Assessment of the Potentials of Production of Bioethanol Using Cyperus esculentus L. (Tigernut) Residue by Simultaneous Saccharification and Fermentation

Background: The substitution of the use of fossil fuels with fuels from renewable energy sources has been widely advocated. Bioethanol is one of the fuels used by automobiles in the transport sector as the sole fuel or blended with fossil fuels in different ratio.

The Aim of the Study: The aim was to assess the potentials of tiger nut residue as feedstock in bioethanol production.

Materials and Methods: Bioethanol was produced by fermentation, using three different slurry concentrations of the residue to water ratio of 1:15, 1:20 and 1:30, by the use of co-culture of Aspergillus niger and Saccharomyces cerevisiae and the co-culture of A. niger, Bacillus subtilis and S. cerevisiae. The concentration of the produced bioethanol was obtained using spectrophotometer using chromium VI reagents.

Results: In the first set-up (using A. niger and S. cerevisiae), the highest percentage mean concentration of 1.16% of the produced bioethanol was recorded in day 3 of the 1:30 (residue to water) slurry ratio and the lowest of 0.11% in day 1 of 1:15 slurry ratio. No significant difference (p<.05) was observed in the percentage mean concentrations produced across the three slurries in the all the days, and also across the days in the 1:20 and 1:30 slurry ratios. The pH also decreases as the time of the fermentation increases. In the second set-up, the highest percentage mean concentration of 0.33% was obtained on day 5 of 1:15 slurry and the lowest of 0.14% on day 1 of 1:20. A significant difference (p<.05) was observed across the slurries in day 4 and 5, but none was observed on day 1, 2 and 3.

Conclusion: The results obtained indicate that bioethanol can be produced using Tigernut residue by simultaneous saccharification and fermentation.