# Ethanol Production from Waste of Cassava Processing
## 3 Results and Discussion  
### Potential for Ethanol Production  
Before and after drying treatment, samples A3 and A4 visually presented darker staining when compared to others revealing the differences in industrial processes. In Table 1, the values obtained from the compositional analysis of cassava bagasse are displayed. Figure 1: This represents systematically the process as a whole, for obtaining ethanol. The bagasse used had approximately 88% average moisture content. [10] Reported that starch-fibrous material has a large water retention capacity, and often the moisture content of the pulp leaving the process is higher than 80%. In accordance with [11], each ton of processed root yields approximately 930 kg of bagasse with 85% moisture content. These values are specific for many bagasse cassava, as there are root variations having different chemical compositions [12]. It was observed that the residual starch concentrations are similar (Table 1). The soluble sugars were also similar, except for the sample from A2, which showed a lower value compared with other samples. The similarity between the other samples is probably due to the action of similar degrading microorganisms, indicating the possible need to use additives for fermentation. The major component, starch, comprised approximately 64% on average and was highest in A4, with a value of 68.30%. The content of starch in the bagasse is within the average value obtained by different authors, ranging from 47.10% [13] to 65.37% [14]. According to Table 1, the levels of various chemical components found may be comparable with the results obtained by [9; 15]. where the values found were as follows: 65.16% moisture in the humid matter, 3.0% protein, 0.30% grease matter, 2.6% fiber, 2.4% ash, and 8.2% sugar. The presence of low concentrations of protein and fatty matter found favors the fermentation process considerably by reducing foaming. Table 2 shows the values obtained after the hydrolysis process. Temperature adopted 60 \({}^{\circ}\)C, density 1.13 g/mL, residence time 1 h, and a volume used of 20 g of substrate. Through infrared spectrometric analysis, it was found that various samples showed similarities in the spectra. As described above, the samples were distilled at 10% concentration utilizing only 5 mL from 50 mL; therefore, treatments that showed the highest amount of ethanol in distilled material were A2 and A4, respectively having 2.4 mL and 2.65 mL of ethanol from 5 mL of solution. A1 had a value of 0.63 mL ethanol from distillation. Figure 2 indicates the curves obtained in the analysis of infrared spectrometry. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Samples** & **Starch** & **Raw Fiber** & **Protein** & **Sugars** & **Grease Matter** & **pH** & **Humidity** & **Ash** \\  & **(\%)** & **(g/100 g)** & **(g/100 g)** & **(g/100 g)** & **(g/100 g)** & **(g/100 g)** & **(\%)** & **(g/100 g)** \\ \hline A1 & 64.80 & 3.42 & 0.49 & 8.30 & 0.21 & 4.31 & 87.14 & 0.23 \\ A2 & 59.90 & 3.85 & 0.53 & 6.61 & 0.20 & 4.45 & 89.29 & 0.29 \\ A3 & 64.10 & 6.07 & 0.90 & 8.04 & 0.20 & 4.50 & 88.70 & 0.12 \\ A4 & 68.30 & 3.94 & 0.52 & 8.24 & 0.01 & 4.91 & 86.75 & 0.23 \\ Mean & 64.27 & 4.32 & 0.61 & 7.79 & 0.15 & 4.54 & 87.97 & 0.21 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Physical and chemical characterization of samples before hydrolysis.