Abstract: Property calculation method has great effect on the accuracy of the CDU simulation results, especially for the vacuum column. It is often observed that the simulated flow rate of vacuum residue is lower than the test-run data. This paper introduces a relatively more convinced methodology to simulate CDU using Aspen Plus. Based on a set of CDU test-run data, an Equation-Oriented model is built and solved in reconciliation mode on the Aspen Plus V10 Platform. Comparing the different results among the different property methods, the most accurate property method for CDU is presented. Finally the influence of different property methods on the analog computation results of CDU is explained theoretically.

Key words: CDU, process simulation, property calculation method, Maxwell-Bonnel, sequential module, equation-oriented model, vacuum deep-cut