The campus dining services at Rochester Institute of Technology will use approximately 4,000 gallons of cooking oil this year. And every time a fryer is emptied or a skillet is drained, that goop has to go somewhere.
How about into a gas tank?
Over the past two years, RIT researchers, through a partnership with Monroe County's Department of Environmental Services, have developed and fine-tuned a process to turn used cooking oil into biodiesel.
The oil comes from the county's Ecopark, a residential waste and recycling drop-off center. RIT researchers have made approximately 400 gallons to 500 gallons of fuel out of the grease, says Tom Trabold, a professor and director of the school's Center for Sustainable Mobility. The county, in turn, uses the fuel — which burns cleaner than standard diesel — in its vehicles, primarily in its lawnmowers at Black Creek Park.
The project is funded by a grant from the Environmental Protection Agency.
Here's where the campus cooking oil comes in: For the next year-and-a-half, researchers will continue to collect grease from Ecopark, but they're also going to refine RIT's cooking oil waste to use in the school's vehicle fleet and to power heating equipment. Trabold
says he hopes that at the end of the research and development period, there will be a routine in place so the school's facilities department can make the fuel itself.
"Our hope is that this would be kind of formally handed off to the RIT facilities people and it would just become a routine part of their operation," he says. And he also sees an opportunity for that operation to be run by students, maybe through semester-long co-ops.
But RIT researchers set out to develop a more refined fuel, one which burns better in the engines and maintains its integrity across a broader range of temperatures and conditions. And they've been successful: essentially designing a process to make batches of vehicle fuel that meets industry standards, and they're doing it with what's basically a waste product.
The process begins at the Ecopark, where staff members examine the discarded waste oil to screen out grease that's too dirty for RIT's use. Once they've collect enough oil to fill a 55-gallon barrel, they take it over to the school.
RIT researchers have a machine to process the oil. First, the drum is emptied into a conical container and left to sit for several hours, so the food particles and water settle to the bottom and the oil rises to the top. The material on the bottom is let out through a valve and the oil is run through a processor, which mixes it with a catalyst to refine it. The whole process can be done in a couple of days, Trabold says.
The resulting fuel is mixed with traditional petroleum-based diesel; the researchers have been using a formula called B20, which is 20 percent biodiesel. That's a common fuel blend — one that can be used to power any diesel engine — and it burns every bit as well as standard diesel. And the federal Department of Energy says that B20 generates about 15 percent less carbon emissions than traditional diesel.
So RIT researchers have shown that they can make vehicle-grade fuel out of kitchen waste. As part of an expanded project, however, they'll attempt to develop and study a process to turn cooking oil into heating oil. Since heating oil doesn't have to be as pure as biodiesel, and because "rougher" stock can be used to make it, it may be more economical to produce, Trabold says. RIT officials plan to use the fuel to heat campus facilities, including the Red Barn, Trabold says, which is home to a popular climbing wall.
Both processes do have a byproduct, but it's a useful one: glycerine. Trabold says they'll use the glycerine to make soap for the RIT Inn and Conference Center.
"The bottom line is, this could be a closed-loop system," he says, where used products are turned into other products without any significant waste.
Used cooking oil may be a waste product, but it's also become a valuable commodity because of the biodiesel field.
There was a time when restaurants had to pay someone to haul away and dispose of the grease. But now, many businesses and institutions can get paid for the waste oil; whole companies are devoted to refining the stuff into fuel.
For RIT, however, on-site conversion of waste cooking oil may make more sense than selling its grease, Trabold says. The food service providers need the oil, and the campus already uses diesel fuel. So by converting the waste grease to fuel, the school may reduce the amount of diesel it needs buy. And the school may find a way to save on heating costs.
Trabold is working with two graduate students to examine the processes further: one student will focus on the vehicle fuel side, the other on the heating oil side. They'll evaluate the economics of the process and the greenhouse gas emissions associated with making and using the fuels. That data will be helpful to other businesses and institutions trying to determine whether on-site fuel generation is a viable option for them, Trabold says. It'll also help determine what sort of environmental benefits the fuels may offer.
Many environmentalists and engineers say that building a cleaner, more sustainable power system means more reliance on localized or on-site energy generation and distribution. And that'll mean using multiple fuel types and different technologies such as solar, batteries, and fuel cells.
"This can be part of a broad energy portfolio that would be more sustainable," Trabold says.