PROCESS AND PLANT FOR UREA PRODUCTION WITH REACTION SPACES HAVING DIFFERENTIATED YIELDS

摘要

In a process for urea production, substantially pure ammonia and carbon dioxide are reacted in a main reaction space (R-1) from which outgoes a reaction mixture subjected to stripping to obtain a partially purified mixture sent to a urea recovery section (3). From this section (3), a dilute carbamate solution is obtained which is recycled to an auxiliary reaction space (R-2) in which the residual carbamate is converted into urea. This process achieves high average conversion yield with reduced energy consumption.