According to this piece in Monday’s New York Times, yes you can.

Apparently, Dr. Michael J. Haas, a research biochemist at the United States Department of Agriculture, in collaboration with a Philadelphia biofuels company turned an 800-pound sculpture of Benjamin Franklin and the Liberty Bell (constructed for the Pennsylvania Farm Show, in Harrisburg) into 75 gallons of biodiesel fuel and a lower-grade bunker fuel.

Unfortunately (or not?), it doesn’t look like the process is economically feasible. “The cost of edible butter is too high,” Dr. Haas said, conceeding “The number of rancid butter sculptures in the U.S. is probably not significant.”

(via New York Times)