US3231632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of isobutene from mixed butenes
Assignee: Dow Chemical Co
•
Filing: 1962-07-18
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Granted: 1966-01-25
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Expires: 1982-07-18
Abstract
No abstract record available.
Inventors
- 👤 Hans R Friedli
- 👤 Otis C Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:04
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/148; C07C7/17; C07C7/171
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
104 words
A PROCESS FOR SEPARATING ISOBUTENE FROM A HYDROCARBON MIXTURE COMPRISING ISOBUTENE AND NORMAL BUTENES WHICH COMPRISES INTIMATELY CONTACTING SAID MIXTURE IN THE GASEOUS STATE AT ABOUT 20*C. TO ABOUT 50*C. WITH A LIQUID ACID MISTURE CONSISTING ESSENTIALLY OF ABOUT 85% TO ABOUT 99% BY WEIGHT OF ACETIC ACID AND ABOUT 15% TO ABOUT 1% OF SULFURIC ACID FOR A LENGTH OF TIME SUFFICIENT TO ESTERIFY AT LEAST A SUBSTANTIAL PORTION OF THE ISOBUTENE PRESENT, SEPARATING THE UNREEACTED HYDROCARBONS FROM THE LIQUID ACID MISTURE THEREBY FORMED, AND HEATING THE LIQUID ACID MISTURE AT ABOUT 50* TO AOUT 100*C. UNDER SUBATMOSPHERIC, PRESSURE, THEREBY LIBERATING FREE ISOBUTENE.
Claim 2
Dependent Claim
104 words
A PROCESS FOR SEPARATING ISOBUTENE FROM A HYDROCARBON MIXTURE COMPRISING ISOBUTENE AND NORMAL BUTENES WHICH COMPRISES INTIMATELY CONTACTING SAID MIXTURE IN THE GASEOUS STATE AT ABOUT 20*C. TO ABOUT 50*C. WITH A LIQUID ACID MISTURE CONSISTING ESSENTIALLY OF ABOUT 85% TO ABOUT 99% BY WEIGHT OF ACETIC ACID AND ABOUT 15% TO ABOUT 1% OF SULFURIC ACID FOR A LENGTH OF TIME SUFFICIENT TO ESTERIFY AT LEAST A SUBSTANTIAL PORTION OF THE ISOBUTENE PRESENT, SEPARATING THE UNREEACTED HYDROCARBONS FROM THE LIQUID ACID MISTURE THEREBY FORMED, AND HEATING THE LIQUID ACID MISTURE AT ABOUT 50* TO AOUT 100*C. UNDER SUBATMOSPHERIC, PRESSURE, THEREBY LIBERATING FREE ISOBUTENE.
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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) | 1969-01-24 | 1969-07-26 | 1970-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-24 | 1973-07-26 | 1974-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-24 | 1977-07-26 | 1978-01-25 | $7700.00 | Window Closed / Lapsed |