Enhancement of Fermentable Sugars Obtained from<i> Amorphophallus</i> Spp. Tuber for Bioethanol Production by Optimizing Temperature and Pretreatment Concentration

Abstract

Biofuels have been regaining popularity due to the increasing price of non-renewable fuels and the higher carbon dioxide emissions. Biofuels are manufactured from plant products and are mainly composed of lignocellulose and starch materials. This investigation aims to produce increased fermentable sugars for enhanced bioethanol production from tubers procured from northern Thailand. Varying concentrations of H2SO4 is used to pretreat the tubers. Before hydrolyzing with cellulase enzymes, the tubers were chopped into small pieces (1-2 cm), dried in a solar oven, powdered. The obtained results confirmed that the fermentable/ reducing sugar content of Amorphophallus spp. (suweg) tuber increased from 2.6 g/L to 19.01 g/L after enzymatic hydrolysis. The enzymes act as an excellent way to speed up the hydrolysis process. The theoretical potential of bioethanol production was calculated under ideal conditions, with the highest bioethanol concentration obtained is 9.69 ± 0.12 g/L at 0.4 % H2SO4 (pretreatment conc.) and 75 °C. The enhanced fermentable sugars obtained from starchy tubers may be utilized for bioethanol production to overcome depleting fossil fuels.