Ethanol Powered Aircraft

Morgans wrote:
"Robert M. Gary" wrote
The only problem with that point of view, is that every energy
transformation and use carries a penalty of a percentage of the energy being
lost.

If the penalty is less than the gain, it's a win. There is a penalty
for producing electricity on the edge of town and wiring it to your
house vs. having your own home generator. Most of us decided that the
gain of using municipal power outweighs the penalty of having to pipe
it to our house (in which it losses power in the transit).

-Robert

"Robert M. Gary" wrote in message
ups.com...

Morgans wrote:
"Robert M. Gary" wrote
The only problem with that point of view, is that every energy
transformation and use carries a penalty of a percentage of the energy
being
lost.

If the penalty is less than the gain, it's a win. There is a penalty
for producing electricity on the edge of town and wiring it to your
house vs. having your own home generator. Most of us decided that the
gain of using municipal power outweighs the penalty of having to pipe
it to our house (in which it losses power in the transit).

-Robert

I guess I didn't state what I meant well enough.



You take some hydrocarbon and burn it to make electricity, you lose some in
waste heat. You take the electricity, and pipe it somewhere, and you lose
some in line loss. You take some of that electricity and put it into making
hydrogen, and you lose some more, or store it in a battery and lose some of
it that way. You use the electricity to make a car go, and you lose some
of the electricity to heat, again, or by burning the hydrogen.

Loss energy due to efficiency is inevitable.
--
Jim in NC

Morgans wrote:
"Robert M. Gary" wrote


As an engineer and an MBA this argument has never made sense to me.
Electric cars use power that may be produced using oil. The idea is a
large, centeral engine is more efficient (less oil, less expensive,
etc) than millions of individual CO dumping engines. Whether that
central engine burns oil or butter makes no difference, as long as its
more efficient than the individual engines.


The only problem with that point of view, is that every energy
transformation and use carries a penalty of a percentage of the energy being
lost.

This is "theoretically" true but not "practically" true. A central
power station that is burning petroleum products to generate electricity
would likely be using large gas turbines with efficiencies pushing 60%.
Transmission losses to the end used might account for 2% and the
electric motors of the cars would be running about 95%. So overall
"system" efficiency would be running over 55%...which is *much* higher
than your typical Otto cycle internal combustion engine at around 25%...

....Ken

Ken Chaddock wrote:

Morgans wrote:

"Robert M. Gary" wrote

Electric cars use power that may be produced using oil. The idea is
a large, centeral engine is more efficient (less oil, less
expensive, etc) than millions of individual CO dumping engines.
Whether that central engine burns oil or butter makes no difference,
as long as its more efficient than the individual engines.

The only problem with that point of view, is that every energy
transformation and use carries a penalty of a percentage of the
energy being lost.

This is "theoretically" true but not "practically" true. A central
power station that is burning petroleum products to generate
electricity would likely be using large gas turbines with efficiencies
pushing 60%. Transmission losses to the end used might account for 2%
and the electric motors of the cars would be running about 95%. So
overall "system" efficiency would be running over 55%...which is
*much* higher than your typical Otto cycle internal combustion engine
at around 25%...

That description is more theory than reality. The current installed base
of thermal power plants in the US, mainly coal-fired is about 35 percent
efficient. Yes, there are new turbine designs that approach 60 percent,
fired by natural gas, but there aren't many of them around, nor are many
being planned. More typical for new natural gas, simple cycle plants is
an efficiency of about 45 percent.

Distribution losses in just the last 1/4 mile from the local substation
to your home are probably 2 or 3 percent. Overall losses of the entire
grid are in the order of 15 percent.

Finally, you have left out the charge/discharge losses of batteries on
the electric cars, which are perhaps 70 percent efficient with current
technologies.

Multiplying all of that out, yields an overall efficiency of about 20 or
25 percent.

On 15 Aug 2006 10:13:59 -0700, "Robert M. Gary"
wrote:


Steve Foley wrote:
If they're burning oil to make this fuel, it makes no sense. If they're
something not easily refined into gasoline (coal, solar, nuke, methane), it
does.

