Experimental study of pyrolysis and combustion of scrap tire

Pyrolysis and combustion behaviors of a single rubber particle in a derivative thermogravimetric (DTG) apparatus were investigated. The influence of temperature (400-850 degrees C) and oxygen content in gas (5-21%) on combustion behavior of rubber samples and solid products of the pyrolysis process (chars) was studied. Development of the porosity and specific surface area of the rubber particle during pyrolysis was investigated. Pyrolysis of scrap rubber samples was carried out under nitrogen atmosphere over a temperature range 20-850 degrees C using a heating rate of 5 degrees C/min. The measured DTG curves show two different weight loss regions during the pyrolysis over a temperature range 250-550 degrees C. In all, 52-55% of the samples weight was lost during the pyrolysis process and another 30% during the combustion of char. Ashes create approximately 17% of the samples weight. The ignition temperature of scrap rubber samples in air was around 512 degrees C and increased with decreasing oxygen content. The reaction time of the combustion process decreased about 1.4 times with increasing temperature from 500 to 750 degrees C and 5.5 times with decreasing oxygen content in the inlet gas from 21 to 5 mol%. The total specific surface area of the rubber sample with the degree of pyrolysis increased rapidly to 83 m(2)/g. The values of total porosity increased significantly from 0.3 to 32% at the end of pyrolysis. Copyright (C) 2006 John Wiley & Sons, Ltd.