US4774365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pervaporation process for separating alcohols from ethers
Assignee: Celgard LLC
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Filing: 1987-11-25
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Granted: 1988-09-27
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Expires: 2007-11-25
Abstract
Abstract The present invention is an improved process for separating alcohols from ethers and/or hydrocarbon raffinate in an etherification process. The excess alcohol reactant, which forms azeotrope mixtures with the product ethers and C 4 -C 7 raffinate, is removed by passing the liquid azeotrope mixture over a pervaporation membrane which effectively breaks the azeotrope and permeates the alcohol with high flux and high selectivity. In a typical etherification process, one or more pervaporation membrane units can be located ahead of the ether/raffinate distillation step, in conjunction with the distillation step with a liquid side draw, after the distillation step, or a combination of any of the above. The present invention also provides an improved process for separating alcohols from ethers and/or hydrocarbon raffinate in an ether decomposition process for the production of high purity iso-alkene products. In this embodiment, one or more pervaporation membranes are used to recover alcohols from the decomposition product stream.
Inventors
- 👤 Michael S. Chen
- 👤 Robert M. Eng
- 👤 Jerome L. Glazer
- 👤 Charles G. Wensley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:34
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/36; B01D61/362; B01D3/00; B01D3/42; B01D3/4211; C; C07; C07C; C07C41/00; C07C41/01; C07C41/05; C07C41/06; C07C41/34; C07C43/00; C07C43/02; C07C43/03; C07C43/04; C07C43/046; C07C7/00; C07C7/144; B01D2311/00; B01D2311/25; B01D2311/251; B01D2311/2512; B01D2311/26; B01D2311/2669
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
144 words
In a process for the production of ethers whereby an olefin is reacted with an alcohol to produce an alcohol/ether/hydrocarbon raffinate stream in which the alcohol forms azeotrope mixtures with both the ether and raffinate, and said ether is separated from the raffinate by distillation, the improvement for removing alcohols to yield a high purity ether product stream which comprises: (a) passing said alcohol/ether/hydrocarbon raffinate stream in the liquid state, over a pervaporation membrane capable of breaking the azeotropes and having a high flux and high selectivity for alcohols to produce a vapor alcohol permeate stream and a liquid ether/raffinate reject stream; (b) recycling the vapor alcohol permeate stream to the reaction step to be reacted with additional olefin feed; and (c) passing the liquid ether/raffinate reject stream to a distillation column to produce a raffinate stream and a high purity ether product stream.
Claim 2
Dependent Claim
144 words
In a process for the production of ethers whereby an olefin is reacted with an alcohol to produce an alcohol/ether/hydrocarbon raffinate stream in which the alcohol forms azeotrope mixtures with both the ether and raffinate, and said ether is separated from the raffinate by distillation, the improvement for removing alcohols to yield a high purity ether product stream which comprises: (a) passing said alcohol/ether/hydrocarbon raffinate stream in the liquid state, over a pervaporation membrane capable of breaking the azeotropes and having a high flux and high selectivity for alcohols to produce a vapor alcohol permeate stream and a liquid ether/raffinate reject stream; (b) recycling the vapor alcohol permeate stream to the reaction step to be reacted with additional olefin feed; and (c) passing the liquid ether/raffinate reject stream to a distillation column to produce a raffinate stream and a high purity ether product stream.
Claim 3
Dependent Claim
36 words
The process in accordance with the claim 1 wherein said high purity ether stream is passed over a pervaporation membrane to further separate, as a vapor permeate, alcohol which may be present in said product stream.
Claim 4
Dependent Claim
18 words
The process in accordance with claim 1 wherein isobutylene is reacted with methanol to form methyl t-butyl ether.
Claim 5
Dependent Claim
18 words
The process in accordance with claim 1 wherein isopentenes are reacted with methanol to form t-amyl methyl ether.
Claim 6
Dependent Claim
29 words
The process in accordance with claim 1 wherein over 50% of the alcohol present in the alcohol/ether/raffinate stream is removed by the pervaporation membrane as a gaseous permeate stream.
