Pretreatment of Starch-Free Sugar Palm Trunk ( Arenga pinnata) to Enhance Saccharification in Bioethanol Production

摘要

Starch-Free Sugar Palm Trunk ( Arenga pinnata ) can be utilized to produce bioethanol because of their high lignocellulosic contents. Production of bioethanol from lignocellulosic materials consist of pre-treatment, saccharification and fermentation processes. In this work, conversion of starch-free sugar palm trunk ( Arenga pinnata ) to fermentable sugar and bioethanol was carried out through g pretreatment, saccharification and fermentation processes. The pretreatment was carried out by addition of 1% (v/v) HNO3 and NH4OH for 30 min and 60 min, respectively. The saccharification was carried out at enzyme celullase loadings of 10 and 20 FPU/g and substrate loadings of 10 and 20 g for NH_(4)OH pretreated samples. Fermentation was carried out using two methods i.e. separated hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) techniques. The results showed that pretreatment using NH_(4)OH was more effective than HNO_(3)for 60 minutes. IFurthermore, the results also presented the reduction of the lignin content of 9.44% and the increase of cellulose content to 18.56% for 1% (v/v) NH_(4)OH 60 min of pretreatment. The increase of enzyme cellulase (20 FPU/g substrate) and substrate loading (20 g) could produce more reducing sugar (17.423 g/L and 19.233 g/L) than that at 10 FPU/g substrate and 10 g substrate (11.423 g/L and 17.423 g/L), respectively. The comparison of SHF and SSF showed that SHF process yielded higher ethanol (8.11 g/L) as compared to SSF (3.95 g/L) and nontreatment process (0.507 g/L) for 72 h..