CONTINUOUS FERMENTATION OF HIGH-STRENGTH GLUCOSE FEEDS TO ETHANOL

Aqueous feeds of 413 and 495 g/L glucose were fermented to ethanol at 90-95% conversion in a continuous flow extractive fermentation system with cell recycle. Compared to the continuous conventional fermentatio n of a 195 g/L glucose medium, the volumetric productivity was more th an doubled in extractive mode, with no deleterious effects on cell via bility, specific glucose consumption rate or ethanol yield. The use of an effective, biocompatible and stable in situ extractant with flash vaporization can also produce a concentrated ethanol vapour stream, re ducing distillation costs of the product.