CATALYTIC CRACKING OF VACUUM GAS OIL ON ALUMINA ZEOLITES MIXTURES - EFFECTS OF PRECIPITATION PH OF ALUMINA AND ZEOLITE TYPE ON PRODUCT DISTRIBUTION/

Catalytic cracking of vacuum gas oil on aluminas mixed with steam-trea ted zeolites (SY and SM) was investigated at 500 degrees C using a mic ro-activity tester. The catalysts containing SY and alumina prepared a t pH 9. 5 showed a higher conversion and more fraction df gasoline and K+D (kerosene+diesel) in products than those containing SM and alumin a prepared at pH 7.8. This could be explained by acidic properties and pore structure of catalyst. The distribution of produced benzene, tol uene and xylene on the catalyst containing SY or SM was different due to the pore size of zeolites. The difference in hydrogen transfer rate over the catalysts containing SY or SM leads to a different compositi on of unsaturated and saturated products.