Biomethanation is commercialized for food waste, cattle waste, sewage sludge, and wastewater. European countries have developed biomethanation technology. Biogas plants have been gradually increasing in Japan. The reaction takes place at high, moderate, or low fermentation temperature, and organic content classifies biomethanation into wet and dry fermentation. High temperature systems reveal high gasification performance compared with other temperatures. Disadvantageous points of biomethanation are low digestion ratio, low removal ratios of ammonium and phosphate, long treatment time, and necessity of heat. Fermented effluent and residue should be recycled for agriculture as an organic fertilizer since treatment cost is high. Technological developments is being conducted to overcome these issues.

Further information

Ahring, B. K., “Biomethanation I”, Springer, (2003)

Nagai, S.; Ueki, K., “Anaerobic microbiology”, Youkenndou, (1993) (in Japanese) Speece, R. E., “Anaerobic biotechnology for industrial wastewaters”, Archae Pr, (1996)