Bioenergy Briquettes


The briquettes have a hollow core to facilitate drying and combustion.

Bio-Energize: Reusing Waste Paper with Algae

It may look like a roll of toilet paper that has gone through the wash, but really, it’s a forward-thinking, bio-engineered fuel source.

Working in conjunction with the chemistry department, engineer technology assistant professor Mike Martin has led his bioenergy class (MET 230) to assist in a research project initiated by chemistry department head Dr. Suzanne Williams.

Greg HorantAccording to consulting engineer Julie Hoffman, who is working with Williams, the project arose from two sources of “waste”: Northern Michigan University’s waste recyclable paper, and waste algae water, leftover from other experiments. Because algae, through photosynthesis, consumes carbon dioxide and emits oxygen, Williams proposed soaking the waste paper in algae water to reduce carbon emissions enough so that the paper could be burned as a clean fuel source.

Martin says the project has benefited his students greatly.

“They’re able to get involved in research at the university as undergrads,” Martin says, “and do cross-departmental research. Also, it gets them up to speed on the new power plant, so they’re up on that current event.”

Sixteen students in all worked with Martin to make the briquettes. They started with a thirty-gallon bag full of shredded paper that otherwise would have been hauled away to a recycling plant, and used it to fill several empty NMU recycling bins. The experiment was designed to test varying concentrations and species of algae, to discover which combination would result in the most carbon absorption, and therefore the cleanest-burning paper.

Christina SpitzAnd so, to the paper, they added solutions of dark green algae, which resembled green Kool-Aid, and let it soak. Then, they poured the solution into a press to remove as much water as possible. The hollow core of the cylindrical briquettes helps them to dry and burn more efficiently, Martin says. The briquettes were set out to dry for a week and then burned in a bomb calorimeter to test the energy output.

The press that the students used was made out of pine two-by-fours and, according to Martin, resembled a “Medieval catapult.” He says that the experiment has generated ideas for future senior projects as well, including an automated press and developing new methods for dealing with the logistics of drying the briquettes on a large scale.