Obtenção e caracterização de biocarvão obtido a partir da pirólise de resíduos urbanos não recicláveis

Abstract

The increase in the amount of municipal solid waste (MSW) discarded by the population represents a major economic and environmental problem today. The pyrolysis process consists of the degradation of a material in the total or partial absence of oxygen, generating several products of great applicability. In order to promote a sustainable alternative to the accumulation of waste, the present work sought to carry out tests in a pyrolysis reactor using municipal solid waste, coming from an association of recyclable material collectors as raw material, varying the main process parameters: reaction time (30 min or 180min), raw material composition (MSW or MSW + wood) and reaction medium (with or without N2). The focus was on obtaining biochar, due to its high added value and wide applicability. At the end, the biochars obtained from pyrolysis were characterized, performing gravimetric tests (moisture, volatiles and ash), percentage of fixed carbon, thermogravimetric analysis and infrared spectroscopy by Fourier transform. In the end, it was possible to conclude that with the time of 30 min, the best yield of biochars was obtained. As for the reaction medium and raw material composition, no major differences were observed in terms of yield. With the characterization data, it was observed that the biochars generated have a high percentage of fixed carbon and low ash content, showing the quality of the product obtained. As for the thermal behavior of the analyzed samples, the first degradation peak occurred at about 650 °C. In addition, all samples showed similar thermal behavior, ruling out the influence of the process variables considered on the thermal behavior. In the infrared spectroscopy, the presence of several functional groups such as hydroxyls, C=C groups and C-O bonds was observed. The presence of these groups was attributed to products that were not fully degraded in pyrolysis.