Carbon-Based Rocket Engines (Was: We're stuck with each other)

From: Michael Roy Ames (
Date: Wed Jan 23 2002 - 15:30:12 MST

"Robert J. Bradbury" <> wrote:

Taking:  C + O2 --> CO2C
has a delta-H of 0.45 and a delta-G of 0.69.
O2 has a 0 delta-H and delta-GCO2 had dH and dG of ~-94.
So the reaction will be exothermic. ....<more of the same>
If you typed that in from memory, I'm impressed! (did you?)  :)
In my earlier reply, I was using memories from a high school chemistry class 
taken 22 years ago... that and (gulp) practical experience.
After hearing (in class) that diamonds were just carbon, me and a couple of 
friends actually tried to burn some diamond.  (We were young , okay?  8-D)  
One of us got a-hold of a couple of small diamonds (he never would say where 
he got them) and we took them over to the Metalworking shop.  There, we 
placed them in a oxy-butane flame (way over 1000C) and after about a minute, 
they turned black... then they got a lot smaller.  Fearing that they might 
dissapear completely, I pulled them out of the flame, fire-brick and all, 
and tipped them into a glass of water.  We then spent 10 minutes trying to 
get them out of the glass without losing them... eventually accomplished by 
filtering the water through my pocket handkerchief.
Note: Small diamonds are very hard to find in a glass of water.
More recently, I have observed diamonds being cut by a jeweler's laser... 
and *they* turned black just like our school-boy experiment!
"Robert J. Bradbury" <> wrote:
You don't have to add power, you just have to ignite it and it should
burn fine.
Obviously, carbon does contain a great deal of potential energy, but unless 
it is in powdered form, it doesn't burn very quickly.  Example: a major 
danger of coal mining was (is) the potential of igniting coal dust... 
because, with the right concentrations of dust+oxygen, only a small spark 
produces a huge explosion.  The above facts would seem to indicate that 
although carbon is energy-rich, it will be very complicated to powder it, 
then feed it (along with oxygen or air) into a rocket nossle in the exact 
combination needed to extract the maximum energy.
On the other hand: what an interesting engineering problem... hmmn?!?
Michael Roy Ames
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