Popular Mechanics
How far can you drive on a bushel of corn?
Crunching the numbers on alternative fuels.
On the outskirts of Garnett, Kan. (pop. 3362), the horizon is broken by what at first sight seems to be a grain elevator rising above the cornfields. But closer inspection reveals a tall, skinny distillation column among the silos and fermenters, identifying the complex as part of the nation's energy future: It is East Kansas Agri-Energy's ethanol facility, one of 100 or so such heartland garrisons in America's slowly gathering battle to reduce its dependence on fossil fuels. The plant processes about 13 million bushels of corn to produce approximately 36 million gal. of ethanol a year. "That's enough high-quality motor fuel to replace 55,000 barrels of imported petroleum," the plant's manager, Derek Peine, says.
Quick thoughts:
Given that 1 barrel (42 gal) of crude yields 19.5 gal of gasoline,
36m gal of ethanol = 55k barrels of crude = 1.07m gal of gasoline
Also,
Given that 13m bushels = 36m gal of ethanol
1 bushel = 2.8 gal of ethanol = 0.08 gal of gasoline
So gasoline is 34x more potent than ethanol?? And each bushel of corn (70 lbs) only produces an equivalent of 0.08 gallons of gasoline? (Conversely, it takes 875 lbs of corn, or 12.5 bushels, to produce the equivalent of 1 gallon of gasoline).
For such a wonder fuel, it seems remarkably inefficient.
Ace also brings up a good question when he wonders what the relative costs (financial and energy) of production between the two are.
Blatantly stolen from Ace of Spades
I believe as the technology progesses, so will the efficiency. Right now though, I think ehtanol production is in its infancy.
Also, those production numbers don't really tell true potency, just efficiency.
By
Anonymous, at
4/26/2006 05:33:00 PM
Also, those production numbers don't really tell true potency, just efficiency.
Actually, if I remember my college physics correctly, they do demonstrate "potency". There very well may be some scientific discovery that would enable more ethanol to be extracted from a bushel of corn in the future, but I doubt that it will change significantly any time soon.
The amount of energy produced by a gallon of gasoline versus a gallon of ethanol is a matter of physics. The law of conservation of energy: energy cannot be created or destroyed, only changed in form. There is no way to extract more energy from something than it contains.
The engines using the fuels may be refined to do so more efficiently, but the amount of energy consumed does not change, only the efficiency with which that energy is converted into another form (in the case of an automobile: motion). But that holds true for gasoline engines as much as for ethanol burning engines...the relative amount of energy contained in a gallon of each remains unchanged.
Another consideration is that gasoline is not the only thing extracted from crude oil. The remaining 20.5 gallons of crude oil is converted into other products such as jet fuel, kerosene (almost the same thing), lubricating oils and plastic among other products.
Probably the most important of the listed "byproducts" of crude oil are plastics. They are everywhere. We would be hard pressed to do without them. I'm sure alternatives exist or could be found, but at what increase in cost?
For that matter, WD-40 is petroleum based. What would we do without THAT? My world would come to a screeching halt (literally).
The rule of unintended consequences has to be considered at all times.
By
Anonymous, at
4/26/2006 08:41:00 PM
^^^ speak up ^^^