Phoenix Beteilgungs Gmbh

Phoenix Beteiligungs Gmbh

Herbert Spindler

Thomas Meier

Ute Bauermeister

Michael Teske

The invention relates to a method and a device for producing nitrogen fertilizer, removing phosphate from organic waste products in liquid phase, sanitizing said waste or reducing emissions, and limiting the potassium concentration. According to the invention, the waste product is heated to temperatures ranging between 40 DEG C. at a subatmospheric pressure, the escaping gas that contains carbon dioxide and ammonia is contacted with a mineral-aqueous suspension, the excess gas is conducted within the circuit while the subatmospheric pressure is autogenously stabilized, and the formed nitrogen fertilizer is discharged. In order to additionally produce phosphate fertilizer and limit the potassium concentration, the obtained fertilizer product is divided into the liquid and solid portion, and all or some of the solid portion is redirected into the stripping receptacle while the liquid waste product that is stripped of nitrogen and compounds and phosphorus compounds is cooled and mixed with at least one sulfate-containing compound to limit the small amount of a basic mineral powder is added thereto. The last solid portion obtained from said treatment can be used directly as phosphate fertilizer, potassium fertilizer, or phosphate-containing and potassium-containing mixed fertilizer.

Method and device for producing nitrogen fertilizer, removing phosphate from organic waste products, and limiting the potassium concentration

The invention relates to a method and a device for producing nitrogen fertilizer from organic waste products in the liquid phase (suspension, emulsion, solution) and for hygienizing the wastes or reducing the emissions by thermal treatment using mineral or organic additions. According to the invention, this is achieved by a method, wherein the waste product is heated at underpressure to temperatures between 40 and 90&#xb0; C., the escaping gas containing carbon dioxide and ammonia is cooled down and introduced into an aqueous absorption agent, the nitrogen fertilizer formed thereby is discharged and the excess gas not having been absorbed and containing carbon dioxide is pumped back into the discharge container, wherein the underpressure generated at the beginning of the process by a vacuum pump is autogenously maintained by the progress of the process. Suitably, the return of the excess gas into the cycle is performed by either conducting it immediately above the waste product to be treated, or through a gas cooling system above the waste product to be treated, or dividing it and conducting a partial flow through the waste product and another partial flow above the waste product. Preferably, a gypsum suspension is used as an aqueous absorption agent.

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Halle, Germany

Herbert Spindler