Fennville Anaerobic Digester System
In 2006 an Anaerobic Digester System was installed at the Fennville site. The system consists of three complete mix anaerobic digesters with each having an operating capacity of ̴870,000 gallons each. Substrates that are fed to the digesters include dairy manure, heifer manure, and swine manure. Along with the animal waste fed to the digester syrup stillage and fats, oils, and greases (FOG) are also used as substrates for the digester.
Biogas that is generated is used to fuel two Caterpillar G3412 Co-Generators (gensets). Each of the gensets is capable of producing 450 kilowatt-hours (kWh). The electricity that is generated from the gensets is first utilized on-site to power the dairy then any excess electric is placed on the local electric grid.
The Digestate removed from the anaerobic digester is processed in FAN Separators to separate the liquids and solids. The liquid which is separated is land applied to utilize the nutrients for crops. The solids also are known as “Biofibers” are used for bedding the animals on and off the site.
Member of American Biogas Council (www.americanbiogascouncil.org)