AEI-Type zeolite, its synthesis and its use in the conversion of oxygenates to olefins
View Patent ↗A crystalline material is described that has an AEI framework type, wherein the material, in its calcined, anhydrous form, has a composition involving the molar relationship: ( n )X 2 O 3 :YO 2 , wherein X is a trivalent element, Y is a tetravalent element n is from 0 to less than 0.01. The material is normally synthesized in a halide, typically a fluoride, medium and exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.
1. A crystalline material having an AEI framework type, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship:
( n )X 2 O 3 :YO 2 ,
wherein X is a trivalent element, Y is a tetravalent element and n is from 0 to less than 0.01.
2. The crystalline material of claim 1 wherein said material is substantially free of framework phosphorus.
3. The crystalline material of claim 1 wherein n is from about 0.001 to less than 0.01.
4. The crystalline material of claim 1 wherein n is from about 0.0025 to about 0.008.
5. The crystalline material of claim 1 wherein n is from about 0.003 to about 0.007.
6. The crystalline material of claim 1 wherein X is aluminum, boron, iron, indium, gallium or a combination thereof.
7. The crystalline material of claim 1 wherein Y is silicon, tin, titanium, germanium or a combination thereof.
8. The crystalline material of claim 1 wherein X is aluminum, boron, iron, indium, gallium or a combination thereof, and Y is silicon, tin, titanium, ermanium or a combination thereof.
9. The crystalline material of claim 1 wherein Y is silicon.
10. The crystalline material of claim 1 wherein X is aluminum.
11. The crystalline material of claim 9 wherein n is zero.
12. A crystalline material having an AEI framework type, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship:
( n )X 2 O 3 :YO 2 ,
wherein X is a trivalent element, Y is a tetravalent element and n is from 0 to less than 0.01 and wherein said material, in its calcined form, contains from about 1 to about 100 ppm by weight of a halide.
13. The crystalline material of claim 12 wherein said material, in its calcined form, contains from about 5 to about 50 ppm by weight of a halide.
14. The crystalline material of claim 12 wherein said material, in its calcined form, contains from about 10 to about 20 ppm, by weight of a halide.
15. The crystalline material of claim 12 wherein said halide comprises fluoride.
16. The crystalline material of claim 12 wherein n is from about 0.001 to less than 0.01.
17. The crystalline material of claim 12 wherein n is from about 0.0025 to about 0.008.
18. The crystalline material of claim 12 wherein n is from about 0.003 to about 0.007.
19. A method of synthesizing a crystalline material having an AEI framework type and comprising YO 2 and optionally X 2 O 3 wherein X is a trivalent element and Y is a tetravalent element, the method comprising:
(a) preparing a reaction mixture capable of forming said material, said mixture comprising a source of water, a source an oxide of the tetravalent element Y, optionally a source an oxide of the trivalent element X and an organic directing agent for directing the formation of said crystalline material;
(b) maintaining said reaction mixture under conditions sufficient to form crystals of said crystalline material comprising a composition involving the molar relationship:
( n )X 2 O 3 :YO 2 ,
where n is from 0 to less than 0.01; and
(c) recovering said crystalline material from (b).
20. The method of claim 19 wherein said reaction mixture also comprises a halide or a halide-containing compound.
21. The method of claim 19 wherein said reaction mixture also comprises a fluoride or a fluoride-containing compound.
22. The method of claim 19 wherein said organic directing agent comprises a cyclic amine or ammonium compound.
23. The method of claim 19 wherein said organic directing agent comprises a substituted piperidinium compound.
24. The method of claim 19 wherein said organic directing agent comprises a tetraalkylpiperidinium compound.
25. The method of claim 19 wherein said organic directing agent comprises an N,N-diethyl-2,6-dimethylpiperidinium compound.
26. The method of claim 19 wherein said reaction mixture has a pH of about 4 to about 10.
27. The method of claim 19 wherein said reaction mixture has the following molar composition
H 2 O/YO 2
0.1 to 20
Halide/YO 2
0 to 2
R/YO 2
0.01 to 2;
X 2 O 3 /YO 2
0 to 0.5,
where R is an organic directing agent.
28. The method of claim 19 wherein said reaction mixture has the following molar composition
H 2 O/YO 2
2 to 10;
Halide/YO 2
0.01 to 1;
R/YO 2
0.1 to 1;
X 2 O 3 /YO 2
0 to 0.1,
where R is an organic directing agent.
29. The method of claim 19 wherein X is aluminum and Y is silicon.
30. The method of claim 19 wherein said reaction mixture also comprises seed crystals.
31. The method of claim 30 wherein said seed crystals are added to said reaction mixture as a colloidal suspension in a liquid medium.
32. The method of claim 30 wherein said seed crystals comprise a crystalline material having an AEI, LEV, CHA or OFF framework type.
33. The method of claim 30 wherein said seed crystals comprise a crystalline material having an AEI framework type.
34. The method of claim 33 wherein the crystalline material having an AEI framework type is an aluminosilicate.
35. The method of claim 19 wherein the conditions in (b) include a temperature of from about 50° C. to about 300° C.
36. The method of claim 19 wherein the conditions in (b) include a temperature of from about 135° C. to about 185° C.
37. An organic conversion process comprising contacting an organic feedstock with a catalyst comprising a crystalline material having an AEI framework type and comprises a composition involving the molar relationship:
( n )X 2 O 3 :YO 2 ,
wherein X is a trivalent element, Y is a tetravalent element and n is from 0 to less than 0.01.
38. The process of claim 37 wherein said feedstock comprises an oxygenate and the process comprises converting said oxygenate into an olefin product.
39. The process of claim 37 wherein said material is substantially free of framework phosphorus.
40. The process of claim 37 wherein said material, in its calcined form, contains from about 1 to about 100 ppm by weight of a halide.
41. The process of claim 37 wherein said material, in its calcined form, contains from about 5 to about 50 ppm by weight of a halide.
42. The process of claim 37 wherein said material, in its calcined form, contains from about 10 to about 20 ppm, by weight of a halide.
43. The process of claim 37 wherein said halide comprises fluoride.
44. The process of claim 37 wherein n is from about 0.001 to less than 0.01.
45. The process of claim 37 wherein n is from about 0.0025 to about 0.008.
46. The process of claim 37 wherein n is from about 0.003 to about 0.007.
47. The process of claim 38 wherein said organic oxygenate compound comprises methanol, dimethyl ether or a mixture thereof.