Conversion of Food Processing Wastes into Ethanol Using a Novel Biological Reactor/Separator. Final Report, September 1, 1984-September 30, 1985

摘要

This project deals with scaling up and operating a novel Immobilized Cell Reactor-Separator (ICRS) developed at Purdue University. This reactor uses gas flow through an immobilized cell reactor to remove a volatile product (ethanol) from the fermentation broth. It was found that the life and performance of a small scale reactor could run continuously - 24 hours/day - for a year with no systematic decay in performance. Some contaminants such as wild yeasts or lactobaccillus were able to successfully colonize the reactor causing a performance decay although most contaminants are inhibited by the selective conditions of high acidity, presence of ethanol, and low oxygen tension. Scale-up parameters investigated. Residence time distributions, mass transfer efficiencies, and liquid hold-up as a function of column diameter and operating conditions. It was found that the Peclet number decreased from 122 for a 1 inch column to 58.5 for a 6 inch ID column and finally to 40.6 for a 13 inch ID column. The 13 inch column data should be representative of larger columns as far as the Peclet number, pressure drop, mass transfer and liquid holdup. Process design studies included work with vapor phase dehydration in which it was determined that molecular sieves seem to be the dessicant of choice. We also investigated rectification of the ethanol in the inert gas leaving the ICRS and found that it is quite feasible and that the change in the shape of the equilibrium curve makes it theoretically possible to achieve anhydrous ethanol through rectification alone. 15 refs., 38 figs., 12 tabs. (ERA citation 11:011139)