A Two-Stage Continuous Fermentation System for Conversion of Syngas into Ethanol
We have established a two-stage continuous fermentation process for production of ethanol from synthesis gas (syngas) with Clostridium ljungdahlii. The system consists of a 1-L continuously stirred tank reactor as a growth stage and a 4-L bubble column equipped with a cell recycle module as an ethan...
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| Format: | Article |
| Language: | English |
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MDPI AG
2013-08-01
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| Series: | Energies |
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| Online Access: | http://www.mdpi.com/1996-1073/6/8/3987 |
| _version_ | 1811262329972588544 |
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| author | Hanno Richter Michael E. Martin Largus T. Angenent |
| author_facet | Hanno Richter Michael E. Martin Largus T. Angenent |
| author_sort | Hanno Richter |
| collection | DOAJ |
| description | We have established a two-stage continuous fermentation process for production of ethanol from synthesis gas (syngas) with Clostridium ljungdahlii. The system consists of a 1-L continuously stirred tank reactor as a growth stage and a 4-L bubble column equipped with a cell recycle module as an ethanol production stage. Operating conditions in both stages were optimized for the respective purpose (growth in stage one and alcohol formation in stage two). The system was fed with an artificial syngas mixture, mimicking the composition of syngas derived from lignocellulosic biomass (60% CO, 35% H2, and 5% CO2). Gas recycling was used to increase the contact area and retention time of gas in the liquid phase, improving mass transfer and metabolic rates. In stage two, the biocatalyst was maintained at high cell densities of up to 10 g DW/L. Ethanol was continuously produced at concentrations of up to 450 mM (2.1%) and ethanol production rates of up to 0.37 g/(L·h). Foam control was essential to maintain reactor stability. A stoichiometric evaluation of the optimized process revealed that the recovery of carbon and hydrogen from the provided carbon monoxide and hydrogen in the produced ethanol was 28% and 74%, respectively. |
| first_indexed | 2024-04-12T19:23:21Z |
| format | Article |
| id | doaj.art-e2bc3c8363f6469585fab365f0d45d33 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-12T19:23:21Z |
| publishDate | 2013-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-e2bc3c8363f6469585fab365f0d45d332022-12-22T03:19:32ZengMDPI AGEnergies1996-10732013-08-01683987400010.3390/en6083987A Two-Stage Continuous Fermentation System for Conversion of Syngas into EthanolHanno RichterMichael E. MartinLargus T. AngenentWe have established a two-stage continuous fermentation process for production of ethanol from synthesis gas (syngas) with Clostridium ljungdahlii. The system consists of a 1-L continuously stirred tank reactor as a growth stage and a 4-L bubble column equipped with a cell recycle module as an ethanol production stage. Operating conditions in both stages were optimized for the respective purpose (growth in stage one and alcohol formation in stage two). The system was fed with an artificial syngas mixture, mimicking the composition of syngas derived from lignocellulosic biomass (60% CO, 35% H2, and 5% CO2). Gas recycling was used to increase the contact area and retention time of gas in the liquid phase, improving mass transfer and metabolic rates. In stage two, the biocatalyst was maintained at high cell densities of up to 10 g DW/L. Ethanol was continuously produced at concentrations of up to 450 mM (2.1%) and ethanol production rates of up to 0.37 g/(L·h). Foam control was essential to maintain reactor stability. A stoichiometric evaluation of the optimized process revealed that the recovery of carbon and hydrogen from the provided carbon monoxide and hydrogen in the produced ethanol was 28% and 74%, respectively.http://www.mdpi.com/1996-1073/6/8/3987syngasethanolClostridium ljungdahliimass transfercontinuous culture |
| spellingShingle | Hanno Richter Michael E. Martin Largus T. Angenent A Two-Stage Continuous Fermentation System for Conversion of Syngas into Ethanol Energies syngas ethanol Clostridium ljungdahlii mass transfer continuous culture |
| title | A Two-Stage Continuous Fermentation System for Conversion of Syngas into Ethanol |
| title_full | A Two-Stage Continuous Fermentation System for Conversion of Syngas into Ethanol |
| title_fullStr | A Two-Stage Continuous Fermentation System for Conversion of Syngas into Ethanol |
| title_full_unstemmed | A Two-Stage Continuous Fermentation System for Conversion of Syngas into Ethanol |
| title_short | A Two-Stage Continuous Fermentation System for Conversion of Syngas into Ethanol |
| title_sort | two stage continuous fermentation system for conversion of syngas into ethanol |
| topic | syngas ethanol Clostridium ljungdahlii mass transfer continuous culture |
| url | http://www.mdpi.com/1996-1073/6/8/3987 |
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