Federal Donuts, the fried-chicken-and-doughnuts concept with four units in Philadelphia, sells around 2,000 chickens a week and several thousand doughnuts a day. Even with filtering, each store uses about 400 gallons of cooking oil a week on average, co-founder Steve Cook estimates. Federal Donuts recently struck a deal with its renderer to deliver its spent cooking oil to a local high school, where the students will convert it into fuel, possibly to power an electrical generator or make home heating oil to donate to a nonprofit. Glycerin is a byproduct of the refinery process; the students will use the glycerin to make donut-shape soap that Federal Donuts will sell out of its four Philadelphia units, and the youngsters will help run that side business. “The education aspect makes it special,” says Cook, who adds the program could be a model for other restaurateurs.