Bioethanol represents a promising alternative to gasoline, given that fossil fuel reserves are witnessing an important depletion in the last few years. This paper addresses improving sugars extraction from two energy crops, sweet sorghum, and sweet pearl millet, to produce ethanol. The stalks of these C4 plants are indeed rich in fermentable sugars, essentially sucrose, fructose, and glucose. After being finely chopped, the biomass was pressed with a hydraulic press, and the obtained bagasse was pressed again to extract residual sugars. The bagasse was first humidified either with the juice obtained from the first pressing or water (ratio 1:1 w/w). After that, the wetted bagasse was pressed immediately, after 30 minutes, or after 60 minutes. For both crops, results showed that the humidification’s duration does not affect the extraction of residual sugars from the bagasse. The use of water was, however, more efficient than recycling the first pressing’s juice. Indeed, an additional 33.4 and 29% of the total fermentable sugars were extracted from sweet sorghum and sweet pearl millet bagasse, respectively, when using water.

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S. Noura, K. Mohamed, A. Mohammed, B. Annick. 2015, “Extraction of residual sugars from sweet pearl millet and sweet sorghum bagasse for an eventual production of bioethanol,” International Journal of Applied and Physical Sciences, vol. 1, no. 1, pp. 14-18.