It was an 800-pound butter sculpture of Ben Franklin that led researchers to decide dairy-to-diesel was even a possibility, according to this report in the New York Times.
Organizers of the Pennsylvania Farm Show that put up the Franklin butter sculpture in 2007 solicited ideas for what to do with all that yellow (rapidly going rancid) stuff once the show was over. Biochemist Dr. Michael J. Haas of the United States Department of Agriculture submitted an idea to turn the butter into biodiesel.
Of course then he had to figure out exactly how to do that.Haas worked together with BlackGold Biofuels, according to the NYT article. BlackGold had already perfected a technique to use different fats as feedstocks for biodiesel.
Franklin's butter sculpture turned into only 75 gallons of fuel, so neither Haas nor BlackGold is suggesting that America's one billion pounds of butter be turned to car fuel.
In fact, in the report Haas prepared for the Journal of Agriculture and Food Chemistry, butter was found to have some drawbacks as a feedstock, and was really only feasible when mixed with other oils.
For its part, BlackGold thinks other less savory forms of waste, such as sewage fats, can be successfully made into biodiesel. In fact, BlackGold's tag line is "Converting our crudest wastes into our cleanest fuels" and a plant in San Francisco will soon endeavor to use wastewater and brown grease to make biodiesel.
Trapping grease before it gets to into a sewer can save considerable wear and tear and be a great biodiesel resource for cities - restaurants and food services spend a lot of money complying with rules about grease disposal. In San Francisco if food services buy expensive grease separators, the city will pick up the grease for free.
As you might have expected, there is non unanimous approval for the butter and grease biodiesel rush. In San Francisco, the Green Party is objecting to the city allowing a rendering plant to upgrade to biodiesel production because the Party says biodiesel's positive green image is a sham. The Party objects to making biofuel from commodity crops or from animal parts.
But even though butter hasn't yet shown itself to be a superior biodiesel feedstock, turning an 800 pound butter sculpture that would otherwise be waste into a few gallons of fuel still seems like a good idea.
Read more about biodiesel at TreeHugger:
Biodiesel and How It's Made
Can Biodiesel Be Green? The Sustainable Biodiesel Summit
A Biodiesel Breakthrough, Candy Bar Wrapper Bags and Pesky Plastic Facts