System and method for producing methane, an organic based fertilizer and usable water from animal waste

摘要

A method of producing methane, an organic based fertilizer and usable water from animal waste includes the step of separating the animal waste into liquid waste and solid waste. The solid waste is subjected to anaerobic digestion to produce methane and a wet by-product. The wet by-product is pressed to into a filter cake which is pelletized into the organic based fertilizer. The liquid waste is clarified to produce a supernatant and a sludge which is pressed into a filter cake together with the wet by-product. Ammonia is extracted from the supernatant to produce ammonium sulfate and an aqueous solution. The aqueous solution is filtered to produce a concentrate and water filtrate. The water filtrate may be used as drinking or washing water. The ammonium sulfate and concentrate may be used to supplement to the solid waste which is pelletized into the organic based fertilizer. In alternative embodiments a portion of the supernatant and aqueous solution may be used as a liquid fertilizer.