Extração da fibra celulósica de resíduo da colheita do milho utilizando líquidos iônicos

Abstract

Cellulose is one of the most abundant natural polymers in the world and is widely used in several areas, such as pharmaceuticals, veterinary, dental and medical applications. The main source of this polymer is wood, from cultivated forests of Pinus spp and Eucalyptus spp, taking years to extract cellulose from these sources. Some agricultural residues are basically constituted of cellulose, hemicellulose and lignin, characterized by lignocellulosic biomass, including the residue of corn harvest. In order to reduce harm on the ecosystems, green technology was born in the late 20th century, bringing changes to production processes. Among the targets of green technologies are the solvents, as they play an important role in processes, seeking sustainable options such as the use of ionic liquids. Therefore, the present study aims to extract the cellulosic fiber from the residue of corn harvest, which is easily found and not so explored, using the ionic liquid triethylammonium hydrogen sulfate, based on the principles of green technology. In order to achieve the objective, the chemical characterization of the residue was carried out, as well as the synthesis of the ionic liquid. Different extraction conditions were tested, varying the extraction time, with and without the alkaline bleaching step, in order to evaluate in which condition the extracted fiber reached higher yield and purity, performing Scanning Electron Microscopy and Infrared Spectroscopy analysis. Among the conditions studied, it was possible to achieve a maximum total yield of 55.47% in the extraction of cellulosic fiber, and verify that the extraction product did not reach a high degree of purity related to the desired cellulosic fiber.