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.