Influence of pyrolysis temperature on the structure and composition of carbon black obtained from used tires

Carbon black (CB) is an input used in several industries, mainly in the production of tires, representing 20 to 30% of the total mass of tires. This product is originally obtained from the partial combustion or thermal decomposition of hydrocarbons, such as those found in petroleum or natural gas. In addition to the conventional route, carbon black can be obtained by the thermal decomposition of solid waste, including used tires, via the pyrolysis process, also resulting in the formation of combustible oils and gases. This process presents itself as a relevant alternative for CB recovery, reducing environmental impacts and making it possible to obtain a product with higher added value. Thus, this work aims to investigate the composition, morphology and impurities of the CB obtained in a fixed-bed reactor operated at different temperatures (300, 350, 400, 450, 500, 550 and 600 °C) to evaluate the quality of the resulting material. For the characterization, techniques such as X-ray diffractometry (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and inductively coupled plasma optical emission spectrometry (ICP-OES) will be used, in addition to elemental analysis (CHNS), allowing the evaluation of the structure of the compound, functional groups, degree of disorder and presence of metals and sulfurous compounds. The analysis of the results obtained from the analytical techniques will enable the understanding of how temperature influences the formation of carbon structures and contamination by residual impurities, providing evidence for the definition of optimal pyrolysis conditions and possible applications of the CB obtained.