PYROLYSIS OF SCRAP TIRES AND CONVERSION OF CHARS TO ACTIVATED CARBON

The primary objective of this work was to demonstrate the conversion of scrap tires to activated carbon. We have been successful in this endeavor, producing carbons with surface areas greater than 500 m2/g and significant micropore volumes. Tire shreddings were pyrolyzed in batch reactors, and the pyrolysis chars activated by reaction with superheated steam. Solid products of pyrolysis and activation were studied with nitrogen adsorption techniques. We find that the porosity development during steam activation of tire pyrolysis char is similar to that reported for various other chars. A maximum in micropore volume is observed as a function of conversion, but the total surface area increases monotonically with conversion. We suggest that the activation process consists of micropore formation, followed by pore enlargement. The process conditions used in this study are a good starting point from which to optimize a process to convert tires to activated carbon.