초록
<P><B>Abstract</B></P> <P>The biobutanol production by ABE (acetone-butanol-ethanol) fermentation with an integrated product recovery system by gas stripping was studied. A mixture of industrial sugarcane-sweet sorghum juices was fermented using <I>Clostridium acetobutylicum</I> DSM 792. Empirical models were developed to determine an operational condition for the integrated process that contributes both to mitigate the butanol inhibitory effect and to obtain a highly concentrated butanol condensate. A Monod model supplemented with a term describing product inhibition was employed to describe cell growth, butanol formation, and substrate consumption, respectively. Gas stripping was described by a first order model. The models showed satisfactory agreement with the experimental data in terms of cell growth, sugar consumption, and butanol production and extraction. A gas recycle flowrate in the range 0.3–0.6 vvm allowed to maintain butanol concentration below the inhibitory concentration (8 g/L) and to obtain a concentrated butanol condensate after phase separation, which could reduce energy consumption in the final product recovery. In a fed-batch fermentation coupled with <I>in situ</I> gas stripping, total sugar conversion and 18.6 g/L butanol distributed 42% in the fermentation broth and 58% in the condensate, were obtained.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Evaluation of an experimental promising raw material for biobutanol production. </LI> <LI> Improving an integrated fermentation-gas stripping process. </LI> <LI> Kinetic modelling of biobutanol production and extraction by gas stripping. </LI> </UL> </P>