초록
<P><B>Abstract</B></P> <P>Microalgal biomass has recently been one of the most widely studied feedstocks for bio-hydrogen production, owing to its richness in fermentable components, <I>e.g.</I> polysaccharides and proteins, and high biomass productivity. In this study, biomass of microalga <I>Chlorella</I> sp. TISTR 8411 was converted to hydrogen through a sequential process consisting of an anaerobic solid-state fermentation (ASSF) followed by a dark fermentation. The microalga was grown photoautothrophically in 80-L rectangular glass tanks and then scaled-up to a 240-L open pond for the production of biomass. The highest biomass concentration attained was 4.45 g L<SUP>−1</SUP>. The biomass was harvested with over 90% flocculation efficiency at pH 11.5 and a biomass concentration of 2.6 g/L. The sequential process gave a total hydrogen yield (HY) of 16.2 mL/g-volatile-solid (VS), of which 11.6 mL/g-VS was from ASSF. The high HY obtained from the ASSF indicated that it was effective and could be integrated with a conventional hydrogen production process to improve energy recovery from biomass.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A sequential process for converting <I>Chlorella</I> sp. biomass to hydrogen was developed. </LI> <LI> Cultivation of <I>Chlorella</I> sp. in a 240-L open pond gave 4.45 g-biomass/L. </LI> <LI> PH 11.5 and a biomass concentration of 2.6 g/L are suitable harvesting conditions. </LI> <LI> Anaerobic solid-state fermentation of <I>Chlorella</I> sp. gave a HY of 11.6 mL-H<SUB>2</SUB>/g-VS. </LI> <LI> Dark fermentation of acid-thermal ASSF hydrolysate gave a HY of 4.6 mL-H<SUB>2</SUB>/g-VS. </LI> </UL> </P>