The synthesis section of urea production plant (high-pressure section) has been simulated with process simulation software. Wilson and ideal gas equations were used as equations of state for liquid and gas phases, respectively. The binary interaction coefficients of Wilson equation were modified to fit the actual data. This set of equations shows satisfactory results in all parts of the studied section with the exception of CO2 compressor. For which Peng-Robinson equation of state was used. Existing units of urea synthesis section have been simulated with standard modules from HYSYS with the exception of the reactor. The reactor has been simulated with sequential CSTRs model. Temperature dependence formula of equilibrium constant of ammonium carbamate reaction has been corrected using the data in the literature as well as those at the exit of the real reactor. Comparison between simulation results and plant data shows good consistency between the model and reality.
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