Methane (Anaerobic) Digesters
A methane digester system, commonly referred to as an AD (anaerobic digester), is a device that promotes the decomposition of manure or 'digestion' of the organics in manure to simple organics and gaseous biogas products.
- Manure is regularly put into the digester after which the microbes break down the manure into biogas and a digested solid.
- The digested manure is then deposited into a storage structure.
- The biogas can be used in an engine generator or burned in a hot water heater modified for biogas. AD systems are simple biological systems and must be kept at an operating temperature of 100 degrees F in order to function properly. (Manure Matters newsletter No. 7 v. 10).
In Nebraska, there is tremendous energy potential within manure on Nebraska's beef, dairy, pork, and poultry operations that could be recovered by anaerobic digestion. Since electrical rates are low relative to other areas of the U.S., generating electricity may not be the most feasible option. Economic feasibility may require taking advantage of other energy outlets, tipping fees, carbon credits, and other revenue streams, as well as grants, low-interest loans, and other financial assistance to help defray capital costs.
The “Complete Mix Swine Manure Digester” YouTube video explains how an anaerobic digester works on a swine farm in Nebraska to produce electricity and compressed natural gas. Additionally, they have reduced odors and have a nutrient-rich liquid that is used as a fertilizer on cropland.
The Carbon Credits from Livestock Production NebGuide can give more information about how you may be able to obtain payment for certain practices on livestock operations. These include:
- lagoon covers
- anaerobic digesters
- rangeland management