This plant was designed to produce electric and thermal power from 22,000 metric tons of manure produced annually by a 1,000-cow dairy operation at Den Dulk Dairy Farm in Ravenna, Michigan.
While reduced utility costs are an obvious benefit of producing renewable energy from waste, owners of these systems also benefit from several environmental factors including a reduction in greenhouse gas emissions and reduction of pathogens when land applying.
Food processors located upstream from municipal treatment plants have also seen lower BOD/COD values in their digested process streams.
The finished plant converts animal waste to biogas through anaerobic digestion, and a high yield is achieved with the assistance of a continuous stir tank reactor (CSTR).
The system contains an in-line hydrogen sulfide scrubber that uses proprietary bacterial technology, a CHP engine and CHP micro turbine for electric and thermal power generation, and a liquid solid separator.
The farmer not only takes advantage of the reduction of utility costs but also uses the solids that are separated as bedding for the barns and the liquids for land application.