Extraction methods and characterization of cellulose fractions from a sugarcane by-product for potential industry applications

Sugarcane bagasse, the major by-product of the sugarcane industry, can be used to produce valuable materials such as cellulose or cellulose-based materials. In order to obtain more accessible and purified cellulose, pretreatment processes of lignocellulosic feedstocks are applied to decompose the complex cellulose-lignin-hemicellulose matrix, which facilitates access to isolated compounds. The influence of various autohydrolysis conditions, alkaline sulfite extraction and bleaching were evaluated in terms of extract yield, chemical profile and structural properties upon a solid fraction rich in cellulose. Among the treatments applied, autohydrolysis at 170 °C for 1 h followed by a bleaching step was the treatment that presented the best results in terms of cellulose purity (77.8%), crystallinity (73.4%), whiteness and glucose production by enzymatic hydrolysis, when compared with the non-treated fraction. The combination of autohydrolysis with a totally chlorine free bleaching step showed as a promising eco-friendliness alternative to obtain a white and solid fraction rich in cellulose, thus contributing to the valorization of this by-product.