MSU’s new anaerobic digester converts recycled campus waste into enough renewable energy to supply power to several south campus buildings, a process that started this August.
A digester is a sealed chamber that heats waste until natural microorganisms convert it into biogas, project engineer Dana Kirk said.
It’s an anaerobic process, meaning the conversion doesn’t require oxygen.
“Methane generated from the digester will burn in a diesel engine, which powers a generator,” Kirk explained. “That energy then goes out through a Consumers Energy power line.”
It takes about 25 days for the waste to be converted into methane and digestate, Kirk said.
Digestate, or the remaining water or solids that don’t become gas, will be used as a fertilizer.
The digester will produce enough methane to generate electricity by Oct. 1, a goal set by MSU officials, Kirk said.
“This is one of the largest digesters on a college campus in the country,” Kirk said. “It’ll generate 450 kilowatts every hour, which is enough electricity to power roughly 300 houses. To give a campus perspective, the digester could completely power Holmes Hall.”
Methane converted to electricity will power several buildings south of Mount Hope Road, Kirk said, including laboratories, farm managers’ houses and the Anaerobic Digestion Research and Education Center.
Waste for the digester comes from several sources, and new material is continuously added to the digester.
The MSU Dairy Teaching and Research Center supplies manure from cows daily, Culinary Services provides food waste from the dining halls every three days and local restaurants supply wasted oil and grease.
Director of Campus Sustainability Jennifer Battle said the digester is a positive project that can engage the campus community.
“The digester (is) a great example of sustainability because it addresses multiple economic and environmental issues,” Battle said. “It takes a lot of food waste in the area and prevents it from entering landfills. At the same time, it creates research opportunities for students and faculty with renewable energy technology.”
The Meijer Distribution Center in Lansing is another source of food waste for the digester.
Brenda Pineau, the center’s director of environmental compliance and sustainability, said it’s proven to be a local solution for dealing with food waste.
“We cut a lot of fresh fruit in our manufacturing facility,” Pineau said. “For example, when you see cored pineapples at Meijer, those cores are going right into the digester.”
Pineau said she hopes the partnership with MSU will be long-term.
“It’s been a great opportunity,” Pineau said. “It saves money, it’s an alternative to landfills, it creates energy and it keeps us from depleting our natural resources.”
The digester also continues MSU’s ongoing goal of increasing sustainability measures across most of campus, officials said.
MSU has been working with digesters and other forms of renewable energy for years, but Kirk said this project was particularly special.
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“It’s big energy,” he said. “And it’s a unique partnership between MSU and the local community, with Michigan industry.”
