These digesters produce biogas at ambient temperatures from diluted manure with less than 2 percent solids. To trap biogas, an impermeable cover floats on top of a lagoon filled with flush manure. Covered lagoons are used for energy production in warm climates but are limited to odor control in colder climates.
A covered lagoon system consists of:
- a solids separator
- one or more lagoons
- a floating lagoon cover
- a biogas utilization system
The most successful arrangement includes two connected lagoons that separate the biological treatment for biogas production from the storage of manure used for land application. For more information, see RCM Covered Lagoon Technical Details.
Dozens of RCM Covered Lagoon digester systems are in operation throughout the globe.