US4254296A
Expired / Lapsed
US
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Process for the preparation of tertiary olefins
Assignee: SnamProgetti SpA
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Filing: 1979-06-07
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Granted: 1981-03-03
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Expires: 1999-06-07
Abstract
Abstract A process is disclosed for preparing tertiary olefins having a high degree of purity and in good yields starting from tertiary ethers such as methyltert.butyl ether and in which the improvement comprises using an extremely efficient catalyst system which consists of a crystalline silica having a high specific surface area and which has been modified by an oxide of a metallic cation having an at least partially amphoteric character. Such catalyst may be, if appropriate, accompanied by an alumina-modified silica as an adjuvant co-catalyst.
Inventors
- 👤 Giovanni Manara
- 👤 Vittorio Fattore
- 👤 Marco Taramasso
- 👤 Bruno Notari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:31
CPC Classifications
B; B01; B01J; B01J35/00; B01J35/60; B01J21/00; B01J21/06; B01J21/08; C; C07; C07C; C07C1/00; C07C1/20; B01J35/61; B01J35/615; C07C2521/00; C07C2521/06; C07C2521/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
A process for the preparation of tertiary olefins starting from the corresponding alkyl-tert.alkyl ethers, characterized in that the tert.alkyl ethers are reacted in the presence of a catalyst selected from the group consisting of a crystalline silica having a high specific surface area corresponding to the general formula 0-1M n O m . 1SiO 2 , wherein M n O m is the oxide of a metallic cation capable of entering into the silica lattice as a substituent for silicon or as a salt of polysilicic acids and/or an aluminum-modified silica corresponding to the general formula as follows: 0.0006-0.0025Al.sub.2 O.sub.3.1SiO.sub.2.
Claim 2
Dependent Claim
100 words
A process for the preparation of tertiary olefins starting from the corresponding alkyl-tert.alkyl ethers, characterized in that the tert.alkyl ethers are reacted in the presence of a catalyst selected from the group consisting of a crystalline silica having a high specific surface area corresponding to the general formula 0-1M n O m . 1SiO 2 , wherein M n O m is the oxide of a metallic cation capable of entering into the silica lattice as a substituent for silicon or as a salt of polysilicic acids and/or an aluminum-modified silica corresponding to the general formula as follows: 0.0006-0.0025Al.sub.2 O.sub.3.1SiO.sub.2.
Claim 3
Dependent Claim
16 words
Process according to claim 1, wherein the high-specific-surface-area crystalline silica has the general formula: 0.0001-1M.sub.n O.sub.m.1SiO.sub.2.
Claim 4
Dependent Claim
42 words
Process according to claim 1 wherein the metallic cations which replace silicon are elements having an at least partially amphoteric nature, selected from the group consisting of chromium, beryllium, titanium, vanadium, manganese, iron, cobalt, zinc, zirconium, rhodium, silver, tin, antimony and boron.
Claim 5
Dependent Claim
21 words
Process according to claim 1 wherein the crystalline silica has a specific surface area of more than 150 m 2 /g.
Claim 6
Dependent Claim
36 words
Process according to claim 1 characterized in that the tert.alkyl ethers are reacted under pressures of from 1 to 10 kg/cm 2 and at a temperature in the range of from 130° C. to 350° C.
Claim 7
Dependent Claim
23 words
Process according to claim 1 wherein the reaction is caused to take place at a space velocity (LHSV) of between 0.5 and 200.
Claim 8
Dependent Claim
12 words
Process according to claim 1 wherein the tertiary ether is methyl-tert.butyl ether.
Claim 9
Dependent Claim
22 words
Process according to claim 1 wherein the crystalline silica has a specific surface area of between 200 and 500 m 2 /g.
Claim 10
Dependent Claim
30 words
Process according to claim 1 characterized in that the tert, alkyl ethers are reacted under pressure of from 1 to 10 kg/cm 2 and at a temperature of 500° C.
Claim 11
Dependent Claim
23 words
Process according to claim 1 wherein the reaction is caused to take place at a space velocity (LHSV) of between 1 and 50.
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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |