US3844903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separating alpha, beta-unsaturated carboxylic acids from aqueous solutions by azeotropic distillation with excess solvent
Assignee: BASF SE
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Filing: 1972-04-27
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Granted: 1974-10-29
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Expires: 1992-04-27
Abstract
Abstract Alpha , Beta -Unsaturated carboxylic acids which have been prepared by catalytic oxidation of the corresponding olefins bearing terminal double bonds or the corresponding Alpha , Beta -unsaturated aldehydes with oxygen or oxygen-containing gases, and by-products formed in this reaction may be removed from their aqueous solutions by azeotropic distillation using hydrophobic solvents which boil at higher temperatures than the carboxylic acids and which do not form azeotropes with the substances to be separated, provided that an organic solvent boiling at a higher temperature than all of the products to be removed by distillation is added in a quantity which is in excess of that required for the azeotropic removal of the water.
Inventors
- 👤 C Willersinn
- 👤 F Reicheneder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:13
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/25; C07C51/252; C07C51/42; C07C51/43; C07C51/44; C07C51/46; Y; Y10; Y10S; Y10S203/00; Y10S203/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
142 words
IN A PROCESS FOR RECOVERY ACRYLIC ACID FROM AN AQUEOUS SOLUTION CONTAINING FROM 10 TO 80 PERCENT BY WEIGHT OF ACRYLIC ACID, 20 TO 80 PERCENT WATER AND BYPRODUCTS OF THE PROPYLENE OXIDATION PROCESS SELCTED FROM THE GROUP CONSISTING OF ACETIC COMPRISING: DISTILLING OFF WATER FROM SAID AQUEOUS SOLUTION AZEOTROPICALLY IN A DISTILLATION COLUMN WHILE ADDING AN AMOUNT OF A HYDROPHOBIC ORGANIC SOLVENT WHICH IS FROM 100 TO 5,00 TIMES GREATER THAN THAT REQUIRED FOR THE AZEOTROPIC REMOVAL OF THE WATER, WHICH HYDROPHOBIC ORGANIC SOLVENT BOILS AT HIGGHER TEMPERATURES THAN ACRYLIC ACID, DOES NOT FORM AZEOTROPES WITH SAID ACIDS AND MALEIC ANHYDRIDE AND, UNDER THE CONDITIONS OF THE AZEOTROPIC DISTILLATION, BOILS AT LEAST 20* C HIGHER THAN MALEIC ANHYDRIDE UP TO 300* C AND WITHDRAWING THE ACRYLIC ACID AND THE BULK OF THE HYDROPHOBIC ORGANIC SOLVENT FROM THE BOTTOM OF SAID COLUMN.
Claim 2
Dependent Claim
142 words
IN A PROCESS FOR RECOVERY ACRYLIC ACID FROM AN AQUEOUS SOLUTION CONTAINING FROM 10 TO 80 PERCENT BY WEIGHT OF ACRYLIC ACID, 20 TO 80 PERCENT WATER AND BYPRODUCTS OF THE PROPYLENE OXIDATION PROCESS SELCTED FROM THE GROUP CONSISTING OF ACETIC COMPRISING: DISTILLING OFF WATER FROM SAID AQUEOUS SOLUTION AZEOTROPICALLY IN A DISTILLATION COLUMN WHILE ADDING AN AMOUNT OF A HYDROPHOBIC ORGANIC SOLVENT WHICH IS FROM 100 TO 5,00 TIMES GREATER THAN THAT REQUIRED FOR THE AZEOTROPIC REMOVAL OF THE WATER, WHICH HYDROPHOBIC ORGANIC SOLVENT BOILS AT HIGGHER TEMPERATURES THAN ACRYLIC ACID, DOES NOT FORM AZEOTROPES WITH SAID ACIDS AND MALEIC ANHYDRIDE AND, UNDER THE CONDITIONS OF THE AZEOTROPIC DISTILLATION, BOILS AT LEAST 20* C HIGHER THAN MALEIC ANHYDRIDE UP TO 300* C AND WITHDRAWING THE ACRYLIC ACID AND THE BULK OF THE HYDROPHOBIC ORGANIC SOLVENT FROM THE BOTTOM OF SAID COLUMN.
Claim 3
Dependent Claim
21 words
A method as in claim 1 wherein said Aqueous solution contains from 1 to 5 percent by weight of maleic acid.
Claim 4
Dependent Claim
20 words
A method as in claim 1 wherein said aqueous solution contains from 40 to 80 percent by weight of water.
Claim 5
Dependent Claim
21 words
A method as in claim 3 wherein said aqueous solution contains from 15 to 60 percent by weight of acrylic acid.
Claim 6
Dependent Claim
28 words
A method as in claim 4 wherein the amount of hydrophobic organic solvent is 120 to 4,000 times what is required for the azeotropic removal of the water.
Claim 7
Dependent Claim
34 words
A method as in claim 1 wherein said organic solvent is selected from the group consisting of adipic acid dinitrile, 2-ethylhexanoic acid, dimethyl and dibutyl phthalates, tributyl phosphate, diphenyl ether, diphenyl and mixtures thereof.
Claim 8
Dependent Claim
13 words
A method as in claim 1 wherein said organic solvent contains dimethyl phthalate.
Claim 9
Dependent Claim
14 words
A method as in claim 1 wherein said organic solvent contains adipic acid dinitrile.
Claim 10
Dependent Claim
18 words
A method as in claim 1 wherein said organic solvent is a mixture of diphenyl ether and diphenyl.
Claim 11
Dependent Claim
13 words
A method as in claim 1 wherein said organic solvent contains di-n-butyl phthalate.
Claim 12
Dependent Claim
13 words
A method as in claim 1 wherein said organic solvent contains tri-n-butyl phosphate.
Claim 13
Dependent Claim
13 words
A method as in claim 1 wherein said organic solvent contains 2-ethylhexanoic acid.
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) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |