A Practical Plant and the Operation of an Anaerobic Fermentation of Cattle Manure in Cold Region

Abstract

1) A plant of anaerobic manure fermentation for 70 dairy cattle (converted to cow) was planned, constructed and operated.
2) The press-juice of cattle feces was treated as fermentation material. A fermentation tank of 30m³ (24t juice-sludge) composed of one-tank-type was also setted. A gas holder of 10m³ and nonwater type was adopted, which consisted of specific gum-cloth.
3) A sludge-circulation system was used for stirring sludge in the fermentation tank, and it was also used for heating sludge. Methane-composite gas, which was self-supplied from the plant, was utilized for heating sludge in the tank.
4) The fermentation was maintained at 35-37 degrees centigrade. It was presumed that the fermentation will be effective at the more lower temperature to minimize a heat loss from the cold.
5) An underground pit of manure was prepared to protect feces from freezing. But the increase of diluting water caused decrease of sludge density and organic-matter digestibility.
6) The earth, sand and admixture in sludge often caused blockages of circulating pump and heat-exchanging equipment. It was necessary to exchange the equipments and to eliminate the sand etc. periodically.
7) A sand-strainer was equipped between the press-juice tank and the sending pump.
8) After a regular fermentation was achieved, 30-70 minutes was needed per day to operate and control the plant. In addition to this labor, 255.5 hours was consumed to repair the plant in 2 years.