Study On FCC Catalysts Modified By Introduction Of Rare-earth Through Solid-state Ion Exchange

For the first time the rare-earth modified FCC catalysts have been prepared by solid-state ion exchange instead of traditional solution ion exchange. Their unit cell parameters, relative crystallinity, BET surface area, pore structure, acidity and catalytic performances have been measured by XRD , static nitrogen volumetric adsorption method under low temperature, NHj-TPD and ACE (Advanced Cracking Evaluation) reactor respectively. The influences of different preparation conditions of the FCC catalysts such as steam calcination conditions, rare-earth loading and rare-earth resources on their physico-chemical properties and catalytic performances have been systematically checked. And they are compared with the relative traditional FCC catalysts prepared by the solution ion exchange. Finally, according to the characterization results of XRD and IR, The reaction mechanism of their solid-state ion exchange has been discussed .It is discovered that solid-state ion exchange exists between REY and NH4Y Zeolites after steam calcination and the composite Zeolites FCC catalyst made by them presents better activity and selectivity and product distributions than the single REHY FCC catalyst.The Results show that their physico-chemical properties and catalytic performances have been improved to a different extent under different steam calcination conditions and with the increase of the rare-earth loading. The FCC catalysts prepared by using different rare earth compounds such as rare-earth carbonate and rare-earth hydroxide possess the similar properties. The FCC catalysts prepared by solid-state ion exchange have equal physico-chemical properties to and a bit better catalytic performance and show especially better physico-chemical properties and catalytic performance after contamination by vanadium than the traditional FCC catalyst prepared by the solution ion exchange. The above results lay a theoretical ground for the innovation oftraditional preparation process of FCC catalyst modified by rare-earth.