Animal Waste to Valuable Power
Beef, dairy cattle, hogs and poultry manure, also known as feedlot biomass, can be put to practical use as a renewable energy source, with dry manure and liquid manure producing different types of energy. Manure can be used for gas, electricity and fuel for a boiler, or it can be burned directly for cooking or lighting.
The best approach to using animal wastes for power depends on the amount of moisture and non-biodegradable solid materials that are contained in the manure. Both methods solve a manure disposal problem while mitigating odors and negative environmental effects.
Dry manure has long provided heating and cooking fuel for rural societies. If the water content of manure is low enough (less than 20%), dry manure can be burnt directly. Solid, dry manure includes manure from beef feedlots and dairy dry lots. Burning dry manure can also release energy for the production of biogas. While supplying its own energy needs, a cattle feedlot operation could also solve its manure disposal problem, reduce odors, provide jobs, and increase the local tax base - all by installing a manure-to-energy generator on site.
The environmental benefits to processing manure into fuel include cleaner air and water. Tillamook, Oregon, the land of Cheese, Trees and Ocean Breeze is in on the cutting edge of the biogas to electricity technology with their MEAD Project.
In 2003, the Port of Tillamook Bay in Tillamook, Oregon constructed a centralized methane digester to biologically process the manure from 4000 of the county's 30,000 dairy cows. The project was 14 years in development as MEAD (Methane Energy and Agricultural Development). The facility, owned and managed by the Port, utilizes simple, proven cost-effective digester, solids separation and biogas-to-electricity technology currently being employed at over a dozen sites nationally.
Manure is picked up by facility personnel, treated, and a portion returned to participating farms. Transportation costs are offset by sale of electricity as "green power" and by sale of fiber recovered for use by a potting soil manufacturer. System benefits to the Tillamook community include: reductions in odors, pathogenic organisms, weedseeds, manure quantities and nutrients to be land-applied.
For more information on the Tillamook MEAD Project, visit http://www.potb.org/methane-energy.htm