Cyclic Deactivation with Steam of Metallated Cracking Catalysts: Catalytic Testing at the Bench Scale and the Pilot Scale

Besides offering an adequate product distributions, a cracking catalyst must exhibit a reasonable resistance to the combined effect of high temperature, steam and metals. Two commercial catalysts, poisoned with Ni + V (~2,500 ppm), are subjected to a large scale cyclic deactivation with steam, then characterized using mostly basic techniques and finally tested via bench scale and pilot scale cracking experiments. As examples of industrial deactivation, corresponding equilibrium catalysts (E-CATs) are investigated in parallel. Depending on their specific formulation, catalysts deactivate differently due to the exposition to high temperature steam and metals. The intrinsic deviations in the catalytic properties of cyclic deactivated catalysts (CD-CATs) related to E-CATs are further biases by the particular history of the latter and the particular reactor configuration and hydrodynamics, such deviations being magnified in the bench scale testing. Relative differences in activity and product yields (except for coke and hydrogen) of CD-CATs referred to E-CATs are below 10% at the pilot scale, and within 23% at the bench scale. Relative biases in hydrogen and coke yield of may be as high as 75 and 26% in the pilot plant and as much as 150 and 32% at the bench scale.