A MODIFIED Y-TYPE ZEOLITE AND PREPARATION PROCESS AND USE THEREOF

摘要

The present invention provides a modified Y-type molecular sieve, characterized by having a unit cell size of 2.420-2.440 nm; as percent by weight of the modified Y-type molecular sieve, a phosphorus content of 0.05-6%, a RE2O3 content of 0.03-10%, and an alumina content of less than 22%; and a specific hydroxyl nest concentration of less than 0.35 mmol/g and more than 0.05 mmol/g, said   specific   hydroxyl   nest   concentration = [ ( M 500  °   C . - M 200  °   C . ) - ( 17 / 9 ) × ( M 800  °   C . - M 500  °   C . ) ] × 1000 36 × ( 1 - M 200  °   C . ) × C  ( Unit  :  mmol  /  g ) wherein M200° C., M500° C. and M800° C. respectively represent the weight loss percents of a sample measured at 200° C., 500° C. and 800° C., and C is the crystallinity of the sample. The modified Y-type molecular sieve has few defect in the crystal lattice. The application of the zeolite in the catalytic cracking catalyst as active component can maintain a long period stable activity, effectively control the coke yield and increase the heavy oil utilization. The present invention also relates to the preparing method and the use of the modified Y-type molecular sieve.