Design and demonstration of an immobilized-cell fluidized-bed reactor for the efficient production of ethanol - Scientific note

Initial studies have been carried out on the scale-up of a medium-scale (2-5 m tall with a 10.2-cm id), fluidized-bed reactor (FBR) designed for fuel ethanol fermentation using immobilized Zymomonas mobilis. These results suggest that further improvements in ethanol productivity along with good operability may be possible when compared with previous results at the bench scale (40-110 g ethanol/L/h) and present industrial reactors (2-10 g ethanol/L/h). On-line and off-line measurement and control systems are also described. Z. mobilis was immobilized in κ{script}-carrageenan at cell loading of approx 60 g (dry wt)/L of biocatalyst. The system is designed for determining optimal operating conditions for achieving high conversion and productivity with variations in feedstocks, temperature, flow rate, and column sizes.