Dynamic Situation of Operation and In-and Output of heat in an Anaerobic Fermentation of Cattle Manure

Abstract

1) Three manure systems in Nasu Experimental Station, Tokyo University of Agriculture, those are a manure disposing system using underground manure-pipes, a system merely dividing feces and urine at cow-barns, and a manure system utilizing anaerobic fermentation, were compared in view of capital investment and handling labor. In each system, clear demerits were recognized in case of the open-type free-stall barn.
2) Digestibilities of organic matter in the anaerobic fermentation were ca. 32% and 21% utilizing overground hopper and underground pit, respectively. In the latter case, a shortness of days for fermentation was caused by the increase of diluted manure.
3) 75.2% of BOD and 63.8% of COD were eliminated by means of the anaerobic fermentation utilizing underground pit.
4) 210-640Mcal per 10 days of the self-supplied methane-composite gas was consumed to heat the pressed manure, and the rest to maintain the tank-temperature. The difference of temperature between sludge in the tank and the surrounding air didn't severely affect the heat-loss from the tank.
5) The next formula was obtained between fermentation temperature(x°C) and methane-composite gas volume (y l/day) utilizing overground hopper.
y=3.31x²+360.4x+9801