There's more than algae for non-food biofuels

As our readers know, the biofuels field of investigation is huge and there are quite a number of upcoming technologies that can make the renewable fuel without competing with feedstocks. The most notable of these technologies use waste streams and often also require less water to make biofuel. Popular Mechanics lists seven of these new biofuel technologies and provides some numbers about how and when they will be available: cellulosic ethanol (both biological and gasified), algal biodiesel, "green gasoline" (obtained from extracting oxygen from sugars to form hydrocarbons), biobutanol, designer hydrocarbons and so-called 4th generation biofuels, the latter two produced directly from genetically modified organisms. As one reader suggests, there's no mention in the piece of alternative feedstocks for biofuels, such as jathropa curcas, which can grow in unused land. Still, regardless of technology, the question is impact: will any of these become the silver biofuel bullet? Thanks to Carl for the tip.

[Source: Popular Mechanics]