Estudo e caracterização de lignina de bagaço de cana-de-açúcar

Abstract

Biomass has played an important role as a renewable product with high use potential. One of its components is lignin and its isolation, regardless of the used method, causes modifications in its original chemical structure. In this context, this study evaluated the sugarcane bagasse lignin and was divided into two parts. The first part is a bibliographical review, in which the complexity of the lignocellulosic biomass, the characteristics of the lignin structure, the methods of production and the challenges for a noble use of sugarcane bagasse are presented. In the second part, two studies are presented. The first study focus on the characterization of the enzymatic lignin of sugarcane bagasse, obtained in the second-generation ethanol production process, using TG, DSC, FTIR, XRF, 13C and 1H NMR and S/G analysis. The second study analyzed the lignin obtained by different methods (Klason, Milled Wood Lignin and Alcali) of the same sample, investigating the modifications caused by the treatments. Initially, the bagasse sample was characterized by elemental analysis, extractives, total lignin, volatiles, ash, fixed carbon, holocellulose and the quantification of the monomers syringyl and guaiacil. The isolated lignin materials were characterized by TG, DSC and FTIR. Thus, this study aimed to contribute with information on the chemical composition and structure of lignin from sugarcane bagasse, investigating the modifications caused by the different obtention methods for greater knowledge on a subject that is still challenging.