This is annoying. The announcement says left-over glycerin works as animal feed reducing the negative impact of diverting corn or soy to biofuel
http://www.ars.usda.gov/is/pr/2009/090410.htm
Agricultural Research Service (ARS) scientists have found environmentally and economically sound uses for the byproducts of biofuel production.
Maybe it’s true, but it’s annoying to think about.