ZSM-5 Additive Deactivation with Nickel and Vanadium Metals in the Fluid Catalytic Cracking (FCC) Proceß

We investigated the roles of nickel and vanadium in the properties of ZSM-5 additives and in the fluid catalytic cracking (FCC) products, yielding 4000 and 12a000 ppm loadings of Ni + V. The ZSM-5 additive was deactivated in a cyclic deactivation unit (CDU), where cracking-regeneration reactions were carried out with vacuum gas oil (VGO) spiked with Ni and V naphthenates. Characterization of the deactivated ZSM-5 additives with N₂ physisorption, SEM, and pyridine FTIR techniques showed a uniform Ni distribution acroß a particle, little variation in the Brønsted acidity, and an increase in Lewis acidity, when Ni and V were added. Tests were carried out in a short contact time microactivity test (SCT-MAT) unit with ZSM-5 and n-hexane and blends of equilibrium catalyst (ECAT) and ZSM-5 with VGO. With hexane Ni and V, the dehydrogenation, aromatization, and coking reactions are enhanced. With VGO, the metals were found to decrease the propylene selectivity whereas that of butylene increased.