. Process Route 3 incorporated fed-batch fermentation and gas-stripping with CO2, an unproven
technology on industrial scale. Process modeling in ASPEN PLUS and economic analyses in ASPEN Icarus
were performed to determine the economic feasibility of these biobutanol production process designs.
Process Route 3 proved to be the only profitable design in current economic conditions in South Africa.
Improved fermentation strains currently available are not sufficient to attain a profitable process design
without implementation of advanced processing techniques. Gas stripping is shown to be the single most
effective process step of those evaluated in this study, which can be employed on an industrial scale to
improve process economics of biobutanol production.