Scale-up and kinetic modeling for bioethanol production

Bioethanol was produced from acidic hydrolysate of rice hulls using recombinant Escherichia coli KO11. Two different issues (scale-up and kinetic modeling) were evaluated simultaneously and concomitantly for bioethanol production. During the step-wise scale-up process from 100 mL shaken flask to 10 L stirred-tank bioreactor, the constant Reynolds number and the constant impeller tip speed were evaluated as scale-up methodologies under laboratory conditions. It was determined that the volumetric bioethanol productivity was 88% higher in 10 L bioreactor in comparison to the value of 0.21 g L-1 h(-1) in shaken flask. The modified Monod and Luedeking-Piret models provided an accurate approach for the modeling of the experimental data. Ethanol concentration reached the maximum level of 29.03 g/L, which was 5% higher than the value of model prediction in 10 L bioreactor. The findings of this research could contribute to the industrial scale productions especially from lignocellulosic raw materials. (C) 2013 Elsevier Ltd. All rights reserved.