Sniffing Out the Value of Anaerobic Digestion

Caroline Frischmon | August 16, 2020


As part of the Hennepin-University Partnership (HUP) Summer Webinar Series, MnDRIVE Environment hosted a panel discussion on the history, current efforts, and future of anaerobic digestion (AD) in Minnesota. 

Anaerobic digestion converts organic material, such as food waste, manure, or wastewater, into biogas and a nutrient-rich component called digestate. AD facilities apply the digestate as fertilizer to agricultural fields while converting biogas to electricity or upgrading it to renewable natural gas. The process of anaerobic digestion is well-established scientifically, but economic challenges have limited its implementation across Minnesota, and in other regions of the US.

Biogas Installation Processing Cow - Image

The featured panelists, Bo Hu, John Jaimez, and Erica Larson, came from varied backgrounds as part of MnDRIVE’s effort to spark collaboration between local government, industry, and the University. All three agreed that considerable potential exists within Minnesota to expand AD operations. 

Jaimez works with Hennepin County on their organics recycling programs and is managing the County’s AD development project. He anticipates Hennepin County will rely on AD technology to achieve its goal of recycling 75% of solid waste by 2030, as it does not have sufficient composting capacity to currently meet this target. A new AD facility would provide more capacity while generating biogas as an added benefit.

Hu, a professor in the Department of Bioproducts and Biosystems Engineering, studies waste management and industrial bioprocess development, including AD. His MnDRIVE research project with Second Harvest Heartland found that the hunger relief organization could cover 70% of its electricity needs by anaerobically digesting the rotten food it receives daily. Besides energy production, Hu lists waste volume reduction, deodorization, and savings in waste disposal fees as other advantages for AD.

As a regulatory analyst for CenterPoint Energy, Larson works to expand the company’s renewable natural gas portfolio. She explained how despite its potential growth, the low price of conventional natural gas has hindered AD implementation in the state. “Even if you have sustainability commitments in mind as a company or homeowner, it is a big price difference,” says Larson. Federal and state incentives for the technology could help AD overcome its economic disadvantage, although Larson emphasizes that there is no silver bullet for incentivizing renewable natural gas. CenterPoint Energy took a broad approach by working with the Minnesota Legislature and the Public Utilities Commission on various solutions.

MnDRIVE offered the webinar to a wide ranging audience of local government teams, public and private industry professionals, and university researchers, as a way of identifying interested stakeholders. “We know from past experience that bringing people together early in the process often leads to progress in many different directions,” says MnDRIVE Environment Industry Liaison Jeff Standish, who moderated the event.

MnDRIVE Environment has funded several AD research projects (see “Improving the Process of Industrial Wastewater Treatment” or “Fueled by Food Waste”) over the last few years as part of the initiative’s overall mission of advancing environmental remediation in Minnesota. Funded projects require UMN researchers to work with at least one local government, non-profit, or industry partner to ensure practical outcomes and implementation opportunities for collaborative research. This webinar is just one of many AD related discussions that Standish hopes will initiate further partnerships and project collaborations. Ultimately, MnDRIVE Environment aims to stimulate discussion and exploration of AD development and generation of renewable natural gas in Minnesota to take advantage of the growth potential identified by the expert panelists.

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