Production of acetone,butanol and ethanol (ABE) from potato wastes: fermentation with integrated membrane extraction

The technical possibilities of the microbial production of acetone, butanol and ethanol (ABE) from potato waste using in-line solvent recovery, are evaluated. Clostridium acetobutylicum DSM 1731 produces up to 20 g·l^–1 of solvents when grown on a medium containing 14% (w/v) potato powder. Using a polypropylene perstraction system and a oleyl alcohol/decane mixture as the extractant, the product yield (based on total solvents and potato dry weight) increased from 0.13 g·g^–1 to 0.23 g·g^–1. The recovery system worked well for 50 h, after which membrane fouling frustrated proper operation. In the second system a microfiltration step was incorporated whereas the solvents were extracted through a hydrophilic membrane using fatty acid methyl esters from sunflower oil as an extractant. This process configuration resulted in a comparable increase of ABE production. Correspondence to: G. Eggink