The ethanol used to make E85 comes mostly from corn. One bushel of corn produces 2.8 gallons of ethanol. The corn is ground into a powder, which is treated with water, enzymes and ammonia. It is heated and stirred, then cooled before yeast is added. That starts the process of converting sugars in the "mash" into alcohol. There are a few more steps before the ethanol is ready to be mixed with gasoline.
The bottom line: Making E85 is an energy-intensive process. Researchers are divided over whether ethanol is an energy loser. It can be if the corn has to be shipped long distances to an ethanol plant. Much of the cost-effectiveness of producing ethanol depends on where the refinery is.
Tuesday, March 18, 2008
More on the energy intensity of E85