Grounds for change: Chemistry instructor turns coffee waste into biofuel

By Nicole Chiu, Research and Innovation Office

When Brenda Addison-Jones, was approached by a Business student with an idea to turn coffee grounds into something profitable, she was intrigued. The Chemistry instructor knew that used grounds could be used as a fuel source – and one that could potentially produce more energy than burning wood.

Chemistry Instructor Brenda Addison-Jones

Along with the Business student, she formed a research team, which included an Engineering instructor, a Business instructor and student research assistants. They partnered with a local coffee shop, JJ Bean Coffee Roasters, on Main Street, who agreed to donate their spent coffee grounds for the research.  

Within a month Brenda and her team had built a manual press and a calorimeter, an apparatus which measures the amount of heat or energy produced in a chemical reaction. The manual press compacted a mixture of coffee ground and wax into small pucks. These pucks were then burned in the calorimeter.

“Our results suggested that coffee grounds produce at least 20 percent more heat per gram than wood,” says Brenda.  

Fueling efficiency

The team also researched the environmental impacts of coffee grounds. What they discovered motivated them to think beyond monetary profit.

Manual press used to compact coffee grounds

“When coffee grounds are dumped into landfills, they create methane, a greenhouse gas 30 times more harmful than carbon dioxide in terms of causing global warming,” says Brenda. Keeping coffee grounds out of landfills is a way to reduce greenhouse gas emissions.”

With that, the team’s new goal was to create a source of energy that would be both profitable and environmentally sustainable.

The team has since created a “bomb” calorimeter to run additional trials. The bomb calorimeter also measures the amount of heat given off by the pucks, but with more accurate results. They are also testing different natural ingredients to mix with the coffee grounds to hold them together, in the hope of creating a superior product to commercial fuel logs, which are made from compressed sawdust and paraffin.  

What the puck

“The most effective pucks will be further tested against wood fire logs. We will also test the gases produced by burning the products to see if it will be safe for consumers.”

Coffee ground puck

If the pucks are deemed safe, the team hopes to sell the product as briquettes and pucks to heat homes and to use for recreational purposes like camping.

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