Modeling and Simulation of Reaction and Fractionation Systems for the Industrial Residue Hydrotreating Process

Figure 5. Workflow of building an integrated residue hydrogenation process model. 

First of all, residue tends to become inferior and heavier since the crude oil gets heavier. 

However, the feed library for residue is predetermined in the simulation software. Furthermore, the 

asphaltene with higher boiling point is not considered in the feed library. In addition, owing to the 

absence of asphaltene, its product lumps are lacking in the feed library. Thus, it is required to make 

some adjustments for the feed in the HCR library and characterize the added six lumps. Moreover, 

due to the different feed properties and reaction conditions, it is necessary to determine the kinetic 

parameters of the reactor model. In the HCR model, the reaction activity variables are to be estimated 

for the built-in residue oil hydrogenation. Correspondingly, in the PFR model, the kinetic parameters 

are determined for the additional asphaltene hydrogenation. Finally, the reactor model is established 

with kinetic lumps grouped by reaction characteristics, whereas the fractionation model is built based 

on the pseudo-components according to fractionation characteristic (i.e., the boiling point). Therefore, 

the adopted kinetic lumps of reactor model may be inappropriate for a fractionator modeling of 

residue hydrogenation process. Consequently, it is prerequisite to transform kinetic lumps into 

suitable pseudo-components through a process called delumping. The detailed workflow of the 

residue hydrogenation model can be described as follows: