ECONOMIC-ASSESSMENT OF ETHANOL-PRODUCTION COMPARING TRADITIONAL AND FLUIDIZED-BED BIOREACTORS

This study analyzes the economic impact that a fluidized-bed reactor ( FBR) using immobilized Zymomanas mobilis would have on a plant convert ing cornstarch into ethanol. The study addresses substituting this new technology into an existing plant or using it for a new plant. We hav e compared the processing steps required by the FBR with conventional technology, and developed process flow schematics, priced required equ ipment, and generated plant capital and operating cost estimates. This allowed a cost evaluation between the FBR and traditional technologie s, such as well-mixed fed-batch fermentation. The study results indica te that the FBR technology can provide a significant reduction in the production costs of ethanol-a savings of >$0.02/gal if inserted into a n existing plant, and a savings of >$0.06/gal if used at a new plant.