Acetone, butanol, and ethanol ABE

Separation of citric acid from fermentation broth Separation of lactic acid from fermentation broth Production of acetone, butanol, and ethanol (ABE) from potato wastes Separation of long-chain unsaturated fatty acids... 

Huang et al. (2015c) evaluated acetone, butanol, and ethanol (ABE) fermentation from food waste with and without the use of a vacuum recovery system. Using 129 g/L food waste-based medium, 19.7 g/L of ABE was produced in 48 h without a vacuum system. Glucose concentration peaked at 28.5 g/L at 15 h, and stabilized at 22 g/L after 24 h. ABE productivity of 0.41 g/L-h was observed. At the end of fermentation 21.7 g/L of residual glucose was left in the fermentation broth (Fig. 9.8). When... 

To compare the performance of the reactor and evaluate the effect of CSL incorporation into the feed, the reactor was fed with CSL medium. Fermentation conditions and the dilution rate were kept constant as in Table 1 for the duration of this experiment. The reactor produced 6.29 g/L of total ABE, of which acetone, butanol, and ethanol were 2.00, 4.16, and 0.13 g/L, respectively (Table 1). This resulted in a productivity of 2.01 g/(L h) and a sugar utilization of 30.5% of that available in the feed (67.5 g/L). Compared to the control, the productivity was reduced by 10%. However, it is anticipated that it would be economical to use CSL compared with the P2 medium. This demonstrated that P2 medium can be replaced by economically available CSL. It is suggested, however, that the CSL... 

Next, an experiment was run in which 2.5 g/L of sodium butyrate was added to P2 medium to investigate whether it could be converted to butanol. A control experiment was run containing P2 medium. A separate control experiment was run before each experiment. This is essential because biomass accumulation in the reactor changes with time, thus affecting performance of the reactor (5). The reactor produced 4.77 g/L of total ABE, of which acetone, butanol, and ethanol were 1.51,3.14, and 0.12 g/L, respectively (Table 1). It resulted in a total ABE productivity of 1.53 g/(L-h) and a glucose utilization of 29.4% of that available in the feed of 59.1 g/L. The acid concentration in the effluent was 1.56 g/L. Following this, P2 medium was supplemented with sodium butyrate and the experiment was conducted at the same dilution rate. The reactor produced 1.55 g/L of acetone, 4.04 g/L of butanol, and 0.11 g/L of ethanol, for a total ABE concentration of 5.70 g/L, compared with 4.77 g/L in the control experiment. The productivity was 1.82 g/(L-h), compared with 1.53 g/(L-h) for the control experiment. These experiments suggested that butyrate was used by the culture to produce additional butanol. Note that 0.9 g/L of butanol was produced from 1.65 g/L of butyrate (2.5 g/L in feed, 0.85 g/L in effluent). The yield calculations do not include the amount of butyrate that was utilized by the culture. 

ABE (acetone, butanol, and ethanol) fermentation has a long history of commercial use and perhaps the greatest potential for an industrial comeback. Acetone, butanol, and ethanol can all be isolated from this remarkable metabolic system carbon dioxide and hydrogen are additional products. The solvents were used as paint solvents in the expanding automobile industry. Ultimately these processes proved uncompetitive because of poor yields, low product... 

Kawedia JD, Pangarkar VG, Niranjan K. 2000. Pervaporative stripping of acetone, butanol and ethanol to improve ABE fermentation. Bioseparation 9(3) 145-154. 

As described above, the clostridial ABE fermentative path leads to synthesis of butanol, together with smaller amounts of acetone, ethanol and acetic and butyric acids, together with carhon dioxide and hydrogen (Branduardi et al. 2014). Normally, the solvent ratio of acetone, butanol and ethanol, respectively, is 3 6 1, and the total solvent concentration is around 20 g/L (Connor and Liao 2009). Many natural clostridial strains have the upper butanol tolerance limit at about 11-12 g/L. However, some mutants and engineered strains can tolerate up to 19 g/L of butanol (Jang et al. 2012a). 

ABE fermentation Another name for the Weizmann process used for the production of acetone, butanol, and ethanol using the acid-resistant bacterium Clostridium acetobutylicum. 

