The Wall Street Journal points out, with corn prices projected to hit record levels as US supply is projected by the USDA to drop 13% to 10.8 billion bushels,  a rather surprising 40% of US corn production is consumed neither by humans nor animals but by ethanol. 
The piece doesn’t make the following point, but it is implicit: if 40% of corn production produces about 13.2 billion gallons of ethanol (because almost all ethanol comes from corn), how do we achieve 36 billion gallons of ethanol in 2022? The US Renewable Fuels Standard requires that much ethanol by 2022, of which 15 billion is to be corn-based and 21 billion gallons from other ethanol forms (e.g. sugar),  but the question is how can that even be achieved? That implies a larger proportion of the US corn crop and then an incredible amount from currently non-economically feasible, essentially non-existent sources.
International aid agencies have asked the US EPA to temporarily suspect the ethanol mandate (the US accounts for a full 60% of global corn exports) but it is unlikely to happen in an election year when President Obama trumpeted support of ethanol in battleground Iowa. I see another failure of US government energy policy.
 http://en.wikipedia.org/wiki/Energy_Independence_and_Security_Act_of_2007, retrieved on 8/12/12.
Picture from Wikipedia Commons.