Scientists make biofuel from old tires and cooking oil

OAK RIDGE, Tenn. — Scientists have figured out how to turn the tiny amount of carbon in a scrap tire plus used cooking oil into biofuel that could power thousands of delivery trucks.

Both old items are considered waste now.

“We are functionalizing the carbon in these tires and using it as a catalyst, converting waste cooking oil into a biofuel,” said Parans Paranthaman, lead scientist at Oak Ridge National Laboratory. Paranthaman; Amit Naskar, carbon and composites group leader; and Zachary Hood, a graduate research fellow, have found a way to extract that carbon.

The United States generates nearly 300 million scrap tires a year, tires that take up a lot of space in landfills and turn into mosquito breeding grounds when left unburied. Globally, the number of scrap tires is more like 2 billion, and each one contains about 35 grams — roughly 1.2 ounces — of carbon.

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The federal Environmental Protection Agency estimates that U.S. hotels and restaurants alone generate about 3 billion gallons of cooking oil. Most of it, too, ends up wasted, the EPA said.

But if that old oil were used in biofuel, one truck would be able to go 800 million miles, driving coast to coast nearly 250,000 times.

To start the process, researchers grind up the tires and soak the pieces in an acid treatment that increases the amount of carbon available by about 15%. Then they pour the pieces into ceramic labware and heat the mixture in an oven at nearly 1,500 degrees Fahrenheit.

That baking process is short, but it…