Hi Landmarks and hi everyone
the answer is YES YOU CAN and in fact lots of people do it, its been done for years , you can like (wvo) filter it and mix it with a solvent and run it striaght ether in a twin tank set up , or ifyour car is up to it, single tank or you can actually themo crack the stuff (its very much like making moonshine) and end up with a product so close to diesel you'd be hard pressed to tell
here is a forum with all the answers
http://www.oiltodiesel.com/forum/
good luck .carl