PROCESS AND PLANT FOR TREATING THE MANURE PARTICULARLY OF LARGE- SCALE POULTRY-FARMS

摘要

Poultry manure obtd. by the deep litter method is mixed with an additive which provides an extra source of carbon, and transferred to a silo. The silo is covered by a flexible tarpaulin which produces a variable volume gas space, and is able to adsorb solar energy. The manure is injected with a liquor contg. methane producing bacteria. The dry matter content of the silo is adjusted in the range 15-45% by liq. addition. The temp. in the silo is adjusted to 40-45 deg.C by a short period of aerobic oxidn., or in some cases, by external heating. Then the aerobic oxidn. is interrupted and the manure is allowed to ferment anaerobically, while the gas produced is removed for utilisation. At the end of the fermentation period the solids content of the silo is removed for use as fertiliser and the liq. phase is reinjected for the next load of manure.