Verfahren zur Herstellung von Harnstoff mit unterschiedlichen Leistungen sowie die Implementierung in existierenden Anlagen

摘要

A process is described for the industrial synthesis of urea, making the ammonia (NH3) and the carbon dioxide (CO2) react, in at least one reaction space, at high pressures and temperatures and recycling at least in part the unreacted products obtained in a recycle section, characterized by: a) a synthesis reaction between reactants of high purity; and b) a synthesis reaction between less pure reactants, substantially recycled by the so-called recycle section. The corresponding new plant includes a reactor (R1) of high yield ("once through"), a reactor (R2) of lower yield and a section of recovery and recycle. The application of the process to preexisting plants requires the simple addition of a reactor of high yield and of pumping devices.