Performance of fed-batch acetone-butanol-ethanol (ABE) fermentation coupled with the integrated in situ extraction-gas stripping process and the fractional condensation

In this study, fed-batch acetone-butanol-ethanol (ABE) fermentation was coupled with the integrated in situ extraction-gas stripping process. The total glucose consumptions were 255 and 310 at the gas flow rates of 0.5 and 1.0 liter per minute (lpm), respectively. The ABE productivity and yield were 0.65 g/L/h and 0.43 g-solvent/g-glucose at the gas flow rates of 0.5 lpm. When the gas flow rates increased from 0.5 to 1.0 lpm, the ABE productivity and yield became 0.69 g/L/h and 0.48 g-solventig-glucose, respectively. The fractional condensation was operated by using two different cold traps where temperatures for the first and second one were 2 and -196 degrees C, respectively. It was found that 71-81 and 64-73% of total stripped water was condensed in the 2 degrees C cold trap at gas flow rates of 0.5 and 1.0 lpm, respectively. Therefore, high ABE concentrations of 360-460 g/L were found in the second cold trap. The overall separation factor for butanol was calculated to be up to 34 where the raffinate solution is the fermentation broth and the extract solution is the condensate in the -196 degrees C cold trap. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.