Monday, April 30, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Cellulose is the most abundant natural polymer on Earth and it is employed in several areas such as paper manufacturing, food and pharmaceutical industries. For obtaining cellulose from a lignocellulosic material is necessary to rupture the complex structure of vegetable cellular wall, removing the hemiceluloses and the lignin. The current research had as goal to determinate the best reaction conditions of the stages involved in the obtaining of the cellulose from sugarcane bagasse, which is a residue of the sugar and ethanol industry. It was investigated, in the following order, the stages of treatment with H2SO4, aiming the hemicellulose removal, alkaline delignification for the lignin withdrawal and chemical bleaching with H2O2, in order to produce a material with high brightness and high purity in cellulose. The best conditions for acid treatment stage were H2SO4 concentration of 10% (v/v), 100ºC and 40 min. In this case, it there was a hemicellulose removal of 70%. For the alkaline delignification stage, the ideal parameters were NaOH concentration of 10% (w/v), 100ºC and 60 min. Under these conditions it was possible to extract 80% of lignin. In the chemical bleaching, the best results were achieved when this stage was carried out with 5% (v/v) of H2O2, 70ºC and 45 min. The final material produced presented a purity of more than 90% in relation to cellulose.