Anaerobic waste digestion system

An anaerobic waste digestion system for use in connection with a source of waste including anaerobically digestible material, for generating methane from the waste by anaerobic digestion using bacteria, the waste being a water-based slurry including solid particles having a particle size larger than a predetermined size unsuitable for digestion and solid particles having a particle size smaller than the predetermined size suitable for digestion, the anaerobic waste digestion system comprising:

• a first phase particle separator adapted for removing from the slurry solid particles having the particle size larger than the predetermined size unsuitable for digestion and for allowing passage therethrough of the slurry, the first phase particle separator including one or more of an equalization pit, an equalization tank, a screen separator, and a solids tank;
• a second phase particle separator including an electrocoagulation unit connected in fluid communication with the first phase particle separator for electrochemically inducing hydrolysis of the slurry, so as to cause particles to settle out of the slurry, the electrocoagulation unit being adapted for allowing passage therethrough of the slurry,
• a third phase particle separator in fluid communication with the electrocoagulation unit, the third phase particle separator including a separation zone, the third phase particle separator adapted to have a residence time for the slurry within the separation zone to cause separation of the solid particles having the particle size larger than the predetermined size unsuitable for digestion from the solid particles having the particle size smaller than the predetermined size suitable for digestion, the separation zone adapted for allowing passage therethrough of the solid particles having the particle size smaller than the predetermined size suitable for digestion as feedstock;
• and
• a fourth phase gas producer configured to provide an operating temperature in a range from approximately 68 to 140° F., the fourth phase gas producer including at least one low solids anaerobic digester connected in fluid communication with the separation zone of the third phase particle separator, wherein an influent including the solid particles having the particle size smaller than the predetermined size suitable for digestion enters the anaerobic digester as feedstock, biogas exits as a product, an effluent exits as wastewater, and a slurry exits as settled solids, the anaerobic digester having at least one biocurtain for growing the bacteria,
• wherein the predetermined size suitable for digestion is less than about 200 μm.