Sure you can. Animal fat can be made into biodiesel quite easily. I worked on biodiesel research for about a year - I used vegetable oil though,
it's a bit more legal.
T_Jesus: do all biodiesel fuels require a diesel motor? are there any kinds that can run on a gasoline motor? If so what are the production methods
if you know?
You need a modified diesel engine to run it, usually. I researched it in MA during the winter so we needed to change alot of piping and such so it
wouldn't "gel." Biodiesel fuel is diesel that smells like french fries (if you make it with used vegetable oil like I did) with more
environmentally safe emissions - so you definitely need a diesel engine to run it.