Figure 1

Scanning electron microscopy images of the sugarcane bagasse. (a) untreated bagasse, transversal section showing conducting vessels reinforced by sclerenchyma (S) and surrounded by parenchyma (P); (b) untreated bagasse, general view of the sample after milling, showing fibers (F) separated from the residues (R); (c) milled bagasse treated with acid, showing that the residues are significantly reduced after the first pretreatment step; (d) milled bagasse treated with acid and NaOH 0.5%, highlighting the predominance of fiber.