Six-lumped kinetic model for catalytic cracking of heavy gas oil over zeolite Y; considering deactivation catalyst

In this study, a six-lump kinetic model is proposed for describing the catalytic cracking of gas oil over Y zeolite. The feedstock and products were classified into six discrete lumps, including feed, kerosene, gasoline, liquefied petroleum gas, dry gas, and coke. A time-on-stream exponential function was used to describe the deactivation mechanism. Experimental data for 5 temperatures between 500-600 °C and residence time of 60-120 s were applied for the estimation of kinetic parameters. The estimated activation energies were in the range of 40–85 kJ.mol−1, the preliminary reactions exhibited lower apparent activation energies than secondary reactions. By increasing the reaction temperature from 500 ° C to 650 ° C at the reaction time of 240 min, the progress of the secondary reactions of coke production increases, and the deactivation function decreases from 0.955 to 0.735, After 300 min it reached 0.892 and 0.466, respectively. This means that at higher temperatures, the catalyst deactivation occurred faster. Analyzing the results for the distribution of products under different operating conditions showed that a temperature of 550 ° C and a residence time of 60 to 80 s are optimal for the production of gasoline and kerosene.