Cracking behavior of MCM-22, ZSM-5 and Beta as FCC catalyst additives

The catalytic cracking of a FCC feedstock on a FCC catalyst with MCM-22 as an additive was studied. The results were compared with those obtained on ZSM-5 and Beta additives. The effect of pore geometry on cracking parameters such as the hydrogen transfer coefficient and the cracking mechanism ratio was examined. The hydrogen transfer activity of the three zeolites was MCM-22 > Beta > ZSM-5. The cracking mechanism ratio of MCM-22 was much lower than that of ZSM-5, little larger than that of Beta, which means that the 12 member ring cavities on the crystal surface of MCM-22 played an important role in the catalytic cracking reaction. The performance of MCM-22 in catalytic cracking reaction was between that of ZSM-5 and Beta, and close to that of Beta.