US5625108A
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Process for preparing amorphous, catalytically active silicoaluminas
Assignee: Agip Petroli SpA
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Filing: 1995-06-01
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Granted: 1997-04-29
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Expires: 2015-06-01
Abstract
Abstract An amorphous, micro/mesoporous silica-alumina gel with controlled pore size, having a surface area of at least 500 m 2 /g and with a molar ratio of SiO 2 :Al 2 O 3 of at least 30:1, is prepared by hydrolysing and causing a tetra-alkyl ammonium hydroxide, an aluminum trialkoxide, and a tetra-alkyl orthosilicate to gelate, by operating at a temperature equal to, or higher than, the boiling temperature, under atmospheric pressure, of any alcohols which are developed as a by-product from said hydrolysis reaction, without said alcohols being removed, or being substantially removed, from the reaction media; and the so produced gel being dried and fired. So obtained gel is an active catalyst in hydrocarbon conversion reactions, in particular in light olefin isomerization and oligomerization processes, e.g., in propylene oligomerization processes to yield useful liquid hydrocarbons for gasoline and jet fuel formulation.
Inventors
- 👤 Carlo Perego
- 👤 Stefano Peratello
- 👤 Roberto Millini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:33
CPC Classifications
B; B01; B01J; B01J35/00; B01J35/60; B01J21/00; B01J21/12; B01J37/00; B01J37/02; B01J37/03; B01J37/031; B01J37/033; C; C07; C07C; C07C2/00; C07C2/02; C07C2/04; C07C2/06; C07C2/08; C07C2/10; B01J35/61; B01J35/617; B01J35/63; B01J35/633; B01J35/635; C07C2521/00; C07C2521/12; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
129 words
A method comprising propylene oligomerization in the presence of a silica-alumina gel catalyst, wherein said catalyst is an amorphous silica-alumina gel having a surface area of at least 500 m 2 /g and a molar ratio of SiO 2 :Al 2 O 3 of at least 30:1, wherein said catalyst is prepared by (1) hydrolyzing and gelling an aqueous reaction medium comprising a tetra-(C 2 -C 5 )-alkyl ammonium hydroxide, an aluminum tri-(C 2 -C 4 )-alkoxide and a tetra-(C 1 -C 5 )-alkyl orthosilicate at a temperature equal to or higher than the boiling temperature at atmospheric pressure of any alcohol produced during said hydrolyzing and gelling steps, without substantially removing said alcohol from said reaction media to produce a gel; and (2) drying and firing said gel.
Claim 2
Independent Claim
129 words
A method comprising propylene oligomerization in the presence of a silica-alumina gel catalyst, wherein said catalyst is an amorphous silica-alumina gel having a surface area of at least 500 m 2 /g and a molar ratio of SiO 2 :Al 2 O 3 of at least 30:1, wherein said catalyst is prepared by (1) hydrolyzing and gelling an aqueous reaction medium comprising a tetra-(C 2 -C 5 )-alkyl ammonium hydroxide, an aluminum tri-(C 2 -C 4 )-alkoxide and a tetra-(C 1 -C 5 )-alkyl orthosilicate at a temperature equal to or higher than the boiling temperature at atmospheric pressure of any alcohol produced during said hydrolyzing and gelling steps, without substantially removing said alcohol from said reaction media to produce a gel; and (2) drying and firing said gel.
Claim 3
Dependent Claim
61 words
The method of claim 1, wherein said tetra-(C 2 -C 5 )-alkyl ammonium hydroxide is selected from the group consisting of tetrapropyl ammonium hydroxide, tetraisopropyl ammonium hydroxide and tetrabutyl ammonium hydroxide, said aluminum tri-(C 2 -C 4 )-alkoxide is selected from the group consisting of aluminum tripropoxide and aluminum triisopropoxide, and said tetra-(C 1 -C 5 )-alkyl orthosilicate is tetraethyl orthosilicate.
Claim 4
Dependent Claim
96 words
The method of claim 1, further comprising prior to said hydrolyzing step, preparing an aqueous solution containing said tetra-(C 2 -C 5 )-alkyl ammonium hydroxide and said aluminum tri-(C 2 -C 4 )-alkoxide and adding said tetra-(C 1 -C 5 )-alkyl orthosilicate to said solution at a temperature lower than the temperature of said hydrolyzing, wherein the molar ratio SiO 2 :Al 2 O 3 is 30:1 to 500:1, the molar ratio tetra-(C 2 -C 5 )-alkyl ammonium hydroxide:SiO 2 is 0.05:1 to 0.2:1 and the molar ratio H 2 O:SiO 2 is 5:1 to 40:1.
Claim 5
Dependent Claim
24 words
The method of claim 3, wherein said hydrolyzing and gelling is conducted at a temperature of about 65° C. up to about 110° C.
Claim 6
Dependent Claim
26 words
The method of claim 1, wherein said aqueous reaction medium contains an alcohol in an amount up to a maximum molar ratio alcohol:SiO 2 of 8:1.
Claim 7
Dependent Claim
10 words
The method of claim 5, wherein said alcohol is ethanol.
Claim 8
Dependent Claim
22 words
The method of claim 1, wherein said hydrolyzing and gelling is conducted for a time ranging from 10 minutes to 3 hours.
Claim 9
Dependent Claim
19 words
The method of claim 7, wherein said hydrolyzing and gelling is conducted for a time ranging from 1-2 hours.
Claim 10
Dependent Claim
16 words
The method of claim 1, further comprising aging said gel at room temperature for 1-24 hours.
Claim 11
Dependent Claim
60 words
The method of claim 1, further comprising removing said alcohol produced during said hydrolyzing and gelling step from said gel and then vacuum drying said gel to produce a dried gel, and firing said dried gel in an oxidizing atmosphere at a temperature in the range from 500° to 700° C. for a time ranging from 4 to 20 hours.
Claim 12
Dependent Claim
22 words
The method of claim 10, wherein said firing is at a temperature of 500°-600° C. for a time ranging from 6-10 hours.
Claim 13
Dependent Claim
22 words
The method of claim 1, wherein said hydrolyzing and gelling are conducted at a temperature of 82° C. to about 110° C.
Claim 14
Dependent Claim
22 words
The method of claim 12, wherein said hydrolyzing and gelling is conducted at a temperature of 88° C. to about 110° C.
Claim 15
Dependent Claim
21 words
The method of claim 1, wherein said dried and fired gel has an average pore radius from 10 to about 20Å.
Claim 16
Dependent Claim
21 words
The method of claim 1, wherein said dried and fired gel has a surface area of from 600-850 m 2 /g.
References Cited (Backward Citations)
EP0340868A1
Cited
US5444032A
Cited
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