The Investigation of Zeolite to Matrix Ratio Effect on the Performance of FCC Catalysts during Catalytic Cracking of Hydrotreated VGO

Abstract

Fluidized catalytic cracking of vacuum gas oil is considered a promising factor in enhancing the gasoline yield to fulfill global energy demands. In this study, a series of FCC catalysts with a zeolite to matrix ratio varying from 18 to 50 was prepared using USY zeolite and amorphous matrix. The matrix was composed of amorphous silica-alumina, kaolin, and silica sol binder. All fresh catalysts were subjected to hydrothermal deactivation treatment at 750 °C for 5 h. The performance evaluation of FCC catalysts was conducted in a fixed bed microactivity test unit, with vacuum gas oil as feed at 550 °C. Comparing a steamed CAT01 sample with a fresh CAT01, the surface area of the steamed sample was 23.3% less. Similarly, the fresh sample CAT05 acidity increased by 102% when compared with the fresh CAT01 sample. As the zeolite to matrix ratio increased, the selectivity of dry gas, LPG, and coke increased, associated with a consistent decrease in gasoline and heavy ends (LCO and HCO). The combined selectivity of product gasoline and LCO with low-zeolite steamed catalyst (CAT01) was 82%, and that of high-zeolite steamed catalyst (CAT05) was 76%. Furthermore, coke selectivity for the steamed CAT01 was 2.1%, whereas 3.7% was observed for the steamed CAT05 sample. The effect of the zeolite to matrix ratio was less pronounced in steamed catalysts as compared with fresh catalysts.

Investigation of the Effect of Silica and Phosphorus Content on the Performance of Active Matrix as Component of Cracking Catalyst

“…The activity of the active matrix in splitting the input into gas and gasoline increases as the number of acid sites in the active matrix increases [21]. Ahmad et al noted a similar pattern in their study [18].…”

“…This phenomenon arises due to the augmentation of catalytic sites when the surface area expands [17]. Ahmad et al noted a similar pattern in their study [18]. Figures 9(a) and (b) demonstrate a positive correlation between the surface area of the active matrix and the production of gas and petroleum products.…”