Study on the Catalytic Cracking Performance of Y-β composite Zeolite

Y-β composite zeolite samples whose β zeolite relative contents were 40%,60%,80% were characterized by XRD,N2 adsorption,XRF,Py-IR and so on.The results show that with increasing of β zeolite content,relative crystallinity of Y zeolite has little change,total specific surface area and micropore volume increase,micropore specific surface area and total pore volume decrease,ratio of Si to Al increases,so acid sites decrease,too.Then the catalytic cracking performance of n-octane on these catalysts was studied in a fixed bed stainless steel tubular reactor.The evaluation results show that catalytic cracking activity,stability and selectivity of the zeolite increase with increasing of relative content of β zeolite under the same conditions;At 500 ℃,catalytic cracking selectivity of n-octane on the FYB-60 is higher than that on FYB-40 and FYB-20 by 11% and 19% respectively.