Ethanol Powered Aircraft

Jay,
You know what the real irony is? One of Wisconsin's largest ethanol plants
is located less than 5 miles SW of the EAA headquarters.
Jim

There are several issues here.

Ethanol is politically popular because it is a farm subsidy to an
extent.

Other sources of heat besides natural gas exist for firing alcohol
plants. I would think that burning the corncobs and other unwanted
biomass from the corn itself would be good, as would burning garbage.
But what do I know.

Natural gas is methane, which can be turned into methanol pretty
cost-effectively. Ethanol, despite its poorer power density and seals
compatibility issues, is far more benign and has more energy per gallon
than does methanol. Be very glad you are being required to deal with
ethanol and not methanol.

Everyone knows that materials compatibility has been something doomed
to bite aviation in the ass, hard, for decades. Certificated aircraft
rubber materials have been manufactured since the postwar period with
the same inferior grades of rubbers at great expense to avoid
recertification while everyone else now uses better, more alcoholproof
materials. Dave Blanton told me that in the mid-80s and he was right.

Operation of aircraft on E10 or E15 auto fuel is a different issue
than operating on E85 or E100 with entirely different problems
especially in terms of water separation issues.

The LyCon engines themselves, in terms of top end life especially,
actually like ethanol a lot. Their fuel systems are a different issue.
But I saw an AEIO-540 powered Pitts do an acro routine on straight
ethanol (E100) in the late eighties. The pilot said that the cylinders
lasted a lot longer than with gasoline and all competition acro pilots
would use it if permitted by aerobatic rules.

On 15 Aug 2006 08:15:58 -0700, "Bret Ludwig"
wrote in om:

Natural gas is methane, which can be turned into methanol pretty
cost-effectively. Ethanol, despite its poorer power density and seals
compatibility issues, is far more benign and has more energy per gallon
than does methanol.


How does the energy density of LNG compare to ethanol?

On Tue, 15 Aug 2006 16:40:11 GMT, Larry Dighera
wrote:
How does the energy density of LNG compare to ethanol?

It's less than gasoline, but I'm not sure how it compares to
ethanol... Do you mean LNG or LPG though?

Propane has an octane rating of 110 to 120... Sounds great, right?
Unfortunately, the weight of the tanks is what would probably get
us... Our tanks would have to be built quite a bit sturdier to handle
the increased pressure... Although typical operating pressures are
around 130 psi, tanks are typically rated to over 300 psi...

With LNG, you need either higher pressure or a cooling system...

Here's some info:
http://www.wps.com/LPG/WVU-review.html

Grumman-581 wrote:
On Tue, 15 Aug 2006 16:40:11 GMT, Larry Dighera
wrote:
How does the energy density of LNG compare to ethanol?

It's less than gasoline, but I'm not sure how it compares to
ethanol... Do you mean LNG or LPG though?

Propane has an octane rating of 110 to 120... Sounds great, right?
Unfortunately, the weight of the tanks is what would probably get
us... Our tanks would have to be built quite a bit sturdier to handle
the increased pressure... Although typical operating pressures are
around 130 psi, tanks are typically rated to over 300 psi...

With LNG, you need either higher pressure or a cooling system...


LNG, as used in the Beech system (Beech Aircraft really did the
pioneering work on LNG, of course it went nowhere....) was stored at
very low temperature at approximately atmospheric pressure in a dewar
type insulated tank. It's important to understand that methane-natural
gas- is an incondensible gas for all intents and purposes, like oxygen
and nitrogen but unlike propane, nitrous oxide, carbon dioxide, ammonia
which can be stored at human-habitable ambient temperatures at
pressures feasible for storage tanks.

Methane and propane can be burned in an IC engine in similar fashion
once they are a gas, but at very different fuel-air mixtures. Methane
is approximately 108 octane and propane is in the 103-106 range
depending on exactly what's in it (LP motor fuel is nothing like
reagent grade and contains methane, butane, methanol, and lots of
other junk).

LNG would be practical but the cost of distribution would be high and
the fuel system is fairly complex, at least in the Beech system. CNG
has no range to speak of. LPG is very practical for all sort of ground
vehicles and has been done successfully in helicopters, but large
volume storage in fixed wing aircraft is problematic. A fixed wing
aircraft designed around a fuselage LP tank as a stressed member might
make some sense.

"Bret Ludwig" wrote in message ups.com...

LNG, as used in the Beech system (Beech Aircraft really did the
pioneering work on LNG, of course it went nowhere....) was stored at
very low temperature at approximately atmospheric pressure in a dewar
type insulated tank. It's important to understand that methane-natural
gas- is an incondensible gas for all intents and purposes, like oxygen
and nitrogen but unlike propane, nitrous oxide, carbon dioxide, ammonia
which can be stored at human-habitable ambient temperatures at
pressures feasible for storage tanks.