Claim 7
Dependent Claim
45 words
The process in accordance with claim 1 wherein a liquid side draw stream is withdrawn from the distillation column and passed over a pervaporation membrane to remove alcohol as a gaseous permeate and produce a liquid ether/raffinate stream which is returned to the distillation column.
Claim 8
Dependent Claim
29 words
The process in accordance with claim 6 wherein the gaseous alcohol permeate produced by passing the side draw stream over the pervaporation membrane is recycled to the reaction step.
Claim 9
Dependent Claim
148 words
In a process for the production of ethers whereby an olefin is reacted with an alcohol to produce an alcohol/ether/hydrocarbon raffinate stream in which the alcohol forms azeotrope mixtures with both the ether and raffinate, and said ether is separated from the raffinate by distillation, the improvement for removing alcohols to yield a high purity ether product stream which comprises: (a) passing said alcohol/ether/hydrocarbon raffinate stream to a distillation column capable of separating ether from raffinate; (b) withdrawing a liquid side draw stream comprising alcohol, ether and raffinate from the distillation column and passing said stream over a pervaporation membrane to produce a vapor alcohol permeate stream and a liquid ether/raffinate reject stream; (c) recycling the vapor alcohol permeate stream to the reaction step; and (d) passing the liquid ether/raffinate reject stream back to the distillation column to produce a raffinate stream and a purified ether product stream.
Claim 10
Dependent Claim
148 words
In a process for the production of ethers whereby an olefin is reacted with an alcohol to produce an alcohol/ether/hydrocarbon raffinate stream in which the alcohol forms azeotrope mixtures with both the ether and raffinate, and said ether is separated from the raffinate by distillation, the improvement for removing alcohols to yield a high purity ether product stream which comprises: (a) passing said alcohol/ether/hydrocarbon raffinate stream to a distillation column capable of separating ether from raffinate; (b) withdrawing a liquid side draw stream comprising alcohol, ether and raffinate from the distillation column and passing said stream over a pervaporation membrane to produce a vapor alcohol permeate stream and a liquid ether/raffinate reject stream; (c) recycling the vapor alcohol permeate stream to the reaction step; and (d) passing the liquid ether/raffinate reject stream back to the distillation column to produce a raffinate stream and a purified ether product stream.
Claim 11
Dependent Claim
18 words
The process in accordance with claim 8 wherein isobutylene is reacted with methanol to form methyl t-butyl ether.
Claim 12
Dependent Claim
18 words
The process in accordance with claim 8 wherein isopentenes are reacted with methanol to form t-amyl methyl ether.
Claim 13
Dependent Claim
29 words
The process in accordance with claim 8 wherein over 50% of the alcohol present in he alcohol/ether/raffinate stream is removed by the pervaporation membrane as a vapor permeate stream.
Claim 14
Dependent Claim
36 words
The process in accordance with the claim 8 wherein said high purity ether stream is passed over a pervaporation membrane to further separate, as a vapor permeate, alcohol which may be present in said product stream.
Claim 15
Dependent Claim
38 words
The process in accordance with claim 8 wherein the raffinate stream produced in the distillation column is passed over a pervaporation membrane to further separate, as a vapor permeate, alcohol which may be present in said product stream.
Claim 16
Dependent Claim
132 words
In a process for the production of high purity alkenes by the decomposition of an ether, wherein said ether is decomposed to form a liquid alcohol/ether/alkene mixture in which the alcohol forms azeotropic mixtures with both the ether and alkene, and said alkenes are separated from the mixture by distillation, the improvement for removing alcohols to yield a high purity alkene product stream which comprises: (a) passing said liquid alcohol/ether/alkene mixture from the decomposition step over a pervaporation membrane capable of breaking the azeotropes and having a high flux and high selectivity for alcohols to produce a vapor alcohol permeate stream and a liquid ether/alkene reject stream; and (b) passing the liquid ether/alkene reject stream to a distillation column to produce an ether bottom product and a high purity alkene overhead product.
