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Dan Thomas
Well-Known Member
- Joined
- Sep 17, 2008
- Messages
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I wonder what those 10,000 psi tanks weigh. I would hope they're not steel, but some composite wrap such as some O2 tanks are now.
Fuel cells might be the game-changer for electric cars, at least, but the electricity still has to come from somewhere. It takes electricity to isolate hydrogen and/or compress it. Electrolysis of water is notoriously inefficient. Currently about 95% of hydrogen is taken from fossil fuels. Oh dear...fossil fuels...
Fuel cells might be the game-changer for electric cars, at least, but the electricity still has to come from somewhere. It takes electricity to isolate hydrogen and/or compress it. Electrolysis of water is notoriously inefficient. Currently about 95% of hydrogen is taken from fossil fuels. Oh dear...fossil fuels...
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rv7charlie
Well-Known Member
Says carbon fiber, right in the article. Pretty safe bet that they (and the fuel cell) weigh less than a 1500 lb battery pack. And not everything electrical is purely about 'save the planet'. A motor that doesn't lose HP with altitude (and doesn't need boost to do it) does have some attraction.
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Bill-Higdon
Well-Known Member
Many years ago a company in Alberta was trying to commercialize a aluminum and carbon fiber hydrogen tank. I'm not sure what happened to them as I left the CNC winding world.
John.Roo
Well-Known Member
2008 - Boeing did some test flight with hydrogen fuel cell Dimona.
2020...
Mad MAC
Well-Known Member
all the composite o2 bottles i have seen, are rapped aluminum tanks, i guess the aluminum is to keep the them gas tight.
I still think that radioactive diamonds made from spent nuclear reactor control rods is the answer for electric power. I say that half in jest and half in all seriousness... about the same power to weight as lithium ion, but a half-life measured in centuries rather than minutes.
Hephaestus
Well-Known Member
That's what they said about propane and natural gas too.
Still only ever seen one propane explosion - and it wasn't car related.
rv7charlie
Well-Known Member
Yeah; this ain't fusion. ;-)
The engineering talk I see indicates that hydrogen is actually a lot safer than traditional fuels; it's so light and 'undense' that it's basically gone by the time it escapes. Supposedly, most of the fire on the Hindenburg disaster was the burning 'dope' that was used on the fabric. The other gasses are heavier than air, and will 'puddle' like gasoline or diesel.
The engineering talk I see indicates that hydrogen is actually a lot safer than traditional fuels; it's so light and 'undense' that it's basically gone by the time it escapes. Supposedly, most of the fire on the Hindenburg disaster was the burning 'dope' that was used on the fabric. The other gasses are heavier than air, and will 'puddle' like gasoline or diesel.
Bille Floyd
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- Sep 26, 2019
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Hephaestus
Well-Known Member
Of all things apparently there's a socata tbm-700 that ran lpg in the 80s down under of course. I think theres still a few LPG projects in the uk / australia.
It's 110 octane, but lower power density - kind of surprising we don't use it more. Up here in oil/gas country we flare it, give it away, pay people to haul it away as an unwanted byproduct... And then have to spend a fortune to get a little bbq tank worth.
In the 80s we could hardly find a cab / pickup that didn't have a propane conversion... It was cheap environmentally friendly, and you could get them right from the dealer.
Disappeared in the 90s.
rv7charlie
Well-Known Member
SpaceX uses natural gas (sorta); methane is used in some of their engines.
Propane is ~85000 btu/gallon (depending on data source); gasoline is ~115000 btu/gallon, and propane requires a pressure vessel; it's stored at up to 200 psi. So, the lower energy content combined with the extra 'container weight' makes it prohibitive as an a/c fuel.
BTW, gasoline calculates at ~19,300 but/pound, and hydrogen is 51,500 btu/pound (but requires god-level containment to store it and keep it dense enough to transport in a vehicle). Fuel cells are 40-60% efficient and electric motors can approach 90% efficiency; IC engines top out at around 35%.
Propane is ~85000 btu/gallon (depending on data source); gasoline is ~115000 btu/gallon, and propane requires a pressure vessel; it's stored at up to 200 psi. So, the lower energy content combined with the extra 'container weight' makes it prohibitive as an a/c fuel.
BTW, gasoline calculates at ~19,300 but/pound, and hydrogen is 51,500 btu/pound (but requires god-level containment to store it and keep it dense enough to transport in a vehicle). Fuel cells are 40-60% efficient and electric motors can approach 90% efficiency; IC engines top out at around 35%.
Propane has more energy per pound than gasoline. There was a large biplane (Skybolt?) powered by propane (archives EAA). Can get more power with high compression. Roush claims equal power with liquid injection.
Aviat had a CH4 powered Husky at Oshkosh recently.
Aviat had a CH4 powered Husky at Oshkosh recently.
I got a honda 4 stroke generator and the conversion from gasoline to propane or butane was unbelievably easy. A 3 minute job. On top the spark plugs dont get dirty as with gasoline. The generator now runs at half the cost.
Hephaestus
Well-Known Member
lol i wonder when a certain peter will decide to add propane to resolve his cooling issues... I mean the diesel guys inject it for better / cleaner burn + its a vaporizing liquid so it has a habit of massively cooling intake air temps behind the turbo's.
I miss my old propane trucks honestly, other than getting them towed to a carwash to thaw when it hits -40...
Yeah, Canadian propane is liquid at ambient temperature.
Hephaestus
Well-Known Member
Until it's pants weather and it freezes.Yeah, Canadian propane is liquid at ambient temperature.
