US4876196A
Expired / Lapsed
US
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Method of continuously producing ethanol from sugar-containing substrates
Assignee: Vogelbusch GmbH
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Filing: 1988-01-27
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Granted: 1989-10-24
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Expires: 2008-01-27
Abstract
Abstract In a method of continuously producing ethanol from sugar-containing substrates by fermentation of sugars by means of a flocculating strain of Zymomonas mobilis under anaerobic conditions and at a pH of from 4.5 to 7 a substrate is led commonly with Zymomonas mobilis cells through at least three fermentation stages without preceding sterilization, a concentration of at least 4% by volume of ethanol is maintained in each fermentation stage, a residence time of the fermentation medium in the entire system of maximally 31/3 h corresponding to a dilution rate of the fermentation medium in the entire system of at least 0.3 h -1 is adjusted, the Zymomonas mobilis cells are separated by sedimentation after the final fermentation stage, the Zymomonas mobilis cells are recycled into the first fermentation stage, and the ethanol-containing substrate separated from the Zymomonas mobilis cells is drawn off.
Inventors
- 👤 Wolfgang Salzbrunn
- 👤 Eva Steiner
- 👤 Wilfried Wohrer
- 👤 Otto Meixner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:35
CPC Classifications
C; C12; C12P; C12P7/00; C12P7/02; C12P7/04; C12P7/06; C12P7/065; Y; Y02; Y02E; Y02E50/00; Y02E50/10; Y02P; Y02P20/00; Y02P20/50; Y02P20/582; Y10; Y10S; Y10S435/00; Y10S435/813; Y10S435/8215; Y10S435/822
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
157 words
A method of continuously producing ethanol from sugar-containing substrates comprising fermentation of the sugar in said substrates by a flocculating strain of Zymomonas mobilis cells under anaerobic conditions, the method consisting essentially of: flowing a fermentation medium comprising said substrates and said Zymomonas mobilis cells through at least three fermentation stages of a fermentation system without preceding sterilization; maintaining a concentration of at least 4% by volume of ethanol and a pH of about 5 in each of said fermentation stages; maintaining a residence time of said fermentation medium in said fermentation stages of up to about 3 h., corresponding to a dilution rate of said fermentation medium in said fermentation stages of at least about 1/3h -1 ; separating the Zymomonas mobilis cells after the final fermentation stage by sedimentation to form ethanol-containing substrates, and recycling said Zymomonas mobilis cells into the first fermentation stage; and removing said ethanol-containing substrates separated from said Zymomonas mobilis cells.
Claim 2
Independent Claim
157 words
A method of continuously producing ethanol from sugar-containing substrates comprising fermentation of the sugar in said substrates by a flocculating strain of Zymomonas mobilis cells under anaerobic conditions, the method consisting essentially of: flowing a fermentation medium comprising said substrates and said Zymomonas mobilis cells through at least three fermentation stages of a fermentation system without preceding sterilization; maintaining a concentration of at least 4% by volume of ethanol and a pH of about 5 in each of said fermentation stages; maintaining a residence time of said fermentation medium in said fermentation stages of up to about 3 h., corresponding to a dilution rate of said fermentation medium in said fermentation stages of at least about 1/3h -1 ; separating the Zymomonas mobilis cells after the final fermentation stage by sedimentation to form ethanol-containing substrates, and recycling said Zymomonas mobilis cells into the first fermentation stage; and removing said ethanol-containing substrates separated from said Zymomonas mobilis cells.
Claim 3
Dependent Claim
49 words
A method as set forth in claim 1, wherein said residence time of said fermentation medium in said fermentation stages is adjusted to from 0.8 to 2.5 h corresponding to a dilution rate of said fermentation medium in said fermentation stages of from 0.4 to 1.25 h -1 .
Claim 4
Dependent Claim
40 words
A method as set forth in claim 1, wherein CO 2 is formed in each one of said at least three fermentation stages and wherein at least a part of the CO 2 formed is circulated in the respective stage.
Claim 5
Dependent Claim
44 words
A method as set forth in claim 1, wherein ethanol is recovered from said drawn-off ethanol-containing substrate and distillery slops remain, and wherein at least a part of said distillery slops is recycled into the first one of said at least three fermentation stages.
Claim 6
Dependent Claim
34 words
A method as set forth in claim 1 wherein additional substrate is added to each stage as required to adapt the ratio of microorganism population to the alcohol and sugar concentration in each stage.
Claim 7
Dependent Claim
24 words
A method as set forth in claim 1 wherein a pH adjusting dent is added to each stage as required to control the pH.
Claim 8
Dependent Claim
32 words
A method as set forth in claim 6 wherein said substrate contains ammonium sulfate, the ammonium ions being taken up by the Zymomonas mobilis organisms, and said pH adjusting agent is lye.
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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) | 1992-10-23 | 1993-04-24 | 1993-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-23 | 1997-04-24 | 1997-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-23 | 2001-04-24 | 2001-10-24 | $7700.00 | Window Closed / Lapsed |