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Evaluation of hydrophobic micro-zeolite-mixed matrix membrane and integrated with acetone-butanol-ethanol fermentation for enhanced butanol production.

Xue C, Yang D, Du G, Chen L, Ren J, Bai F - Biotechnol Biofuels (2015)

Bottom Line: The overall butanol productivity and yield increased by 16.0 and 11.1%, respectively, which was attributed to the alleviated butanol inhibition by pervaporation and reassimilation of acids for ABE production.Zeolite loading in the PDMS matrix was attributed to improving the pervaporative performance of the membrane, showing great potential to recover butanol with high purity.Therefore, this zeolite-mixed PDMS membrane had the potential to improve biobutanol production when integrating with ABE fermentation.

View Article: PubMed Central - PubMed

Affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Linggong Road 2, Dalian, 116024 China.

ABSTRACT

Background: Butanol is regarded as an advanced biofuel that can be derived from renewable biomass. However, the main challenge for microbial butanol production is low butanol titer, yield and productivity, leading to intensive energy consumption in product recovery. Various alternative separation technologies such as extraction, adsorption and gas stripping, etc., could be integrated with acetone-butanol-ethanol (ABE) fermentation with improving butanol productivity, but their butanol selectivities are not satisfactory. The membrane-based pervaporation technology is recently attracting increasing attention since it has potentially desirable butanol selectivity.

Results: The performance of the zeolite-mixed polydimethylsiloxane (PDMS) membranes were evaluated to recover butanol from butanol/water binary solution as well as fermentation broth in the integrated ABE fermentation system. The separation factor and butanol titer in permeate of the zeolite-mixed PDMS membrane were up to 33.0 and 334.6 g/L at 80°C, respectively, which increased with increasing zeolite loading weight in the membrane as well as feed temperature. The enhanced butanol separation factor was attributed to the hydrophobic zeolites with large pore size providing selective routes preferable for butanol permeation. In fed-batch fermentation incorporated with pervaporation, 54.9 g/L ABE (34.5 g/L butanol, 17.0 g/L acetone and 3.4 g/L ethanol) were produced from 172.3 g/L glucose. The overall butanol productivity and yield increased by 16.0 and 11.1%, respectively, which was attributed to the alleviated butanol inhibition by pervaporation and reassimilation of acids for ABE production. The zeolite-mixed membrane produced a highly concentrated condensate containing 169.6 g/L butanol or 253.3 g/L ABE, which after phase separation easily gave the final product containing >600 g/L butanol.

Conclusions: Zeolite loading in the PDMS matrix was attributed to improving the pervaporative performance of the membrane, showing great potential to recover butanol with high purity. Therefore, this zeolite-mixed PDMS membrane had the potential to improve biobutanol production when integrating with ABE fermentation.

No MeSH data available.


Related in: MedlinePlus

ABE fermentation by pervaporation with the zeolite-mixed PDMS membrane. a Kinetics of products and glucose concentrations in the fermentation broth, b pervaporation performance of the membrane during ABE fermentation.
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Fig2: ABE fermentation by pervaporation with the zeolite-mixed PDMS membrane. a Kinetics of products and glucose concentrations in the fermentation broth, b pervaporation performance of the membrane during ABE fermentation.

Mentions: The time course of fed-batch ABE fermentation incorporating the zeolite-mixed membrane is shown in Figure 2a. As shown in Figure 2a, the ABE fermentation was initiated with P2 medium containing ~80.0 g/L glucose, and then ABE and acids were produced gradually with time. When glucose was reduced to 9.0 g/L at 37 h, the fed-batch medium containing ~400 g/L glucose was fed into the bioreactor intermittently until the end of fermentation. When the butanol titer increased to 5.7 g/L, the pervaporation was started at 24 h. As seen in Figure 2a, from 28 h to the end of the fermentation, due to the removal of products from the fermentation broth by pervaporation, butanol, acetone and ethanol titer in the fermentation broth were relatively stable in the range of 6.7–8.5, 4.4–5.3 and 0.6–2.9 g/L. The demonstrating results above indicated that the in situ product recovery with the zeolite-mixed membrane could make the products titer in fermentation broth within the stable ranges by the continuous removal of ABE solvents.Figure 2


Evaluation of hydrophobic micro-zeolite-mixed matrix membrane and integrated with acetone-butanol-ethanol fermentation for enhanced butanol production.

