Process for urea production

摘要

A process for the production of urea from ammonia and carbon dioxide via synthesis where the urea formation takes place in a synthesis zone (or zones) in which an excess of free ammonia is kept to favor high conversions, said synthesis zone (or zones) being followed by an ammonia separation and direct recycle to the reaction step, where the urea solution from said reaction zone (or zones) is intimately contacted for a short duration time with a minor portion of the fresh CO2. The separation step is followed by a CO2 stripping step where the residual carbamate is removed using a countercurrent fresh CO2 stream.