Patent US4995868A successfully refreshed from Google Patents.
US4437939A
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Process for separating ethylene oxide from aqueous solutions
Assignee: Scientific Design LLC
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Filing: 1981-11-16
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Granted: 1984-03-20
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Expires: 2001-11-16
Abstract
Abstract Ethylene oxide is extracted from aqueous solutions by carbon dioxide under (near) super-critical conditions and thereafter recovered by distillation at sub-critical conditions. Improved distillation is obtained by adding to the carbon dixoide a gas (or gases) which adjust the critical temperature of the gas mixture of the top of the distillation column within the range of about 32° C. to about 75° C. Preferred gases are the saturated hydrocarbons, particularly propane, n-butane, isobutane and pentane.
Inventors
- 👤 Vijay S. Bhise
- 👤 Robert Hoch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:24
CPC Classifications
B; B01; B01D; B01D11/00; B01D11/04; B01D11/0403; B01D11/0407; C; C07; C07D; C07D301/00; C07D301/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
79 words
In a process for recovering ethylene oxide from aqueous solutions wherein carbon dioxide at near-critical or super-critical conditions extracts ethylene oxide and thereafter the extracted ethylene oxide is separated from the carbon dioxide by distillation at sub-critical conditions, the improvement comprising adding an amount of a gas or gases to said carbon dioxide sufficient to provide a critical temperature for the carbon dioxide-ethylene oxide-added gas mixture at the top of said distillation column between 32° C. and 75° C.
Claim 2
Dependent Claim
79 words
In a process for recovering ethylene oxide from aqueous solutions wherein carbon dioxide at near-critical or super-critical conditions extracts ethylene oxide and thereafter the extracted ethylene oxide is separated from the carbon dioxide by distillation at sub-critical conditions, the improvement comprising adding an amount of a gas or gases to said carbon dioxide sufficient to provide a critical temperature for the carbon dioxide-ethylene oxide-added gas mixture at the top of said distillation column between 32° C. and 75° C.
Claim 3
Dependent Claim
47 words
A process of claim 1 wherein said added gas is at least one member selected from the group consisting of propane, n-butane, isobutane, pentane, and halogenated refrigerants and the amount added is about 0.01-0.5 mols per mols of carbon dioxide of the top of said distillation column.
Claim 4
Dependent Claim
31 words
A process of claim 2 wherein said added gas is n-butane and the amount added is about 0.05-0.15 mols per mol of carbon dioxide at the top of said distillation column.
Claim 5
Dependent Claim
31 words
A process of claim 2 wherein said added gas is propane and the amount added is about 0.1-0.3 mols per mol of carbon dioxide at the top of said distillation column.
Claim 6
Dependent Claim
31 words
A process of claim 2 wherein said added gas is n-pentane and the amount added is about 0.01-0.1 mols per mol of carbon dioxide at the top of said distillation column.
Claim 7
Dependent Claim
33 words
A process of claim 2 wherein said added gas is a halogenated refrigerant and the amount added is about 0.1-0.3 mols per mol of carbon dioxide at the top of said distillation column.
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) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |