Patent attributes
Waste material is screened to produce unders and overs, the overs are treated to produce a partially hydrolyzed biomass, and the partially hydrolyzed biomass and the unders are anaerobically digested. Treating the overs includes fermenting and mixing the overs with an aerotolerant anaerobic bacteria in a controlled environment, such as a rotating drum, while air is passed through the controlled environment. The moisture content, pH, and biological content of the overs can be adjusted before the overs are treated. Volatile fatty acids from the air passed through the controlled environment can be collected for anaerobic digestion or can be recirculated back into the controlled environment. The cleansed air can also be recycled back into the controlled environment.
