Recycling of waste tire by pyrolysis to recover carbon black: an alternative reinforcing filler

Thermal pyrolysis of waste tires is an industrially beneficial method for material and energy recovery. Pyrolytic carbon black (CBp) is considered to be the secondary main product of this process. In the present study, an eco-friendly and economically feasible autoclave reactor-based thermal pyrolysis method was employed for the pyrolysis of waste tire tread. The average yields obtained for CBp and pyrolytic liquid are 48.2 wt% and 46.3 wt%, respectively. This CBp was well characterized by several techniques and results were compared with those of commercially available N330 carbon black. Elemental analysis shows that CBp has higher oxygen (O) and sulfur (S) content. Furthermore, the surface attachment of ash with carbon black from morphological analysis reveals the presence of higher ash content in CBp, which is further justified by proximate and thermal analysis. Zinc oxide (ZnO) plays a vital role in sulfur vulcanization and is added during the compounding stage of the tire-manufacturing process. Results obtained from TEM-EDX analysis indicate the presence of ZnO in the carbon black derived from thermal pyrolysis. Prior to conducting further research in this area, we may draw the conclusion from the experimental results that the obtained CBp has similar characteristic features and can be used in place of commercially available carbon black for the manufacture of rubber products. [graphics]