Problem: In the United States, roughly 40% of all food goes to waste, including food donated to non-profit food banks like Minnesota’s Second Harvest Heartland. Unusable or spoiled food is an unpredictable and fluctuating cost for foods banks who need to pay for the removal of the wasted food.
Solution: MnDRIVE Environment researchers designed an anaerobic bioreactor to digest food waste on site. Not only could this approach address the issue of excess food waste and disposal, but the bioreactor also produces methane, the principal component of natural gas. This offers a new energy source or revenue stream. In addition, a second bio-electrochemical system removes hydrogen sulfide, a toxic and odorous component, from the biogas so that the digester can be operated more safely in the neighborhood.
Impact: The demonstration project will help Second Harvest evaluate the feasibility of a commercial-scale anaerobic bioreactor installation that could one day heat their facility and/or create new revenue streams to stabilize the non-profit organization. This type of digestion technology is of significant interest from public solid waste disposal sites.