US5210296A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of lactate esters and lactic acid from fermentation broth
Assignee: Ecological Chemical Products
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Filing: 1991-06-20
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Granted: 1993-05-11
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Expires: 2011-06-20
Abstract
Abstract The production of high purity lactate ester or lactic acid from a concentrated fermentation broth by continuous acidification in the presence of an alcohol diluent with sequential or simultaneous esterification, distillation off of high purity ester, and, if desired, hydrolysis of the ester to high purity lactic acid.
Inventors
- 👤 Michael C. M. Cockrem
- 👤 Pride D. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:57
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/40; C12P7/56; C07; C07C; C07C67/00; C07C67/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
106 words
A process for recovering high purity lactate ester from a concentrated fermentation broth comprising the steps of: (1) simultaneously mixing a strong acid, an alcohol, and a concentrated fermentation broth which contains mainly basic salts of lactic acid, which react to form a crystal precipitate comprising basic salts of the strong acid and an impure lactate ester of the alcohol; (2) removing water from the mixture as a water/alcohol azeotrope which can be accomplished either sequentially or substantially simultaneously with step (1); (3) removing the crystal precipitate from the mixture; and (4) distilling the impure lactate ester to remove impurities, and recovering the high purity ester.
Claim 2
Dependent Claim
106 words
A process for recovering high purity lactate ester from a concentrated fermentation broth comprising the steps of: (1) simultaneously mixing a strong acid, an alcohol, and a concentrated fermentation broth which contains mainly basic salts of lactic acid, which react to form a crystal precipitate comprising basic salts of the strong acid and an impure lactate ester of the alcohol; (2) removing water from the mixture as a water/alcohol azeotrope which can be accomplished either sequentially or substantially simultaneously with step (1); (3) removing the crystal precipitate from the mixture; and (4) distilling the impure lactate ester to remove impurities, and recovering the high purity ester.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein the alcohol contains from 4 to 5 carbon atoms.
Claim 4
Dependent Claim
39 words
The process of claim 2 wherein the alcohol contains an alcohol selected from the group consisting of: iso-butanol (2-methyl-1-propanol), 1-butanol, 2-methyl-2-butanol (tert amyl alcohol), (DL, L or D)-3-methyl-2-butanol, 3-pentanol (sec-amyl alcohol), 2-pentanol, and (DL, L or D)-2-methyl-1-butanol (iso-amyl alcohol).
Claim 5
Dependent Claim
22 words
The processes of claims 1 to 3 comprising the additional step of hydrolyzing the lactate ester to form high purity lactic acid.
Claim 6
Dependent Claim
30 words
The processes of claims 1 to 4 wherein the concentrated fermentation broth contains at least 10% water and at least 45% ammonium lactate, and the strong acid is sulfuric acid.
Claim 7
Dependent Claim
16 words
The process of claim 5 wherein ammonium sulfate is crystallized out in draft tube baffled crystallizers.
Claim 8
Dependent Claim
16 words
The processes of claims 1 to 6 wherein the precipitated crystals are washed with dry alcohol.
Claim 9
Dependent Claim
28 words
The process of claim 1 wherein the fermentation broth contains ammonium lactate of at least 98% optical purity and the lactate ester is at least 97% optically pure.
Claim 10
Dependent Claim
15 words
The process of claim 4 wherein the lactic acid is at least 97% optically pure.
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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) | 1996-05-10 | 1996-11-09 | 1997-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-10 | 2000-11-09 | 2001-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-10 | 2004-11-09 | 2005-05-11 | $7700.00 | Window Closed / Lapsed |