earticle

영어

Bioethanol experiments using three forms of waste from sugarcane production process has been conducted by utilizing pre treatments and enzimatic hydrolisis and fermentation in an SSF bioreactor. The solid form of waste (i.e. bagasse), the liquid waste (i.e. molasse and the sludge (i.e. Blotong) from a sugarcabe industry in Malang, East Java were firstly characterised to determine the lignin, cellulose, carbohydrate, fibre and ash composition. Combination of pre treatment with white rot fungi and steaming were done to degrade the linocellulotic bound in bagasse. A 3000 ml Simultaneous Saccharification and Fermentation (SSF) bioreactor converted the raw material into bioethanol. No pre treatment was needed for molasse. Most of blotong contain ash and only slight carbohydrate, i.e. 5-7 %, rendering very difficult process to produce ethanol and the yield was hardly detected although combination of cellulase and cellubiase were used. The highest ethanol production was from molasses with around 81.3-87.9% yield. Modest ethanol yield was from bagasse 12.0%. However, combination of pretreatments and enzymes increased the ethanol yield to 36.4%. The increasing of ethanol production in cellulase-cellubiase hydrolysis confirmed that beside glucose, cellubiose was also produced in partial hydrolysis of cellulose. Afterwards, cellubiose was converted to glucose by cellubiase. This fact was indicated by the increase in glucose content about 16.2%. And then glucose was converted to ethanol simultaneously with S. cerevisiae. Furthermore, combination of cellulase-cellubiase-xylanase enzymes showed more ethanol yield. The reaction includes hydrolysis of cellulose to glucose and cellubiose, hydrolysis of xylan to xylose and hydrolysis of cellubiose to glucose. These reactions were indicated by the weight loss of cellulose and hemicellulose of bagasse after SSF process from 50% and 20% to 22% and 10%.