Fibers from Sugarcane Bagasse

Abstract

Sugarcane is the world’s largest crop grown in about 23.8 million hectares with a total harvest of about 1.69 billion tons in 2010. After squeezing the canes for sugar, the remaining materials, generally called bagasse, are obtained as coproducts. About 30–32 % by weight of the cane is generated as coproducts [08Lee]. Bagasse is a lignocellulosic material consisting of 45–55 % cellulose, 20–25 % hemicellulose, and 18–24 % lignin. Sugarcane stems consist of three major parts: the pith (5 %), fibers (73 %), and the rind (22 %). Both the pith and the outer rind have been studied as sources for fibers. The pith has a considerably lower density (220 kg/m³) and consists of coarse fibers and many large cavities compared to the rind with a density of 550 kg/m³. In Brazil, the average price for a ton of bagasse is between $3.5 and $11.8, making it one of the cheapest lignocellulosic agricultural by-products [04Fil]. Unlike the fibers obtained from the oil plants, bagasse fibers are reported to have considerably low elongation (1.1 %) and moderate strength of about 222 MPa (1.7 g/den) and modulus of 27 GPa (208 g/den) [04Tri, 09Gui]. Compared to the lignocellulosic fibers obtained from other agricultural by-products, relatively fewer studies have been conducted to understand the potential and properties of obtaining fibers from sugarcane bagasse. Fibers obtained from sugarcane bagasse were reported to have a fineness of 6.5–14 tex and length from 2.5 to 20 cm. In another research, fibers with strength of 290 MPa (2.2 g/den) and modulus of 17 GPa (13.1 g/den) were obtained from sugarcane stems [12Far].