MU students, faculty give coffee grounds a new purpose

COLUMBIA — That cup of coffee that gets you going every morning may one day get your car going.

Researchers from MU’s Agriculture Systems Management Biofuels Lab have succeeded in converting leftover coffee grounds into biodiesel fuel.

The grounds may offer another “kitchen alternative” to diesel fuel, along with soybeans and animal fat.

“There is a large focus on finding other alternatives,” said MU Professor Leon Schumacher, who is with the agriculture systems management department.

“Even if we had soy beans planted all over the world, and even if we took all of the fat from all of the slaughterhouses, we still wouldn’t be able to replace all the diesel.”

Research on coffee grounds began at the University of Nevada a few years ago, but MU is the only university continuing the research now, said Bulent Koc*, assistant professor in agriculture systems management.

The research began last semester when two visiting students from Germany took an interest in the project. Working with Koc, they began to collect leftover coffee grounds from the Agriculture Engineering Building.

“The hardest part was collecting enough coffee grounds to get a substantial amount of oil,” Koc said. “Ten grams of coffee would yield 1.3 grams of oil.”

After the researchers had collected a sufficient amount, they began the process of converting it into fuel that could be used in a gas tank.

First, the grounds are dried in an oven to release the moisture, then submitted to  a standard oil extraction process, followed by a process called transesterification, which uses an alcohol to convert the dry base into biodiesel.

The result? Java-scented fuel.

This semester, Mudahar Abdullah, a graduate student at MU, is continuing the research, trying to eliminate the drying step in the process. This would save time and energy, Koc said.

Typically, to create energy, another form of energy must be consumed. It becomes a question of trade-offs, Schumacher said.

“We have to look at how much energy we are losing in comparison to how much we are gaining and weigh it,” Koc said.

Researchers must also compare the usefulness of coffee grounds to the other kitchen alternatives, such as soy beans.

Coffee grounds contain 13 percent oil, while soy beans can contain anywhere from 18-22 percent oil, Schumacher said. Using coffee grounds, however, has certain benefits.

“The biggest advantage to using coffee grounds is that otherwise they would be thrown away,” Schumacher said. “Throwing them in a landfill would be throwing potential oil away.”

Growers produce more than 16 billion pounds of coffee each year, according to the National Coffee Association. Coffee will be grown whether it's used for fuel or not; the leftovers might as well be used for a purpose, Schumacher said.

Other alternatives, like soy beans, are resources grown intentionally for fuel. This not only affects the biodiversity of the land where they are being harvested, it also takes a potential food source away from impoverished countries.

The "food for fuel" argument is based on this principle: Where hunger and poverty are widespread, food should be used for food, not to power cars in wealthier countries — especially not at the cost of rising food prices, according to Food and Fuel America.com.

This would not be an issue with coffee grounds, a surplus resource.

Starbucks alone generates 210 million pounds of spent coffee grounds each year in the United States.

"You shouldn't be throwing away plastic, cans or glass," Schumacher said. "Coffee grounds are the same."

There is more to creating an alternative fuel source than just the technology of the conversion, however. The costs, supply and delivery have to be taken into account as well, said Seth Meyer, an analyst for the Food and Agricultural Policy Research Institute.

"Science leads the way with these extractions and then economics steps in," Meyer said.

It is probably too early to tell whether this will become a widespread alternative, he said.

Even if the 210 million pounds of Starbucks coffee grounds were collected in one year, it would amount to about 2.92 million gallons of biodiesel, according to Gas2.0.org.

The United States produced 650 million gallons of biodiesel in 2008, according to Biodiesel 2020, a publication that tracks U.S. and global markets for biodiesel growth.

"It may not be economically viable to go around collecting the grounds from the Starbucks here in Columbia," Meyer said. "But maybe it would be in New York, who knows?"

"It is not a matter of whether it can be done, but should it be done."