The effects of lanthanum on the performance of a zeolite-containing FCC catalyst are shown in Table 2. This data was obtained from laboratory work in which two catalysts were compared in the short-contact- time riser test (SCT-RT) after a two-step cyclic metal deactivation with 5000 ppm of nickel (Ni), 5000 ppm of vanadium (V) and a residue feedstock. The catalysts have the same composition, but the first one has not been exchanged with rare earth and the second one contains
1 wt% RE2O3. (These zeolites have not undergone ADZT-200 stabilisation technology, which is discussed later in this article.)