Catalyst for catalytic cracking in a fluidized bed

摘要

A catalyst for catalytic cracking in a fluidized-bed is disclosed. The catalyst comprises a support and a composition having the chemical formula (on the basis of the atom ratio): AaBbPcOx for use in the industrial production of ethylene and propylene by catalytically cracking naphtha.

主权项

1. A catalyst for catalytic cracking in a fluidized-bed, comprising a support and a composition having the following chemical formula, which is on the basis of atom ratio:
AaBbPcOx, wherein A therein is at least one selected from the group consisting of rare earth elements; B is at least one element selected from the group consisting of VIII, IB, IIB, VIIB, VIB, IA and IIA; a ranges from 0.01-0.5; b ranges from 0.01-0.5; c ranges from 0.01-0.5; and X is the total number of oxygen atoms satisfying the requirements on the valence of each of the elements in the catalyst; wherein the support is a composite molecular sieve or a mixture of a composite molecular sieve and at least one selected from the group consisting of SiO2 and Al2O3, and said composite molecular sieve is (i) a ZSM-5/mordenite composite molecular sieve co-grown by adding ethylene diamine into a mixture obtained by pouring an aqueous solution of aluminium sulphate into an aqueous solution of sodium metasilicate; (ii) a ZSM-5/Y zeolite composite molecular sieve co-grown by adding ethylene diamine and Y zeolite crystal seeds into a mixture obtained by pouring an aqueous solution of aluminium sulphate into an aqueous solution of sodium metasilicate; (iii) a mordenite/β zeolite composite molecular sieve co-grown by adding (a) a mixture of ethylene diamine and tetraethyl ammonium hydroxide and (b) β zeolite crystal seeds into a mixture obtained by pouring an aqueous solution of aluminium sulphate into an aqueous solution of sodium metasilicate; or (iv) a ZSM-5/β zeolite composite molecular sieve co-grown by adding (a) a mixture of ethylene diamine and tetraethyl ammonium hydroxide and (b) β zeolite crystal seeds into a mixture obtained by pouring an aqueous solution of aluminium sulphate into an aqueous solution of sodium metasilicate, wherein the composite molecular sieve has at least two types of structures, and the at least two types of structures are tightly interlaced with each other and have a distinct phase interface, wherein the composite molecular sieve in the catalyst is in an amount of from more than 0 to 60% by weight of the catalyst, and wherein the acid amount of the co-grown composite molecular sieve is greater than the acid amount of the physical mixture selected from the group consisting of ZSM-5/mordenite, ZSM-5/Y zeolite, and ZSM-5/β zeolite, and is within a range of from 9.50×10−4 mole/g to 12.02×10−4 mole/g.