Effect of heating power on the scrap tires pyrolysis derived oil

Experimental investigation is carried out in order to study the effect of power input on the pyrolysis process of waste tires (WT). Three different power input levels i.e., 750W, 1500W and 3000W have been used to heat the reactor to 500 degrees C. The part of energy that was effectively consumed for thermal cracking of rubber and in evaporating the volatile products was deduced by subtracting reactor heating energy (blank tests) from total power input. Changes in physico-chemical characteristics of products were noticed while changing power inputs, which can be the consequence of changes in energy distribution between heating and cracking processes. In addition to the liquid product yield, its tar content is considered to be one of the most important characteristics according to the European standard EN590. From one side, the yield of liquid product for both 1500W and 3000W is higher than 45% while it is around 40% for 750W. On the other side, tar content in the liquid product is higher than 35% at 1500W and 3000W power inputs while it is around 11% at 750W. When high power is introduced to the reactor, it promotes the cracking of CC and CH bonds leading to higher liquid yield and H-2 formation during the pyrolysis. Furthermore, it promotes dehydrogenation/cyclization/aromatization/reactions leading to tar and coke formation. Diels-Alders reaction mechanism explains as well the tar yield in the liquid product via dehydrogenation/aromatization/cyclization/reactions. (C) 2015 Elsevier B.V. All rights reserved.