US3957900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the dehydration of diols
Assignee: Compagnie Francaise de Raffinage SA
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Filing: 1975-01-21
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Granted: 1976-05-18
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Expires: 1995-01-21
Abstract
Abstract Method for dehydrating diols into diolefins and/or olefin alcohols by contacting said diols under dehydration conditions with a catalyst prepared by forming an intimate mixture of finely divided solid particles of at least one pyrophosphate and at least one acid orthophosphate of at least one metal belonging to the group consisting of lithium, sodium, strontium, and barium into a formed mass which is thereafter calcined to transform the acid orthophosphate into pyrophosphate.
Inventors
- 👤 Joseph Edouard Weisang
- 👤 Georges Szabo
- 👤 Jean Maurin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:55
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/51; C07C45/52; B; B01; B01J; B01J27/00; B01J27/14; B01J27/16; B01J27/18; B01J27/1802; B01J27/1806; B01J37/00; B01J37/0009; B01J37/0018; C07C1/00; C07C1/20; C07C1/24; C07C29/00; C07C29/60; C07C2527/00; C07C2527/14; C07C2527/16; C07C2527/167
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
141 words
In a method for dehydrating vicinal diols into diolefins and olefin alcohols, the improvement comprising contacting said vicinal diol under dehydration conditions, effected with said diol in the vapor phase, pure or diluted with an inert gas, at a temperature between 350° and 800°C, and with an hourly space velocity of between about 0.5 and 2.5, with a mechanically strengthened catalyst prepared by the method consisting essentially of forming an intimate mixture of finely divided solid particles of at least one pyrophosphate and at least one acid orthophosphate of at least one metal belonging to the group consisting of lithium, sodium, strontium, and barium into a formed mass in a proportion sufficient to give improved mechanical strength to the resulting catalyst and calcinating said mass at a temperature of between about 400° to 600°C to transform said acid orthophosphate into pyrophosphate.
Claim 2
Dependent Claim
141 words
In a method for dehydrating vicinal diols into diolefins and olefin alcohols, the improvement comprising contacting said vicinal diol under dehydration conditions, effected with said diol in the vapor phase, pure or diluted with an inert gas, at a temperature between 350° and 800°C, and with an hourly space velocity of between about 0.5 and 2.5, with a mechanically strengthened catalyst prepared by the method consisting essentially of forming an intimate mixture of finely divided solid particles of at least one pyrophosphate and at least one acid orthophosphate of at least one metal belonging to the group consisting of lithium, sodium, strontium, and barium into a formed mass in a proportion sufficient to give improved mechanical strength to the resulting catalyst and calcinating said mass at a temperature of between about 400° to 600°C to transform said acid orthophosphate into pyrophosphate.
Claim 3
Dependent Claim
16 words
A method according to claim 1, comprising recycling the olefin alcohols for dehydration to said diolefin.
Claim 4
Dependent Claim
16 words
A method according to claim 2, wherein said diol is 2-methyl-2,3-butanediol and said diolefin is isoprene.
Claim 5
Dependent Claim
16 words
A method according to claim 2, wherein said diol is 2,3-butanediol and said diolefin is butadiene.
Claim 6
Dependent Claim
30 words
A method according to claim 2 wherein the method for preparing said catalyst said phosphates are mixed in powdered form, wetted to form a paste, extruded, dried, and finally calcinated.
Claim 7
Dependent Claim
30 words
A method according to claim 3 wherein the method for preparing said catalyst said phosphates are mixed in powdered form, wetted to form a paste, extruded, dried, and finally calcinated.
Claim 8
Dependent Claim
30 words
A method according to claim 4 wherein the method for preparing said catalyst said phosphates are mixed in powdered form, wetted to form a paste, extruded, dried, and finally calcinated.
Claim 9
Dependent Claim
15 words
A method according to claim 3 wherein said dehydration temperature is between 400° and 500°C.
Claim 10
Dependent Claim
15 words
A method according to claim 4 wherein said dehydration temperature is between 400° and 500°C.
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) | 1979-05-18 | 1979-11-17 | 1980-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-18 | 1983-11-17 | 1984-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-18 | 1987-11-17 | 1988-05-18 | $7700.00 | Window Closed / Lapsed |