The University of California-Davis has applied for a patent on new methane generator technology recently developed by its researchers.

Known as the APS Digester, the system converts animal waste to energy by using a mix of bacteria in an oxygen-deprived environment to break down organic materials. The result is a medium-Btu gas that’s about 60 percent methane. Scientists say this biogas is suitable for producing either heat or electricity.

While conceding that anaerobic digestion is not a new concept, UC-Davis ag engineer Ruihong Zhang says that this two-phase, closed-loop system is distinctly different from other digesters, adding that this unit promotes the best environmental conditions for the bacteria involved. This two-phase system allows solids to be loaded and unloaded without disrupting the anaerobic environment of the bacteria system.

Currently, the technology has been licensed exclusively to Onsite Power Systems of Fresno, Calif., which is coordinating the construction of a small-scale pilot plant at UC-Davis. A commercial version featuring 10 350,000-gallon tanks is in the works at a horseracing facility in Florida.

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