US4233228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of tetrahydrofuran
Assignee: BASF SE
•
Filing: 1978-10-19
•
Granted: 1980-11-11
•
Expires: 1998-10-19
Abstract
Abstract Tetrahydrofuran is purified by treatment with bleaching earth.
Inventors
- 👤 Herbert Mueller
- 👤 Otto H. Huchler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:09
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/04; C07D307/06; C07D307/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
69 words
A process for purifying tetrahydrofuran which comprises: intimately mixing the tetrahydrofuran to be treated at from room temperature to the boiling point of the tetrahydrofuran with a bleaching earth containing less than 3% by weight of water for from 3 minutes to 12 hours, and thereafter separating the bleaching earth from the tetrahydrofuran, whereby the carbonyl number, the bromine number and the peroxide content of the tetrahydrofuran are reduced.
Claim 2
Dependent Claim
69 words
A process for purifying tetrahydrofuran which comprises: intimately mixing the tetrahydrofuran to be treated at from room temperature to the boiling point of the tetrahydrofuran with a bleaching earth containing less than 3% by weight of water for from 3 minutes to 12 hours, and thereafter separating the bleaching earth from the tetrahydrofuran, whereby the carbonyl number, the bromine number and the peroxide content of the tetrahydrofuran are reduced.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the bleaching earth contains less than one percent by weight of water.
Claim 4
Dependent Claim
22 words
The process of claim 1, wherein the amount of bleaching earth used is from 0.1 to 5% by weight, based on tetrahydrofuran.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein the treatment is carried out at a temperature of from 30° to 66° C.
References Cited (Backward Citations)
DE700036C
Cited
US2790813A
Cited
US3074967A
Cited
US3221030A
Cited
US3980672A
Cited
DE2461922A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |