Patent ID: 6521129
Filing Date: 2003-02-18
Classification: C02F,C05F,Y02A,Y02E,Y02P,Y02W

Abstract:
A process for treating manure using anaerobic digestion, comprising the steps of:providing manure having a mineral content; introducing the manure into a mixing vessel containing a digester liquid which is substantially free of digestible organic materials and contains a mineral content; agitating the manure and digester liquid in the mixing vessel for an effective amount of time to produce a pumpable slurry; withdrawing the pumpable slurry from the mixing vessel; filtering the pumpable slurry to remove substantially all water insoluble solids therefrom and provide a resultant liquid containing ammonia and reactive organic materials; heating the resultant liquid to a temperature in the range of from about 150Â° F. to about 230Â° F. for an effective amount of time to break chemical bonds and destroy active bacteria present in the resultant liquid; removing ammonia from the heated resultant liquid to produce a substantially ammonia-free liquid containing reactive organic materials; cooling the substantially ammonia-free liquid containing reactive organic materials to a temperature in the range of from about 70Â° F. to about 140Â° F. to provide a cooled liquid stream containing reactive organic materials; and passing the cooled liquid stream to a digester containing anaerobic bacteria to convert the reactive organic materials in the cooled liquid stream to biogas, thereby producing a digester liquid substantially free of digestible organic materials; withdrawing the biogas from the digester; and withdrawing an effective amount of the digester liquid from the digester and recycling the withdrawn digester liquid to the mixing vessel for mixing with manure.