Anaerobic Digestion Information
Biogas recovery systems are sometimes known as anaerobic digesters or "biodigesters" because they use a process called anaerobic digestion. During anaerobic digestion, bacteria break down waste in an oxygen-free environment. One of the natural products of anaerobic digestion is biogas, which typically contains between 60 to 70 percent methane, 30 to 40 percent carbon dioxide, and trace amounts of other gases. Applications of anaerobic digestion for biogas capture include Wastewater Treatment Plants, Dairies, and at organic waste processing facilities.
Biogas can be used to produce electricity using engines or fuel cells, or it can be converted to transportation fuel or “biomethane” (which has the same properties as natural gas).
CalEPA is working to help permit anaerobic digesters at both dairies and Wastewater Treatment Plants.
Links for more information on biogas:
- U.S. EPA’s AgStar Program
- California Energy Commission
- U.S. EPA Region 9, Waste to Biogas Mapping Tool