Manure Digestion/Energy Generation

14 Aug 2013

Tuesday, I traveled to Michigan State University (MSU) for the start up of MSU’s South Campus Anaerobic Digester (SCAD). Reportedly, this is the largest such digester in the United States that is owned by a university.

Anaerobic digestion converts organic materials (feedstocks) without oxygen into biogas.

Once fully operational, MSU’s digester will use roughly 17,000 tons of organic waste from MSU and elsewhere nearby to produce biogas that will generate over 2.8 million kWh of electricity per year.

Most of the system’s feedstock will be dairy manure from the MSU Dairy Teaching and Research Center, with some food waste from campus dining halls, fruit and vegetable waste from a nearby Meijer Distribution Center, and fats, oil and grease from local restaurants.

Biogas produced will power a 450 kW combined heat and power system. The electricity generated will power buildings on the south side of campus.  Hot water generated will maintain the digester temperature at 100 degrees F and to help heat other nearby buildings.

The solids and liquid remaining after digestion (digestate) will be pumped to a solid-liquid separator; solids will be composted; the liquid will be stored in the larger tank in the photo and will be applied to the land as carbon-rich fertilizer.

While the technology is proven, MSU will test this digester to see how this can be implemented in a cost-effective manner. The payback at this point is projected to be between 7 and 12 years. There may be many opportunities for these to be located near large farm “hubs” and even as part of municipal wastewater treatment – if they can be operated economically.

Leave a Comment to “Manure Digestion/Energy Generation”

  1. Victor Thompson 26. Aug, 2013 at 11:00 am #

    I am very excited to see this new showcase Digester come on line at MSU. It will be a wonderful example of how these systems can handle a diverse waste stream and turn it into a number of valuable products: natural gas, electricity and high quality organic fertilizer.

    These systems can handle a wide variety of waste, be it food scraps, animal manure, sludge from waste water treatment plants, or virtually any organic material.

    I think the US is on the verge of seeing a large number of these systems being installed over the next few years. There are over 2000 AD systems in operation in Germany alone, while there are less than 300 currently operating in the US. I believe this number will increase significantly very soon!

    Vic Thompson
    Star Distributed Energy

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