Researchers reported on a novel method this week at the 247th National Meeting of the American Chemical Society, to produce biodiesel from crude animal fats, including waste fat from alligators, using supercritical methanol in a flow reactor. “Conversion of animal fat to biodiesel has been around for some time, but the traditional biodiesel process generates significant quantities of solid waste,” said Thomas Junk with the University of Louisiana at Lafayette. “Our new method creates hardly any such residues.” In an earlier study, Junk used alligator fat and a batch reactor, but for his new research, a flow reactor and supercritical methanol were used. “We set up a flow reactor, and the reaction converting alligator fat to biodiesel happened within a few minutes,” said Junk. “That's important for commercial manufacturing, where you want to produce as much fuel as quickly as possible.”

The supercritical method doesn't require a catalyst, which Junk said creates a residue. Another advantage of the supercritical method, according to Junk, is that the fat doesn’t have to be extracted for the process to work. It can be used in its raw form. Crude fat and methanol would be homogenized into a slurry (semiliquid mixture) and pumped into the system.

In searching for alternative biodiesel materials in his earlier work, Junk discovered that alligator fat, millions of pounds of which are disposed of annually, is a viable feedstock for biodiesel. Junk and his colleagues plan to test other waste fats, such as chicken fat and tallow.