http://www.internationaltransportforum.org/jtrc/DiscussionPapers/DiscussionPaper3.pdf
This is a document about the economics of biofuels.
Here is a link to an article that describes how Obama is encouraging the use of these biofuels.
http://www.nature.com/embor/journal/v10/n6/full/embor2009121.html