Zeolite ZSM-18, its synthesis and its use

Patent metadata

Field	Value
Publication number	US-9452424-B2
Application number	US-201514931347-A
Country	US
Kind code	B2
Filing date	Nov 3, 2015
Priority date	May 8, 2012
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

ZSM-18 is synthesized from a mixture comprising water, a source of an oxide of a tetravalent element (Y), a source of an oxide of a trivalent element (X), a source of a first cation Q selected from either butamethonium cations or N,N,N,-trimethyl-N-butylammonium cations and a source of at least one second cation M, wherein the second cation M is selected from lithium, strontium, sodium, tetraalkylammonium and mixtures thereof when the first cation, Q is butamethonium cations, and wherein the second cation M is tetramethylammonium when the first cation Q is N,N,N,-trimethyl-N-butylammonium cations.

First claim

The invention claimed is:

1. A process for converting a feedstock comprising an organic compound to a conversion product which comprises contacting said feedstock at organic compound conversion conditions with a catalyst comprising an active form a molecular sieve having the structure of ZSM-18 and comprising cations of formula (CH 3 ) 3 N + (CH 2 ) 4 N + (CH 3 ) 3 in its pores.

2. The process of claim 1 , wherein said molecular sieve having a composition comprising the molar relationship:
mM:qQ:(y)YO 2 : X 2 O 3 ,

wherein 0<m≦2, 0<q≦1.2, 7≦y≦14, M comprises a cation selected from the group consisting of lithium, strontium, sodium, tetraalkylammonium and mixtures thereof, Q comprises a butamethonium cation, X is a trivalent element and Y is a tetravalent element.

3. The process of claim 2 , wherein said tetraalkylammonium cation comprises a tetramethylammonium cation.

4. The process of claim 1 , wherein said molecular sieve of claim 1 , having in its calcined form an N 2 micropore volume of 0.34 (±0.04) cc/g.

5. The process of claim 1 , wherein said molecular sieve having the structure of ZSM-18 is produced by the process comprising the steps of:
(i) preparing a synthesis mixture capable of forming said molecular sieve, said synthesis mixture comprising water, a source of an oxide of a tetravalent element (Y), a source of an oxide of a trivalent element (X), a source of a first cation Q selected from the group consisting of either cations of formula (CH 3 ) 3 N + (CH 2 ) 4 N + (CH 3 ) 3 or N,N,N,-trimethyl-N-butylammonium cations and a source of at least one second cation M of valence n, wherein the second cation M is selected from the group consisting of lithium, strontium, sodium, tetraalkylammonium and mixtures thereof when said first cation Q is a cation of formula (CH 3 ) 3 N + (CH 2 ) 4 N + (CH 3 ) 3 , and wherein said second cation M is tetramethylammonium when said first cation Q is N,N,N,-trimethyl-N-butylammonium cations, and said synthesis mixture having a composition, in terms of mole ratios, within the following ranges:
YO 2 /X 2 O 3 about 6 to about 25;
(nM n+ )/X 2 O 3 about 0.25 to about 4;
Q/X 2 O 3 greater than 4; and
H 2 O/YO 2 about 10 to about 60;
(ii) heating said synthesis mixture under crystallization conditions comprising a temperature of from about 100° C. to about 200° C. and a time from about 1 day to about 21 days until crystals of said molecular sieve are formed; and
(iii) recovering said molecular sieve from step (ii).

6. The process of claim 5 , wherein said tetravalent element Y comprises silicon and said trivalent element X comprises aluminum.

7. The process of claim 5 , wherein said first cation Q comprises cations of formula (CH 3 ) 3 N + (CH 2 ) 4 N + (CH 3 ) 3 .

8. The process of claim 7 , wherein said second cation M is lithium and Li + /X 2 O 3 is about 0.3 to about 2.

9. The process of claim 7 , wherein said second cation M is strontium and 2Sr 2+ /X 2 O 3 is about 0.3 to about 1.

10. The process of claim 7 , wherein said second cation M is tetramethylammonium (TMA) and TMA + /X 2 O 3 is about 0.3 to about 4.

11. The process of claim 7 , wherein said second cation M is a mixture of lithium and tetramethylammonium (TMA) and (Li + +TMA + )/X 2 O 3 is about 0.3 to about 4.

12. The process of claim 7 , wherein said second cation M is a mixture of sodium and strontium and (Na + 2Sr 2+ )/X 2 O 3 is about 0.3 to about 2.

13. The process of claim 7 , wherein said second cation M is a mixture of tetramethylammonium (TMA) and strontium and (TMA + +2Sr 2+ )/X 2 O 3 is about 0.3 to about 2.

14. The process of claim 5 , wherein said synthesis mixture also contains seeds.

15. The process of claim 5 , wherein said synthesis mixture further comprises from about 0.01 ppm by weight to about 10,000 ppm by weight of seeds.

16. The process of claim 5 , wherein said synthesis mixture further comprises from about 100 ppm by weight to about 5,000 by weight of seeds.

17. The process of claim 5 , wherein said seeds comprise a crystalline material having a MEI framework-type.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Burton Allen W
• Vroman Hilda B

Classifications

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/37

  Crush or impact strength · CPC title

• B01J37/082

  Decomposition and pyrolysis · CPC title

• B01J35/002

  Operations & Transport · mapped topic