In the United States, the availability of inexpensive fossil fuels has limited the use of digesters solely for biogas production. However, the waste treatment and odor reduction benefits of controlled anaerobic digestion are receiving increasing interest, especially for large-scale livestock operations such as dairies, feedlots, and slaughterhouses. Where costs are high for sewage, agricultural, or animal waste disposal, and the effluent has economic value, anaerobic digestion and biogas production can reduce overall operating costs. Biogas production for generating cost effective electricity requires manure from more than 150 large animals. Below-ground, concrete anaerobic digesters have proven to be especially useful to agricultural communities in parts of the world such as China, where fossil fuels and electricity are expensive or unavailable.
Biogas production is secondary.
The Handbook is a technical resource for commercial agricultural operations. Contact General Bioenergy for specific ordering information. This Service has several publications on farm manure management and utilization. This service has numerous publications related to livestock manure management, including a 68 page booklet, Anaerobic Digestion for Dairy Farms , which includes information on how to build them, how much output to expect per pound of manure, and how to modify gas appliances to use the gas. An overview of biogas digesters is available on their Web site.