Methane and propane can be burned in an IC engine in similar fashion
once they are a gas, but at very different fuel-air mixtures. Methane
is approximately 108 octane and propane is in the 103-106 range
depending on exactly what's in it (LP motor fuel is nothing like
reagent grade and contains methane, butane, methanol, and lots of
other junk).

LNG would be practical but the cost of distribution would be high and
the fuel system is fairly complex, at least in the Beech system. CNG
has no range to speak of. LPG is very practical for all sort of ground
vehicles and has been done successfully in helicopters, but large
volume storage in fixed wing aircraft is problematic. A fixed wing
aircraft designed around a fuselage LP tank as a stressed member might
make some sense.


For those of you who have not yet decided that this guy Ludwig is a dufus and / or a troll.... natural gas is not
methane. Although methane makes up approximately 96% of the local natural gas here, there are many other
constituents. Several of the products that he says are stored at human habitable temperatures... well lets just say
that he is wrong at least on the ones that I am most familiar with. For instance, ammonia is stored at temperatures
around -28 degrees f. As a matter of fact, nitrogen, carbon dioxide, and ammonia are all cryogenically stored. BTW,
we condense methane at -282 degrees f. at my work place 24 hours a day as a step in recovery hydrogen for reuse.

Joe Schneider
N8437R



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For those of you who have not yet decided that this guy Ludwig is a dufus and / or a troll.... natural gas is not
methane. Although methane makes up approximately 96% of the local natural gas here, there are many other
constituents.

96% is "most", most of the time. Where I'm from.

Several of the products that he says are stored at human habitable
temperatures... well lets just say
that he is wrong at least on the ones that I am most familiar with. For instance, ammonia is stored at temperatures
around -28 degrees f. As a matter of fact, nitrogen, carbon dioxide, and ammonia are all cryogenically stored.

Nitrogen must be cryogenic to be in liquid form. CO2 and NH3 are
stored in regular steel tanks and when both gas and liquid are in the
tank, and the tank is allowed to sit with no flow, the tank assumes
ambient temperature (or higher in the sun) and the pressure inside is a
direct function of the product's temperature. Same with Freon (most
kinds), propane, etc. Nitrogen, oxygen, hydrogen, helium, are a liquid
at earth temperatures only under freakish pressures. There is said to
be solid methane at the bottom of the ocean in certain places but what
is the absolute pressure at those depths? About ten thousand psi is the
practical limit for pressure vessels. That's why these gases are
transported cryogenically or as _gases_ in the 2-3000 psi welding type
cylinders.

Larry Dighera wrote:

On 15 Aug 2006 08:15:58 -0700, "Bret Ludwig"
wrote in om:

Natural gas is methane, which can be turned into methanol pretty
cost-effectively. Ethanol, despite its poorer power density and seals
compatibility issues, is far more benign and has more energy per gallon
than does methanol.


How does the energy density of LNG compare to ethanol?

LNG has about 73,000 BTU/US Gal., while ethanol has about 80,000. Gasoline
ranges between 110,000 and 125,000.

Keep in mind that the LNG is also accompanied by a very heavy tank, which
has payload implications.

On Tue, 15 Aug 2006 13:56:11 -0500, James Robinson
wrote:
LNG has about 73,000 BTU/US Gal., while ethanol has about 80,000. Gasoline
ranges between 110,000 and 125,000.

Of course you also get to factor in the difference in weight per
gallon...

Keep in mind that the LNG is also accompanied by a very heavy tank, which
has payload implications.

LPG has lighter tanks, but still heavy compared to the ones we have
now for gasoline... Now, on the other hand, I can see the Grumman AA1
series aircraft fuel tanks possibly being converted to LPG in that
they use the tubular spar for a fuel tank... One could perhaps argue
that under pressure the spar might even be stronger... Still, that's a
20g fuel tank... Range will be decreased, but cargo capacity will go
up a few pounds from the reduced weight of the fuel... I suspect that
most aircraft would not be able to have their fuel tanks so easily
modified...

On Tue, 15 Aug 2006 13:56:11 -0500, James Robinson
wrote in :

Larry Dighera wrote:

On 15 Aug 2006 08:15:58 -0700, "Bret Ludwig"
wrote in om:

Natural gas is methane, which can be turned into methanol pretty
cost-effectively. Ethanol, despite its poorer power density and seals
compatibility issues, is far more benign and has more energy per gallon
than does methanol.


How does the energy density of LNG compare to ethanol?

LNG has about 73,000 BTU/US Gal., while ethanol has about 80,000. Gasoline
ranges between 110,000 and 125,000.

Keep in mind that the LNG is also accompanied by a very heavy tank, which
has payload implications.


If Kevlar reinforced aluminum is used in the construction of the tank
(as is used for aviation O2), tank weight shouldn't be such a large
factor:
http://www.mhoxygen.com/index.phtml?...product_id=372
1,800 psig service pressure
The KF series cylinders are the perfect solution for cylinder
installations far aft in the aircraft previously not possible
before. A thin-wall, seamless aluminum (6061-T6) alloy
'liner-cylinder' is reinforced by a full over-wrapping of Kevlar
fibers sealed in epoxy. This yields about a 50% to 60% weight
savings over conventional cylinder technology without any
compromise in safety.

