Food waste re-purposed as lawnmower fuel

Breathe in deep that fresh cut grass smell during springtime.

Notice anything?

John Brown University engineer professor Ted Song said, “It smells like toast!”


Because it is not diesel fuel that you smell; it is biodiesel.

For the past year, the renewable energy department has been in the process of converting the leftover cafeteria grease into a viable energy source. This was first suggested by Susan Newton, assistant professor of chemistry.

The direct beneficiary of the fuel is the University’s lawnmower population.

Next time a friend tries to make you feel guilty for eating something greasy in the cafeteria, you can tell them you are doing it for posterity. No grease, no biodiesel.

Here is how it works: ARAMARK gives Facilities the grease. Facilities take it to the renewable energy lab. An engineering department work-study converts the grease into biodiesel, and Facilities picks it up for use.

The converting process itself takes about 48 hours. First, the grease is strained. Lawnmowers do not work as well when their gas has French fries in it.

After the grease is strained, it goes into the biodiesel generator and is combined with chemicals such as methanol and sulfuric acid at different points in the cycles.

The grease goes through about 13 different steps before being fully converted.

Steve Brankle, facility manager, said he personally admires this system because of what it represents.

“The conversion of kitchen grease to biodiesel is another facet of John Brown University’s commitment to sustainability,” Brankle said. “It is a way to lessen our
impact on God’s creation and provide a learning tool for our students. My team appreciates getting to be a part of the process.”

In addition to the biodiesel fuel, the renewable energy department is working toward aiding and abetting the energy side of things through the use of solar energy.

Song said he “likes to see students get involved and get aware of how they can be helpful and connected with the facilities side of the University.”