Few things in the D.C. public schools are more reliable than the deep-fryers in their cafeterias. Student lunch menus feature an endless, sizzling series of potato wedges, chicken nuggets, and fish sticks. In the high schools, every day is “Boardwalk Fries” day on the à la carte bill of fare.
Each month, the system goes through somewhere between 300 and 500 gallons of cooking oil, says schools spokesperson Rachel Christopherson. This is probably why the Physicians Committee for Responsible Medicine earlier this year gave the District an F grade for the healthfulness of its school menuranking D.C. dead last among 18 public-school districts the group surveyed.
But where some see a dietary crisis, others see an ecological opportunity. This winter, the grease that doesn’t end up on the chins of kids is slated to be reusednot grandma-style to “add flavor” to the griddle, but as fuel.
For the past two years, the company that hauls away used cooking oil from District schools has been powering its operations in part with the reprocessed grease. Valley Proteins, a Winchester, Va.-based rendering company, gets paid $12,000 per year to
collect used oil from
37 schools in customized 55-gallon drums or dumpsters.
Valley Proteins then processes the grease at its Baltimore rendering plant, first running the oil through a heating process to cook off any moisture, according to Vice President Michael Smith. Next, the fat goes through a refining process to extract any impurities, such as meat particles. The finished eau de fry goes into the plant’s boilers, which heat steam that in turn powers the plant’s rendering equipment.
Recycling cooking oil is “good for the school system,” says Valley Proteins President J.J. Smith. “You want it to go for its best use. The highest use is human food. The second is animal food. Then energy. It’s better to fuel something living first and fuel something not living second.”
Used cooking oil from restaurants and schools makes up only about 10 percent of Valley Proteins’ rendering business, says J.J. Smith. The rest comes from animal parts from slaughterhouses and the occasional road kill, which Valley Proteins renders into animal fat and sells to livestock owners to add to animal feed.
Valley Protein began touting refined animal fat and used cooking oil as an alternative fuel about two years ago, when the price of animal fat plummeted thanks to a bumper corn crop and weak exports, says J.J. Smith. At the same time, the price of energy was rising. As a result, “our fat products had more energy per pound on a cost basis than regular fuel and natural gas,” he adds.
“Used in an industrial boiler, our oil burns significantly cleaner as far as sulfur and other air pollutants,” says Michael Smith. So far, though, Valley Proteins hasn’t had much of a market for its alternative fuel. “Some wood manufacturers have also looked into it. A brewery looked into it. Some rubber manufacturers…and fabric mills in North Carolina,” says Michael Smith. “One customer, a rental-uniform service, did a test drive on the fuel. They were very impressed with it. But since then, fuel costs are low again.”
D.C. schools cooking grease may eventually fuel trucks and buses, as well. Valley Proteins has applied for permits to build a plant to make biodiesel fuel made from refined animal fat and used cooking oil. CP