Here is a little comparison of the energy inputs in producing ethanol and in producing gasoline. Obviously, you expend some energy. You don't get all the energy from the oil in your gas tank. You expend some of that in drilling it, in pumping it, transporting it, refining it and hauling it to the service station, and so forth. So you use 1.23 million Btu's to get 1 million Btu's.
Well, what is the story with corn? Now, you have a lot of free energy with corn. You have the solar energy, the photosynthesis that makes the corn grow. And this is about as good as it is going to get. To get 1 million Btu's of energy out of corn, you are going to have to spend about three-fourths of a million Btus in growing the corn, harvesting it, processing the ethanol, and so forth.
Down at the bottom here is a very interesting pie chart, and it shows something that very few people know, and that is that almost half the energy that goes into producing corn comes from nitrogen fertilizer, which is now made from natural gas. So this is a fossil fuel input. This is all fossil fuel input, by the way.
You just go around this little pie here and you are talking about mining the potash, and mining the phosphate, and mining the lime that makes the soil sweeter so that the nutrients can be absorbed. The diesel fuel in the tractor, the gasoline, the liquid propane gas, the electricity you use is produced by
fossil fuels. The natural gas you use for drying your crops, for instance, the custom work, the guy you hire to come.
And then all of the chemicals, something that we rarely, rarely reflect on. Gas and oil are huge feedstocks for a very important petrochemical industry. Most of our insecticides, most of our herbicides and so forth are made from gas and oil. And this is the contribution they make to growing corn. It is really, really quite large there, isn't it?
I have been told that 13 percent of our corn crop would displace 2 percent of our gasoline. But the only fair way to look at the contribution ethanol can make is to grow corn with energy from corn, and you can do that. But if you grow corn with energy from corn, to get a bushel of corn to use here, you have to use three bushels of corn. Remember, the 750,000 Btu inputs to get a million? You need three bushels going in to get one out, which means that it is one to four. You only get a fourth of it out, which means that you are going to have to use 52 percent of your corn crop to displace just 2 percent of our gasoline.
So when you are hearing the euphemistic projections of how much of our gasoline we are going to displace with ethanol, just remember these numbers.
2007-01-19
06:15:59
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13 answers
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asked by
CaptainObvious
7
in
Politics