Here's something worth reading: "Ethanol From Biomass: Can It Substitute for Gasoline?" from a forthcoming book by Michael McElroy, a professor of environmental studies at Harvard University.
http://www-as.harvard.edu:16080/people/faculty/mbm/Ethanol_chapter1.pdf

So according to McElroy (Table 12.2), the ERoEI of corn ethanol is somewhere between 0.68 and 1.052. Interesting ...

Started reading the link above since I'm currently rather fascinated with ethanol, but quickly noticed that Pimentel is being repeatedly referenced so I stopped so would not waste any more of my time.

Myself, I find every nightmare I have about Dave Pimental also features starving Mexicans.