| 摘要 |
The combined production of ammonia and urea by the reaction of gases containing hydrocarbons with steam is conducted by using a steam reformer, downstream secondary reformer, and shift converter. The ammonia synthesis gas (hydrogen, nitrogen and carbon dioxide) is subjected to a high pressure scrubbing step with a physical solvent, to remove the acid impurities, especially CO2. The pressure on the loaded solvent is reduced to a first intermediate pressure for degasing of the coabsorbed inerts and then to a second intermediate pressure for removal of the bulk of the absorbed CO2, which is then used for urea synthesis. To remove residual CO2, the solvent is stripped with air and the resultant air stream containing the stripped residual CO2 is fed to the secondary reformer. |
