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Patent US4115408A successfully refreshed from Google Patents.
US4115408A
Expired / Lapsed
US
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Conversion of poly(tetramethylene ether) glycol in aqueous effluent stream to tetrahydrofuran
Assignee: EIDP Inc
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Filing: 1977-08-05
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Granted: 1978-09-19
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Expires: 1997-08-05
Abstract
Abstract A process for removing poly(tetramethylene ether) glycol from dilute aqueous acidic effluent streams thereof comprising the steps of (1) maintaining the stream in the liquid phase at a temperature above about 150 DEG C for a period of at least about 15 minutes and (2) removing tetrahydrofuran therefrom.
Inventors
- 👤 Melvin Charles Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:22
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/04; C07D307/06; C07D307/08; C02; C02F; C02F1/00; C02F1/02; C02F1/025; C02F2101/00; C02F2101/30; C02F2101/34; C02F2103/00; C02F2103/34; C02F2103/36; C02F2103/38
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
47 words
A process for removing poly(tetramethylene ether) glycol from dilute aqueous acidic streams thereof comprising the sequential steps of (a) maintaining the stream in the liquid phase at a temperature above about 150° C for a period of at least about 15 minutes and (b) separating tetrahydrofuran therefrom.
Claim 2
Dependent Claim
47 words
A process for removing poly(tetramethylene ether) glycol from dilute aqueous acidic streams thereof comprising the sequential steps of (a) maintaining the stream in the liquid phase at a temperature above about 150° C for a period of at least about 15 minutes and (b) separating tetrahydrofuran therefrom.
Claim 3
Dependent Claim
26 words
The process of claim 1 in which the hydrogen ion concentration of the acidic stream is equivalent to 2-15% by weight H 2 SO 4 .
Claim 4
Dependent Claim
19 words
The process of claim 1 in which the stream is maintained at 150°-200° C for at least 0.5 hour.
Claim 5
Dependent Claim
15 words
The process of claim 1 in which tetrahydrofuran is removed from the stream by vaporization.
Claim 6
Dependent Claim
33 words
The process of claim 4 in which the acidic stream from which tetrahydrofuran has been removed is neutralized to effect precipitation of neutralized solids and filtered to separate water from the neutralized solids.
References Cited (Backward Citations)
US3925484A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |