In the U.S., the total amount of municipal solid waste is continuously rising each year. Millions of tons of solid waste and scum are produced annually that require safe and environmentally sound disposal. The availability of a zero-cost energy source like municipal waste scum is ideal for several types of renewable energy technologies. However, the way the energy is produced, distributed and valued also contributes to the overall process sustainability. An economic screening method was developed to compare the potential energy and economic value of three waste-to-energy technologies; incineration, anaerobic digestion, and biodiesel. A St. Paul, MN wastewater treatment facility producing 3175 “wet” kilograms of scum per day was used as a basis of the comparison. After applying all theoretically available subsidies, scum to biodiesel was shown to have the greatest economic potential, valued between $491,949 and $610,624/year. The incineration of scum yielded the greatest reclaimed energy potential at 29 billion kilojoules/year.
Bibliographical noteFunding Information:
The authors are grateful to Kirk Cobb at Superior Process Technologies, Inc. for helping and supplying industrial knowledge and perspective. This project was supported in part by the Legislative-Citizen Commission on Minnesota Resources ( LCCMR ), the Metropolitan Council for Environmental Services ( MCES ), the University of Minnesota MNDrive program , and the Center for Biorefining .
© 2016 Elsevier Ltd
- Anaerobic digestion
- Wastewater treatment