Patent ID: 7560026

Claim:
A waste digestion system comprising: a blend tank for blending a quantity of waste and heating the waste to a temperature suitable for mesophilic bacteria; and a horizontal anaerobic digester comprising: a first chamber within the digester, said first chamber arranged for digesting the waste at a mesophilic temperature; a second chamber within the digester, said second chamber arranged for digesting the waste at a thermophilic temperature; a bulkhead separating the first chamber and the second chamber so that the waste in the first chamber and the waste in the second chamber are in fluid contact, said bulkhead being arranged to allow underflow of liquid and solids only from the first chamber to the second chamber; an inlet for receiving waste from the blend tank into the first chamber at least one discharge outlet for removing the waste from the second chamber; and an agitator for moving the waste from the first chamber to the second chamber, said digester being arranged to be elevated at one end such that there is a downward slope from the first chamber to the second chamber.