Flash Pyrolysis of Tires: Process Development for Upcycling Waste Tires

Every year over two billion of scrap tires are generated throughout the world, and this number keeps growing due to increased road transportation. In view of the depleting fossil resources that are used for tire production and the adverse environmental issues associated with waste tire disposal, there is a compelling demand for implementing a cradle-to-cradle approach for sustainable recycling of these waste tires, and thereby creating a circular economy. Pyrolysis is a promising technology for recycling of waste tires to recover valuable raw materials. But the current technologies mainly involving slow pyrolysis have their limitations due to the low quality of products recovered during the process, thereby greatly influencing the economic feasibility of the waste tire pyrolysis plant operation. A better understanding of the tire pyrolysis process is thus required to improve the quality of tire pyrolysis products, mainly focusing on the pyrolytic carbon black product, which is the aim of this research study. Tire granulates are treated via a flash pyrolysis process to determine the influence of process parameters on the yield and properties of the pyrolysis products i.e. pyrolytic carbon black, oil and gas. Based on the process knowledge achieved, a suitable reactor is developed for the flash pyrolysis of coarse tire granulates. The pyrolytic carbon blacks thus produced are compared with commercial carbon blacks in terms of physical and chemical properties, and comparable products are produced by this technology. This is a collaborative research project between the University of Twente, Continental Tires AG, and M2i Materials Innovation Institute