초록
<P><B>Abstract</B></P> <P>Significant development in conversion technologies to produce bioethanol from microalgae biomass is causing paradigm-shift in energy management. In this study, carbohydrate-rich microalgae, <I>Scenedesmus dimorphus</I> (49% w/w of carbohydrate) is selected with the aim to obtain qualitative correlation between pretreatment and fermentation process. In view of this, separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) were conducted experimentally. The fermentation behavior were investigated for microalgae biomass treated via organosolv, enzymatic and acidic pretreatment. Fermentation process was carried out by ethanologen microbe, <I>Saccharomyces cerevisiae</I>. From the result, it is observed that a combination of two treatment is found to be the most effective in producing fermentable sugar for the subsequent fermentation process. The organosolv treatment which is followed with the SSF process produced a theoretical yield of bioethanol that exceeded 90%. On the other hand, hydrothermal acid-hydrolyzed fermentation produced the bioethanol yield with 80% of its theoretical yield. Enzymatic-hydrolyzed SHF produced 84% of theoretical yield at longer reaction time compared with others. The results were obtained with constant fermentation parameters conducted at pH 5, temperature of 34°C, and microalgae biomass loading at 18g/L. Ultimately, the coupling of organosolv-treated biomass with SSF process is found to be the most cost-effective for <I>S. dimorphus</I> biomass as bioethanol feedstock.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biomass of <I>Scenedesmus dimorphus</I> is degradable to produce fermentable sugar. </LI> <LI> Sugar yield improves with acidic, enzymatic and organosolv pretreatment. </LI> <LI> Pretreatment strategies are positively correlated with fermentation process. </LI> <LI> SSF with organosolv-treated biomass is promising for bioethanol production. </LI> </UL> </P>