Claims
- 1. A process for producing a zeolite containing less than 10 percent by weight silica binder, comprising aging at elevated temperature a silica-bound zeolite aggregate in an aqueous ionic solution which contains hydroxy ions such that the initial molar ratio of OH-:SiO.sub.2 is in the range of 0.1 up to 1.2 and which causes the silica binder to be converted to zeolite of the type initially bound or a type which is a crystallographic match for the zeolite initially bound, said silica-bound zeolite selected from the group consisting of MFI, KFI, Y, Beta, Omega, Chabasite, T, Offretite, ZSM-22, ZSM-23, titanosilicate, ZSM-34 and ZSM-12 type zeolites.
- 2. The process according to claim 1 wherein the OH-:SiO.sub.2 molar ratio is in the range of 0.3 to 0.6.
- 3. The process according to claim 1 wherein said aging is conducted at a temperature in the range of from 95.degree. C. to 200.degree. C.
- 4. The process according to claim 1, which further comprises aging a silica-bound aggregate of:
- (a) a KFI-type zeolite which contains a strontium source in the presence of a solution containing a source of potassium aluminate; or
- (b) an MFI-type zeolite in the presence of a solution containing a positive tetrapropylammonium (TPA) species and a NA.sup.+ source.
- 5. The process according to claim 4 wherein the aging is carried out at 145.degree. to 155.degree. C.
- 6. The process according to claim 5, wherein the aging is carried out for 60 to 140 hours.
- 7. The process according to claim 4, wherein the KFI-type zeolite is a ZK-5 zeolite.
- 8. The process according to claim 7, wherein the ZK-5 zeolite is aged for 110 to 130 hours.
- 9. The process according to claim 4 wherein said zeolite is an MFI type zeolite.
- 10. The process according to claim 9, wherein the MFI-type zeolite is ZSM-5.
- 11. The process according to claim 9, wherein the MFI-type zeolite is a silicalite.
- 12. The process according to claim 1 wherein said zeolite is a Y type zeolite.
- 13. The process according to claim 12, which comprises aging a silica-bound aggregate of a Y-type zeolite in the presence of a solution containing sodium aluminate.
- 14. The process according to claim 13, wherein the aging is carried out at 95.degree. C. to 110.degree. C.
- 15. The process according to claim 14, wherein the aging is carried out for 18 to 28 hours.
- 16. The process according to claim 15, wherein the aged zeolite is washed and dried.
- 17. The process according to claim 1, wherein the aggregate particles have a hexane adsorption of at least 9 wt % at 30.degree. C. and p/po=0.25.
- 18. The process according to claim 1 wherein said silica contains no more than 2,000 ppm of alumina.
- 19. The process according to claim 1 wherein said binder-free zeolite contains less than 3% by weight of unconverted binder.
- 20. The process according to claim 1 wherein said silica binder is converted into zeolite crystals of sub-micron size.
- 21. A binder-free zeolite prepared by the process of claim 1.
- 22. A process for producing a zeolite containing less than 10 percent by weight silica binder, comprising aging at elevated temperature a silica-bound MFI type zeolite aggregate in an aqueous ionic solution containing hydroxy ions such that the initial molar ratio of OH-:SiO.sub.2 is up to 1.2 and which causes the silica binder to be converted to zeolite MFI or a crystallographic match for zeolite MFI.
- 23. The process according to claim 22 wherein said aqueous ionic solution contains a source of tetrapropylammonium ions.
- 24. The process according to claim 23 wherein said source of OH-ions is sodium hydroxide and wherein said solution is free of added alumina.
- 25. The process according to claim 22 wherein said aging is conducted at a temperature in the range of 130.degree. C. to 170.degree. C. for a period of from 60 to 140 hours.
- 26. The process according to claim 25 wherein said aging is conducted at a temperature in the range of 145.degree. C. to 155.degree. C. for a period of from 70 to 80 hours.
- 27. The process according to claim 23 wherein said aged zeolite is further washed and calcined.
- 28. The process according to claim 27 wherein said calcination is conducted at a temperature in the range of 450.degree. C. to 550.degree. C.
- 29. The process according to claim 22 wherein said MFI type zeolite is selected from the group consisting of silicalite and ZSM-5.
- 30. The process according to claim 29 wherein said MFI type zeolite is ZSM-5.
- 31. The process according to claim 22 wherein the OH-:SiO.sub.2 molar ratio is up to 0.6.
- 32. The process according to claim 31, wherein the MFI-type zeolite is aged for 70 to 80 hours.
- 33. The process according to claim 32, wherein the aged MFI-type zeolite is calcined after washing.
- 34. The process according to claim 33, wherein the calcination is carried out at 450.degree. to 550.degree. C.
- 35. The process according to claim 22 wherein said binder-free zeolite contains less than 3% by weight of unconverted binder.
- 36. A binder-free zeolite prepared by the process of claim 22.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9101456 |
Jan 1991 |
GBX |
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Parent Case Info
This is a continuation of application Ser. No. 08/090,157, filed Jul. 23, 1993, now abandoned, which is based on PCT/EP92/00144, filed Jan. 23, 1992, which is based on GB 9101456.3, filed Jan. 23, 1991.
US Referenced Citations (18)
Foreign Referenced Citations (6)
Number |
Date |
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0110650 |
Jun 1984 |
EPX |
0284206 |
Sep 1988 |
EPX |
0201264 |
Feb 1989 |
EPX |
1048426 |
Mar 1986 |
JPX |
1072621 |
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852012 |
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ZAX |
Continuations (1)
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Number |
Date |
Country |
Parent |
90157 |
Jul 1993 |
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