Speak EV - Electric Car Forums banner

21 - 29 of 29 Posts

·
Registered
Joined
·
1,852 Posts
But not by hydrogen.
Which is how we drifted here - I was pointing out why Hydrogen is a right royal PiTA.
 

·
Registered
Joined
·
1,852 Posts
Could h2 work in planes
No, see earlier in this very thread. What was being said about methane not being suitable goes (more than) double for H2. Hydrogen is a pain in the backside. Not nearly dense enough even as a liquid, and that liquid is deeply cryogenic, so requires massive insulation.
 

·
Registered
Joined
·
2,137 Posts
For all the reasons outlined by jmacneil, state of the art for aviation fuels, if they have to be carbon neutral, would be a synfuel. Discuss!
 

·
Registered
Joined
·
3,417 Posts
Simply put, no. They don’t have the space to store it.
Well, yes and no.

As a rocket fuel, cryogenic liquid methane is only about 20% less dense than cryogenic kerosene for the amount of thrust/energy you can get out of it. There's a penalty but it's not huge, otherwise it wouldn't be used for (future) rockets, which are the most mass critical mode of transport you can think of, even more so than planes.

The problem comes about with kerosene being liquid at room temperature and methane needing cryogenic containment to remain a dense liquid. Having a cryogenic fuel system on a plane would be a big challenge and introduce space overheads but maybe not an insurmountable challenge in a large plane in a future where fuels like kerosene simply aren't allowed.
 

·
Registered
Joined
·
2,137 Posts
"cryogenic liquid methane is only about 20% less dense than cryogenic kerosene"

What is cryogenic kerosene. Surely that is just a big blob of wax
 

·
Registered
Joined
·
3,417 Posts
"cryogenic liquid methane is only about 20% less dense than cryogenic kerosene"

What is cryogenic kerosene. Surely that is just a big blob of wax
You got me, my mistake. :oops:

Kerosene used in rockets like the Falcon 9 is only cooled to -7C, to make it a bit more dense. It's the liquid oxygen that's cooled to -207C.
 
21 - 29 of 29 Posts
Top