While I support Biofuels for local or individual use, the commercial idea to continue / displace current fuel usage seems totally insufficient.
US petroleum consumption:
from: hxxp://www.eia.doe.gov/oiaf/aeo/excel/aeotab_2.xls
approximately 38.9 Quads (2004)
US corn production (record 2004 crop):
roughly 11 BILLION bushels.
Conversion (gallons of ethanol from 1 bushel of corn):
from: hxxp://www.ethanolmt.org/php/marchapril05.php
2.8 gallons / bushel
Energy content of gallon of ethanol:
from: hxxp://running_on_alcohol.tripod.com/id18.html
84100 BTU / gallon
Gross Energy Result:
- 6 Quad(s)
- US Gasoline consumption:
- 31 Quad(s)
Now what if the corn stover was also utilized?
from: hxxp://www.eia.doe.gov/oiaf/analysispaper/biomass.html
"At conversion yields of around 60 to 100 gallons per dry ton,
the available corn stover inventory would be sufficient to support 7 to 12 billion gallons of ethanol production per year"
For $#|+s and giggles, lets use the 12 BILLION Gallons / year number, assuming the same energy content per gallon stated above:
Gross Energy Result:
1.0 Quad(s)
Lets take a look at soy derived bio-diesel...
Another record crop from 2004, of approximately 3 BILLION bushels
Gallons of Bio-diesel / bushel of soybean ratio:
from: hxxp://www.agmanager.info/agribus/energy/Biodiesel%20Is%20it%20Worth%20Considering.pdf
1.5 Gallons Bio-diesel / Bushel Soybeans
Energy content of bio-diesel:
from: hxxp://www.agriculture.state.ia.us/biodiesel.html
120000 BTU / gallon
Gross Energy Result:
- 54 Quad(s)
- US Distillate consumption:
- 29 Quad(s)