A continuous lumping model for hydrocracking on a zeolite catalysts: model development and parameter identification

• A continuous lumping model was applied to hydrocracking of VGO.
• Experimental data from a pilot plant was used for calibration and validation.
• Good results are obtained for a wide range of operating conditions and feeds.
• A detailed statistical analysis of model parameters is presented.

Process models are a vital tool for the development of industrial hydrocracking units and to drive innovation of process design and novel catalysts. A hydrocracking model, based on the continuous lumping approach, is presented in this work. A zeolite catalyst was used for hydrocracking of pre-treated VGO feeds. The model includes inhibition terms for organic nitrogen and NH3 gas. A total of 74 data points, from experimental runs in a fixed-bed pilot plant, have been used for parameter identification (52 points) and model validation (22 points). The model has been found to provide a good estimation of total residue (>370 °C cut) conversion and yield structure (naphtha, kerosene and diesel). A statistical analysis of the 12 model parameters, based on the Eigenvectors of the Hessian has been presented. The impact of the individual parameters on the objective function was thus evaluated. This analysis can help guide future refinement of the model.