Study On The Properties Of Catalytic Carcking Supported On Compound Catalysts With Heavy Aromatics

This paper describes heavy aromatics catalytic cracking to benzene, toluene, xylene(BTX). A kind of compound catalysts were prepared by mixing Hmcm-56 andβ-zeolite. A series of different content MoO3 as active component and La2O3 as catalytic additives were added to compound catalysts that have different composite ratio. Under the conditions of T=460℃. P=3.0Mpa, WHSV=3.62h-1, V(H2):V(C9+)=1600, characterization and catalytic properties were studied.The best composite ratio of Hmcm-56:β-zeolite is 7:3, the conversion of C9+ heavy aromatic was 38.00%, the yield of BTX was 30.08%, and the selectivity to BTX was 81.05%. When the loading of MoO3 is less than 2%, MoO3 can be distributed in the surface of zeolite. When the loading continues to increase, the excess MoO3 will plug the pores, and affect the reation. The best loading of MoO3 is 1.5%. The conversion of C9+ heavy aromatic was 70.29%, the yield of BTX was 64.37%, and the selectivity to BTX was 91.58%. In order to enable the catalytic additives and stability, La2O3 were added. The best loading of La2O3 is 0.6%. The conversion of C9+ heavy aromatic was 70.89%, the yield of BTX was 67.2%.