| 摘要 |
<p>1,173,195. Urea. MONTECATINI EDISON S.p.A. 20 Jan., 1967 [21 Jan., 1966], No. 3058/67. Heading C2C. Urea is synthesized from ammonia and carbon dioxide in a process wherein the reaction products are separated in a number of stages at decreasing pressures by heating them, evaporating the gaseous components and condensing them in the presence of water and recycling the ammonium carbamate solution produced and wherein carbon dioxide is fed to the condenser of one of the separation stages. The heat available in the condensers of the first separation stage may used to produce steam which may be employed to partly cover the thermal requirements of the process.</p> |
