Evolution of pyrolysis characteristics and modeling of particle shrinkage of carbon black from waste tire pyrolysis

During the pyrolysis of waste tires, various factors such as particle size, specific surface area, and surface characteristics undergo changes. These changes not only impact the pyrolysis outcomes but also play a crucial role in the design and optimization of pyrolysis reactors. However, it is important to note that these pyrolysis characteristics have not been fully considered in previous studies. Therefore, this research aims to determine the pyrolysis steps of waste tires through thermogravimetric analysis and analyze the contribution of each step to the evolution of the characteristics of pyrolytic carbon black (CBp). To conduct this study, a pyrolysis unit was constructed for semi-batch pyrolysis experiments. The resulting CBp, obtained at different pyrolysis times, was then analyzed for size, specific surface area, pore structure, and surface properties. Additionally, a particle shrinkage model was developed and optimized using multistep kinetic and pyrolysis experimental data. The findings revealed that the specific surface area of CBp was significantly reduced due to surface deposits, while the pore structure developed rapidly within the temperature range of 318-510 degrees C. The particles exhibited a swelling phase followed by rapid shrinkage during the pyrolysis process, with the maximum shrinkage rate reaching-18.8 %. The optimized particle shrinkage models demonstrated an accuracy level above 96 %. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.