The City of Grand Rapids has been recognized as a green city and a beer city. Now that Founders Brewing Co. is sending brewing wastes to the City’s new biodigester, those designations are converging to literally energize the city. Each day, the two-mile-long, 10-inch waste transmission pipeline under Market Avenue SW will deliver approximately 140,000 gallons of water discharge carrying highly concentrated brewing wastes from Founders to the City’s Water Resource Recovery Facility (WRRF) at 1300 Market Ave. SW.
“Most people know how beer is made. You put hops and water in a tank with yeast,” says Mike Lunn, City of Grand Rapids utilities director. “The biodigester heats the wastes from the process to 98 degrees for 15 to 18 days. Bacteria and microorganisms break down the waste and make biogas and you end up with less solids [to dispose of].”
After treating the biogas—gaseous fuel, especially methane, produced by the fermentation of organic matter—the recovered methane will fuel a generator to produce electricity. Lunn calculates that the biodigester will produce 15- to 16-million kilowatts of energy a year, “a good chunk” of the 23-million kilowatts a year used to operate the WRRF facility. As the City adds more biodigester customers, Lunn expects it to provide 100 percent of the WRRF facility’s electricity by 2023, including the energy required to heat the biodigester tanks. This is two years ahead of the City’s goal to provide all energy for City facilities from renewable sources by 2025. The City expects the biodigester project to reduce operating costs mainly by lowering solids volumes by 20 percent and producing electricity savings of $600,000. This Youtube video demonstrates how a biodigester works.
“We’ll also have ability to bring in liquid industrial byproduct that will help,” Lunn says. “The biodigester project is addressing growth in the region. We have a much larger plan. We’d like to start out first year with ten trucks a day and work up to maybe forty or fifty trucks—10,000 gallons each of waste.”
While Founders is the biodigester’s first customer, SET Environmental, also located on Market Avenue, is in line to be the next. The City plans on receiving wastes from additional business customers located along the pipeline.
“It’s been great working with the City of Grand Rapids on the biodigester project,” says Brad Stevenson, Founders' chief production officer. “This coming together of the public and private sectors in the name of sustainability will have a positive impact on the future of our brewery and our city.”
Written by Estelle Slootmaker, Development news Editor
Photo courtesy City of Grand Rapids