초록
<P><B>Abstract</B></P> <P>Economics of cellulosic ethanol production could be supported by high-value chemicals co-production, e.g. xylitol, which has high market value in food and pharmaceutical industries. Herein, we present an integrated sugarcane bagasse processing for the co-production of ethanol and xylitol from cellulose and hemicellulose, respectively. Process integration comprised pretreatment followed by separation of hemicellulosic hydrolysate and pretreated cellulose, in combination with enzymatic hydrolysis and fermentation. <I>Saccharomyces cerevisiae</I> was used for ethanol production in a simultaneous saccharification and fermentation process of pretreated cellulose, and <I>Candida tropicalis</I> was selected for xylitol fermentation of hemicellulosic hydrolysate. Batch process parameters were systematically optimized resulting in 7.5 FPU/g optimal enzyme load, 0.03 g/L and 0.035 g/g optimal inoculum size, 89 h<SUP>−1</SUP> optimal <SUB> k L </SUB> a and 54 g/g optimal sugar-to-nitrogen ratio. Finally, fed-batch strategy was accomplished yielding maximum concentrations of ethanol by <I>S. cerevisiae</I> and xylitol by <I>C. tropicalis</I> at 56.1 g/L and 24.0 g/L, respectively. Of the total glucose and xylose available in bagasse, the product yield of 0.44 g/g (ethanol) and 0.50 g/g (xylitol) were reached. Economic analysis revealed that the incorporation of xylitol with ethanol in an integrated biorefinery together with fed-batch strategy for high-titer product could improve profitability by 2.3-folds compared to base case of cellulosic ethanol production. Hence, this integrated biorefinery for co-production could be attractive to current cellulosic ethanol for advancing economic feasibility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Integrated sugarcane bagasse biorefinery for ethanol/xylitol co-production was presented. </LI> <LI> DoE based process optimization was implemented for high product titers. </LI> <LI> Techno-economics analysis revealed improved production profit of the integrated process. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>