US4405409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for dehydrating mixtures of organic liquids and water
Assignee: Gft Gesellschaft fur Trenntechnik MbH
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Filing: 1981-10-05
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Granted: 1983-09-20
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Expires: 2001-10-05
Abstract
Abstract A method and apparatus for dehydrating mixtures of organic liquids and water comprising consecutive distillation and membrane permeation, wherein at least a portion of the material retained by the separator is passed into indirect heat exchange relationship within the distillation column and recycled to the separator to provide the heat input required for the permeation process.
Inventors
- 👤 Gunter Tusel
- 👤 Achim Ballweg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:33
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/36; B01D61/364; B01D61/3641; B01D3/00; B01D3/14; B01D3/32; B01D3/322; C; C07; C07C; C07C29/00; C07C29/74; C07C29/76; C07C29/80
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
In a method of dehydrating a mixture of an organic liquid and water, which comprises subjecting the mixture to initial distillation to remove an initial quantity of water followed by membrane permeation to remove substantially the remaining water, the improvement which comprises withdrawing at least a portion of the material retained by the membrane separator, passing that material into indirect heat exchange relationship within the distillation column and recycling at least a portion of that withdrawn material back to the separator, the quantity of such recycle stream being such that substantially the whole of the heat required for the membrane permeation is transmitted to the recycle stream during said heat exchange within the distillation column.
Claim 2
Dependent Claim
115 words
In a method of dehydrating a mixture of an organic liquid and water, which comprises subjecting the mixture to initial distillation to remove an initial quantity of water followed by membrane permeation to remove substantially the remaining water, the improvement which comprises withdrawing at least a portion of the material retained by the membrane separator, passing that material into indirect heat exchange relationship within the distillation column and recycling at least a portion of that withdrawn material back to the separator, the quantity of such recycle stream being such that substantially the whole of the heat required for the membrane permeation is transmitted to the recycle stream during said heat exchange within the distillation column.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein the volume of the recycle stream is large enough to make the temperature at which the retained material leaves membrane permeation well above the temperature of the cooling water.
Claim 4
Dependent Claim
35 words
The method of claim 1, wherein the membrane permeation is carried out in two stages, with a membrane of lower selectivity being used in the first stage and one with higher selectivity in the second.
Claim 5
Dependent Claim
20 words
The method of claim 3, wherein the recycle stream of retained material is drawn solely from the first membrane stage.
Claim 6
Dependent Claim
47 words
The method of claim 4, wherein the withdrawn stream of retained material from the first separator, after passing through said heat exchange within the distillation column is split with one part being recycled to the first separator and the remainder being passed to the second membrane separator.
Claim 7
Dependent Claim
36 words
The method of claim 5, wherein the water content of the mixture fed to the second membrane stage is chosen so that the heat capacity of the mixture is sufficient for permeation of the remaining water.
Claim 8
Dependent Claim
54 words
The method of claim 3, as applied to the dehydration of an aqueous ethanol mash wherein the mash is dehydrated to approximately 80% by weight ethanol in the distillation stage, and that the ethanol content is brought to approximately 95% by weight in the first membrane stage and made virtually anhydrous in the second.
Claim 9
Dependent Claim
107 words
Apparatus for dehydrating mixtures of an organic liquid and water comprising a distillation column and a membrane separator connected in series for the initial distillation and subsequent membrane separation of the mixture to remove water remaining in the distillate from the distillation column and including a recycle circuit for withdrawing at least a portion of the material retained by the separator, a heat exchanger within the distillation column connected in said recycle circuit for indirect heat exchange between said portion of withdrawn material, and a recycle conduit for return of at least a portion of the heated withdrawn material from the heat exchanger to the membrane separator.
Claim 10
Dependent Claim
107 words
Apparatus for dehydrating mixtures of an organic liquid and water comprising a distillation column and a membrane separator connected in series for the initial distillation and subsequent membrane separation of the mixture to remove water remaining in the distillate from the distillation column and including a recycle circuit for withdrawing at least a portion of the material retained by the separator, a heat exchanger within the distillation column connected in said recycle circuit for indirect heat exchange between said portion of withdrawn material, and a recycle conduit for return of at least a portion of the heated withdrawn material from the heat exchanger to the membrane separator.
Claim 11
Dependent Claim
68 words
Apparatus according to claim 8 including two membrane separators, wherein said recycle circuit connects the first separator to the heat exchanger for the feeding therethrough of the whole of the material retained by the first separator, and the recycle conduit connects with both the first and second separators for recycling a part of the heated retained material to the first separator and the remainder to the second separator.
References Cited (Backward Citations)
US2636846A
Cited
US2981680A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |