How continually see increased demand for energy, especially in the face of rapid
population growth and industrial development, it is necessary to increase alternative
energy sources. To that end, it has developed a process for producing ethanol using
at the same time and in various combinations, sweet potatoe, corn and cassava,
optimizing this process is in three trials. The first trial was conducted to evaluate the
effect of the concentrations of the enzymes α-amylase (Liquozyme ® SC) and
glucoamylase (Spirizyme Fuel ®) in the process of hydrolysis of starch on glucose
level. The second trial evaluated the effect of fermentation time and the concentration
of the yeast Saccharomyces cerevisiae on the concentration of ethanol. In the last
step was explored the fermentation of the three raw materials (industrial sweet potato,
cassava and maize) in different combinations, using the best conditions found in the
1st and 2nd tests. The raw sweet potato, cassava and corn had average moisture
equal to 66.77%, 66.52% and 13.77%, respectively. The soluble sugar content was
3.41% in sweet potato industry (BDI), 1.73% in cassava (Ma) and 1.65% in corn (Mi).
As the starch content, the raw material in nature showed 22.11% and 20.22% for
industrial sweet potato and cassava, respectively. Corn kernels, crushed, possessed
41.72%. The test results showed that the optimum range for maximum yield of
reducing sugars occurred when 0.36 ml (0.45 g/Kgstarch) of α-amylase (Liquizyme ®
SC) and 10.18 ml (11.71 g/Kgstarch) of glucoamylase (Spirizyme Fuel ®) were used
per kg of starch (dry basis), and that the optimal condition for fermentation of the
mixture (BDI Ma and Mi) was 2.25% yeast and 24 hours of fermentation, in which
gave the highest yield of ethanol. When comparing different combinations of raw
materials, it was found that the mixture of starch (BDI Ma and Mi), with proportional
starch produced the largest amount of ethanol, with an average value of 13,301.62
L/h.
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