Study on ZSM-5/Y composite zeolite for catalytic cracking of hydrocarbons
ZSM-5/Y复合分子筛在烃类催化裂化催化剂中的应用研究

Catalytic performances of hydrothermal dealuminated ZSM-5/Y composite zeolite in the cracking of Daqing VGO were studied in comparison with the mechanical mixture of ZSM-5 and Y zeolite. The results showed that, compared with mechanical mixture, the composite zeolite gives higher diesel and gas yields, especially higher gas olefins such as ethylene, propylene and isobutene, and lower gasoline yield. The difference of gasoline and diesel yields between the composite and mechanical mixture was elucidated from the structure of composite zeolite and shape-selective catalysis of ZSM-5. The agglomerated structure of the composite zeolite was in favor of gasoline cracking, and prevented the larger hydrocarbon molecular component from entering into it and cracking. The analysis of gas composition (also) supported the structural characteristic of composite zeolite.