A novel selectivity test for the evaluation of FCC catalysts Original Research Article

Microactivity testing is the most commonly used procedure for determining the selectivities of FCC catalysts and researchers have followed several strategies in order to optimise this approach. Grace Davison developed the short contact-time microactivity test (SCT-MAT) and catalyst evaluations performed with this method have been shown to agree well with those obtained from circulating riser pilot units. Nevertheless, the experimental setup of the SCT-MAT still has further possibilities of improvement, which was the motivation for this work.In the presented work unconventional concepts were followed to upgrade the SCT-MAT method. A novel product collection system was developed and modifications were made to the reactor design as well as the method of feed injection. The operational parameters which ensured the superior accuracy of the original SCT-MAT, such as contact-time, reaction temperature and catalyst bed geometry, were not altered. Experimental results obtained by the novel selectivity test demonstrated a considerably improved precision and a better discrimination of the catalytic properties of FCC catalysts over the original SCT-MAT without any trade-offs in accuracy. The overriding characteristic of the novel selectivity test is its simplicity which imparts a high precision to this equipment.