NOVELTY - The anaerobic digestion reaction system comprises a continuously stirred reaction tank (18) having an agitator (20) and outlet pipes, a blend tank (14) for receiving organic waste feedstock (12), a plug flow reactor present in communication with the reaction tank, an outlet gas separation vessel tank present in communication with the plug flow outlet pipe, a sludge pump present in communication with the outlet gas separation vessel tank, a discharge line provided at a base of the reaction tank to remove non-volatile solids, and a conditioning tank (28).    USE - The anaerobic digestion reaction system is useful for treating wastewater, producing an industrial gas, and processing animal, plant and other primarily organic waste by a bacterial process of digestion.    ADVANTAGE - The anaerobic digestion reaction system ensures efficient production of biogas from the organic wastes, and can be effectively integrated into the bio-refinery facility.    DETAILED DESCRIPTION - The anaerobic digestion reaction system comprises a continuously stirred reaction tank (18) having an agitator (20) and outlet pipes, a blend tank (14) for receiving organic waste feedstock (12), a plug flow reactor present in communication with the reaction tank, an outlet gas separation vessel tank present in communication with the plug flow outlet pipe, a sludge pump present in communication with the outlet gas separation vessel tank, a discharge line provided at a base of the reaction tank to remove non-volatile solids, and a conditioning tank (28) present in communication with the reaction tank and the plug flow reactor. The blend tank is present in communication with the reaction tank and the plug flow reactor. The organic waste feedstock is transferred from the blend tank into the reaction tank and the plug flow reactor to conduct stages of biomass reaction of the organic waste feedstock into a biogas. The plug flow reactor has a plug flow reactor outlet pipe. The organic waste material is discharged from the outlet pipe, and is transferred from the plug flow outlet pipe into the outlet gas separation tank. The biogas is separated from liquids and solid slurried waste that is removed from the outlet gas separation vessel tank. The organic waste feedstock passes through the conditioning tank, and passes between the reaction tank and the plug flow reactor. The conditioning tank provides additives to the organic waste feedstock to adjust its pH factor. The blend tank provides agitation and heat to the organic waste feedstock before the organic waste feedstock is transferred into the reaction tank. The reaction tank is sized to provide a sufficient residence time to conduct bacterial conversion reactions. The plug flow reactor is spirally wound around the reaction tank, and has sufficient volume to provide an enough residence time to complete a portion of the organic waste digestion. The reaction tank and the plug flow reactor comprise a heated fluid jacket. The reaction tank is heavily insulated to allow a sufficient temperature gradient between the heating fluid and the organic waste material located within the plug flow reactor. The temperature gradient is 10-30 degrees C hotter in the plug flow reactor than the temperatures in the reaction tank.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of an anaerobic digestion reaction system.    Organic waste feedstock (12)    Blend tank (14)    Continuously stirred reaction tank (18)    Agitator (20)    Conditioning tank. (28)