Production of Bioethanol from Colocasia esculenta (L.) Schott (Talas Liar) by Hydrolysis Process

Abstract

Wild taro tubers (Colocasia esculenta (L.) Schott Var. Antiquorum) contain 70-80% (wt%) of starch, thus serve as potential feedstock for glucose production, providing raw materials for bioethanol production. The tubers used in this study was collected from Padang city, Indonesia. The aim of this research was to find the optimum of bioethanol yield through variation of acid catalyst (HCl, H2SO4 and HClO4), acid concentration (0,00 N; 0,05 N; 0,10 N; 0,15 N; 0,20 N), enzyme (α-amylase, glucoamylase), enzyme volume (0.308 ml; 0.74 ml), hydrolysis time (1 hour, 2 hours, 4 hours), and fermentation time (48 hours,72 hours, 96 hours, 122 hours, 144 hours).At varied acid catalyst usage, the highest glucose content (27.54%) was obtained by using HClO4 acid with a concentration of 0.10 N and the lowest glucose level of 16.64% was obtained from the usage of H2SO4 acid with a concentration of 0.10 N in the hydrolysis process with temperature of 120°C for 45 minutes. The highest bioethanol content as 19.10% was obtained at the time of fermentation of 96 hours with the usage of Sacharomyces cerevisiae enzyme.The highest glucose content of 20.35% was obtained by using glucoamylase enzyme of 0.308 ml.