Weizmann process A fermentation process used to produce acetone, butanol, and ethanol using the acid-resistant bacterium Clostridium acetobutylicum. The bacteria derived from soil and cereals is able to convert whey, sugar, and starch. The process was developed by Russian-born chemist Chaim Weizmann (1874-1952) and was used in the UK in the First World War for the production of acetone, which was used in the production of cordite. He became a UK citizen in 1910 and then the first president of Israel in 1949. The process is also known as the ABE fermentation. 

Butanol (C4H9OH) is an alcohol produced from starch through ABE fermentation (ie, using acetone, butanol, and ethanol). It can be used in gasoline engines without modifications. 

Nondispeisive phase contact Extraction of products in fermentation process producing ethanol and acetone-butanol-etha-nol (ABE) (microporous/porous hydrophobic membranes)... 

Corn steep liquor (CSL), a byproduct of the com wet-milling process, was used in an immobilized cell continuous biofilm reactor to replace the expensive P2 medium ingredients. The use of CSL resulted in the production of 6.29 g/L of total acetone-butanol-ethanol (ABE) as compared with 6.86 g/L in a control experiment. These studies were performed at a dilution rate of 0.32 hr1. The productivities in the control and CSL experiment were 2.19 and 2.01 g/(Lh), respectively. Although the use of CSL resulted in a 10% decrease in productivity, it is viewed that its application would be economical compared to P2 medium. Hence, CSL may be used to replace the P2 medium. It was also demonstrated that inclusion of butyrate into the feed was beneficial to the butanol fermentation. A control experiment produced 4.77 g/L of total ABE, and the experiment with supplemented sodium butyrate produced 5.70 g/L of total ABE. The butanol concentration increased from 3.14 to 4.04 g/L. Inclusion of acetate in the feed medium of the immobilized cell biofilm reactor was not found to be beneficial for the ABE fermentation, as reported for the batch ABE fermentation. 

Cell concentration in the reactor effluent was estimated by optical density (OD) and cell dry weight method using a predetermined correlation between OD at 540 nm and cell dry weight. Acetone-butanol-ethanol (ABE) and acids (acetic and butyric) were measured using a 6890 Hewlett-Packard gas chromatograph (Hewlett-Packard, Avondale, PA) equipped with a flame ionization detector and 6 ft x 2 mm glass column (10% CW-20M, 0.01% H3P04, support 80/100 Chromosorb WAW). Productivity was calcu-... 

Fig. 2. Kinetics of continuous ABE fermentation at various dilution rates and pH 4.3. Glucose and OD are on the right axis acetone, butanol, ethanol, acetate, and butyrate are on the left axis. (A) Reactor L (B) reactor R.

Ezeji, T.C., Qureshi, N. and Blaschek, H.P. 2004. Acetone Butanol Ethanol (ABE) Production from Concentrated Substrate Reduction in Substrate Inhibition by Fed-Batch Technique and Product Inhibition by Gas Stripping. Appl. Microbiol. Biotechnol., 63,653-658. 

Shukla R, Kang W, and Sirkar KK, Acetone-butanol-ethanol (ABE) production in a novel hoUow Hber fermentor-extractor. Biotechnology and Bioengineering 1989, 34, 1158-1166. 

Banat, F.A. and Al-Shannag, M. Recovery of dilute acetone-butanol-ethanol (ABE) solvents from aqueous solutions using membrane distillation, Bioproc. Eng., 23(6), 643, 2000. 

Fiiedl A, Qureshi N, Maddox IS. 1991. Continuous acetone-butanol-ethanol (ABE) fermentation using immobilized cells of C. acetobutylicum in a packed bed reactor and integration with product removal by pervaporation. Biotechnol. Bioeng. 38 518-527. 

In the group of Sirkar, the application of microporous hollow fibers in the fermentative production of ethanol, acetone-butanol-ethanol (ABE), etc. has been explored. In these systems, the role of the membrane is twofold. First, oxygen or nitrogen is supplied and the reaction products CO2 and H2 are removed. Sec-... 

The industrial production of biobutanol started in 1916 as a fermentation process using bacteria Clostridia acetobutylicum (39). This type of fermentation has been addressed as acetone-butanol-ethanol (ABE) fermentation and is used with molasses and cereal grains. The materials used for ABE fermentation are detailed in Table 11.2. 

Ezeji T, Qureshi N, Blaschek HP. (2007b). Production of acetone-butanol-ethanol (ABE) in a continuous flow bioreactor using degermed com and Clostridium beijerinckii. Process Biochem, 42, 34—39. 

---