Anaerobic Digestion: Co-Digestion and Operational Issues

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A study was conducted to assess the performance of various mixing regimes on methanogen biomass content in anaerobic digesters.  Methane production in anaerobic digesters is directly related to the methanogens within the system.  Current systems involve mixing to increase biogas production and system efficiency, however little is known about the underlying mechanisms of this relationship.  In this study three pilot scale anaerobic digestion systems with three different mixing regimes were run with replication to examine the impacts to methanogen biomass content and biogas production.  The results will provide insight for operational recommendations as well as the basic microbial processes with digestion systems which are critical for optimization.


Rebecca Larson, University of Wisconsin-Madison  


To evaluate various feedstocks and operational parameters for anaerobic digesters, including impacts to biogas production, quality, and operational issues.

What Did We Do?

Evaluated numerous co-feedstocks with manure in laboratory and large scale systems to identify biogas production impacts and potential operational issues associated with each.

What Have We Learned?

Analysis of ffedstocks is critical for determination of digester fundtioning.  Constituents can significantly impact the quantity and quantity of biogas produced.

Future Plans

To evaluate scale up to determine if small scale biomethane potential analyses can be used to determine full scale biogas production.


Rebecca Larson, Assistant Professor, University of Wisconsin – Madison

Corresponding author email address

Asli Ozkaynak, Post-Doctoral Researcher, University of Wisconsin – Madison

Additional Information

Data is to be published



Funded by the USDA


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