Research on Citric Acid Modified Y-Type Molecular Sieve
1. Using NaY molecular sieve with a high silicon-to-aluminum ratio as raw material, the 2-cross-2 roasting process and citric acid are used for dealumination treatment, which is conducive to the removal of non-framework aluminum in the molecular sieve.
2. REUSY was dealuminated with citric acid for 3 hours. The total acid B/L value increased from 1.46 to 3.43, an increase of 135%. The B/L value of the stronger acid increased from 1.90 to 4.55, which increased by 139%. The specific surface area Increased by 6%, the pore volume increased by 12%, the average pore diameter increased slightly, the particle size became smaller, and the particle dispersion was better
3. Process conditions such as citric acid dealumination treatment temperature and time, system water-to-sieve ratio, etc. have no significant impact on the properties of molecular sieves. When the system pH value is 3.0~3.5, it is beneficial to the dealumination of molecular sieves.