KF-050, Item #CYL1050 For built-in applications
MAX DIAMETER: 17.27 cm. (6.8 in)
MAX LENGTH: 64.00cm. (25.2 in)
AVG WEIGHT: 3.58kg. (7.9 lbs)
SERVICE VOLUME: 1416 liters (50 cu. ft.)


Below are the results of my research on BTU content of various fuels:


http://bioenergy.ornl.gov/papers/misc/energy_conv.html
Natural gas: LHV = 930 Btu/ft3 = 34.6 MJ/m3
Therm (used for natural gas, methane) = 100,000 Btu (= 105.5 MJ)
Ethanol energy content (LHV) = 11,500 Btu/lb = 75,700 Btu/gallon =
26.7 GJ/t = 21.1 MJ/liter.

Barrel of oil equivalent (boe) = approx. 6.1 GJ (5.8 million Btu),
equivalent to 1,700 kWh. "Petroleum barrel" is a liquid measure
equal to 42 U.S. gallons (35 Imperial gallons or 159 liters);
about 7.2 barrels oil are equivalent to one tonne of oil (metric)
= 42-45 GJ.

Gasoline: US gallon = 115,000 Btu = 121 MJ = 32 MJ/liter (LHV).
There are 19.5 gallons of gasoline in a barrel of oil,
4.1 gallons of kerosene-type jet fuel in a barrel of oil

Petro-diesel = 130,500 Btu/gallon (36.4 MJ/liter or 42.8 GJ/t)

Efficiency of an internal combustion engine is about 22% and
electric motor...about 96%(plus or minus a few points...depending
on who built it).

Electricity at 3412 Btu input per kWh.



http://www.ethanol-gec.org/netenergy/NEYShapouri.htm
http://www.ethanol.org/EthanolNewsSpecial1.28.05.htm
This report estimates the net energy balance of corn ethanol utilizing
the latest survey of U.S. corn producers and the 2001 U.S. survey of
ethanol plants.

On the average, dry mill ethanol plants used 1.09 Kwh of
electricity and about 34,700 Btu of thermal energy (LHV) per
gallon of ethanol. When energy losses to produce electricity and
natural gas were taken into account, the average dry mill ethanol
plant consumed about 47,116 Btu of primary energy per gallon of
ethanol produced. Wet mill ethanol plants that participated in the
survey used 49,208. Btu per gallon of natural gas and coal, on
average, to produce steam and electricity in the plants. After
adjustments for energy losses to produce natural gas and coal, on
the average, a wet mill ethanol plant used 52,349 Btu of energy to
make a gallon of ethanol.

All energy inputs used in the production of ethanol is adjusted
for energy efficiencies developed by GREET model. The estimated
energy efficiencies are for gasoline (80.5 percent), diesel fuel
(84.3 percent), LPG (98.9 percent), natural gas (94 percent), coal
(98 percent), electricity (39.6 percent), and transmission loss
(1.087 percent). After adjusting the energy inputs by these energy
efficiencies, the total estimated energy required to produce a
bushel of corn in 2001 was 49,753 Btu.


http://www.herecomesmongo.com/ae/comptab.html
1 gallon non-reformulated gasoline = approximately 113,500 BTU
(depending on seasonality and other factors... Oil Industry
Literature reportedly indicates that real-world gasoline sold at
US pumps can go to 108,500 BTU or lower).

1 gallon of #2 diesel = approximately 131,295 BTU (LHV)

1 gallon of biodiesel = approximately 117,093 BTU (LHV)
(10/08/02: BTU per gallon for diesel and biodiesel updated using
best-available info from US DOE website).

1 cubic foot of natural gas = approximately 1000 BTU

1 lb of H2 = approximately 61,000 BTU

1 gallon = approximately 3.785 liters (1 quart = 1 quarter of a
gallon = .946 Liters)

Definitions: 1 kWh = 3412 BTU = 3,599,660 Joules

1 barrel (of Petroleum) = 42 gallons

1.0 US bushel = 0.0352 m3 = 0.97 UK bushel = 56 lb, 25 kg (corn or
sorghum) = 60 lb



http://www.eere.energy.gov/cleanciti...ri_webcast.pdf
Btu content (LHV):- Diesel fuel 128,450 per gallon
- Gasoline 116, 090 per gallon
- LPG 84,950 per gallon
- Natural gas 983 per cubic ft.
- Electricity 3,412 per kwh
- Coal 9,773 per pound
- Ethanol 76,330 per gallon


http://www.ers.usda.gov/Data/CostsAn...s/testpick.htm
Commodity Costs and Returns: U.S. and Regional Cost and Return
Data


http://energy.cas.psu.edu/costcomparator.html
Energy Cost Calculator is an EXCEL spreadsheet.