Washtenaw County startup companies are innovating in "green technology" with efforts that range from cleaning up PFAS contamination to converting waste into environmentally friendly fuels.
Bill Mayer, senior vice president of entrepreneurial services at
Ann Arbor SPARK, says clean energy and related "green" technologies were big around 2009 and 2010, with investors lining up to get in on the next big thing. But when fossil fuels actually got cheaper rather than more expensive as had been predicted, it "literally killed the momentum of clean tech innovation," he says.
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Doug CoombeBill Mayer.
Since 2017, Mayer says, "the focus has come back onto doing clean energy projects."
He says the industry landscape for clean technology right now is similar to that for autonomous vehicles in 2019. There was a great deal of excitement and enthusiasm in the industry, but now people are taking a more "metered and pragmatic approach to incremental innovation" in both technologies, Mayer says.
Sequestro: Cleaning up PFAS with sawdust
Using sawdust, which would otherwise go to a landfill, to clean water containing
a contaminant called PFAS is the mission of Ann Arbor-based
Sequestro. Co-founder Anne McNeil invented the technology while working as a chemistry professor at the University of Michigan, while Juergen Koller came on board as CEO and incorporated Sequestro in July 2024 to commercialize the technology and shepherd it to market.
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Doug CoombeAnne McNeil.
Sequestro's technology builds what Koller calls "functional groups" onto wood fibers, with each group capturing one molecule of PFAS.
Koller says this transforms what is usually treated as a waste product and fire hazard into a PFAS cleaning technology. Once the PFAS is captured, it must be buried or burned. Similar technologies use activated carbon, which Koller says is "cheap but bad at grabbing PFAS molecules." Others use resin beads that are better at grabbing those molecules but would release toxins if burned. That's not a problem with wood pulp that has captured PFAS, though.
"Any time you try to address a problem, your solution can't be worse than the problem it solves," Koller says.
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Doug CoombeJuergen Koller.
Solutions also must be affordable, and Koller says Sequestro's model should be able to provide remediation companies a solution at a reasonable cost.
Koller says the greater Ann Arbor area and Michigan in general are serendipitously great places to work on PFAS remediation, noting that Michigan was one of four states at the forefront of aggressively regulating PFAS. PFAS has also been
detected in the Huron River.
Koller says the state of Michigan and various pitch competitions and accelerator programs have been "as supportive as I could imagine." Sequestro even won a "people's choice" award for a presentation at a recent pitch competition.
"Our story seemed to resonate, and that was super validating for us, making sure we were working on a meaningful problem that is meaningful to other people," Koller says.
CaptureTech: Restoring soil and water with biochar
Ann Arbor-based
CaptureTech's technology is based on an ancient practice called Terra Preta in Portuguese. Terra Preta entails using a mix of charcoal, organic matter, and broken pottery to
fertilize the Amazon forest and make it more resilient.
Jonathan Weyhrauch, co-founder and CEO of CaptureTech, says his company is basically creating Terra Preta quickly and on a large scale. The company produces a form of charcoal known as biochar. A gram of biochar has more surface area than a football field, and nutrients or contaminants will stick to it.
Biochar can be used both to clean contaminants out of soil and water, and to help regulate the flow of nutrients in and out of a body of water. This balances the water in the same way a person might need to regulate their gut biome after not eating well for a while, Weyhrauch says.
"The main driver, though, is the ability to create fertilizers that restore fields not for the next year but for the next 100 years," Weyhrauch says. "Biochar creates castles in the soil. ... Traditional treatments might destroy the biodiversity in the soil, but the diversity in the biochar won't be destroyed. And it will contribute to nutrient cycling, holding onto nutrients instead of them washing away."
Weyhrauch says he and his colleagues have been presenting at pitch competitions and networking a lot. They're also trying to revive a now-defunct group of technology companies called The Hatchery.
"We'd like to breathe new life into The Hatchery… so we can communicate the benefit of true circularity. One business' output flows into the input of another," he says.
Aquora Biosystems: From waste to green fuels
Ann Arbor-based
Aquora Biosystems is also partaking in a circular economy, finding new ways to turn a variety of waste streams into eco-friendly fuels.
Tim Fairley-Wax is CEO of the company, which spun out of the University of Michigan. He says Aquora's technology can convert municipal sewage, brewery wastewater, and other waste streams into usable energy.
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Tim Fairley-WaxTim Fairley-Wax.
"We're always looking at different waste streams that are harder to use," Fairley-Wax says. "That's our focus, on upcycling this stream of waste that was otherwise going to a landfill."
The general public may have heard of trucks that run on waste grease from deep-fryers. Aqora's technology is similar.
"We take things like food waste and put them in a tank that has microorganisms. And those bugs produce products, whether they're energy, like methane, or chemicals, like alcohols or acids," Fairley-Wax says. "And we can extract those into everyday energy use. So you can go from food waste directly to the natural gas grid quite easily. This is already an established approach, and so we're looking to expand the number of feedstocks that can go into renewable natural gas and increase the efficiency of this process drastically."
Aquora Biosystems has already
done some pilot projects with this technology in collaboration with the city of Ann Arbor. Fairley-Wax is currently at Argonne National Lab in Lemont, Ill., funded by the U.S. Department of Energy, to validate the process for commercial application.
Future of clean tech
Mayer says he's watching the U.S. regulatory environment "with interest." He hopes that loosening environmental regulations and new tariffs don't squash the burgeoning clean tech and clean energy markets in Michigan, throughout the U.S., and even globally, citing efforts in the U.K. and China.
"I'll admit to having a bead of sweat or two on my forehead about our competitive position in the world going forward," Mayer says. "I'm curious to see, with some of the changes happening recently, if that is going to have a material impact on innovation and the work people are doing here in Michigan."
Photos by Doug Coombe.