Production of biodiesel as an alternative to fossil fuels is on the rise in the US, and one reason, proponents say, is that it can be made from a long list of raw materials.
“Biodiesel is made from all sorts of fats and oils,” said Ben Evans of the National Biodiesel Board, a trade group based in Washington. While oils made from soybeans, rapeseed and other plants account for at least 85 per cent of US production — 1.8 billion gallons in 2013, a record — “any type of animal fat that’s properly processed” will work as well, he said.
As if to demonstrate Evans’ point, a team of chemists and engineers at the University of Louisiana, Lafayette, has spent the last several years investigating the possibility of producing biodiesel from an unusual source: alligators.
Mincing and microwaving chunks of the reptiles’ fat in their laboratory, the researchers found it could be converted into fuel of sufficient quality that, like biodiesel from other sources, could be blended with conventional petroleum-based diesel.
“We’re trying to work on the exact conditions now,” said August A Gallo, a chemistry professor at the university and a leader of the research team.
At first, Gallo said, he and the other researchers, including Thomas Junk, a chemist, and Rakesh K Bajpai, a chemical engineer, did not intend to make biodiesel from alligators. The alligators — or more precisely, alligator farmers — came to them. “Some local entrepreneurs do a lot of alligator farming,” he said.
The reptiles are slaughtered for their hides and for food, and alligator meat is a common sight on menus in parts of the South. But the farmers had to pay to discard the rest of the animals, including the fat, which Gallo estimated makes up about 10 per cent of an alligator’s weight.
The researchers made biodiesel in small batches in the lab, cutting up the fat tissue first and heating it in a microwave to remove most of the moisture. Heating this rendered fat with an alkaline compound and methanol — a common production method — resulted in the chained hydrocarbons that are characteristic of biodiesel.
Analysis showed that the gator-based product met almost all of the technical specifications for fuel-grade biodiesel. Alligator fat “was a bit more unsaturated than we thought it would be,” Gallo added. That gave it a lower melting point and meant that the resulting biodiesel would flow better in lower temperatures.