Claim 17
Dependent Claim
132 words
In a process for the production of high purity alkenes by the decomposition of an ether, wherein said ether is decomposed to form a liquid alcohol/ether/alkene mixture in which the alcohol forms azeotropic mixtures with both the ether and alkene, and said alkenes are separated from the mixture by distillation, the improvement for removing alcohols to yield a high purity alkene product stream which comprises: (a) passing said liquid alcohol/ether/alkene mixture from the decomposition step over a pervaporation membrane capable of breaking the azeotropes and having a high flux and high selectivity for alcohols to produce a vapor alcohol permeate stream and a liquid ether/alkene reject stream; and (b) passing the liquid ether/alkene reject stream to a distillation column to produce an ether bottom product and a high purity alkene overhead product.
Claim 18
Dependent Claim
27 words
The process in accordance with claim 14 wherein said ether is initially formed by the reaction of an alcohol with an alkene in an ether synthesis reactor.
Claim 19
Dependent Claim
45 words
The process in accordance with claim 15 wherein a liquid side draw stream is withdrawn from the distillation column and passed over a pervaporation membrane to remove alcohol as a gaseous permeate to produce a liquid ether/alkene stream which is returned to the distillation column.
Claim 20
Dependent Claim
20 words
The process in accordance with claim 15 wherein the vapor alcohol permeate stream is recycled to the ether synthesis reactor.
Claim 21
Dependent Claim
20 words
The process in accordance with claim 16 wherein both vapor alcohol permeate streams are recycled to the ether synthesis reactor.
Claim 22
Dependent Claim
14 words
The process in accordance with claim 14 wherein the alkene is isobutene or isopentene.
Claim 23
Dependent Claim
141 words
In a process for the production of high purity alkenes by the decomposition of an ether, wherein said ether is decomposed to form a liquid alcohol/ether/alkene mixture in which the alcohol forms azeotropic mixtures with both the ether and alkene, and said alkenes are separated from the mixtures by distillation, the improvement for removing alcohols to yield a high purity alkene product stream which comprises: (a) passing the liquid alcohol/ether/alkene mixture to a distillation column capable of separating ether from alkene; (b) withdrawing a liquid side draw stream comprising alcohol/ether/alkene from the distillation column and passing said stream over a pervaporation membrane to produce a vapor alcohol permeate stream and a liquid ether/alkene reject stream; and (c) passing the liquid ether/alkene reject stream back to the distillation column to produce an ether bottom product and a high purity alkene overhead product.
Claim 24
Dependent Claim
141 words
In a process for the production of high purity alkenes by the decomposition of an ether, wherein said ether is decomposed to form a liquid alcohol/ether/alkene mixture in which the alcohol forms azeotropic mixtures with both the ether and alkene, and said alkenes are separated from the mixtures by distillation, the improvement for removing alcohols to yield a high purity alkene product stream which comprises: (a) passing the liquid alcohol/ether/alkene mixture to a distillation column capable of separating ether from alkene; (b) withdrawing a liquid side draw stream comprising alcohol/ether/alkene from the distillation column and passing said stream over a pervaporation membrane to produce a vapor alcohol permeate stream and a liquid ether/alkene reject stream; and (c) passing the liquid ether/alkene reject stream back to the distillation column to produce an ether bottom product and a high purity alkene overhead product.
Claim 25
Dependent Claim
27 words
The process in accordance with claim 20 wherein said ether is initially formed by the reaction of an alcohol with an alkene in an ether synthesis reactor.
Claim 26
Dependent Claim
20 words
The process in accordance with claim 21 wherein the vapor alcohol permeate stream is recycled to the ether synthesis reactor.
Claim 27
Dependent Claim
14 words
The process in accordance with claim 20 wherein the alkene is isobutene or isopentene.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-27 | 1992-03-28 | 1992-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-27 | 1996-03-28 | 1996-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-27 | 2000-03-28 | 2000-09-27 | $7700.00 | Window Closed / Lapsed |