Xue C, Yang D, Du G, Chen L, Ren J, Bai F - Biotechnol Biofuels (2015)

ABE fermentation by pervaporation with the zeolite-mixed PDMS membrane. a Kinetics of products and glucose concentrations in the fermentation broth, b pervaporation performance of the membrane during ABE fermentation.
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4513751&req=5

Fig2: ABE fermentation by pervaporation with the zeolite-mixed PDMS membrane. a Kinetics of products and glucose concentrations in the fermentation broth, b pervaporation performance of the membrane during ABE fermentation.
Mentions: The time course of fed-batch ABE fermentation incorporating the zeolite-mixed membrane is shown in Figure 2a. As shown in Figure 2a, the ABE fermentation was initiated with P2 medium containing ~80.0 g/L glucose, and then ABE and acids were produced gradually with time. When glucose was reduced to 9.0 g/L at 37 h, the fed-batch medium containing ~400 g/L glucose was fed into the bioreactor intermittently until the end of fermentation. When the butanol titer increased to 5.7 g/L, the pervaporation was started at 24 h. As seen in Figure 2a, from 28 h to the end of the fermentation, due to the removal of products from the fermentation broth by pervaporation, butanol, acetone and ethanol titer in the fermentation broth were relatively stable in the range of 6.7–8.5, 4.4–5.3 and 0.6–2.9 g/L. The demonstrating results above indicated that the in situ product recovery with the zeolite-mixed membrane could make the products titer in fermentation broth within the stable ranges by the continuous removal of ABE solvents.Figure 2

Bottom Line: The overall butanol productivity and yield increased by 16.0 and 11.1%, respectively, which was attributed to the alleviated butanol inhibition by pervaporation and reassimilation of acids for ABE production.Zeolite loading in the PDMS matrix was attributed to improving the pervaporative performance of the membrane, showing great potential to recover butanol with high purity.Therefore, this zeolite-mixed PDMS membrane had the potential to improve biobutanol production when integrating with ABE fermentation.

View Article: PubMed Central - PubMed

Affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Linggong Road 2, Dalian, 116024 China.

ABSTRACT

Background: Butanol is regarded as an advanced biofuel that can be derived from renewable biomass. However, the main challenge for microbial butanol production is low butanol titer, yield and productivity, leading to intensive energy consumption in product recovery. Various alternative separation technologies such as extraction, adsorption and gas stripping, etc., could be integrated with acetone-butanol-ethanol (ABE) fermentation with improving butanol productivity, but their butanol selectivities are not satisfactory. The membrane-based pervaporation technology is recently attracting increasing attention since it has potentially desirable butanol selectivity.

Results: The performance of the zeolite-mixed polydimethylsiloxane (PDMS) membranes were evaluated to recover butanol from butanol/water binary solution as well as fermentation broth in the integrated ABE fermentation system. The separation factor and butanol titer in permeate of the zeolite-mixed PDMS membrane were up to 33.0 and 334.6 g/L at 80°C, respectively, which increased with increasing zeolite loading weight in the membrane as well as feed temperature. The enhanced butanol separation factor was attributed to the hydrophobic zeolites with large pore size providing selective routes preferable for butanol permeation. In fed-batch fermentation incorporated with pervaporation, 54.9 g/L ABE (34.5 g/L butanol, 17.0 g/L acetone and 3.4 g/L ethanol) were produced from 172.3 g/L glucose. The overall butanol productivity and yield increased by 16.0 and 11.1%, respectively, which was attributed to the alleviated butanol inhibition by pervaporation and reassimilation of acids for ABE production. The zeolite-mixed membrane produced a highly concentrated condensate containing 169.6 g/L butanol or 253.3 g/L ABE, which after phase separation easily gave the final product containing >600 g/L butanol.

Conclusions: Zeolite loading in the PDMS matrix was attributed to improving the pervaporative performance of the membrane, showing great potential to recover butanol with high purity. Therefore, this zeolite-mixed PDMS membrane had the potential to improve biobutanol production when integrating with ABE fermentation.

No MeSH data available.


Related in: MedlinePlus