Any none ever really worked. In fact, even the coal/oil surries for
Indian locomotives never worked out. GE had about 20 different
additives to keep the suspension and it _still_ didn't work.
Moreover, diesel is a little heavy and unreliable for commercial
Finally, at high altitudes you need gas turbines.
With a heat exchanger unrefined coal can power gas turbines.
It's disputed whether that actually happened:
And even if it did, the BMW801D engines were
not diesel engines:
Alexander Lippisch designed a supersonic fighter plane
intended to be powered by coal dust, but it was not built.
This project led to the conventionally fueled XF-92A:
Which in turn led directly to the F-102 and F-106,
also conventionally fueled.
Does there exists high octane kerosene? I though octane number is
measured (and is only valuable for) gas engines, measuring how difficult
is do self ignite gasoline in high pressure and temperature.
'High Octane' (if it's analog existed for kerosene) wouldn't be valuable
for jet engine.
For diesel engines which use more or less kerosene other number - cetane
number is used, which is more or less opposite to octane number. High
cetane number diesel fuel is more valuable, but probably not for jet
I think Bill was too subtle. Kerosene, Jet A, and diesel fuel are all very
The Jumo series of diesel aircraft engines first entered service in 1932.
One of the latest developments in piston engines for light aircraft is the
Thielert diesel, which runs on Jet A. This is an advantage because many
existing smaller aircraft engines were originally designed for 80 octane
leaded, and can develop mechanical problems if run exclusively on the 100 LL
which is currently available at airports. It's enough of a problem that
people have spent the money to produce supplemental type certificates, which
allow (sometimes with certain changes) existing certified aircraft to
legally run on auto fuel, and a fair number of airports now have an "auto
There are other companies developing small aircraft diesels, Delta Hawk and
Zoche come to mind, though I don't know if they have actually delivered any
People have also run diesel cars on Jet A, though I have heard that the
lubricity is not as good as #2 diesel, and can cause problems with some
Also, I understand NATO is moving toward a requirement that all vehicles of
the participating armed forces be able to operate on either diesel or
So most jet fuel isn't very exotic, and diesel engines work fine in
On Sun, 15 Jul 2007 10:37:16 +0000, Wonderer wrote:
Half right. It's a longer chain hydrocarbon like kerosene or diesel, but
it's not "high octane". Detonation or preignition are not problems in
diesels or turbines. The main issues for JP fuel are vapor pressure and
cleanliness. You don't want your fuel to boil away, freeze up, clog, or
wear some of the fiddly bits in the injection system.
My point was that JP and diesel are very similar, so diesel cannot be
rejected out of hand as too heavy or unreliable for commercial aviation.
It _has_ been done. During the second world war, when gasoline was hard
to come by, many (most?) cars in Sweden were equipped with a coal gas
generator, and the cars were able to run on the "generator gas" (mainly
CO) those units produced. The generator units could even be fueled with
firewood, in a pinch. The efficiency is very low, though. And somehow I
doubt that modern, computerized cars will be as easy to convert as the
simpler cars of the forties.
On Wed, 18 Jul 2007 01:25:02 GMT, Sevenhundred Elves
More likely charcoal. The raw producer gas made from wood has a lot of
moisture and volatile materials in it. From charcoal it is carbon
monoxide and nitrogen, plus some hydrogen if water or steam injection
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