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Title: Continuous membrane fermentor separator for ethanol fermentation

Thesis/Dissertation ·
OSTI ID:6914669

The inhibiting effect of ethanol on yeast growth and ethanol production has been studied using the strain Saccharomyces cerevisiae NRRL-Y-2034 under anaerobic conditions. Batch and continuous fermentation data were fitted to a kinetic model. The integration of continuous fermentation and separation of ethanol in the same unit has been proposed. Pervaporation with ethanol selective silicone rubber hollow fiber membranes was considered for separation. A laboratory scale Continuous Membrane Fermentor Separator (CMFS) unit utilizing a shell and tube configuration was designed and fabricated. Two types of continuous fermentation experiments were carried out: fermentation with dead membranes as the reference and fermentation with live membranes through which ethanol was continuously removed by pervaporation from the fermentor. Performance of the CMFS results in higher yeast cell densities, reduction of ethanol inhibition, longer residence time of substrate, more glucose consumption, and recovery of clean and concentrated ethanol. A mathematical model was developed and used to determine the effects of design and operation parameters of the CMFS, including dilution rate, dimensionless membrane volume, substrate concentration, membrane properties, etc. Computer simulation results indicated that the CMFS could provide significant improvements not only in ethanol productivity but also in glucose consumption for highly concentrated substrate when the dimensionless membrane volume and/or permeability of ethanol was increased.

Research Organization:
Cincinnati Univ., OH (USA)
OSTI ID:
6914669
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English