Stacked modules for anaerobic digestion

Claim 1

An anaerobic digestion sub-system for a system for production of methane gas by anaerobic digestion of feed materials containing suitable organic materials, comprising: (a) a plurality of anaerobic digestion modules, stacked and interfaced in a vertical array, each having a gas sampling and discharge port having a three-way valve positioned therein and each having a digesting slurry sample port having a valve positioned therein; (b) a plurality of sloped plates, each positioned between a pair of adjacent digestion modules to function as a bottom for the digestion module immediately above it and as a top for the digestion module immediately below it and each having an opening through its lowest point for transfer of digesting slurry from the digestion module immediately above it to the digestion module immediately below it; (c) a plurality of valves, each operatively positioned for closing one of said openings through said plates during anaerobic digestion operations; (d) means for independently operating each of said valves from the exterior of said anaerobic digestion modules; (e) a top cover fastened to the top digestion module in said vertical array, said top cover having a slurry inlet port for transfer of freshly prepared slurry from a slurry preparation sub-system to said top digestion module; (f) a bottom cover fastened to the bottom digestion module in said vertical array, said bottom cover having a slurry outlet port for transfer of digested slurry from said bottom digestion module to a sludge separation sub-system; (g) a valve positioned in said slurry outlet port of said bottom digestion module for closing said slurry outlet port during anaerobic digestion operations; (h) means for independently heating and controlling the temperature in the interior of each of said anaerobic digestion modules; and (i) a gas collection manifold for collecting gas from the gas sampling and discharge ports.