Method for making molecular sieve SSZ-95

Patent metadata

Field	Value
Publication number	US-10052619-B2
Application number	US-201715438295-A
Country	US
Kind code	B2
Filing date	Feb 21, 2017
Priority date	May 21, 2014
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A new crystalline molecular sieve designated SSZ-95 is disclosed. In general, SSZ-95 is synthesized from a reaction mixture suitable for synthesizing MTT-type molecular sieves and maintaining the mixture under crystallization conditions sufficient to form product. The product molecular sieve is subjected to a pre-calcination step, and ion-exchange to remove extra-framework cations, and a post-calcination step. The molecular sieve has a MTT-type framework and a H-D exchangeable acid site density of 0 to 50% relative to molecular sieve SSZ-32.

First claim

What is claimed is:

1. A process for preparing SSZ-95, comprising:
(a) providing molecular sieve SSZ-32x having a silicon-to-alumina ratio of 20 to 70, wherein the molecular sieve comprises a structure directing agent;
(b) subjecting the molecular sieve to a pre-calcination step at a temperature between 200° C. and 400° C., for a time sufficient to convert a portion of the structure directing agent to a decomposition residue;
(c) ion-exchanging the molecular sieve to remove extra-framework cations; and
(d) subjecting the molecular sieve to a post-calcination step at a temperature below the full decomposition temperature of the structure directing agent, for a time sufficient to convert at least a portion of the structure directing agent to a decomposition residue;
wherein the post-calcined molecular sieve has a cumulative weight loss (CWL) of 0<CWL≤10 wt. % and a total micropore volume of between 0.005 and 0.02 cc/g.

2. The process of claim 1 , wherein the pre-calcined molecular sieve has a micropore volume of between 0.002 and 0.015 cc/g.

3. The process of claim 1 , wherein the pre-calcined molecular sieve has an external surface area of between 215 and 250 m 2 /g.

4. The process of claim 1 , wherein the pre-calcined molecular sieve has a BET surface area of between 240 and 280 m 2 /g.

5. The process of claim 1 , wherein the post-calcined molecular sieve has a cumulative loss-on-ignition of between 4 and 9 wt. %.

6. The process of claim 1 , wherein the post-calcined molecular sieve has a cumulative loss-on-ignition of between 5 and 8.5 wt. %.

7. The process of claim 1 , wherein the post-calcined molecular sieve has a total micropore volume of between 0.008 and 0.018 cc/g.

8. The process of claim 7 , wherein the post-calcined molecular sieve has a total micropore volume of between 0.008 and 0.015 cc/g.

9. The process of claim 1 , wherein the post-calcined molecular sieve has an external surface area of between 200 and 250 m 2 /g; and a BET surface area of between 240 and 280 m 2 /g.

10. The process of claim 1 , wherein during the post-calcination step, the molecular sieve is subjected to one or more temperatures between 120 and 490° C. for between 1 and 6 hours.

11. The process of claim 1 , wherein the pre-calcined molecular sieve has a micropore volume of between 0.002 and 0.015 cc/g, and the post-calcined molecular sieve has a total micropore volume of between 0.008 and 0.02 cc/g.

12. The process of claim 1 , further comprising the steps of: (1) impregnating the post-calcined molecular sieve with one or more active metals selected from the group consisting of metals from Groups 8 to 10 of the Periodic Table; and (2) calcining the impregnated molecular sieve at temperatures from 200° C. to 500° C.

13. The process of claim 12 , wherein the impregnated molecular sieve is calcined at temperatures from 390° C. to 482° C.

14. The process of claim 1 , wherein the post-calcined molecular sieve has a MTT-type framework, a mole ratio of 20 to 70 of silicon oxide to aluminum oxide, and a H-D exchangeable acid site density of up to 50% relative to SSZ-32.

15. The process of claim 14 , wherein the post-calcined molecular sieve has a mole ratio of 20 to 50 of silicon oxide to aluminum oxide.

16. The process of claim 14 , wherein the post-calcined molecular sieve has a total micropore volume of between 0.008 and 0.018 cc/g.

17. The process of claim 14 , wherein the post-calcined molecular sieve has an external surface area of between 200 and 250 m 2 /g; and a BET surface area of between 240 and 280 m 2 /g.

18. The process of claim 14 , wherein the post-calcined molecular sieve has a H-D exchangeable acid site density of 0.5 to 30% relative to molecular sieve SSZ-32.

19. The process of claim 14 , wherein the post-calcined molecular sieve has a H-D exchangeable acid site density of 2 to 25% relative to molecular sieve SSZ-32.

Assignees

• Chevron Usa Inc

Inventors

• Ojo Adeola Florence
• Zhang Yihua
• Lei Guan-Dao
• Zones Stacey Ian

Classifications

• C01B39/06

  Preparation of isomorphous zeolites characterised by measures to replace the aluminium or silicon atoms in the lattice framework by atoms of other elements {, i.e. by direct or secondary synthesis} · CPC title

• B01J20/3078

  Thermal treatment, e.g. calcining or pyrolizing · CPC title

• B01J2229/183

  in framework positions · CPC title

• B01J35/1038

  Operations & Transport · mapped topic

• C01B39/48

  using at least one organic template directing agent · CPC title