초록
<P><B>Abstract</B></P> <P>The dark fermentation process promises a sustainable route for biohydrogen production. But the low substrate conversion efficiency hinders its commercial feasibility. The present study aims towards simultaneous hydrogen and butanol production to enhance the net energy recovery. Process parameters optimization revealed that pH of 6.5, temperature of 37 °C and inoculum size of 7% (v/v) were suitable for obtaining maximum hydrogen and butanol yields by <I>C. saccharoperbutylacetonicum</I>. Starch and xylan were observed to be preferred carbon sources suggesting effective utilization of C<SUB>5</SUB> and C<SUB>6</SUB> sugars. The maximum hydrogen yield of 264.3 mL g<SUP>−1</SUP> starch and 216 mL g<SUP>−1</SUP> xylan and butanol yield of 0.27 g g<SUP>−1</SUP> starch and 0.24 g g<SUP>−1</SUP> xylan were obtained with overall energy recovery of 85.61% (starch) and 75.22% (xylan), respectively. The present research work indicates the potency of bi-phasic fermentation to boost energy recovery from starch/xylan based feedstock.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Simultaneous hydrogen and butanol production from single process. </LI> <LI> Effective utilization of C5 and C6 sugar for H<SUB>2</SUB> and Butanol production. </LI> <LI> Di-ammonium phosphate used as suitable alternative of tryptone as nitrogen source. </LI> <LI> Energy recovery of 75.22% and 85.61% from xylan and starch achieved, respectively. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>