Catalyst deactivation and the effect of catalyst makeup on the FCC unit

Abstract

One of the significant processes of the crude oil refining process is the fluid catalytic cracking (FCC) unit. This unit produces olefins and other feedstock for the petrochemical industry as well as high octane gasoline, naphtha, light cycle oil, and heavy cycle oil. Attrition is one of the forms of catalyst deactivation on FCC catalyst which affects its operation, thereby giving rise to a high amount of catalyst makeup to compensate for the losses in this unit. This study investigated the effect of catalyst attrition on a commercial FCC unit through an analysis of its technical data from 4-run operations. The catalyst loss profile was evaluated while the scanning electron microscopy (SEM) showed abrasion as the dominant attrition type in the unit, hence resulting in many catalyst particles being lost as micro fines through elutriation. A simulation study was carried out using ASPEN HYSYS version 8.8 to assess the effects of reduction and increment of fresh catalyst makeup on the product yield while a cost analysis was done to evaluate the economic implication. The results showed that a 2% reduction of the current daily catalyst makeup gave the same yield as that of the reference value. The products also had similar qualities showing that $117,000.00/annum could be saved by a 2% reduction of the current catalyst makeup.