Heating rate effects on pyrolytic vapors from scrap truck tires

Powder of scrap truck tire was pyrolysed in a fixed bed reactor equipped with a water-cooled liquid recovery system and a gas sampling valve. A sampling system was set up and the quantitative and qualitative analyses of pyrolytic vapors were performed for heating rates (HR) ranging from 5 to 25 degrees C min(-1). HR which practically has no influence on the quality and yield of char (38 wt%), has a significant effect on the pyrolytic vapors, especially on the cracking reactions of heavy vapors. By increasing HR from 5 to 25 degrees C min(-1), the gas yield increases from 7.24 to 18.04 wt% at the expense of oil yield. The high heating rates favor production of CH4 and disadvantage production of C4H8. In addition, heating rates between 10 and 15 degrees C min(-1) minimize the H-2, CO and CO2 concentrations and maximize the C2H6, C3H6, C4H6 and H2S concentrations. Its lower heating value is between 47 and 56 MJ Nm(-3). As regards the produced oils, they consist mainly of aromatic products whose higher heating value is about 40 MJ kg(-1). Regardless of heating rates, around 97.15% of the energy contained in raw material (tire) is found in the three pyrolysis products. The sulfured organic compounds appear in forms of C7H5NS, C15H16O3S and C16H14O2N2S. (C) 2016 Published by Elsevier B.V.