OPTIMAL OPERATING POLICY OF THE ULTRAFILTRATION MEMBRANE BIOREACTOR FOR ENZYMATIC-HYDROLYSIS OF CELLULOSE

The dilution rate of an ultrafiltration membrane bioreactor in the enzymatic hydrolysis of cellulose was optimized using the kinetic model developed by Fan and Lee.4 The sequence of optimal dilution rates was found to generally consist of an initial period of a minimal value (batch period), a subsequent period of maximum dilution rate, a period of a second batch, and a final period of a singular dilution rate. The effects of operating conditions, such as beta-glucosidase activity, operating time, maximum dilution rate, substrate feeding rate, and enzyme-to-substrate ratio on both the conversion yield and the sequence of optimal dilution rates were investigated. To evaluate the validity of kinetic model employed in this work, enzymatic hydrolysis was carried out using alpha-cellulose as a substrate in the ultrafiltration membrane bioreactor. The experimental data were well consistent with the simulation results. (C) 1993 John Wiley & Sons, Inc.