As an engineer and an MBA this argument has never made sense to me.
Electric cars use power that may be produced using oil. The idea is a

Unfortunately if you are talking electricity production you are not
talking oil, but rather coal and lots of it. I read an article
earlier this week that stated all but a few of the new proposed power
plants will be coal fired.

large, centeral engine is more efficient (less oil, less expensive,
etc) than millions of individual CO dumping engines. Whether that
central engine burns oil or butter makes no difference, as long as its
more efficient than the individual engines.
Whether that centeral engine puts out electricity or ethanol make no
difference.

If that central engine puts out a lot of particulate matter, sulphur,
and other pollutants it makes one.


Think of ethanol as a battery (stored energy) rather than raw crude and
it will probably be easier to understand.

Now that's Hydrogen. We'd need to nearly double our grid capacity
to go to Hydrogen and/or electric power on a large scale and it takes
more power to produce Hydrogen than you get out of it.




-Robert
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Fri, 18 Aug 2006 01:44:35 -0400, Roger
wrote:
it takes more power to produce Hydrogen than you get out of it.

Correct, but the idea is that with fusion, you have the energy to
waste in order to convert it into a more useful form of energy for
existing technology... Unfortunately, hydrogen either needs to be kept
really ****in' cold or under quite a bit of pressure in order to
provide a useful reserve of BTUs of energy that could be used in
vehicles... I'm not sure that is going to happen anytime soon...
Retrofitting existing aircraft to run on hydrogen would definitely be
problematic... LPG is possible due to less strength needed in the
pressure vessel... Automobiles on the other hand would be able to more
readily handle the added size and weight of hydrogen tanks...

Not sure how many cu-ft of gasoline vapor you get out of a gallon of
gasoline, but you get around 36 cu-ft of propane vapor out of a gallon
of propane liquid... A standard (i.e. AL80) SCUBA tank holds 80 cu-ft
of gas at 3000 psi and ends up weighing about 38 lbs... For a 50g
tank, you get 1800 cu-ft of gas... This would take around 22.5
equivalent SCUBA tanks, or 855 lbs... The 50g of avgas would have
weighed 300 lbs, therefore we're looking at 555 lbs extra in tankage
-- assuming your aircraft even has roof for this many tanks...

Carbon fiber tanks might work a bit better though... They're 11.3 lbs
empty for an 88 cu-ft tank... Hydrogen weighs 0.005229 lbs per cu-ft,
thus the 88 cu-ft tank would weigh approximately 11.76 lbs... We would
need approximately 20.45 tanks, for a total weight of 240.492 lbs...

From what I understand, hydrogen contains quite a bit more BTUs of
energy in it per pound than gasoline -- 61,000 vs around 20,500... As
such, it sounds like we might actually be able to use hydrogen in our
aircraft, assuming we could find room for the tanks...

There's also the issue of how fast these carbon fiber tanks can be
filled...

Other stuff here...
http://planetforlife.com/h2/h2swiss.html

Basically, it boils down to the best way to use hydrogen might be to
add carbon back to it and convert it to gasoline...

Jay Honeck wrote:
For those who think ethanol is a fuel that can't be made to work in
aircraft, I present the following:

I still would not feel safe with ethanol. Materials compatibility aside
(and that is a big issue all by itself), ethanol is hydrophilic. It
attracts and absorbs water, increasing the chance of fuel
contamination. Airplane fuel tends to be stored a lot longer than
automobile fuel anyway. I know that ethanol advocates claim that
ethanol has a storage life equivalent to that of gasoline, but ethanol
advocates claim a lot of other things, too. So far, no hard data on
storage life, but anecdotal evidence indicates that ethanol has a much
shorter storage life than claimed. You can bet that if it really was as
good as gasoline that the ethanol advocates would have published hard
data showing it a long time ago.

In a car, the worst ethanol can do is ruin your engine. In an airplane
it could kill you.