Patent ID: 8241389

Claim:
A method for producing nitrogen fertilizer from organic waste products in liquid phase, for removing phosphate and sanitizing the waste and reducing emissions by thermal treatment using mineral or organic additives where the waste product is heated in a stripping tank under negative pressure to temperatures between 40° C. and 90° C., the escaping carbon dioxide and ammonia containing gas is cooled and introduced into a mineral-aqueous suspension and/or brought into contact with such suspension respectively, the nitrogen fertilizer formed in this way is removed and the non-absorbed carbon dioxide containing excess gas is conducted within the circuit and the negative pressure generated by a vacuum pump at the beginning of the process is maintained autogenously and the non-absorbed carbon dioxide containing excess gas is returned into the circuit by either conducting it directly above the waste product to be treated via a gas cooling system or by splitting it and conducting a partial stream through the waste product and introducing another partial stream above the waste product, characterized in that for phosphate removal, the fertilizer product formed in the receiver tank and present in a solid and a liquid phase is separated into a liquid and a solid portion, wherein the solid portion is completely or partially returned to the stripping tank and the liquid waste product stripped of nitrogen and phosphorus compounds is cooled and further wherein at least one sulfate containing compound is added to the solid portion that is completely or partially returned to the stripping tank, in order to limit the potassium content and the precipitate obtained in this process is separated from the liquid portion.