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US4413136A
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US
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Purification of tetrahydrofuran
Assignee: EIDP Inc
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Filing: 1982-08-02
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Granted: 1983-11-01
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Expires: 2002-08-02
Abstract
Abstract The amount of methacrolein impurity in tetrahydrofuran made from acetylene and formaldehyde can be significantly reduced by treating it with hydrogen peroxide during an interval in the multi-stage distillation tetrahydrofuran refining procedure.
Inventors
- 👤 Richard E. Ernst
- 👤 Harry B. Copelin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:51
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/04; C07D307/06; C07D307/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
74 words
In the multi-stage refining of tetrahydrofuran made from acetylene and formaldehyde, a method of reducing the content of methacrolein impurity, which method comprises treating the tetrahydrofuran before any of the distillation stages with hydrogen peroxide in about the same weight as the methacrolein to be destroyed and from 10 to 100 milliequivalents excess of base at a temperature of from 20° to 65° C., and then separating tetrahydrofuran and the resulting chemically modified impurity.
Claim 2
Dependent Claim
74 words
In the multi-stage refining of tetrahydrofuran made from acetylene and formaldehyde, a method of reducing the content of methacrolein impurity, which method comprises treating the tetrahydrofuran before any of the distillation stages with hydrogen peroxide in about the same weight as the methacrolein to be destroyed and from 10 to 100 milliequivalents excess of base at a temperature of from 20° to 65° C., and then separating tetrahydrofuran and the resulting chemically modified impurity.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the base is an alkali metal hydroxide.
Claim 4
Dependent Claim
21 words
The process of claim 2 wherein the hydrogen peroxide treatment is carried out at a temperature of 25° to 45° C.
Claim 5
Dependent Claim
24 words
The process of claim 2 wherein there is from 10 to 20 milliequivalents of alkali metal hydroxide present in the hydrogen peroxide treatment step.
Claim 6
Dependent Claim
11 words
The process of claim 4 wherein the base is sodium hydroxide.
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) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |