| 摘要 |
<p>1,181,039. Urea synthesis. SNAM PROGETTI S.p.A. 11 June, 1968 [14 Dec., 1967], No. 27796/68. Heading C2C. A process for the production of urea comprises feeding carbon dioxide and ammonia to a reactor, reacting them to produce an effluent aqueous solution of urea contaminated with ammonium carbamate, splitting the latter in a splitter so as to convert it into carbon dioxide and ammonia and produce an aqueous solution of urea substantially free from ammonium carbamate, and recycling to the reactor in the gaseous phase and at substantially the same temperature at which splitting was effected the carbon dioxide and ammonia produced in the splitter, the recycling being effected by entraining the gases by means of an ejector in the ammonia and/or carbon dioxide which is fed to the reactor. The temperature and pressure in the reactor may be 160-220‹ C. and 130- 220 kg. cm.<SP>-2</SP> respectively and, in the splitter, 160-220‹ C. and 70-200 kg.cm.<SP>-2</SP> respectively.</p> |
