Effect of acid properties of catalysts on fluid catalytic cracking of residual oil

Abstract

This article describes the relationship between the different acidic properties of catalytic active sites and their catalytic cracking ability using desulfurized atmospheric residue (DSAR) as a feed. Experiments were carried out in a fixed fluid bed reactor. The acid strength was determined by the temperature of NH3 desorption peak and the number of acid was defined by the amounts of NH3. The catalysts from Y-type zeolites with different unit cell sizes were prepared and evaluated. The lowest number of acid site catalyst shows the lowest conversion and the highest gasoline yield, while the highest one shows the highest conversion and the lowest gasoline yield. Furthermore, the catalysts using wider range of acid site number are evaluated. It was found that the gasoline yield reaches a maximum at a certain number of acid sites for the catalytic cracking of DSAR, but not for that of desulfurized vacuum gas oil (DSVGO). It is important for cracking from DSAR to gasoline to control the number of acid site. Based on these results, an attempt was made to identify the intermediate materials produced during the catalytic cracking of DSAR.