Patent US4460476A successfully refreshed from Google Patents.
US4460476A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of organics containing water
Assignee: Coal Industry Patents Ltd
•
Filing: 1983-08-03
•
Granted: 1984-07-17
•
Expires: 2003-08-03
Abstract
Abstract Organic solvents miscible with water and containing from 2 to 50% of water can be dried by passage over a molecular sieve capable of retaining water after it has been dehydrated, at a superficial velocity of less than 15 cm/min and using columns having specified lengths relative to the mass transfer zone.
Inventors
- 👤 David J. A. McCaffrey
- 👤 William D. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:47
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/78; C07C45/79; C07C29/00; C07C29/74; C07C29/76; C07C67/00; C07C67/48; C07C67/56
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
124 words
In the method of drying an organic solvent miscible with water to a water content of at most 0.1% by weight by passing the solvent through a column containing a dehydrated molecular sieve, the improvement comprising treating a solvent selected from the group consisting of isopropanol, ethanol, industrial methylated spirit, methyl isobutyl ketone, acetone, tetrahydrofuran and pyridine containing from 4 to 25% by weight of water at a superficial velocity of from 0.25 to 7.5 cm/min in a column having a ratio of length to mass transfer zone defined as the volume of liquid at between 5 and 30% by weight of the feed water content passing through the column divided by the cross-sectional area of the column of at least 4 to 1.
Claim 2
Dependent Claim
124 words
In the method of drying an organic solvent miscible with water to a water content of at most 0.1% by weight by passing the solvent through a column containing a dehydrated molecular sieve, the improvement comprising treating a solvent selected from the group consisting of isopropanol, ethanol, industrial methylated spirit, methyl isobutyl ketone, acetone, tetrahydrofuran and pyridine containing from 4 to 25% by weight of water at a superficial velocity of from 0.25 to 7.5 cm/min in a column having a ratio of length to mass transfer zone defined as the volume of liquid at between 5 and 30% by weight of the feed water content passing through the column divided by the cross-sectional area of the column of at least 4 to 1.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein the ratio of column length to mass transfer zone is at least 10 to 1.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein the molecular sieve is a type A3 zeolite.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein the water content of the solvent is 4-15% by weight and the solvent is ethanol.
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) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |