Urea is synthesized in commercial plants from ammonia, carbon dioxide and recycle ammonium carbamate at high pressures and temperatures. In this paper, revamp of urea synthesis reactor at Agritech Limited (Formerly Pak-American Fertilizers Ltd.) has been studied. The revamp includes capacity enhancement to 135% and a change of existing technology to Stamicarbon. A simulation model has been developed using ASPEN Plus (V7.2) and validated against existing plant data. Various simulation runs were carried out to investigate the effect of ammonia to carbon dioxide molar ratio (N/C ratio), temperature and pressure on CO2 conversion and urea fraction in liquid phase. Then, the model is simulated for the Revamp Case (with an increase in reactor volume) and the results compared with the data provided by the licensor. The results show a good agreement with the
licensor’s data of the revamp case.

2011_09_Rasheed_Agritech_UreaKnowHow.com_Revamping_Urea_Reactor_using_Aspen.pdf