CO2: NH3

Urea

To produce urea from ammonia and carbon dioxide using ammonia stripping process.

Description: Ammonia and carbon dioxide react at 150 bar to yield urea and ammonia carbamate. The conversion in the reactor (1) is very high due to favorable NH3/CO2 ratio of 3.5:1 and operating temperature of 185-190℃. These conditions prevent corrosion problems. Carbamate is decomposed in three stages at different pressures: vessel (2) at the same pressure as the reactor, vessel (3) at 18 bar and another (4) at 4.5 bar.
   Reactants not transformed into urea are recycled to the reactor by means of an ejector. Main equipment is installed at ground level: this layout is essential for large plants. Heat recoveries are particularly developed in such a way as to have low energy usage.
   Any finishing (5,6) can be coupled with the synthesis: prilling and granulation, both direct or via crystallization. Different product quality (biuret, moisture,hardness and size) are obtained according to client requests.
   The plant is completey free from any pollution problems. All vents are washed in a very efficient way so that they are discharged to the atmosphere practically free of ammonia and urea. Also, liquid discharge can be physically treated in such a way to discharge it according to any local regulations or client requests, even so clean that it can be reused as boiler feed water.

Component Names and Formula