US3725494A
Expired / Lapsed
US
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Two-stage dehydrogenation process for producing diolefins
Assignee: Phillips Petroleum Co
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Filing: 1971-08-02
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Granted: 1973-04-03
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Expires: 1991-08-02
Abstract
Abstract A two-stage dehydrogenation process for producing diolefins from monoolefins wherein the monoolefin stream is first dehydrogenated under non-oxidative conditions, followed by an oxidative dehydrogenation with an iron phosphate catalyst. Isoprene is produced from a feedstream containing isoamylenes by a two-stage dehydrogenation process wherein the necessity of removing hydrogen from the non-oxidative effluent is eliminated through a selective second stage oxidative dehydrogenation stage.
Inventors
- 👤 D Ripley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:53
CPC Classifications
C; C07; C07C; C07C11/00; C07C11/12; C07C11/173; C07C11/18; C07C5/00; C07C5/32; C07C5/321; C07C5/322; C07C5/324; C07C5/325; C07C5/42; C07C5/48
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
53 words
A process according to claim 1 wherein the primary zone non-oxidative dehydrogenation temperature ranges from about 600* to about 1,300*F under a pressure of about 0 to about 500 psig and the oxidative dehydrogenation zone temperature ranges from about 700* to about 1,300*F under a pressure of about 0.05 to about 250 psig.
Claim 2
Dependent Claim
41 words
A process according to claim 1 wherein the oxidative dehydrogenation zone has a molecular oxygen-containing gas-to-feed ratio of from about 0.1 to about 3.0 and a steam-to-feed ratio of from about 0.1:1 to 100:1 based upon gas hourly space velocity rates.
Claim 3
Dependent Claim
62 words
A process according to claim 1 wherein the iron-phosphate oxidative dehydrogenation catalyst has a phosphorus content of about 1.01 to about 5.0 times the stoichiometric amount required to react with all of the iron present wherein the phosphate is in the form of (PO4 3) ions, and the oxygen-to-phosphorus atomic ratio is in the range of from about 3:1 to about 3.999:1.
Claim 4
Dependent Claim
22 words
A process according to claim 1 wherein the first-stage, non-oxidative dehydrogenation catalyst is comprised of potassium carbonate, iron oxide, and chromium oxide.
Claim 5
Dependent Claim
22 words
A process according to claim 1 wherein the monoolefinic feedstream is comprised of isoamylenes and the resulting diolefins are comprised of isoprene.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |