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The two laboratory deactivation techniques (cyclic deactivation (CD) and cyclic propylene steaming (CPS) methods) conventionally used to simulate deleterious feed metal effects on FCC catalysts are investigated, exploring their efficiency in simulating real deactivation in a commercial FCC unit. Moreover, advanced protocols of these methods (two-step CD and advanced-CPS) are tested and compared to the standard protocols. Two commercial FCC catalysts are selected for this study emphasizing on the effect of their different accessibility on the deactivation mechanisms during application of each different deactivation protocol. E-cats (equilibrium samples from a commercial FCC unit) of both catalyst types and the corresponding laboratory deactivated samples were thoroughly studied. Extensive characterization (XRD, N2 physisorption, Albemarle accessibility index (AAI), FTIR with pyridine adsorption) of all samples was realized to closely examine variations of their crucial properties and relate them both to the operating parameters of the deactivation methods and the catalysts’ evaluation results. The samples that have suffered the 2s-CD method were more active than the samples from the classic CD, but 2s-CD seems to better simulate the poisonous metal effects. ADV-CPS samples were also more active than the standard CPS samples and also more realistic on the impacts of the contaminant metals. The improvement in the simulation of metal effects in both methods is mostly attributed to the introduction or modification of redox cycles, which are probably improving the aging of the metals. Thus, a pathway to a more efficient and realistic laboratory deactivation protocol is revealed.

Two commercial FCC catalysts were investigated to explore the effect of their different accessibility on the catalyst activity, selectivity and deactivation due to deleterious feed metals (V and Ni). Feed metal Fe was not included in the present study. E-Cats (equilibrium samples from a commercial FCC unit) of both FCC catalysts and the corresponding laboratory-deactivated samples (applying the cyclic deactivation (CD) and the cyclic propylene steaming (CPS) methods) were thoroughly studied. Extensive characterization (XRD, N 2 physisorption, measurement of Akzo Accessibility Index (AAI), SEM-EDS analysis) of all samples was realized to investigate variations in their crucial properties due to metal deposition. Comparison of E-Cats, CD and CPS samples revealed a very different nickel deposition profile over the CPS samples. In all cases, V was homogenously distributed throughout the particle, as expected due to its mobility. Ni–Al mixed phases, observed on the E-Cat samples, were probably formed during ageing and are expected to be inactive. The absence of such phases on the laboratory-deactivated samples can be attributed both to the inability of the two deactivation methods to simulate metal ageing during commercial utilization of the FCC catalyst and the absence of Fe incorporation during laboratory deactivation. All catalytic samples (E-Cats and artificially deactivated FCC catalysts) were evaluated in the laboratory using two bench-scale Microactivity Test (MAT) units of different reactor configuration: fixed-bed (SCT-MAT unit) and fluid-bed (AUTOMAT unit). Similar ranking of the catalysts is achieved when using both units. However, AUTOMAT unit seems to provide a clearer diversification of catalysts with different accessibility. Both laboratory deactivation methods seem to be rather inefficient in simulating the real deactivation, since they are always exaggerating metal effects.