Food waste anaerobic digester planned for Minnesota town

By Lisa Gibson | September 29, 2011

An 8-megawatt anaerobic digester that would run on a mix of food processing waste including sweet corn silage and potato and bean waste is proposed for the southeast Minnesota town of Le Sueur.

The city was known as a food processing hub as the former home of vegetable company Green Giant. The area still has a number of food processing companies, some with contracts in place to supply waste to the new biomass power plant, according to Kelsey Dahlen, project manager for developer Minnesota Municipal Power Agency. More feedstock supply contracts are in the works, she added.

The plant will supply power to Le Sueur, as well as produce a solid biofuel from the used digestate, dried using waste heat from the gensets, Dahlen said. The plant will be capable of producing between 7,500 and 15,000 tons per year. “That will be sold to coal and biomass boilers.” In addition, the liquid waste stream from the plant will be used as a fertilizer for local farmers.

MMPA is still in the permitting process, which Dahlen expects will take about six months. If all goes well, construction can begin in the summer or spring of 2012, with operation in 2013.

The cost of the facility is estimated to be around $30 million and Dahlen said MMPA will pursue funding through the U.S. Department of Treasury’s Section 1603 cash grants in lieu of tax credits program.