公开(公告)号：AU4034797A

公开(公告)日：1998-03-19

申请号：AU4034797

申请日：1997-08-29

Applicant: STAMICARBON

Inventor： WIJCK JULIUS GERARDUS THEODORU

IPC: C07C273/12 ,  C07C275/00 ,  C07D251/60

Abstract: In the present process for the preparation of urea, an off-gas stream released during the synthesis of melamine in a high-pressure melamine process which consists predominantly of ammonia and carbon dioxide, is introduced into at least one high-pressure section of a urea stripping plant and is used in the synthesis of urea. The off-gas stream can be used directly without any further treatment.

公开(公告)号：AU5578898A

公开(公告)日：1998-08-18

申请号：AU5578898

申请日：1998-01-20

Applicant: STAMICARBON

Inventor： WIJCK JULIUS GERARDUS THEODORU ,  MEESSEN JOZEF HUBERT

IPC: C07C273/12

Abstract: Process for the preparation of urea, in which the gas stream which is released during the synthesis of melamine and is composed essentially of ammonia and carbon dioxide is used to synthesize urea, in which process the gas stream which originates from a high-pressure melamine process and is composed essentially of ammonia and carbon dioxide is condensed at a pressure virtually equal to the pressure in the melamine reactor, in which process substantially anhydrous ammonium carbamate is formed, after which said ammonium carbamate is fed to a high-pressure section of a urea stripping plant.