Optimisation of particle size in waste tyre pyrolysis

During pyrolysis of waste tyre, the operating parameters such as tyre composition, the process temperature, the heating rate and the particle size affect the result of the pyrolysis. Some of these parameters have been closely considered but the particle size of the waste tyre is often ignored. The goal of this paper is to study the effect of particle size in waste tyre pyrolysis under different heating approaches and to use optimization techniques to determine the optimized particle size for each scenario. In this paper, the size of the waste tyre particle is considered as a major factor in determining the magnitude of the overall energy used as well as the completion time of the pyrolysis reaction. Simulations were conducted to compare the effects of the particle size on the completion time and the overall energy usage under different heating rates and operational strategies. Shredding energy needed to reduce waste tyre particles was also included into the calculation of the overall energy consumption. Optimisation of the particle size was conducted under a number of specified maximum completion times and heating rates. This study confirms the trade-off between the overall energy used and the completion time. It also shows the impact of using some optimisation techniques to determine the optimized particle size for different heating approaches. (C) 2011 Elsevier Ltd. All rights reserved.