulting in climate change.
My point is it takes 7x as much energy/resources to produce renewable tech that has a shelf life of 10 years. How is that going to achieve cooling the planet if everything we use now takes 7x the resources and every middle class person wants it?
7x what we emit now is not better.
It would help if you had credible sources backing up the specific claims you want to work with, and not a link to a fifteen page self-post ramble.
So you didn't read it, got it.
Of course I didn't read it. My time has worth, and I have very little reason to believe that that post does.
Well that was a rant, but anything I have to say about it was already said in the comments on that post.
Really, you put a lot of effort towards being wrong.
So you're just going to ignore physics then.
First of all, materials such as iron and copper have to be mined. Mining is extremely destructive to the environment, and is carried out by machines such as giant excavators and huge trucks. All these machines are of course I diesel powered.
To create steel, iron ore and carbon, both non-renewable resources, have to be heated to about 1500 degrees. [The production of one tonne of steel emits about 1.8 tonnes of CO2] (https://www.mckinsey.com/industries/metals-and-mining/our-insights/decarbonization-challenge-for-steel). There are between 225 and 285 tonnes of steel in each turbine, so that's 400 tonnes of CO2 just to produce the steel for one turbine! It also takes plastic to build wind turbines. There are over 50 tonnes of plastic in the blades of a 5 MW wind turbine. Plastic is obviously a petroleum by-product. On top of that, each wind turbine needs between 200 and 1400 litres of a petroleum-based lubricant to work properly, which has to be replaced once every 4-7.
And that's not all. To prevent overloads and short circuits in the switchgear of wind turbines, sulphur hexafluoride (SF6) is used. SF6 is 22,800 times more powerful than CO2 and remains in the atmosphere for almost 3000 years! It is the most powerful greenhouse gas known. Each wind turbine contains about 5kg of SF6, which, if released into the atmosphere, would add the equivalent of about 117 tonnes of CO2. This is about the same as the annual emissions of 25 cars. That's not counting the fact that all the materials have to be mined/extracted, transported to a factory, and then the turbines transported over long distances to their final destination by special convoy, adding tonnes of CO2.
Your viewpoint is as damaging as the corporations releasing fossils fuels. People like you will lead the way to a downward spiral of society by telling everyone theres nothing we can do.
Not a single one of those problems is unsolvable. Not a single one of those statements makes green energy less efficient than coal.
We are already on the downward spiral. "people like you" you mean someone who sees what has to happen. Humans are a species in the overshoot of their ecological environment. This is commonplace. Species go into overshoot all the time and from the point of view of nature, it is a feature and not a bug because overshoot introduces creative disruptions. This may however be the first time that a species has gone into overshoot globally rather than locally.
The size and complexity of civilization is an emergent property of exploiting the stored sunlight in fossil energy. The party will soon end. All use of energy to perform work increases entropy which degrades the physical environment in which it is used. Our problem is that we discovered 500 million years of stored sunlight and used it all up in 200 years.
People searching for substitutes for fossil fuels with the expectation that we won’t have to live with less energy have not thought it through. Learning to live with the same energy people in 1721 used is the challenge we face this century.
Cynicism is not productive, it does not make you enlightened. Its just another form of gullibility.
As opposed to techno-optimism or hopium?
All of those also get us nowhere.
We can have a sustainable society. Its not impossible, but its going to take work. Hard work. And no small amount of sacrifice.
Yep, it's going to take an absolute monumental shift in the way we live, work and exist. I'm actually really excited for the change, it's going to be hard for many but if it pivots us out of our death spiral I'm all for it.
The only way to deal with a Gish gallop is to start picking out claims randomly. So:
> Each wind turbine contains about 5kg of SF6, which, if released into the atmosphere, would add the equivalent of about 117 tonnes of CO2. This is about the same as the annual emissions of 25 cars
Never mind the fact that the article you link mentions that wind farms are now being built that phase out SF6. Let’s just look at scale.
Conservatively, the average electric car needs 5000 kWh per year to run. An average wind turbine produces 843,000 kWh per month. So the turbine pays off those 25 car-years worth of emissions in under 5 days
It's literally the 2nd sentence in the article (presumably because they're tired of people not wanting or being able to read):
> The ground test, using a converted Rolls-Royce AE 2100-A regional aircraft engine, used green hydrogen created by wind and tidal power, the British company said on Monday.
Article is paywalled so no can read it
just make an account with reuters. they dont charge you anything.
Yea that’s not really the point though. It’s very easy to test with green hydrogen, but to commercialize the product the price of green hydrogen will have to drop below the price of gray hydrogen.
Yes it’s true that hydrogen is mostly from natural gas, but that is still better than aviation-gas. Because av-gas is the only fuel that still uses lead.
Long haul transport ships also still use leaded fuel.
I didn’t know that. Thank you u/spartanfred104. Is it only the “dirty fuel” they use on the open sea that have lead or do the “clean fuel” they use in ports also have lead?
u/spartanfred104, not @spartanfred104
Avgas is used for propeller engine planes, which are mainly flown by hobbyists in rich countries, meaning it's use is not very large scale.
Commercial aviation mainly uses turbine engines powered by Jet fuel, which is not leaded but we burn a lot more of it.
[deleted]
Apparently they are using fully green hydrogen for these tests
Where do you think they get all that electricity for the electrolysis?
The test was carried out at the British military aircraft testing site at Boscombe Down, using green hydrogen fuel generated by harnessing the power of wind and waves at the European Marine Energy Center in the remote Orkney Islands, between Scotland and Norway.
Literally from the article I linked
[deleted]
Europe is building out infrastructure to manufacture and transport 10 million tonnes of hydrogen by 2030 https://energy.ec.europa.eu/topics/energy-systems-integration/hydrogen_en
[deleted]
Not to mention where will they even store the Hydrogen fuel. It aint gonna be cryogenic, and super high pressure storage tanks don't mix particular well with jetliners, especially because of the failure modes. They tend to really violently explode when they fail.
Another hurdle is where to store the hydrogen on a plane? Current tanks in the wings, rudder, body of the plane will not work.
The amount of space needed for the tanks is substantial and has to come at the expense of passengers and their luggage. It's the same issue for battery powered airliners. The technology isn't feasible with todays or near-future technologies.
And Hydrogen is a tiny molecule, it takes so much more tech to be able to store and use it as conventionally as gasoline.
If you were replacing jet fuel for every jet on the planet, you'd have to go with cryogenic.
Nat gas is currently the most common but there is significant and substantial work being done to use nuclear and renewable resources for hydrogen production. By the time RR and others get this to commercial production we’ll already have a robust clean hydrogen network.
[deleted]
I mean, while it’s like that now it’s still POSSIBLE to get green hydrogen and battery powered planes won’t be a thing for long commercial flights, this is important tech as long as the storage is light enough
PDNYFL t1_iy8nl7o wrote
Hydrogen is key for commercial/industrial applications if we are committing to climate change. We just need to source it cleanly.