Reply #1: Study available here [View All]

[OKIsItJustMe]

http://www3.interscience.wiley.com/cgi-bin/fulltext/121647166/HTMLSTART

…

Conclusions

Recent improvements in crop production, biorefinery operation, and coproduct utilization in U.S. corn-ethanol systems result in greater GHG emissions reduction, energy efficiency, and ethanol-to-petroleum output/input ratios compared to previous studies. Direct-effect GHG emissions reductions were found to be 48% to 59% compared to gasoline, which is two to three times greater than estimated in previous reports (Farrell et al. 2006). The NER has improved from 1.2 in previous studies to 1.5 to 1.8 on the basis of updated data. Ethanol-to-petroleum ratios were 10:1 to 13:1 for today's typical corn-ethanol systems but could increase to 19:1 with progressive crop management that increases both yield and input use efficiency. A closed-loop biorefinery with an AD system reduces GHG emission by 67% and increases the net energy ratio to 2.2. Such improved performance moves corn-ethanol much closer to the hypothetical estimates for cellulosic biofuels.

…