March 8, 2004 To the uninitiated, "biodiesel" might
sound like a futuristic fuel source. In fact, nothing could be further
from the truth, as four students set out to prove with their winter
term project, "Off
the Grid: Biodiesel Production."
The students--Stephen Merrett '05, Colin Gunn '06, Nate Anderson '06, and Mike
Ialeggio '07--designed and built an 85-gallon processing tank to convert vegetable
into the clean-burning, alternative fuel known as biodiesel. Although many different
types of these fuel processors already exist, this one is set apart by the fact
that it runs "off the grid."
"'Off the grid' means that we're not connected to local utilities suppliers," Merrett
says. "Because we are making a renewable fuel that can be used in place
of fossil fuels, we wanted to design a process that did not rely on the electricity
that is generated from burning fossil fuels."
"It would be easier to do this if we used electricity to run the processor," adds
Anderson, "but that would negate the point of this project."
To keep their project off the grid, Merrett, Gunn, Anderson, and Ialeggio looked
to the Oberlin Bike Co-op for an ingenious solution. Using discarded materials
from old bicycles, they constructed a pedal mechanism that is attached--by way
of an intricate set of chains and gears--to the blade inside the processing tank.
With this innovation in place, members of the group were able to pull up chairs
and sit comfortably while mixing the concoction inside the vat into a usable
How exactly does vegetable oil convert into something that can power a diesel
engine? First, you need vegetable oil--and a lot of it. Merret, Gunn, Anderson,
and Ialeggio collected oil from Dascomb's kitchen fryers to produce their initial
batches of biodiesel. Their first order of business, however: straining the oil
to remove remnants of food.
"Straining the oil isn't a particularly appetizing process," says Merrett, "but
using waste oil closes a recycling loop in the community. By taking something
that has been used and turning it into something that can be used again, we avoid
wasting our resources."
Once the oil is strained, Ialeggio heats it with a Babington burner. Other members
of the team, meanwhile, place a mixture of methanol and lye into the processing
tank, then mix it for approximately 15 minutes. Once the oil heats to 135 degrees,
it's pumped into the processing tank. Students take turns pedaling the processor,
which in turn catalyzes the chemical reaction that converts the oil into biodiesel.
It takes about one hour of steady pedaling to produce this reaction," Gunn
says. "But that's more or less an estimate. If you pedal faster, it probably
would get done faster."
Once the pedaling is done, the mixture is left to settle. Approximately eight
hours later, the transformation is complete and, according to Merrett, "you
have a usable batch of biodiesel that can be put into any unmodified diesel engine,
including cars, trucks, tractors, or lawnmowers."
With all the hype about hybrid cars and lower-emission gasoline, why bother with
biodiesel? Simple, says Merrett.
"Biodiesel doesn't release sulfur oxides into the air, and it cuts down
particulate matter released by diesel engines," he says. "Not to mention
the fact that it can decrease our dependence on oil. Think about it--farmers
can produce food for local restaurants, then use waste oil from those same restaurants
to power their farm machinery. In this loop, the farmer produces the liquid fuels
required for operation, increases local air quality, and saves money in the process.