US3852164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of 1,4-butanediol by vacuum distillation with side stream recovery
Assignee: Individual
•
Filing: 1973-03-30
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Granted: 1974-12-03
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Expires: 1993-03-30
Abstract
Abstract Substantially pure 1,4-butanediol is recovered as a side stream with very low water content by vacuum distillation with water and low boiling impurities taken off overhead and high boiling organic tars and inorganic salts taken off in a liquid bottoms stream.
Inventors
- 👤 J Verbsky
- 👤 S Chow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:10
CPC Classifications
C; C07; C07C; C07C29/00; C07C29/74; C07C29/76; C07C29/80; Y; Y10; Y10S; Y10S203/00; Y10S203/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
88 words
A PROCESS FOR RECOVERING 1,4-BUTANEDIOL CONTAINING A MINIMUM OF WATER FROM A CRUDE MIXTURE CONTAINING,BY WEIGHT, 1 TO 20% WATER PLUS LOW BOILING ORGANIC IMPURITIES, 80 TO 99% 1,4-BUTANEDIOL, AND 0.05 TO 5% COMBINED HIGH BOILING ORGANIC TARS AND INORGANIC SALTS, WHICH METHOD COMPRISES PAASSING THE CRUDE MIXTURE TO A DISTILLATION COLUMN OPERATING AT SUBATMOSPHERIC PRESSURE AND ADAPTED WITH A REBOILER, WITHDRAWING THE OVERHEAD, PASSING THE BOTTOMS TO THE REBOILER, WITHDRAWING LIQUID FROM THE REBOILER, PASSING VAPOR FROM THE REBOILER TO THE BOTTOM OF THE DISTILLATION COLUMN,AND WITH-
Claim 2
Dependent Claim
88 words
A PROCESS FOR RECOVERING 1,4-BUTANEDIOL CONTAINING A MINIMUM OF WATER FROM A CRUDE MIXTURE CONTAINING,BY WEIGHT, 1 TO 20% WATER PLUS LOW BOILING ORGANIC IMPURITIES, 80 TO 99% 1,4-BUTANEDIOL, AND 0.05 TO 5% COMBINED HIGH BOILING ORGANIC TARS AND INORGANIC SALTS, WHICH METHOD COMPRISES PAASSING THE CRUDE MIXTURE TO A DISTILLATION COLUMN OPERATING AT SUBATMOSPHERIC PRESSURE AND ADAPTED WITH A REBOILER, WITHDRAWING THE OVERHEAD, PASSING THE BOTTOMS TO THE REBOILER, WITHDRAWING LIQUID FROM THE REBOILER, PASSING VAPOR FROM THE REBOILER TO THE BOTTOM OF THE DISTILLATION COLUMN,AND WITH-
Claim 3
Dependent Claim
20 words
The process of claim 1 in which a portion of the overhead is returned to the distillation column as reflux.
Claim 4
Dependent Claim
28 words
The process of claim 1 in which the vapor withdrawn from the bottom portion of the distillation column is a portion of the vapor produced by the reboiler.
Claim 5
Dependent Claim
22 words
The process of claim 1 in which the distillation column is operated at an absolute pressure under about 200 millimeters of mercury.
Claim 6
Dependent Claim
22 words
The process of claim 1 in which the distillation column is operated at an absolute pressure of about 100 millimeters of mercury.
Claim 7
Dependent Claim
19 words
The process of claim 1 in which the recovered 1,4-butanediol contains less than about 0.1% by weight of water.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |