Patent ID: 7887615
Filing Date: 2011-02-15
Classification: C05C,C05D,C05F,Y02A,Y02E,Y02P,Y02W

Abstract:
1. A method for producing nitrogen fertilizer from organic waste products in the liquid phase and for hygienizing the wastes and reducing emissions by thermal treatment using mineral or organic additions, wherein the waste product is heated in a first vessel without acids or alkali to temperatures between 40 and 90° C., as the pressure is first evacuated to 10 to 30 kPa, and then the pressure is increased to 40 to 80 kPa, so as to remove carbon dioxide and almost all ammonia without being accompanied by appreciable amounts of water, wherein the escaping gas containing carbon dioxide and ammonia is cooled down and then introduced into a second vessel, to an aqueous absorption agent, or brought into contact therewith, the nitrogen fertilizer formed thereby is discharged into a container and the excess gas not having been absorbed and containing carbon dioxide is conducted back into the process and circulated between the first and the second vessel, whereby the temperature of the discharge container is maintained at a predetermined value such that the underpressure between 10 and 80 kPa generated at the beginning of the process by a vacuum pump is autogenously maintained by the progress of the process, and the ammonium nitrogen fertilizer may be nearly fully removed.