Continuous production of butanol from a glucose/xylose mixture with an immobilized cell system coupled to pervaporation.

Glucose and xylose can be converted continuously and simultaneously to butanol using immobilized cells. Xylose is only converted when glucose is completely consumed and the biocatalyst is not fully inhibited by butanol. With pervaporation for in-situ butanol recovery the complete conversion of a feed containing 60 kg/m3 of mixed sugars is achieved.