Production of Ethanol Bio-Fuel from Cassava

The objectives of this experiment are to know the effect of starch and enzymes
concentration towards the glucose production, to observe the texture ofstarch during the
gelatinization process; to study fermentation process of ethanol from Saccharomyces
cerevisiae, and to study the rate of ethanol production, by obtaining amount of glucose
produced per 1 kg of cassava starch. This study is conducted since there are critical
issues of (1) petroleum sustainability, (2) volatility of world's crude oil price; rising
significantly that effect all the living costs and (3) the urgent need of alternative,
renewable, economic and environmental-friendly fuel. A renewable source, bio ethanol
derived from cassava starch is studied as an alternative to petroleum fuel for
transportation. The author has studied on starch characterization during gelatinization,
and manipulated the concentration of enzymes during hydrolysis. It is found that during
the continuous heating, the viscosity of starch keep increasing until a transparent paste is
formed, which is a bit sticky. Theoptimum concentration of enzymes for liquefaction of
20%, 30% and 40% starch slurry is found to be 0.25% a-amylase with 0.2%
amyloglucosidase which is similar as reported by Ku Ismail K. S, 2008. The authorhas
proved the study by Aggarwal and Nigam, 2001 regarding the effective period of
saccharification which is 24 hours, since the glucose concentration obtained in this
experiment is much higher than the results reported by Ku Ismail K. S, 2008, who only
saccharified for 1 hour. An improved calibration curve which has greater correlation
should be obtained in order to improve the accuracy of the results. Ethanol yield from
20%, 30% and 40% starch with the same amount of enzymes (0.25% a-amylase and
0.2%amyloglucosidase) cassava starch are 14%, 16%, and 20%respectively, which are
considered low comparedto Seinosuke studies(who obtained around 82.3 and 99.6%). 5
gram of Saccharomyces cerevisiae is assumed to be inadequate for an effective ethanol
production. This low production might be due to no supplement provided for yeast,
unsuitable environment condition for enhancing yeast growth and inadequate amount of
yeast.
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