US2939889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of styrene from nu-propylbenzene
Assignee: Dow Chemical Co
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Filing: 1956-05-25
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Granted: 1960-06-07
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Expires: 1976-05-25
Abstract
No abstract record available.
Inventors
- 👤 James L Amos
- 👤 Frederick J Soderquist
- 👤 Harold D Boyce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:44
CPC Classifications
C; C07; C07C; C07C4/00; C07C4/08; C07C4/12; C07C2521/00; C07C2521/10; C07C2521/18; C07C2523/00; C07C2523/06; C07C2523/16; C07C2523/24; C07C2523/26; C07C2523/70; C07C2523/74; C07C2523/745
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
100 words
A METHOD WHICH CONSISTS IN PASSING VAPORS OF N-PROPYLBENZENE THROUGH A REACTION ZONE IN CONTACT WITH A DEMETHANATING CATALYST OF THE GROUP CONSISTING OF FE2O3, ZNO AND MGO DEHYDROGENATION CATALYSTS AND MAXTURES THEREOF, CR2O3, AND CHARCOAL, WHEREIN THEY ARE HEATED AT REACTION TEMPERATURES BETWEEN 500* AND 800*C. AT A SPACE VELOCITY BETWEEN 50 AND 500 GRAMS OF N-PROPYLBENZENE PER LITER OF CATALYST PER HOUR, WHEREBY DEMETHANATION OF THE PROPYL GROUP PREDOMINATES TO THE SUBSTANTIAL EXCLUSION OF DEHYDROGENATION TO GIVE STYRENE, COOLING THE EFFUENT VAPOURS TO CONDENSE AROMATIC HYDROCARBONS THEREFROM AND FRACTIONALLY DISTILLING THE MIXTURE OF AROMATIC HYDROCARBONS TO SEPARATE STYRENE.
Claim 2
Independent Claim
100 words
A METHOD WHICH CONSISTS IN PASSING VAPORS OF N-PROPYLBENZENE THROUGH A REACTION ZONE IN CONTACT WITH A DEMETHANATING CATALYST OF THE GROUP CONSISTING OF FE2O3, ZNO AND MGO DEHYDROGENATION CATALYSTS AND MAXTURES THEREOF, CR2O3, AND CHARCOAL, WHEREIN THEY ARE HEATED AT REACTION TEMPERATURES BETWEEN 500* AND 800*C. AT A SPACE VELOCITY BETWEEN 50 AND 500 GRAMS OF N-PROPYLBENZENE PER LITER OF CATALYST PER HOUR, WHEREBY DEMETHANATION OF THE PROPYL GROUP PREDOMINATES TO THE SUBSTANTIAL EXCLUSION OF DEHYDROGENATION TO GIVE STYRENE, COOLING THE EFFUENT VAPOURS TO CONDENSE AROMATIC HYDROCARBONS THEREFROM AND FRACTIONALLY DISTILLING THE MIXTURE OF AROMATIC HYDROCARBONS TO SEPARATE STYRENE.
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) | 1963-06-07 | 1963-12-07 | 1964-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-07 | 1967-12-07 | 1968-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-07 | 1971-12-07 | 1972-06-07 | $7700.00 | Window Closed / Lapsed |