How your Thanksgiving cooking oil can be transformed into biofuel
For many, Thanksgiving is synonymous with cooking food, but the holiday can put many home chefs in a pickle: What to do with large amounts of spent cooking oil.
The oil can't go outside or down the drain, and putting it safely in the trash can get complicated. Inspired by November's turkey-centric holiday, some Chicago area groups began offering the green alternative of recycling spent oil into biofuel about 10 years ago.
"I knew all these people were frying turkeys, and I know you can't put liquids into your garbage. What do you do with four and a half gallons of peanut oil or other vegetable cooking oil?" said Kay McKeen, founder and executive director of environmental education nonprofit SCARCE.
McKeen, whose brother owns and operates a restaurant, knew recycling was an option. She just needed to create a pathway for residents to get there.
Working with advocacy group Illinois Environmental Council, McKeen helped fashion a state law that would allow nonprofits or governmental entities that collect cooking oil from the public to be exempt from licensure, fees or reporting.
Today, SCARCE coordinates with 13 drop-off locations throughout DuPage County that collect cooking oil year-round. Because most of these locations are not open on weekends, additional temporary drop-off locations are available the Saturday after Thanksgiving each year.
Most of SCARCE's drop-off sites forward collected oil to recycling company Green Grease, which works with about 900 customers in the Chicago area and processes 60,000 gallons of spent cooking oil each month.
The company filters and heats the oil - essentially cleaning it - at its base in South suburb Burnham before sending it off to a refinery, where it gets blended into diesel fuel used by heavy-duty trucks, ships and other vehicles. Essentially, the cooking oil goes toward fuels like B20, which is a common blend that ranges from 6% to 20% biodiesel mixed with petroleum diesel.
"We are displacing diesel fuel the same way ethanol displaces unleaded," Green Grease owner Tony Demma said. "If you're throwing (cooking oil) away, it goes to a landfill but it could be going to reducing pollution and fuel. You're throwing away fuel."
If you don't have cooking oil recycling near you, Demma said you can likely reach out to a local restaurant.
"If it really is vegetable oil, bring it to a restaurant and put it in their bin," he said. "It's not going to change their operation and they may even get paid for it."
The restaurants Demma works with, which provide the bulk of his stock, typically receive payment in the form of a rebate check from Green Grease. The company also picks up the cooking oil at no cost.
Demma emphasized that vegetable oil should never go down the drain because it will turn solid at a certain temperature, which differs depending on the type of oil. For instance, olive oil will begin to solidify around 45 degrees Fahrenheit.
"It's different for every vegetable oil, but when you put it down your sewers, you're creating a clog in the drain somewhere. You're making more work and problems for yourself, taxpayers and municipalities," Demma said.
One of SCARCE's drop-off locations, the Downers Grove Sanitary District, has hands-on experience with such clogs.
"We have a few locations on a three-month cleaning cycle that are downstream of some areas where there's high quantities of grease, and staff clean the pipes on a regular basis in places where we have found grease to build up," Amy Underwood, general manager of the district's Wastewater Treatment Center, said.
Unlike SCARCE's other drop-off locations, the center keeps the cooking oil it collects: It recycles and uses the resulting biofuel on-site.
"We use that cooking oil in our digester. It's digested with the solids from our wastewater plant. Because the digester gets anaerobic, the bacteria in there produces methane gas, which we call biogas, or digester gas," Underwood said.
The center uses the gas in its combined heat and power engines to produce electricity. When it has those engines running, the treatment plant is off the electrical grid and even sends power back onto the grid, selling it to ComEd.
"That's another win for our customers, because that oil - even though it's a tiny fraction of the gas - is saving them money because when we go to budget, we can budget a lower expense for electricity," Underwood said.
* Jenny Whidden, jwhidden@dailyherald.com, is a climate change and environment writer working with the Daily Herald through a partnership with Report For America supported by The Nature Conservancy. To help support her work with a tax-deductible donation, see dailyherald.com/rfa.