Reaction Aspen HYSYS Petroleum Refining

This section discusses the key features of the Aspen HYSYS Petroleum Refining model we use throughout this work. While the features we discuss are specific to Aspen HYSYS Petroleum Refining, there are other simulation programs that have similar functionality. The goal of this section is to discuss the key features of the simulator that are relevant to developing an integrated reaction and fractionation model. 

Table 5.6 Key reactions classes in Aspen HYSYS Petroleum Refining Catalytic Reformer model. ...

Figure 6.5 Reaction network of Aspen HYSYS Petroleum Refining HCR paraffin HCR, ring open, ring dealkylation and aromatic saturation.

Figure 6.6 HDS reaction network of Aspen HYSYS Petroleum Refining HCR.

Table 6.4 lists the 31 optional objective functions, and Table 6.5 shows the 48 reaction activity factors for selection. Aspen H YSYS Petroleum Refining combines the input plant product distribution to construct the reactor effluent and partition the reactor effluent into Cl, C2, C3, C4, C5, and four square cuts , namely, naphtha (C6 to 430 °F cut), diesel (430-700 °F cut), bottom (700-1000 °F) cut and residue (1000 °F-i- cut) which are shown in Table 6.4. AU of the objective functions listed in Table 6.4 are either the prediction errors of crucial operations or important product yields for the HCR process. Aspen HYSYS Petroleum Refining allows us to select the desired objective functions during calibration. After selecting the objective functions, we choose appropriate activity factors to calibrate the reactor model. Figure 6.12 illustrates the relationships among the activity factor, catalyst bed, and reactor type, and Table 6.5 shows the major effect of each activity factor on the model performance, such as global activity (Rgiobai) on the bed temperature profile to help the selection of activity factors.

Because of heat effects of the reactions, the calculated reactor temperature profiles from previous steps would show deviations from actual plant data. We tune the global activity factors again to ensure that the deviations of reactor temperature predictions are within tolerance. We repeat the calibration of reactor temperature profiles and mass yields ofhquid products several times until the errors of model predictions are within the acceptable tolerance. These back-and-forth procedures compose the first phase shown in Figure 6.13 which is a generalized guideline of initial calibration for the Aspen HYSYS Petroleum Refining HCR model. This follows because reactor temjjerature profiles and major liquid product yields are always crucial considerations for any hydrocracker. 

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