Pré-tratamento de sabugo de milho aplicando sal alcalino e argila bentonita acidificada.

Abstract

The main sources of renewable energy in Brazil are biomass, which is lignocellulosic or the main component of plant biomass, basically formed by cellulose, hemicellulose and lignin. Corn on the cob can be considered a potential raw material for the production of biofuels and chemical products with high added value, due to its composition. Therefore, the objective of this work was to evaluate the applicability of alkaline salts together with bentonite clay in the pre-treatment process of corn cob. The pre-treatment tests were carried out in 250 mL Erlenmeyers, with temperature control carried out in an autoclave at 120 °C, the catalysts being sodium carbonate and acidified betonite clay. A 2² factorial design was applied with three replications at the central point to evaluate the influence of the catalyst mass on the amount of reducing sugars (RA) present in the reaction medium and lignin in the cob after pretreatment. Then, the tests were performed on a larger scale, applying the catalysts to the planning conditions that generated the best results in relation to the amount of AR generated. The use of salt together with clay did not provide an efficient obtaining reducing sugars, probably due to the lack of action in the solubilization of the constituents cellulose and hemicellulose. In control 2, without the presence of catalysts, an increase in sugars was generated, showing that the samples in the presence of only water, together with the operational conditions, suffered the solubilization of part of the holocellulose. The lignin contents, including in the central points, were reduced, which indicates the efficiency of the catalyst mixture in the degradation of this component. Thus, the pre-treatment process, applying the catalysts together, proved to be inefficient for obtaining AR and efficient for the degradation of lignin, which can be advantageous for the subsequent application of the solid product in enzymatic hydrolysis processes, aiming at the cellulose degradation.