Cracking catalytic for the production of light olefins and its preparation

摘要

A catalyst for catalytic cracking process for the production of light olefins comprises 10 SIMILAR 70wt% (based on the weight of catalyst) of clay, 5 SIMILAR 85wt% of inorganic oxides and 1 SIMILAR 50wt% zeolite, wherein said zeolite is a mixture of 0 SIMILAR 25wt% of Y type zeolite and 75 SIMILAR 100wt% of phosphorus and aluminum or phosphorus and magnesium or phosphorus and calcium containing high silica zeolite having a structure of pentasil; said pentasil high silica zeolite being one selected from the group consisting of ZSM-5, ZSM-8 and ZSM-11 of zeolites containing 2 SIMILAR 8wt% of phosphorus and 0.3 SIMILAR 3wt% of aluminum or magnesium or calcium (calculated as the oxides), having a silica/alumina mole ratio of 15-60. The catalyst exhibits excellent activity stability and high yields of light olefin, especially for ethylene, also method for preparation of the catalyst. It can attain the same level of yields of light olefins as that of steam thermal cracking at a lower reaction temperature than that of steam thermal cracking.