The two stage immobilized column reactor with an integrated solvent recovery module for enhanced ABE production

The production of acetone, butanol, and ethanol (ABE) by fermentation is a process that had been used by industries for decades. Two stage immobilized column reactor system integrated with liquid–liquid extraction was used with immobilized Clostridium acetobutylicum DSM 792, to enhance the ABE productivity and yield. The sugar mixture (glucose, mannose, galactose, arabinose, and xylose) representative to the lignocellulose hydrolysates was used as a substrate for continuous ABE production. Maximum total ABE solvent concentration of 20.30 g L−1 was achieved at a dilution rate (D) of 0.2 h−1, with the sugar mixture as a substrate. The maximum solvent productivity (10.85 g L−1 h−1) and the solvent yield (0.38 g g−1) were obtained at a dilution rate of 1.0 h−1. The maximum sugar mixture utilization rate was achieved with the present set up which is difficult to reach in a single stage chemostat. The system was operated for 48 days without any technical problems.