Extração e caracterização da lignina do endocarpo do coco seco assistida por micro-ondas pelo processo organosolve

Abstract

The search for alternative renewable sources and the reuse of unwanted by-products, in order to at a reduction of waste generated in an industrial production line. Among these alternatives, a lignocellulosic plant biomass becomes a promising solution in the generation of energy and more ecological chemicals. The lignolulosic biomass is basically composed of cellulose, hemicellulose and lignin, the latter being a polymer rich in aromatic units of phenolic nature, which makes it attractive for the production of materials of higher value added. The lignin isolation of the biomass was carried out using the organosolve procedure, under acid catalysis and microwave irradiation, where it was possible to obtain high purity lignin free of ash and sulfur and a 56% yield. The lignin characterization was performed by infrared absorption spectroscopy, two-dimensional 1H-13C HSQC nuclear magnetic resonance and gel permeation chromatography, and its thermal properties were determined by thermogravimetric analysis and differential exploratory calorimetry. Through the study of the structural and thermal analyzes, it can be seen that the development of this work promoted the lignin of the dry coconut endocarp powder, transforming an agroindustrial residue into a chemical input for achievable industrial applications.