Estudo da pirólise de biomassa residual da cadeia produtiva da castanha-do-brasil, em reator induzido por micro-ondas (2,45 ghz)

Abstract

The environmental impacts caused by gas emission in the burning of fossil fuels and improper handling of solid waste has caused the increase of the greenhouse effect and the contamination of rivers and soils, among others. In this context, this work aims to develop an innovative technology for microwave-induced pyrolysis of the residues of the Brazil nut production chain, such as the shells, contributing to the sustainability of the production chain, through the production of renewable biofuels and mitigating the environmental problems generated by the improper disposal of these residues. Thus, the broken shells as obtained in the process of separating the kernels from the nuts and the shredded shells after this process, were submitted to pyrolysis by two methods. In the first method two pyrolysis experiments were performed in atmospheric air, the second method integrated a single experiment performed in nitrogen atmosphere. Both methods proceeded with agitation variation, in order to investigate the best operating conditions to obtain better yields of the products formed. The solid and liquid products were characterized by 1H and 13C NMR techniques and by IVTF with total attenuated reflectance (ATR) on KBr tablets. For both methods used, the yields were similar: 9.66% (biooil), 30.48% (biochar) and 31.23% (biogas) for experiment 01; 7.40% (bio-oil), 41.68% (biochar), 32.98% (biogas) for experiment 02, and finally 6.97% (bio-oil), 32.62% (biochar) and 38.18% (biogas) for the third experiment. However, pyrolysis occurs more vigorously when the system is operated without agitation, showing that agitation decreases the heating rate. The products obtained in all experiments present structural similarities observed in the 1 H NMR, 13C NMR and IVTF spectra.