Minneapolis has announced the construction of a biochar facility near Huntington Bank Stadium to help achieve the city’s goal of carbon neutrality by 2050.

Construction was set to begin in fall 2024, but the project’s unexpected costs after the planning stage pushed construction to spring 2025, according to Minneapolis carbon sequestration manager Jim Doten. 

Biochar is a specialized charcoal created from heating wood or other biosolids that helps reduce carbon dioxide in the air, improve soil health and reduce tree waste, Doten said. He said they are currently reworking the facility’s design to keep it affordable.

“What we’re doing is capturing that carbon and putting it to good environmental use,” Doten said. 

To combat an invasive insect that infects ash trees, Minneapolis and St. Paul have worked to remove ash trees throughout the Twin Cities. A side effect of that effort is the removal of these trees results in a lot of wood waste, which can release stored carbon dioxide back into the atmosphere over time, Doten said. 

“We have a large imbalance in our wood waste right now and a lot of that had originally been driven by emerald ash borer,” Doten said. 

For the biochar facility, the city is working with BluSky Carbon to create pyrolyzers, the spinning drums used to heat the wood. 

BluSky CEO and Co-founder William Hessert said biochar is a promising method for removing carbon dioxide from the atmosphere.

“The more (the pyrolyzer) runs, the less gas is used,” Hessert said.

Additionally, BluSky Carbon will provide censors and general assistance or help for the facility, Hessert said. 

“If Jim needs something, I’m happy to help,” Hessert said. 

Due to its low levels of emissions, the facility does not require a permit from pollution control, according to Doten.

“If you burn this wood, it’d be a lot dirtier,” Doten said. “But what we’re doing is heating it up, de-gassing it and then using that gas in order to drive the process. There’s no flame that encounters the wood and that’s how we’re able to alter the carbon instead of destroying it.”

Biochar and environmental justice

Biochar can be used in planting projects to improve soil and plant health, Doten said.

The biochar produced in the facility will primarily be used in the city’s green zones, areas of the city with high diversity and high air pollution, and on projects to create carbon sinks, improve greenspace and reduce temperatures in marginalized communities, according to Doten.

“Climate change affects everybody, but not everybody is affected by climate change the same,” Doten said.

The equity of the biochar program is one of the reasons Minneapolis became one of seven cities worldwide to receive funding from the Bloomberg Philanthropy Grant, according to Doten. The other six cities are Darmstadt, Germany; Helsingborg, Sweden; Sandnes, Norway; Lincoln, Nebraska; Helsinki, Finland and Cincinnati, Ohio.

This grant will enable Minneapolis to become a leader in utilizing biochar, Doten said. 

“We were the first ones to set up a program to systematically use (biochar) in projects,” Doten said. “We pioneered the use of municipal biochar and now this is seen as an example globally.”

The biochar program is currently working with some University researchers and professors but are looking to expand University collaboration in the future, Doten said. Internship opportunities and research projects through the University’s Institute on the Environment could be available in the future.

Biochar’s ability to capture carbon dioxide from the atmosphere makes it a valuable resource in achieving carbon neutrality, Doten said. 

“It’s a Swiss Army Knife of climate tools,” Doten said.