Kinetic modeling and simulation of hydrocracking process in this study was performed by continuous lump method. The case study of this research is vacuum gas-oil produced by Isfahan refinery distillation unit, which is subjected to hydrocracking reaction in the reactors of Isomax unit of Isfahan refinery. Continuous lump modeling was performed based on feed temperature boiling point data and its conversion to dimensionless temperature using the reactivity intermediate distribution function. First, according to the model conditions the number of pseudo-component divisions in the lump's model was selected and after optimization, the sensitivity analysis was done. The concentration distribution of the components of the main product of Isomax unit, produced diesel, was calculated using the number of optimal divisions in the residence time of 0.44 hours. The lump model was simulated in MATLAB 2016 software environment. The proposed solution process was continuously eva‎luated by the execution time of the solution to observe its operation's speed and efficiency. Then, the multidimensional optimization of the continuous lump model was performed based on minimizing the sum of squares of the predicted weight fraction difference of the hydrocracking product and the actual data of the operating unit; furthermore, The optimal value of the maximum point position characteristics in the curve of the intermediate distribution function of reactivity, The size of pseudo-components, Initial shape of weight fraction diagram in terms of dimensionless temperature and And pseudo-component cracking rates with the highest reactivity were determined. Sensitivity analysis of these characteristics was performed for the products of Isomax unit of Isfahan refinery. This analysis showed that the characteristics of the maximum point position in the curve of the intermediate distribution function of reactivity and the initial shape of the weight fraction diagram in terms of dimensionless temperature have little effect on the predicted weight percentage composition of the output product, while the pseudo-component size and pseudo-component cracking rates characteristics of Pseudo-compounds with the highest reactivity have a more decisive role in weight percentage changes. Finally, using the optimal value of the characteristics of model, comparing the predicted weight percentage combination of the model with the actual weight percentage of diesel produced by the Isomax unit showed that the main physical condition in the model is the sum of the predicted weight fractions with an error value (R2), which is equal to 0.7617. Establishing this important physical condition proved that the continuous lump method is relatively efficient for predicting the product of the hydrocracking reaction.

ارجمند مهرباني

محسن محمدي

احمد محب، عطاالله ساري