Progress 07/01/00 to 06/30/04
Outputs
C-FAR 2001 Internal. Butanol is an important industrial chemical which can be produced by fermentation from agricultural products such as corn using hyper butanol producing strain Clostridium beijerinckii BA101 developed at the University of Illinois. Compared to the current popular fuel additive, ethanol, butanol is more miscible with gasoline and diesel fuel and has a higher energy content. Production of butanol is hampered due to cost-ineffective recovery by distillation. For this reason we investigated recovery of butanol by gas stripping, a process which does not require expensive chemical/s or membrane. Additionally, with this process, gases that are used to recover butanol are produced within the system. In order to recover butanol from fermentation broth four successful systems have been developed. These include: 1) Batch; 2) Concentrated feed batch; 3) Fed-batch; and 4) Continuous. In all these processes butanol was removed simultaneously as it was produced.
Inbibition caused by butanol was reduced and concentrated product streams (butanol) were obtained.
Impacts
Four different successful processes have been developed for the conversion of corn to butanol using Clostridium beijerinckii. Compared to previous studies on the production and recovery of butanol (by various techniques), the developed techniques/systems are more energy efficient and have potential for commercialization. We have been providing our results to the Illinois Corn Marketing Board and are working with Archer Daniels Midland (ADM) company on commercialization.
Publications
- Ezeji, T.C., Qureshi, N. and Blaschek, H.P. 2004. Acetone-butanol-ethanol production from concentrated substrate: Reduction in substrate inhibition by fed-batch technique and product inhibition by gas stripping. Appl. Microbiol. & Biotechnol. 63: 653-658.
- Ezeji, T.C., Qureshi, N. and Blaschek, H.P. 2003. Production of butanol by Clostridium beijerinckii BA101 and in-situ recovery by gas stripping. World J. Microbiol. & Biotechnol. 19: 595-603.
- Ezeji, T.C., Karcher, P.M., Qureshi, N. and Blaschek, H.P. 2005. Improving performance of a gas stripping-based recovery system to remove butnaol from Clostridium beijerinckii fermentation. Bioprocess & Biosystems Engineering (Submitted).
- Patent Disclosure: Process for continuous solvent production (2004). Disclosure number TF02226.
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Progress 01/01/03 to 12/31/03
Outputs
C-FAR 2001 Internal. We developed an integrated and highly efficient acetone-butanol (AB) fermentation system which allows for simultaneous AB production and product recovery by gas stripping. Gases (CO2 & H2) produced during the fermentation are used for the stripping process and recycled. This technique was developed in order to overcome butanol toxicity to the culture without compromising culture stability or performance. The system offers the advantages of high productivity, use of concentrated feed streams, reduction in reactor size, efficient recovery of products, and is relatively easy and inexpensive to operate. In a control batch reactor the culture produced 17.6 g/L total solvents, while in the continuous integrated process and recovery by gas stripping, it produced 460.4 g/L total solvents (acetone 204.01 g/L, butanol 251.27 g/L and ethanol 5.08 g/L). The continuous reactor was operated and intentionally terminated after 21 days. Average solvent yield and
productivity were 0.39 and 0.91 g/L/h, respectively. Solvent productivity in the integrated continuous ABE fermentation was improved by more than 300 % relative to the control batch fermentation.
Impacts
It is anticipated that if the results that we achieved at the IL laboratory scale could be achieved in a scaled-up reactor, the butanol fermentation would be that much closer to commercialization.
Publications
- Ezeji, T.C., Qureshi, N. and Blaschek, H.P. 2003. Production of acetone, butanol and ethanol by Clostridium beijerinckii BA101 and in situ recovery by gas stripping. World J. Microbiol. and Biotechnol. 19:595-603.
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Progress 01/01/02 to 12/31/02
Outputs
C-FAR 2001 Internal. Butanol was produced in batch reactors with substrate concentration ranging from 60 - 162 g/l. During fermentation, butanol was recovered simultaneously by gas stripping. Butanol, which is toxic to the cells of Clostridium beijerinckii BA101, was produced in the integrated system where production and recovery were combined. This helped alleviate the toxicity problem. From 162 g/L sugar approximately 76 g/L butanol (plus acetone and ethanol) was produced. Further the studies were extended to a fed-batch reactor where 500 g/L sugar solution was used to reduce process stream volume. Continuous fermentation studies are underway.
Impacts
The integrated process of butanol production and recovery by gas stripping appears to be an economical option compared to other solvent fermentation and recovery systems. These studies would bring butanol production from corn closer to commercialization.
Publications
- Ezeji, T.C., Qureshi, N., Blaschek, H.P. 2003. Production of acetone butanol ethanol by Clostridium beijerinckii BA101 and in-situ recovery by gas stripping. World J Microbiol & Biotechnol. (In Press).
- Ezeji, T.C., Qureshi, N., Blaschek, H.P. 2003. Butanol production in a Fed-batch reactor and recovery by gas stripping. J. Ind. Microbiol. and Biotechnol. (In Preparation).
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Progress 01/01/01 to 12/31/01
Outputs
C-FAR 2001 Internal. Experiments on removal of butanol from model butanol solutions by gas stripping have been performed and rates of butanol removal at various butanol concentrations have been calculated. These experiments were useful in planning experiments for removal of butanol from actual fermentation broth. Batch fermentations containing 60 g/L carbohydrates were run and acetone butanol ethanol (ABE) was removed by gas stripping. The experiments were clear indications that butanol producing mutant strain (Clostridium beijerinckii BA101) was not negatively affected by in-situ gas stripping. An experiment was run with 160 g/L carbohydrate and ABE was removed by gas stripping. The culture utilized approximately 120 g/L carbohydrate leaving behind 40 g/L unused carbohydrate. A continuous free cell fermentation has been run with an objective to separate growth and butanol production. Once adequate data have been collected, the culture growth and butanol removal will
be separated. Further experiments are in progress.
Impacts
Simultaneous butanol fermentation and gas stripping would economize the process of butanol production from corn. This would benefit Illinois and U.S. farmers.
Publications
- No publications reported this period
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Progress 01/01/00 to 12/31/00
Outputs
C-FAR 2001 Internal. Since this project was funded a literature search on the recovery of butanol from fermentation broth by gas stripping has been completed. The results from different authors work have been analyzed. Those results are proving to be useful in planning butanol gas stripping studies. Butanol fermentation kinetics in single and double stage reactors and butanol removal is being planned.
Impacts
These studies would economize bioconversion of corn to butanol. Illinois and United States farmers would benefit from this research.
Publications
- No publications reported this period
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