"The thick, milky white liquid looks like Elmer's glue, though it's greasy to the touch. It has a sweet, alcohol smell. It's not your father's heating oil, to be sure. But it will do the same job, says Cary J. Claiborne, and a lot more cleanly.

Claiborne is president and chief executive officer of New Generation Biofuels, a Florida-based startup that's producing fuel from vegetable and soybean oil at a small production plant it set up this year in southern Baltimore.