A Four Lump Kinetic Model for the Simulation of the Hydrocracking Process

Hydrocracking is a very important secondary refining process used to convert low value vacuum gas oils into high value fuels. The chemistry of the hydrocracking process is very complex due to the involvement of high molecular weight complex hydrocarbons in the reactions. Process modeling and simulation of the hydrocracking unit is very challenging due to the complexities of chemistry and the process. In the present work, a mathematical model is described to analyze the performance of the hydrocracking process in terms of product yields. A four lump discrete lumping approach is employed with a hydrocracking reaction scheme involving six reactions. The kinetic constants for the reactions were estimated by minimizing the error between the experimental and predicted yields of kinetic lumps. Experimental data reported by Ali et al. (2002) were used to validate the proposed model. The model predictions were found to agree well with the experimental data. The proposed model can be used to simulate the performance of commercial hydrocrackers using kinetic parameters estimated from pilot plant experiments.