Appendix: Case Studies

Introduction

In this appendix, we present several case studies that illustrate potential ownership models, materials handling processes, and design parameters for community digesters.

The Dane County community digester is an example of a centralized approach of manure aggregation. The Dane County community digester was developed to address phosphorus reduction goals in a targeted watershed. Manure is piped from three adjacent dairy farms to a centralized digester, which is located on one of the farms. The digester is managed by a private company. Products include methane for energy, separated solids for cattle bedding and manufacture of a potting soil.

The Hooly Community digester aggregates manure from seven to eleven individual farms. Manure is delivered by tanker truck to the centralized digester for electricity from  methane production. Digested manure affluent is then sent to an adjacent compost facility for conversion to soil amendment, livestock bedding and other products.

The Jer-Lindy Dairy case study highlights a farm operation that is producing biogas using an anaerobic digester for small and mid-sized dairy operations in the Midwest. This pilot project tests the technological and economic feasibility of smaller scale digesters.

New technologies and processes are being developed for  small-scale anaerobic digestion for dairy manure treatment and for sewage and wastewater treatment. The USEMCO Bi-gester fact sheet describes the technology being developed by Universal Sanitary Equipment Manufacturing Company for anaerobic digestion of organic waste. The BioFerm Energy Systems fact sheet describes a technology being developed for small farm digestion of a mix of high solids, low moisture materials. BioFerm is piloting a dry digestion system at the Univeristy of Wisconsin-Oshkosh.

 

Case Study:

The Dane County Community Digester. Vienna, Wisconsin. Available at:

https://publish.extension.org/andig1/files/2012/12/CS_DaneCounty.pdf

 

Case Study:

The Hooly Community Digester. Port of Tillamook Bay, Oregon. Available at:

https://publish.extension.org/andig1/files/2012/12/CS_HoolyDigester.pdf

 

Case Study:

Jer-Lindy Dairy Small-Scale Digester. Brooten, Minnesota

Available at:

https://publish.extension.org/andig1/files/2012/12/CS_Jer-Lin.pdf

 

Fact Sheet:

Emerging Small-Scale Digester Technology: USEMCO Bi-gester. Available at:

https://publish.extension.org/andig1/files/2012/12/FS_USEMCO.pdf

 

Fact Sheet:

Emerging Small-Scale Digester Technology: BioFerm Energy Systems – EUCOlino. Available at:

https://publish.extension.org/andig1/files/2012/12/FS_BioFerm.pdf