Gasoline! Do you have any idea how flammable that stuff is? How will you
transport it? How will you store it?
Gasoline is waaay to dangerous for use in internal combustion engines.
Paul D Oosterhout
Hollywood likes to have a lot of exploding cars but in real life I've
only seen many accidents that resulted in burning cars in one place:
My only theories on the issue all hinged on the proximity of the petro
chemical industry. They had gotten into such a habit of sabatoging
refineries for "upsets" they even did it to the fuel lines on their own
You'll often hear about a chemical plant generating electricity from
burning, say, sulphur to heat a boiler as well as to make the product,
They often also expand a product gas through a turbine to recoup some
of the power used to compress it in the first place, but I haven't
heard too much about "internal" chemical reaction engines.
Remember the universal statement of thermodynamics: deltaG = deltaH -
TdeltaS. If you're going to make a highly exothermic reaction reversible,
the reverse reaction had better have a huge positive entropy, and you need
to run the reaction at very high temperatures, in order to get a deltaG
anywhere near a practical definition of reversibility (as close to 0 as
possible). In practical terms, this means the reverse reaction needs to
involved lots of fragmentation--a very few molecules of condensed material
being converted to a very large number of molecules of gas. Take the
polymerization of ethylene for example (it's one reaction that I know the
thermodynamics of well). It's very modestly exothermic (ca. 25 kcal/mol),
and the depolymerization meets the criterion I described above. However, it
takes very high temperatures to depolymerize PE. Fundamentally, since
you're expecting an exothermic forward reaction, you're going to have to be
making some very strong bonds. Reversing the formation of those bonds is
kinetically also going to require either extremely high temperatures or a
very reactive catalyst--and you better hope that something else in the
molecule doesn't decide to react before those very strong bonds.
I guess you're trying to cause a reaction without need for ignition?
Furfuryl alcohol will react hypergolically with a nitric acid oxidizer.
It's made by reducing furfural (from distilling corn cobs, sawdust,
etc.) I think they used to use it in rockets. Have fun.
So we are stuck with PV, and closed "air" and vapor cycle engines, nuke
as well as solar?
That's IT? That's ALL we have for sustainable power?
With all this talk about getting off of fossil fuels there seems to be
very little discussion about engines that run on any chemicals other
than fossil fuels.
There are lots of H2 pipelines in SE Texas.
No, it is not....We have stirling cylce engines, AMTEC devices, Thermionic
diodes, betavoltaics, thermoelectrics
You can run a stirling from solar, The betavoltaics run from energy released
in natural decay of radioisotopes, thermionic diodes and thermoelectrics are
direct energy conversion devices, while AMTEC convert heat to electricity
through phase change of metal salts....
So for these you just need heat, whether it be from the sun with solar
concentrators, direct combustion of a fuel (wood, kerosene, gas, oil, whale
blubber, your ex wifes menopausal heat flashes....even biodiesel) combustion
due to catalytic reaction (external combustion engines)....
then there are other "fuels" like boron..
And you can use combinations of these...like a microturbine generator where
the energy to turn the shaft is from the compression of the incoming air
charge and the rapid expansion by combustion of a fuel....the process of
which releases a large amount of heat, that can be used by other
devices...the most common being the micro CHP systems that use the waste
heat to heat hot water and the rotational energy to turn a generator and
Stirlings are heat engines, the "air" or "He" is a working fluid so it is
not consumed and only changes phase...the heat source can be concentrated
solar.....or you get your heat by direct burning of fuel by ignition or
I like the amtecs because they are reasonably efficient when compared to
internal combustion engines, and much more efficient than
thermoelectrics....and about twice as efficient as PV.
Not sure what you 100 quadrillion BTUs/year for, but none of these will
likely be cost effective or even available in the numbers that you would
require....there is also direct solar, and solar concentrators which might
suit your needs at much less cost.....
Assuming it requires no boiler, THAT'S a start.
Now we need a COMPLETE list of exothermic reactions where
1. the reactants are liquid at ambient temperatures and moderate
2. the products are 1000 - 1500 degree K hot gases that can be
expanded in a piston/cylinder or turbine
3. the products are a liquid at ambient temperatures and moderate
4. the reaction can be reversed with < 5,000 K temperatures.
5. All components are cheap and non toxic.
That excludes hydrogen-plus-nitrogen;
it won't heat itself above about 500 K.
This may be interesting: deuterium-plus-nitrogen making ND3
should go about 70 K hotter.
Liquid fuel, liquid ash? Water and SO3 come to mind.
H2SO4 breaks up at much lower 'T',
but it breaks up to water and oxygen and SO2
(this is part of the sulphur-iodine process).
That should work, though: SO2 is easy to condense.
And the whole deal should be never before thought of,
and only now revealed to you.
Oil is cheap and many varieties are nontoxic.
Water and CO2 are condensible. Why not burn oil
and pipe the ashes back to the oil maker?
--- G. R. L. Cowan, former hydrogen fan
Boron: internal combustion with nuclear cachet:
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