US4868146A
Expired / Lapsed
US
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Zeolite catalyst composition and synthesis method
Assignee: Mobil Oil AS
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Filing: 1988-08-25
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Granted: 1989-09-19
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Expires: 2008-08-25
Abstract
Abstract A surface-inactive shape selective metallosilicate catalyst, useful for the conversion of lower molecular weight olefins to liquid hydrocarbons such as gasoline, distillate, and high viscosity lube oils, is prepared by forming a silica shell on a medium pore metallosilicate core by crystallizing silica in the presence of fluoride ion onto the surface of the core. A novel catalyst composition is provided comprising an inner core portion and an outer portion disposed as a porous shell around the inner portion, wherein the inner portion consists essentially of metallosilicate zeolite having a medium pore structure, such as ZSM-5 or ZSM-23, and the outer portion comprising a fluoride-containing crystalline shell consisting essentially of silica substantially free of acid sites and having substantially the same crystalline structure as the inner core portion.
Inventors
- 👤 Pochen Chu
- 👤 Albert B. Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:09
CPC Classifications
C; C10; C10G; C10G50/00; B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/40; B01J29/90; C07; C07C; C07C2/00; C07C2/02; C07C2/04; C07C2/06; C07C2/08; C07C2/12; B01J2229/00; B01J2229/10; B01J2229/12; B01J2229/123; B01J2229/16; B01J2229/30; B01J2229/32; C07C2529/00; C07C2529/04; C07C2529/06; C07C2529/40; C07C2529/70; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/584
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
138 words
A process for preparing a siliceous zeolite particle, comprising an inner portion and an outer portion disposed as a porous shell around the inner portion, the inner portion comprising a tetrahedrally coordinated crystalline acidic metallosilicate, and the outer portion comprising a crystalline silica shell, the process comprising: maintaining an aqueous dispersion of a tetrahedrally coordinated acidic metallosilicate particulate solid having an average crystal size of about 0.02 to about 0.5 microns, an alkaline source of silicate ions, and a source of hydroxide ions; adding a source of fluoride ions to the aqueous dispersion in amount sufficient to complex any dissolved metal ion to obtain a reactive mixture; and heating the reactive mixture at a temperature to effectively form a surface-inactive particle comprising a crystalline silica outer shell substantially free of acid sites and a tetrahedrally coordinated metallosilicate core.
Claim 2
Dependent Claim
138 words
A process for preparing a siliceous zeolite particle, comprising an inner portion and an outer portion disposed as a porous shell around the inner portion, the inner portion comprising a tetrahedrally coordinated crystalline acidic metallosilicate, and the outer portion comprising a crystalline silica shell, the process comprising: maintaining an aqueous dispersion of a tetrahedrally coordinated acidic metallosilicate particulate solid having an average crystal size of about 0.02 to about 0.5 microns, an alkaline source of silicate ions, and a source of hydroxide ions; adding a source of fluoride ions to the aqueous dispersion in amount sufficient to complex any dissolved metal ion to obtain a reactive mixture; and heating the reactive mixture at a temperature to effectively form a surface-inactive particle comprising a crystalline silica outer shell substantially free of acid sites and a tetrahedrally coordinated metallosilicate core.
Claim 3
Dependent Claim
34 words
A process according to claim 1 wherein the particle is withdrawn from the composition and treated by a series of washing, drying and calcining steps to yield an active catalyst having internal acid sites.
Claim 4
Dependent Claim
32 words
A process according to claim 1 wherein the crystalline metallosilicate core has a silica:metal oxide molar ratio of about 10:1 to about 300:1 and a Constraint Index of about 1 to 12.
Claim 5
Dependent Claim
37 words
A process according to claim 1 wherein the fluoride compound is selected from the group consisting of ammonium fluoride, alkali metal fluoride, hydrogen fluoride, and fluorine gas, and wherein the aqueous dispersion comprises an organic directing agent.
Claim 6
Dependent Claim
27 words
A process according to claim 4 wherein the organic directing agent is selected from the group consisting of quaternary ammonium salts, alkyl amines and diamines, and pyrrolidines.
Claim 7
Dependent Claim
18 words
A process according to claim 1 wherein the crystalline metallosilicate contains aluminosilicate, borosilicate, ferrosilicate, gallosilicate or mixture thereof.
Claim 8
Dependent Claim
34 words
A process according to claim 1 wherein the outer portion of the particle is substantially free of tetrahedrally coordinated metal oxide, and has a surface acid activity less than 10% of the inner portion.
Claim 9
Dependent Claim
19 words
A process according to claim 1 wherein the crystalline silica shell outer portion contains a substantial amount of fluoride.
Claim 10
Dependent Claim
20 words
A process according to claim 1 wherein the metallosilicate comprises medium pore zeolite having pore size of about 5-7 Angstroms.
Claim 11
Dependent Claim
18 words
A process according to claim 9 wherein the crystalline silica outer shell comprises a product of epitaxial growth.
Claim 12
Dependent Claim
73 words
A composition of matter comprising an inner core portion and an outer portion disposed as a porous shell around the inner core portion wherein the inner portion comprises a tetrahedrally coordinated crystalline acidic metallosilicate solid core having an average crystal size of about 0.02 to about 0.5 microns and the outer portion comprises crystalline silica substantially free of acid sites, the outer portion being crystallized from an alkaline silicate solution containing fluoride ion.
