The composition, the molecular sieves of the pentasil - type entholt, as well as their preparation and use

摘要

A molecular sieve containing composition, which can be applied in catalytic cracking reaction for producing more ethylene and propylene, and its preparation method. The composition contains a pentasil-type molecular sieve having a SiO2/A12O3 molar ratio of 15-60, prepared by activation and modification with phosphorus, alkaline earth metal and transition metal. The composition essentially comprises 85 to 98%wt of pentasil-type molecular sieve, 1 to 10%wt of P2O5, 0.3 to 5%wt of alkaline earth oxide, and 0.3 to 5%wt of transition metal oxide. The molecular sieve structure and active centers have high thermal and hydrothermal stability. The salient feature of this composition is that when applied as an active component of cracking catalyst for catalytic pyrolysis process, the yield of ethylene is above 18% and the total yield of ethylene and propylene is more than 40%.