US3944606A
Expired / Lapsed
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Process of producing alkali metal or ammonium citrates
Assignee: Joh A Benckiser GmbH
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Filing: 1974-10-29
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Granted: 1976-03-16
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Expires: 1994-10-29
Abstract
Abstract Alkali metal or ammonium citrates are produced from solutions of citric acid obtained by chemical reaction or by fermentation by extraction by means of a specific water-immiscible mixture of aliphatic amines and organic solvents and re-extracting the resulting organic solvent mixture with an aqueous solution of an alkali metal hydroxide, carbonate or bicarbonate, ammonia, or their salts.
Inventors
- 👤 Manfred Rieger
- 👤 Johannes Kioustelidis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:50
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/40; C12P7/44; C12P7/48; B; B01; B01D; B01D11/00; B01D11/04; B01D11/0488; C07; C07C; C07C51/00; C07C51/41; C07C51/412
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
105 words
In a process of producing alkali metal or ammonium citrates from citric acid solutions produced chemically or by fermentation, by extraction, the steps which comprise a. extracting the starting citric acid solution by means of a water-immiscible solvent mixture of an amine of the formula ##EQU4## in which R 1 and R 2 are alkyl radicals with 7 to 15 carbon atoms and R 3 is hydrogen or an alkyl radical with 1 to 15 carbon atoms, and an organic solvent as extracting agent and b. subsequently re-extracting the resulting organic solvent extract with a compound forming alkali metal or ammonium salts of citric acid.
Claim 2
Dependent Claim
105 words
In a process of producing alkali metal or ammonium citrates from citric acid solutions produced chemically or by fermentation, by extraction, the steps which comprise a. extracting the starting citric acid solution by means of a water-immiscible solvent mixture of an amine of the formula ##EQU4## in which R 1 and R 2 are alkyl radicals with 7 to 15 carbon atoms and R 3 is hydrogen or an alkyl radical with 1 to 15 carbon atoms, and an organic solvent as extracting agent and b. subsequently re-extracting the resulting organic solvent extract with a compound forming alkali metal or ammonium salts of citric acid.
Claim 3
Dependent Claim
23 words
The process of claim 1, in which the proportion, by volume, of amine to organic solvent is between about 0.05 and about 2.0.
Claim 4
Dependent Claim
22 words
The process of claim 1, in which the proportion, by volume, of amine to organic solvent is between about 0.3 and 0.7.
Claim 5
Dependent Claim
22 words
The process of claim 1, in which the molar proportion of amine to citric acid is between about 0.5 and about 10.0.
Claim 6
Dependent Claim
22 words
The process of claim 1, in which the molar proportion of amine to citric acid is between about 1.5 and about 3.5.
Claim 7
Dependent Claim
22 words
The process of claim 3, in which the molar proportion of amine to citric acid is between about 0.5 and about 10.0.
Claim 8
Dependent Claim
22 words
The process of claim 3, in which the molar proportion of amine to citric acid is between about 1.5 and about 3.5.
Claim 9
Dependent Claim
11 words
The process of claim 1, in which the amine is tri-isononylamine.
Claim 10
Dependent Claim
11 words
The process of claim 1, in which the amine is tri-n-decylamine.
Claim 11
Dependent Claim
27 words
The process of claim 1, in which the organic solvent is a water-immiscible solvent selected from the group consisting of hydrocarbons, alcohols, esters, ketones, and mixtures thereof.
Claim 12
Dependent Claim
27 words
The process of claim 1, in which the equivalent proportion of re-extracting solvent to citric acid in the organic extract is between about 0.1 and about 1.2.
Claim 13
Dependent Claim
27 words
The process of claim 1, in which the equivalent proportion of re-extracting agent to citric acid in the organic extract is between about 0.4 to about 0.95.
Claim 14
Dependent Claim
38 words
The process of claim 1, in which the re-extracting agent is a solution selected from the group consisting of solutions of alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia, and salts of alkali metal and ammonia.
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |