This publication provides a general overview of anaerobic digestion and the current status of biomethane technology on livestock farms in the United States. It is part of the Bioenergy Engineering Education Program (BEEP) of the Biological Systems Engineering Department at Virginia Tech. Most of the discussion uses dairy manure as an example of feedstock for an anaerobic digester. Resources which provide more detailed information on anaerobic digesters are listed.

As energy prices reach historic highs, there is a broad interest across the state in utilizing and producing renewable bioenergy from domestic agricultural products. Nationwide, it is expected that a 20 percent replacement of petroleum usage will happen over the next ten years. This is equivalent to 35 billion gallons of alternative fuel use by 2017, with fuel ethanol playing an important role in this transition. Fuel ethanol can be blended with gasoline (from 10 percent to 85 percent), and thus reduce the amount of gasoline used. In the United States, corn kernels are commonly used for producing fuel ethanol, and thus reduce the nation’s dependence on foreign oils. The purpose of this publication is to introduce the basics of fuel ethanol and answer questions regarding fuel ethanol.