Patent ID: 11964262
Assignee: CHINA PETROLEUM & CHEMICAL CORPORATION
Field: Chemical engineering (Chemistry)
Classification: CPC B  C  Y | IPC B  C

Claim 2:
3. A process of producing the modified molecular sieve according to claim 1, comprising:
a. filtering and washing a slurry containing a molecular sieve of MFI structure obtained by crystallization to provide a water-washed molecular sieve having a sodium content, calculated as sodium oxide, of less than 5 wt % based on the total dry weight of the water-washed molecular sieve calculated as sodium oxide;
b. desiliconizing the water-washed molecular sieve obtained in step a in an alkaline solution, and then filtering and washing to provide a base washed molecular sieve;
c. carrying out an ammonium exchange treatment on the base washed molecular sieve obtained in step b to provide an ammonium exchanged molecular sieve having a sodium content, calculated as sodium oxide, of less than 0.2 wt %, based on the total dry weight of the ammonium exchanged molecular sieve; and
d. carrying out a phosphorus modification treatment, a supporting treatment with the supported metal M1, a supporting treatment with the supported metal M2, and a baking treatment on the ammonium exchanged molecular sieve obtained in step c to obtain the modified molecular sieve.