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Old 10-02-2008, 01:04 AM   #18 (permalink)
jamesqf
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Quote:
Originally Posted by Duffman View Post
If a farm uses 1000 gal of gasoline (or energy equivalent other processes) to produce ethanol, it doesnt produce 1300 gal of ethanol, it produces 1300x1.25=1625 gal of ethanol. What we are doing is taking a concentrated energy source and turning it into a lower concentrated energy source but more of it (as well as running it through the 1.3 energy multiplier).
Suppose we think about that a minute. First, using current tech you put in 1000 gallons of gas, and get out the equivalent of 1300 gallons. That seems like a net gain to me. Now if you only got 999 gallons out, and had no prospect of improvement, you'd have a good argument that the whole idea is a boondoggle.

Now remember that there are two things you want out of this process: 1) To get energy out of it; and 2) To get than energy in a concentrated liquid form that can run current engines. So thinking a bit, why does the energy in all have to be from gasoline? As mentioned, some/all of the processing could be done with waste heat from power plants. Or if you have farms that use center-pivot irrigation, it'd be fairly easy to adapt that to run electric tractors, harvesters, etc, with the electricity coming either from your farm wind turbines, or your friendly local nuclear plant.

Then there are probably better sources of feedstock than corn, or even switch/sawgrass. Using mixed native prairie plants produces more net energy, and wouldn't require lots of cultivation or chemicals: Prairie grasses emerge as rich energy source : UMNews : University of Minnesota And if the bottom falls out of the biofuel market, you could always graze a few buffalo :-)
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