Claim 13
Dependent Claim
73 words
A composition of matter comprising an inner core portion and an outer portion disposed as a porous shell around the inner core portion wherein the inner portion comprises a tetrahedrally coordinated crystalline acidic metallosilicate solid core having an average crystal size of about 0.02 to about 0.5 microns and the outer portion comprises crystalline silica substantially free of acid sites, the outer portion being crystallized from an alkaline silicate solution containing fluoride ion.
Claim 14
Dependent Claim
35 words
A composition of matter according to claim 11 wherein the crystalline metallosilicate inner portion has a silica:metal oxide molar ratio of about 20:1 to about 200:1 and a Constraint Index of about 1 to 12.
Claim 15
Dependent Claim
48 words
The composition of matter according to claim 12 wherein the crystalline metallosilicate has the structure of ZSM-5 aluminosilicate zeolite, and wherein the outer portion of the particle is substantially free of tetrahedrally coordinated aluminum oxide and has a surface acid activity less than 10% of the inner portion.
Claim 16
Independent Claim
139 words
A method for reducing the acid activity on the surface of a shape selective porous crystalline acidic aluminosilicate zeolite catalyst having a silica:alumina molar ratio greater than about 20 and an acid cracking alpha-value of at least about 40 comprising: contacting the acidic zeolite catalyst with alkaline solution comprising silicate ions, organic directing agent, and a source of hydroxide ions to form a homogeneous colloidal suspension; adding a source of fluoride ions to the suspension in an amount sufficient to complex any dissolved aluminum ion to form a chemically reactive aqueous composition; and heating the composition under reaction conditions sufficient to grow an epitaxial outer shell on the acid zeolite catalyst consisting essentially of silica containing a minor amount of fluoride and substantially free of tetrahedrally coordidated alumina, thereby reducing the acid activity on the surface of the catalyst.
Claim 17
Independent Claim
139 words
A method for reducing the acid activity on the surface of a shape selective porous crystalline acidic aluminosilicate zeolite catalyst having a silica:alumina molar ratio greater than about 20 and an acid cracking alpha-value of at least about 40 comprising: contacting the acidic zeolite catalyst with alkaline solution comprising silicate ions, organic directing agent, and a source of hydroxide ions to form a homogeneous colloidal suspension; adding a source of fluoride ions to the suspension in an amount sufficient to complex any dissolved aluminum ion to form a chemically reactive aqueous composition; and heating the composition under reaction conditions sufficient to grow an epitaxial outer shell on the acid zeolite catalyst consisting essentially of silica containing a minor amount of fluoride and substantially free of tetrahedrally coordidated alumina, thereby reducing the acid activity on the surface of the catalyst.
Claim 18
Dependent Claim
14 words
A method according to claim 14 wherein the organic directing agent contains tetrapropylammonium bromide.
Claim 19
Dependent Claim
46 words
A method according to claim 14 wherein the acidic zeolite catalyst having an epitaxial outer shell of silica and fluoride is separated from the chemically reactive aqueous composition, washed, dried and calcined to form a zeolite catalyst having internal acid sites and a substantially acid-free surface.
Claim 20
Dependent Claim
40 words
A method according to claim 14 wherein the porous crystalline acidic zeolite catalyst has the structure of ZSM-5 zeolite, and the outer shell has an epitaxial ZSM-5 crystalline structure having less than 10% of the acid activity of aluminosilicate ZSM-5.
Claim 21
Dependent Claim
73 words
A catalyst composition useful for shape selective oligomerization of lower olefins comprising: an inner core portion and an outer portion disposed as a porous shell around the inner portion, wherein the inner portion consists essentially of metallosilicate zeolite having the structure of ZSM-23; and the outer portion comprising a fluoride-containing crystalline shell consisting essentially of silica substantially free of acid sites and having substantially the same crystalline structure as the inner core portion.
Claim 22
Dependent Claim
73 words
A catalyst composition useful for shape selective oligomerization of lower olefins comprising: an inner core portion and an outer portion disposed as a porous shell around the inner portion, wherein the inner portion consists essentially of metallosilicate zeolite having the structure of ZSM-23; and the outer portion comprising a fluoride-containing crystalline shell consisting essentially of silica substantially free of acid sites and having substantially the same crystalline structure as the inner core portion.
Claim 23
Dependent Claim
116 words
A catalyst comprising an inner portion and an outer portion disposed as a porous shell around the inner portion, the inner portion comprising a shape-selective tetrahedrally coordinated crystalline acidic aluminosilicate, having a silica:alumina molar ratio of about 20 to 300, and the outer portion comprising a fluoride-containing crystalline silica shell substantially free of acid sites, wherein the amount of fluoride incorporated within the outer portion of the catalyst is in the range of about 0.05 to 0.5% by weight based on total crystal weight, wherein the crystalline inner portion has the structure of ZSM-5 zeolite, and the outer shell has an epitaxial ZSM-5 crystalline structure having less than 10% of the acid activity of aluminosilicate ZSM-5.
Claim 24
Dependent Claim
116 words
A catalyst comprising an inner portion and an outer portion disposed as a porous shell around the inner portion, the inner portion comprising a shape-selective tetrahedrally coordinated crystalline acidic aluminosilicate, having a silica:alumina molar ratio of about 20 to 300, and the outer portion comprising a fluoride-containing crystalline silica shell substantially free of acid sites, wherein the amount of fluoride incorporated within the outer portion of the catalyst is in the range of about 0.05 to 0.5% by weight based on total crystal weight, wherein the crystalline inner portion has the structure of ZSM-5 zeolite, and the outer shell has an epitaxial ZSM-5 crystalline structure having less than 10% of the acid activity of aluminosilicate ZSM-5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |