Anaerobic Digestion System Views
Anaerobic digestion is an alternative solution to livestock waste management that offers economic and environmental benefits. This publication provides an introduction to the technology of biogas, digester design considerations, and system costs with discussion of the digestion process, production, uses, and risks. Useful tables and further resources are included.
While hundreds of anaerobic-digestion systems have been installed in Europe and the U.S. since the 1970s, it was not until the 1990s that better designed, more successful projects started to come on line in the U.S. Today, an estimated 97 farm-scale projects are in operation, in start-up, or under construction on swine, dairy, and poultry farms across the country. (1)
Despite the many benefits, anaerobic digestion systems are not appropriate for all farm operations. A cooperative effort among the U.S. Departments of Agriculture, Energy and the Environmental Protection Agency to promote biogas projects is known as AgStar. AgStar estimates that anaerobic digestion could be cost-effective on about 7,000 U.S. farms. (3) A critical issue is planning; each system needs to be designed to accommodate a variety of factors. This publication provides an overview of those factors and identifies resources for additional detailed information. Several of these resources include computational analysis tools to help users determine whether an anaerobic digestion system could be a cost-effective addition to their operation.
Putting these energy-content values in the context of an anaerobic-digestion system means the energy production per animal can be estimated, as seen in Table 2. In Table 3, North Carolina State Universitycrs"s Cooperative Extension Service has converted the energy-content figures from Table 2 into biogas net returns relative to four other common energy sources.
Anaerobic Digestion System Images
