Study of Drying of Banana Pseudo-stem and Influence of Particle Sizes on Biomass Saccharification and Cellulosic Ethanol Production

Various fiber lengths of banana pseudo-stem bagasse (L = 3 and 15 cm) were dehydrated at various temperatures (T = 50 °C, 60 °C, and 70 °C) with and without forced air convection (Sair > 0). The experiments were conducted in a screened bottom tray equipped with a dryer with rising air flow. The effect of dehydrated fiber size (30 mesh, 3 cm, and 15 cm) on the saccharification of the biomass with subsequent alcoholic fermentation of the must was investigated using two different concentrations of reducing sugars (RS = 40 and 90 g/L). In the pretreatment by drying, the temperature (T) was the variable that showed the greatest effect on the productivity of the process (Qd), followed by fiber length (L) and T by L interaction. The use of dehydrated fibers in the form of bran (30 mesh granulometry) in the saccharification process provided the best theoretical average yield based on the stoichiometric conversion of cellulose and hemicellulose in RS (YRS = 37.87%). Fermentation of concentrated must by Saccharomyces cerevisiae up to RS = 90 g/L provided a yield (YP/RS) and productivity (QP) in ethanol of 0.48 g/g and 1.62 g/L/h, respectively. These values were significantly higher (p < 0.05) than those observed in the same fermentation type at RS = 40 g/L (YP/RS = 0.34 g/g, QP = 0.96 g/L/h).