| 摘要 |
<p>1,188,051. Urea. SNAM PROGETTI S.p.A. 1 May, 1968 [6 Feb., 1968], No. 20720/68. Heading C2C. Process for the production of urea which comprises feeding ammonia and carbon dioxide into a reactor, reacting the ammonia and carbon dioxide so as to produce an effluent aqueous solution of urea contaminated with ammonium carbamate, splitting the latter into NH 3 and CO 2 , stripping in a stripper the products of the splitting from the said aqueous solution in the presence of a stripping agent selected from ammonia and carbon dioxide so as to produce an aqueous solution of urea substantially free from ammonium carbamate, condensing the products which have been stripped and recycling the condensed products to the reactor by entraining the condensed stripped products in the ammonia or carbon dioxide which is fed to the reactor. The stripping is usually carried out in a single stage at a high pressure, preferably from 80 to 200 kg/cm.<SP>2</SP>, and usually at a temperature of from 160‹ to 250‹ C. The stripper may be positioned so that the effluent aqueous solution falls into it from the reactor under the force of gravity.</p> |
