How Biogas Systems Work
Organic materials are the "input" or "feedstock" for a biogas system. Some organic materials will digest more readily than others.
As material is deposited in the landfill and covered, anaerobic microbes consume organic material and burb out biogas, which is vacuumed out through buried, perforated pipes.
Add organic material to these engineered tanks, which are usually stirred and heated to about 100º F, and the same anaerobic microbes produce biogas, which is captured in the digester's air-tight, flexible roof.
Biogas consists mostly of methane and carbon dioxide, plus water vapor, and other trace compounds (e.g., siloxanes)
DIGESTED MATERIAL (DIGESTATE)6>
In addition to biogas, digesters produce solid and liquid digestate, containing valuable nutrients (nitrogen, phosphorus & potassium) and organic carbon.
RENEWABLE NATURAL GAS
Biogas processed to gas pipeline quality is often called biomethane, renewable natural gas, or RNG.