Simulation of an industrial hydrocracking unit by discrete lumping kinetics mathematical model incorporating catalyst deactivation

The purpose of this work was to establish a process model of a vacuum gas oil industrial hydrocracking. In this model, we divide the lumps by 10 K as the interval, the reaction kinetics model is established based on discrete lumping method. Besides, a relevant catalyst deactivation function for catalyst activity calculation was proposed, which includes the flow and properties of the feed for a long period. The simulated hydrocracking unit is the process with hydrotreating and hydrocracking reactors in series. Therefore, it is necessary to build a hydrotreating model to represent the feed oil properties at the inlet of the hydrocracking reactor. Owing to absence industrial hydrotreating reactor monitor data, the hydrotreating model is established by using the data of the pilot plant loaded with the same catalyst. The hydrocracking reactor model is established through the material balance, heat balance, and momentum balance equations. Multiple sets of data are used to verify the established hydrocracking reactor model, the errors between the calculated value and the actual value of hydrocracking products are basically less than 10 %, and the relative errors of the predicted temperature and pressure are less than 0.5 %. Based on the catalyst deactivation function, the average relative errors of the model can be reduced by 50%. The variation of the reactor along the height is analyzed, and the result shows that the model accuracy simulated the target hydrocracking unit.

Graphical abstract