Can anaerobic digesters be used for non-traditional animal manure, such as that from rabbits or horses?
Anaerobic digesters work for manure that is collected as a liquid or slurry and does not contain a large amount of sand or dirt. To generate biogas, the manure must be collected and handled wet because the biogas is generated from anaerobic biochemical processes (those occurring in the absence of air). Anaerobic digestion systems can be used on operations that do not meet these parameters if the operations employ pre-treatment practices to ensure that the slurry is of appropriate consistency for the digester. However, the key consideration is the biodegradability of the waste. Depending on the animal and its feed characteristics, anaerobic digestion may be a viable option. These systems can be worth the investment if the number of animals is high, the operator is motivated by odor issues, and/or where utility contracts are especially favorable.
